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Dengue virus (DENV) is an endemic disease in the hot and humid low-lands of Colombia. We characterize the association of monthly series of dengue cases with indices of El Niño/Southern Oscillation (ENSO) at the tropical Pacific and local climatic variables in Colombia during the period 2007-2017 at different temporal and spatial scales. For estimation purposes, we use lagged cross-correlations (Pearson test), cross-wavelet analysis (wavelet cross spectrum, and wavelet coherence), as well as a novel nonlinear causality method, PCMCI, that allows identifying common causal drivers and links among high dimensional simultaneous and time-lagged variables. Our results evidence the strong association of DENV cases in Colombia with ENSO indices and with local temperature and rainfall. El Niño (La Niña) phenomenon is related to an increase (decrease) of dengue cases nationally and in most regions and departments, with maximum correlations occurring at shorter time lags in the Pacific and Andes regions, closer to the Pacific Ocean. This association is mainly explained by the ENSO-driven increase in temperature and decrease in rainfall, especially in the Andes and Pacific regions. The influence of ENSO is not stationary, given the reduction of DENV cases since 2005, and that local climate variables vary in space and time, which prevents to extrapolate results from one region to another. The association between DENV and ENSO varies at national and regional scales when data are disaggregated by seasons, being stronger in DJF and weaker in SON. Overall, the Pacific and Andes regions control the relationship between dengue dynamics and ENSO at national scale. Cross-wavelet analysis indicates that the ENSO-DENV relation in Colombia exhibits a strong coherence in the 12 to 16-months frequency band, which implies the frequency locking between the annual cycle and the interannual (ENSO) timescales. Results of nonlinear causality metrics reveal the complex concomitant effects of ENSO and local climate variables, while offering new insights to develop early warning systems for DENV in Colombia., (Copyright © 2021. Published by Elsevier B.V.)

The far Eastern Tropical Pacific (EPAC) and Western Colombia are one of the rainiest places on Earth, and the Choco low-level jet (ChocoJet) is one of the processes that influence the formation of copious precipitation and convection organization in this region. This study investigates the projected changes in precipitation in this region using historical and future simulations based on model output from two models contributing to the Coupled Model Intercomparison Project phase 6 (CMIP6). In close agreement with observations, models simulate that ChocoJet intensity is directly proportional to precipitation in the region. This relationship is also found far inland in Central America, the northwestern part of South America Pacific Coast, and the intermountain valleys of the Colombian Andes. Late 21st century simulations show a southward migration in mean and regional daily precipitation consistent with a decreased ChocoJet intensity. The weaker ChocoJet is related to a projected increase in EPAC tropical sea surface temperatures (SSTs) and an increased frequency and intensity of the warm phase of the Niño 1+2 SST interannual variability. [ABSTRACT FROM AUTHOR]

Satellite-based monitoring provides insights on synergies and trade-offs between energy production and land use and land cover (LULC) changes (LULCC) around hydropower dams. Using Landsat data, we mapped LULCC related to hydropower expansion to understand change dynamics of cash crop production in the Magdalena River basin (Colombian Andes). We leveraged secondary map products and an active learning routine to produce thematically detailed LULC maps, for 2009, 2015, and 2020, including key cash crops (rice and oil palm). Our area-adjusted accuracy assessment revealed high overall and class-specific user's and producer's accuracies, exceeding 80% for oil palm, rice, non-agricultural vegetation, wetlands, and grasslands, and accuracies of ~60% for other temporary and permanent crops. We identified substantial losses of rice (10,6%) and grasslands (25,9%) in El Quimbo due to reservoir flooding. For Hidrosogamoso, there was a loss of wetlands downstream. Our products provide the basis for balancing social, economic, and environmental trade-offs related to conflicting land uses. [ABSTRACT FROM AUTHOR]

Zika, a viral disease transmitted to humans by Aedes mosquitoes, emerged in the Americas in 2015, causing large-scale epidemics. Colombia alone reported over 72,000 Zika cases between 2015 and 2016. Using national surveillance data from 1121 municipalities over 70 weeks, we identified sociodemographic and environmental factors associated with Zika's emergence, re-emergence, persistence, and transmission intensity in Colombia. We fitted a zero-state Markov-switching model under the Bayesian framework, assuming Zika switched between periods of presence and absence according to spatially and temporally varying probabilities of emergence/re-emergence (from absence to presence) and persistence (from presence to presence). These probabilities were assumed to follow a series of mixed multiple logistic regressions. When Zika was present, assuming that the cases follow a negative binomial distribution, we estimated the transmission intensity rate. Our results indicate that Zika emerged/re-emerged sooner and that transmission was intensified in municipalities that were more densely populated, at lower altitudes and/or with less vegetation cover. Warmer temperatures and less weekly-accumulated rain were also associated with Zika emergence. Zika cases persisted for longer in more densely populated areas with more cases reported in the previous week. Overall, population density, elevation, and temperature were identified as the main contributors to the first Zika epidemic in Colombia. We also estimated the probability of Zika presence by municipality and week, and the results suggest that the disease circulated undetected by the surveillance system on many occasions. Our results offer insights into priority areas for public health interventions against emerging and re-emerging Aedes-borne diseases. [ABSTRACT FROM AUTHOR]

Enhanced anthropogenic climatic variability challenges small farmers. In the Sumapaz páramo (Colombia), higher irregularity in precipitation and temperature reduces the quality of pasture and cattle health. Data from surveys, semi-structured interviews, and focus groups were analyzed to understand livestock farmers' responses to the impacts of climatic variability. To estimate the communities' resilience in the páramo, we used the capitals framework, the Baseline Resilience Indicator for Communities (BRIC), and cluster analysis. The responses of most households aim to reduce the impacts of climatic variability on the production system, chiefly intensifying practices such as the rotation of paddocks, livelihood diversification, purchase of grass, and buying and selling livestock. Interestingly, farmers did not recognize the value of the types of capital for responding to climatic variability. Results showed that the use of available physical, social, and economic capitals render the farming system resilient. Our probit model estimated that economic and human capitals are the largest and most significant contributors to communities' capacity to respond to climatic variability. However, pre-existing non-climatic vulnerabilities are also important. For example, poverty hinders farmers from using their income in response to climatic variability. The place-based measurements used in this research are easily understood and applicable by local policy makers to address increasing climate variability. [ABSTRACT FROM AUTHOR]

Air pollution includes particle-bound polycyclic aromatic hydrocarbons (PAHs), which eventually reach the placenta, triggering adverse perinatal outcomes through long-term exposure. Lately, air pollution has increased over the Metropolitan Area of Medellin-Colombia (MAMC), but its effects on pregnancy are still unknown. In this research, a real-time analysis of total airborne PAHs was made using a photoelectric sensor for residential places influenced by the industrial and traffic sources affecting the southern and northern MAMC during the second peak of the bimodal tendency for PM2.5 emissions in this region. Additionally, individual PAHs were analyzed by GC/MS coupled with pressurized hot water extraction methodology. The data were applied using an inhalation intake model to assess pregnancy exposure. The average concentration of PAHs in the southern MAMC was three times higher than in the northern MAMC, where the missed abortion rate has been 1.4 times higher according to the database. Previous research indicates that PAHs act as endocrine-disrupting chemicals (EDCs) during pregnancy and that even heavy congeners could reside in umbilical cord blood. Finally, the annual series of missed abortion rates in the MAMC exhibited a significant correlation with the annual average levels of PM2.5, which were associated with PAHs through correlation analysis (r2 = 0.69, p < 0.01). While this significant correlation does not imply causality, our results suggest an important connection between both variables, opening a gap for a deeper understanding of how regions with high PAH convergence influence the missed abortion rates in MAMC. [ABSTRACT FROM AUTHOR]

This paper presents a methodology to detect the coastal erosion and progradation effects in the 'Atrato River' delta, located in the Gulf of Urabá in Colombia, using SAR (Synthetic Aperture Radar) images. Erosion is the physical–mechanical loss of the soil that affects its functions and ecosystem services while producing a reduction in its productive capacity. Progradation is the deposition of layers in the basinward direction while moving coastward. Other studies have investigated these two phenomena using optical images, encountering difficulties due to the persistent presence of clouds in this region. In order to avoid the cloud effects, in this study, we used 16 Sentinel 1 SAR images with two different polarizations between 2016 and 2023. First, each image was rescaled from 0 to 255, then the image was despeckled by a deep learning (DL) model. Afterwards, a single RGB image was composed with the filtered polarizations. Next, a classifier with 99% accuracy based on Otsu's method was used to determine whether each pixel was water or not. Then, the classified image was registered to a reference one using Oriented FAST and Rotated BRIEF (ORB) descriptor. Finally, a multitemporal analysis was performed by comparing every image to the previous one to identify the studied phenomena, calculating areas. Also, all images were integrated to obtain a heatmap that showed the overall changes across eight years (2016–2023) in a single image. The multitemporal analysis performed found that the newly created mouth is the most active area for these processes, coinciding with other studies. In addition, a comparison of these findings with the Oceanic Niño Index (ONI) showed a relative delayed coupling to the erosion process and a coupling of progradation with dry and wet seasons. [ABSTRACT FROM AUTHOR]

Geodiversity, comprising both endogenous and exogenous geological processes, plays a crucial role in shaping the structure and functionality of natural systems, alongside its substantial impact on human well-being. However, the often-overlooked interconnection between geodiversity components limits our comprehension of geosystems. In the Chinchiná River Basin (CRB) in Colombia, located in the northern Andes in South America, we established criteria to differentiate geodiversity classes, calculated indices to understand the distribution of geological elements, and discussed systemic relationships. This comprehensive approach lays the foundation for a holistic comprehension of the territory's structure and functionality. Our findings revealed the convergence in an area of 1052 km2 of 10 rock types, 7 slope ranges, 13 landforms, 5 drainage density features, 610.4 km of faults with 9 kinematic tendencies, 5 soil orders, 5 climate types, a 3328 km surface drainage network with 7 hydrographic orders, 1 underground aquifer, 4 areas with lakes, 2 zones with glaciers, 27 polygenetic and monogenetic volcanoes, and several thermal springs. This discussion explores the implications of various methodologies used to establish the value of the general geodiversity index while also examining the relationships between abiotic elements and their distribution patterns. This forms a fundamental basis for understanding the geosystem services of the basin in terms of regulation, support, and provisioning processes, as well as the culture and knowledge derived from geodiversity. These conceptual elements are indispensable for enhancing the sustainability of a region that is susceptible to the impacts of climate change. Furthermore, they serve as the foundations for the objective's achievement, as set by the UNESCO Global Geopark project "Volcán del Ruiz", currently ongoing within the region. [ABSTRACT FROM AUTHOR]

Malaria remains a significant public health problem worldwide, particularly in low-income regions with limited access to healthcare. Despite the use of antimalarial drugs, transmission remains an issue in Colombia, especially among indigenous populations in remote areas. In this study, we used an SIR Ross MacDonald model that considered land use change, temperature, and precipitation to analyze eco epidemiological parameters and the impact of time lags on malaria transmission in La Pedrera—Amazonas municipality. We found changes in land use between 2007 and 2020, with increases in forested areas, urban infrastructure and water edges resulting in a constant increase in mosquito carrying capacity. Temperature and precipitation variables exhibited a fluctuating pattern that corresponded to rainy and dry seasons, respectively and a marked influence of the El Niño climatic phenomenon. Our findings suggest that elevated precipitation and temperature increase malaria infection risk in the following 2 months. The risk is influenced by the secondary vegetation and urban infrastructure near primary forest formation or water body edges. These results may help public health officials and policymakers develop effective malaria control strategies by monitoring precipitation, temperature, and land use variables to flag high-risk areas and critical periods, considering the time lag effect. [ABSTRACT FROM AUTHOR]

Natural ingredients (NIs) from plant biodiversity represent a value creation strategy in the transition to a sustainable biobased economy, especially in biodiversity rich countries. A necessary action to achieve this purpose is to orientate research and strengthen the knowledge base of NIs following a value chain (VC) approach. Although the promotion of NIVCs has gained increasing attention in the bioeconomy, a description of the scientific progress, research advances and gaps towards their development is necessary. This review aimed to scrutinize the existing literature on NIVCs to determine its state of progress. Firstly, we explored the global diffusion of research on natural plant ingredients. Secondly, we examined the research landscape in Colombia, focusing on the cooperation between countries, economic sectors impacted, and plant species reported. Lastly, we selected the most reported plant species as a promising NI source in Colombia to assess the literature that constitute the knowledge base of this plant in relation to the VC building blocks: biomass production, biomass processing, product development, and transversal aspects such as sustainability and governance. We show that research on NIs has risen worldwide, with notable scientific output from China, India, and the United States. In Colombia, the interest in NIs from plant biodiversity has also gained importance in the research agenda. Its progress is based on extensive collaboration between institutions, mainly from Spain, the United States, and Brazil. Its research prospects include diverse applications in the pharmaceutical and food sectors. We identify Lippia origanoides as the most reported native plant in scientific literature in Colombia. Using this plant as case study, we provide an overview of the knowledge base of L. origanoides in relation to the VC. Our results indicate that most publications focus on product development, suggesting a lack of comprehensive coverage of the VC and potentially neglected aspects. Based on this, we describe the current and desired scenario of L. origanoides VCs, as well as needs and opportunities for their sustainable implementation in Colombia. This contributes to build research and development roadmaps of sustainable NIVCs from plant diversity supported by multi-stakeholder collaboration. [ABSTRACT FROM AUTHOR]

The coevolution approach in socio‐hydrological systems (SHS) allows the analysis of the interactions between social and hydrological systems over time. SHS's characteristics such as non‐linearity, causality, integration of spatiotemporal scales and feedbacks must be considered. However, in simulation processes, there are challenges in analyzing these characteristics while integrating quantitative and qualitative source variables. We propose a general causal network for study of coevolution in tropical wetlands, operationalized through Bayesian Networks for a case study in Ayapel Wetland, Colombia. We defined the flood pulse and economic production to analyze the co‐evolution of tropical wetlands. We identified that the probability of having more than 146,998 individuals of livestock is 30% and of obtaining a fish production considered "high" by fishers is 44.2% for a period from 1995 to 2019. However, under permanent conditions, the probability of this livestock decreases to 18.7%, and "high" fishing increases to 87.5%. Under seasonal conditions, the probability of high livestock production increases to 42.8%, and fish production decreases to 3.85%. We demonstrated how the loss of functionality of the existing hydraulic technology in the study area modifies the production dynamics and how a maximum level of agricultural and livestock production is associated with an increase in forest and grassland cover. We consider that the application of the network strengthens adaptation strategies for climate change or The El Niño‐Southern Oscillation events, the risk management plans and land use decision plans in the tropical wetlands. Plain Language Summary: Human populations impact in wetlands through land use/land cover changes, hydraulic infrastructures and other actions, thus modifying their ecological and hydrological functions. In the same sense, wetland hydrological and ecological processes affect social behaviors. Understanding these human‐wetland co‐evolutionary processes requires the characterization of the variables that define this relationship. We developed a conceptual model that allows us to identify how social dynamics change at different hydrological moments (droughts and floods) and to analyze the social processes that modify the functional attributes of tropical wetlands. We used this conceptual model to perform model simulations through probability relationships focused on one of the most important wetlands in Colombia, a tropical country. We identified that under permanent flooding conditions, the probability of high livestock production decreases, but the probability of high fish production increases. The opposite occurs under seasonal wetland conditions, livestock increases and fish decreases. We found that the loss of functionality of existing hydraulic technology in the study area modifies productive dynamics and analyzed how a maximum level of agricultural and livestock production is associated with an increase in forest and grassland cover. Our analyses contribute to risk management and land use plans decisions in tropical wetlands and thus, to the strengthening of adaptation strategies to the impacts generated by El Niño‐Southern Oscillation phenomena such as El Niño and La Niña that may be even more significant under climate change scenarios. Key Points: We developed a causal network to evaluate socio‐hydrological interactions in tropical floodplainsWe applied a Bayesian Network model to analyze co‐evolution in a tropical floodplainFlood dynamics cause opposite effects on livestock and fisheries [ABSTRACT FROM AUTHOR]

Climate change may have significant impacts on water balance and may considerably influence flooding dynamics of river systems by increasing extreme precipitation. This study evaluates the potential effects of climate change on river discharge and inundation in the Magdalena River basin, the main river in Colombia, using the synergy between the MGB (Modelo de Grandes Bacias) hydrological–hydrodynamic model and downscaled Eta-regional climate model (RCM) projections based on four global climate models (GCMs): BESM (Brazilian Earth System Model), CanESM2 (Canadian Earth System Model), MIROC5 (Model for Interdisciplinary Research on Climate Version Five), and HadGEM2-ES (Hadley Centre Global Environment Model version 2). We used two different greenhouse gas scenarios (RCP4.5 and RCP8.5 (Representative Concentration Pathway)) for the "historical" (1986–2005) and "mid-term prospective" (2046–2065) periods. Model results for the "mid-term prospective" period under scenarios RCP4.5 and RCP8.5 indicate increase in mean river discharges in the east portion of the basin, decreased river discharges (mainly in the dry season) in the upper Magdalena basin, and increased inundation extent. By coupling hydrological–hydrodynamic and GCMs/RCMs models, modelling frameworks like the one used in this study provide an effective management tool for stakeholders interested in potential climate change impacts on tropical river basins. [ABSTRACT FROM AUTHOR]

This manuscript introduces an exploratory case study of the SIMFAC's (Sistema de Información Meteorológica de la Fuerza Aérea Colombiana) operational implementation of the Weather Research and Forecasting (WRF) model with a 3DVAR (three-dimensional variational) data assimilation scheme that provides meteorological information for military, public, and private aviation. In particular, it investigates whether the assimilation scheme in SIMFAC's implementation improves the prediction of the variables of interest compared to the implementation without data assimilation (CTRL). Consequently, this study compares SIMFAC'S 3DVAR-WRF operational implementation in Colombia with a CTRL with the same parameterization (without 3DVAR assimilation) against the ground and satellite observations in two operational forecast windows. The simulations are as long as an operational run, and the evaluation is performed using the root mean square error, the mean fractional bias, the percent bias, the correlation factor, and metrics based on contingency tables. It also evaluates the model's results according to the regions of Colombia, accounting for the country's topographical differences. The findings reveal that, in general, the operational forecast (3DVAR) is similar to the CTRL without data assimilation, indicating the need for further improvement of the 3DVAR-WRF implementation. [ABSTRACT FROM AUTHOR]

Colombia is highly vulnerable to climate change which may be intensified due to the climatic effects of regional deforestation. Here, we quantify the impact of historical (1900–2011) land cover changes (LCC) and of global warming during ENSO events (CC) on precipitation, temperature and surface energy balance components by running the Weather Research and Forecasting model WRF v3.9 at 10 km resolution. We find that historical anthropogenic CC causes a mean temperature increase of 0.77 ± 0.02 °C in Colombia, which is more pronounced in high altitudes. Precipitation is enhanced by 0.98 ± 0.30 mm/day (+ 9%), particularly over forested areas and reduced at the Pacific coast. LCC imply a reduction of precipitation particularly above the Andes (− 0.48 ± 0.10 mm/day) and Caribbean Coast (− 0.67 ± 0.12 mm/day), where LCC effects dampen CC effects by 24% and 72%, respectively. La Niña tends to intensify LCC and CC effects in the Andes but dampens them at the Coast, roughly by a factor of two compared to El Niño impacts in both regions. At the subregional level, LCC and CC can have impacts of similar magnitude on precipitation highlighting the need to precisely account for both drivers in hydroclimatic assessments. Contrary to almost all observations and similar simulations with climate models, WRF simulates a cooling bias after historical deforestation in Colombia, even with alternative WRF land surface models. We identify two main sources of biases in the default WRF parametrization to explain this inaccuracy: (1) surface shortwave radiation reflected after deforestation is overestimated; (2) associated evapotranspiration loss is underestimated. Improved model representation and validation of tropical vegetation properties are necessary to provide more robust and confident projections. [ABSTRACT FROM AUTHOR]

In Colombia, most of the energy is produced by using water resources. However, the morphological impact of damming has not been thoroughly studied yet. Therefore, upstream and downstream changes in the channel width and sinuosity along the river due to the Betania, Prado, Salvajina, and Urrá I Dams, four of the oldest hydroelectric projects, were estimated. These changes were reported by using aerial photographs and satellite images to compare the river before and after dam construction. The analysis was complemented by including hydrological trends and geological characteristics of the areas to evaluate their relevance on the impacts on channel morphology. It was shown that factors such as valley confinement and the bank's composition are key to determining the magnitude of the impact downstream of the dam. Upstream of the dam, contrastingly, the influence of the reservoir geometry controls the magnitude of the morphological changes, marking the boundaries of affected areas. The impacts of dam construction on river morphology vary notably, but including the geological characteristics of the river reach can be useful to improve predictions of the channel morphology response. The proposed methodology can be used to identify biotic compensation measures for new projects, a task that is not well defined in several countries. [ABSTRACT FROM AUTHOR]

Examining the ecological consequences of the late Quaternary megafaunal extinctions within biodiversity hotspots is crucial for our understanding of the potential consequences of contemporary extinctions. We present the first multi-species record of spores of coprophilous fungi (SCF) from Monquentiva and the high-Andean forests of Colombia to reconstruct Late Pleistocene and Holocene megafaunal abundance. Fossilised pollen and charcoal are used to examine the consequences of megafaunal declines on the surrounding vegetation and fire activity. Our SCF record indicates the presence of Pleistocene megafauna at least since 30,290 BP, with two waves of megafaunal decline at ca. 22,900 BP and 10,990 BP. At Monquentiva, megafaunal decline in the Early Holocene resulted in transitional non-analogue vegetation, loss of some herbivore-dispersed plant taxa, an encroachment of palatable and woody flora, and a rise in fire activity. Differences with other published South-American records suggest that ecological consequences of megafaunal declines were habitat-specific. Overall, we show that ecosystems in the eastern Colombian Cordillera were highly sensitive to the decline of megafaunal populations. Under the current biodiversity crisis, management and conservation efforts must account for the effects of local herbivore declines on plant dispersal, on fire activity, and the potential loss of ecosystem services. [ABSTRACT FROM AUTHOR]

Improving the remote sensing frameworks related to land cover mapping is necessary to make informed policy, development, planning, and natural resource management decisions. These efforts are especially important in tropical countries where technical capacity is limited. Land cover legend specification is a critical first step when mapping land cover, with consequences for its subsequent use and interpretation of results. We integrated the temporal metrics of SAR (Synthetic Aperture Radar) and multispectral data (Sentinel-1 and Sentienel-2) with visual pixel classifications and field surveys using five machine learning algorithms that apply different statistical methods to assess the prediction and mapping of two different land cover legends at a high spatial resolution (10 m) in a tropical region with seasonal flooding. The evaluated legends were CORINE (Coordination of Information on the Environment) and ECOSO, a legend that we defined based on the ecological and socio-economic conditions of the study area. Compared with previous studies, we obtained high accuracies for land cover modeling (kappa = 0.82) and land cover mapping (kappa = 0.76) when using ECOSO. We also found that the CORINE legend generated lower accuracies than the ECOSO legend (kappa = 0.79 for land cover modeling and kappa = 0.61 for the land cover mapping). Although CORINE was developed for European environments, it is the official land cover legend of Colombia, a South American country with tropical ecosystems not found in Europe. Therefore, some of the CORINE classes have ambiguous definitions for the study area, explaining the lower accuracy of its modeling and mapping. We used free and open-access data and software in this research; thus, our methods can be applied in other tropical regions. [ABSTRACT FROM AUTHOR]

The Colombian Andean Mountains include the headwaters of the main basins of the country. However, the isotope composition of water in these high mountain ecosystems has been poorly studied. In this study, we analysed the first set of stable isotope data collected along a wide elevation range (2600–4950 m a.s.l.) in the Central Andes of Colombia. The stable isotope composition of stream water and precipitation was determined for a period between 2017 and 2018 in the Upper Claro River basin. The driving factors influencing the spatial and temporal variability of δ2H, δ18O, and d‐excess were identified, and compared with daily air temperature and precipitation data from seven meteorological stations. The local regression line was described by δ2H = 8.2 δ18O + 12.3, R2 = 0.98. The δ2H and δ18O values showed more depletion in heavy isotopes, and the d‐excess values were more negative during the rainy season. An altitude effect of −0.11‰/100 m and −0.18‰/100 m was estimated for stream water and precipitation δ18O values, respectively, with the latter showing non‐linear behaviour. The dataset was compared with Colombian stations of the Global Network of Isotopes in Precipitation database, and a back‐trajectory analysis of air masses was conducted and compared with the d‐excess values. The δ18O weighted mean values changed with respect to the position in the Central Andes, indicating contrasting altitude effects depending on the moisture sources. The most positive d‐excess values were attributed to moisture recycling enhanced by local ecosystem conditions and the origin of precipitation from the Amazon basin, which change during the year and across the northern Andes. The results showed a high level of variation because of differences in elevation, seasonality, and atmospheric circulation patterns during the year. This study contributes to knowledge of spatial and temporal isotope composition data in the northern Andes, delineation of water supply basins, and to the definition of ecosystem boundaries in the high mountains of Colombia. [ABSTRACT FROM AUTHOR]

The far eastern tropical Pacific is one of the rainiest locations on Earth. This region is characterized by a robust diurnal cycle with precipitation initiating over the Andes mountains in Colombia in the late afternoon and moving offshore overnight while organizing into mesoscale convective systems (MCSs). As the MCSs move westward, they can seed tropical easterly waves that develop into tropical cyclones. Novel measurements of near‐surface wind speeds and latent heat flux (LHFLX) from the Cyclone Global Navigation Satellite System (CYGNSS) mission and ERA5 reanalysis are used to evaluate changes to regional flow patterns, moisture, and LHFLX that favor a strong westward propagating diurnal cycle of precipitation in this region. Days with strongly versus weakly westward propagating diurnal precipitation are compared during the extended boreal summer of the CYGNSS era (May–October 2018–2021). Strongly propagating days have a more moist lower troposphere with stronger vertically integrated moisture flux convergence than days with weakly propagating precipitation. The enhanced low‐level moisture is supported by increased wind‐driven LHFLX from stronger regional flows including the Choco and Caribbean Low‐Level Jets and Panama and Papagayo gap winds. Increased offshore convergence and vorticity also help sustain convection during the days with strongly propagating precipitation. Background variations in the physical environment, as opposed to diurnal variations, seem more important for supporting a robust diurnal cycle of precipitation in the region. Plain Language Summary: The eastern tropical Pacific Ocean off the coast of Colombia is one of the rainiest locations on Earth. Thunderstorms frequently form in the late afternoon over the foothills of the Andes mountains and then move offshore into the eastern Pacific overnight and into the early morning while growing into bigger thunderstorms. These large thunderstorms are important because they can eventually lead to tropical cyclone development as they move westward over the eastern Pacific parallel to central America. We evaluate environmental conditions that favor days when thunderstorms move far away from the Colombian coast along central America versus days when thunderstorms stay closer to the Colombian coast. We find that days when the thunderstorms move farther away from the Colombian coast have more moisture near the Earth's surface. This enhanced moisture is supported by increased winds near the surface in the east Pacific and Caribbean that help transport moisture from areas near the Pacific equator and Caribbean to offshore of Colombia and transfer moisture from the far eastern Pacific Ocean surface into the overlying atmosphere. Measurements from eight microwave‐size satellites in space were critical to determine the role of the transfer of moisture from the ocean surface to the atmosphere. Key Points: An index is developed to distinguish between days with strong versus weak westward‐propagating diurnal precipitation in the far east PacificStrongly propagating days have increased low‐level moisture, regional circulations, and gap winds relative to weakly propagating daysCyclone Global Navigation Satellite System measurements show that increased moisture on the strongly propagating days is supported by increased wind‐induced latent heat fluxes [ABSTRACT FROM AUTHOR]

The coporo, Prochilodus mariae, plays a fundamental role in aquatic ecosystems as a detritivorous species facilitating the flow of carbon to the rest of the ecosystem's food web. It is also one of the most exploited freshwater fish species. Fishing, pollution and environmental changes in the Orinoquia region of Colombia have considerably reduced its population size. We analysed the population dynamics of P. mariae during an annual river cycle, including extreme drought and flood scenarios, by means of a mathematical model and simulations. The model we propose is novel because it relates biological, ecological and environmental factors to the population dynamics, including reproduction, growth in size and biomass of fish, recruitment, predation, fishing mortality and river flow. The proposed mathematical model apparently gives an approximate description of the population dynamics of P. mariae for 2010 because a good fit of the model to the catch data of the species of that year was obtained. The simulations showed that the first 3 months of the year are crucial for the species because this is when it is most affected by a combination of fishing, biological factors which increase natural mortality (e.g. upstream migration and predation) and environmental factors (e.g. low river flow). Hypothetical scenarios show that local extinction could occur if fishing were to increase and river flow were to decrease. [ABSTRACT FROM AUTHOR]

The increasing reliance on global models to address climate and human stresses on hydrology and water resources underlines the necessity for assessing the reliability of these models. In river basins where availability of gauging information from terrestrial networks is poor, models are increasingly proving to be a powerful tool to support hydrological studies and water resources assessments (WRA). However, the lack of in situ data hampers rigorous performance assessment, particularly in tropical basins where discordance between global models is considerable. Remotely sensed data of the terrestrial water storage obtained from the Gravity Recovery and Climate Experiment (GRACE) satellite mission can provide independent data against which the performance of such global models can be evaluated. However, how well GRACE data represents the dynamics of terrestrial water storage depends on basin scale and hydrological characteristics. Here we assess the reliability of six global hydrological models (GHMs) and four land surface models (LSMs) available at two resolutions. We compare the dynamics of modelled Total Water Storage (TWS) with TWS derived from GRACE data over the Magdalena–Cauca basin in Colombia. This medium-sized tropical basin has a well-developed gauging network when compared to other basins at similar latitudes, providing unique opportunity to contrast modelled TWS and GRACE data across a range of scales. We benchmark monthly TWS changes from each model against GRACE data for 2002–2014, evaluating monthly variability, seasonality, and long-term variability trends. The TWS changes are evaluated at basin level, as well as for selected sub-basins with decreasing basin size. We find that the models poorly represent TWS for the monthly time series, but they improve in representing seasonality and long-term variability trends. The high-resolution GHM World-Wide Resources Assessment (W3RA) model forced by the Multi-Source Weighted Ensemble Precipitation (MSWEP) is most consistent in providing the best performance at almost all basin scales, with higher-resolution models generally outperforming lower-resolution counterparts. This is, however, not the case for all models. Results highlight the importance of basin scale in the representation of TWS by the models, as with decreasing basin area, we note a commensurate decrease in the model performance. A marked reduction in performance is found for basins smaller than 60 000 km 2. Although uncertainties in the GRACE measurement increase for smaller catchments, the models are clearly challenged in representing the complex hydrological processes of this tropical basin, as well as human influences. We conclude that GRACE provides a valuable dataset to benchmark global simulations of TWS change, in particular for those models with explicit representation of the internal dynamics of hydrological stocks, offering useful information for continued model improvement in the representation of the hydrological dynamics in tropical basins. [ABSTRACT FROM AUTHOR]

We evaluate the efficacy of the stable isotope composition of precipitation and plant waxes as proxies for paleoaltimetry and paleohydrology in the northern tropical Andes. We report monthly hydrogen (δ2Hp) and oxygen (δ18Op) isotope values of precipitation for an annual cycle, and hydrogen isotope values of plant waxes (δ2Hwax) obtained from modern soils along the eastern and western flanks of the Eastern Cordillera of Colombia. δ2Hp, δ18Op, as well as the unweighted mean δ2Hwax values of n‐C29, n‐C31, and n‐C33n‐alkanes in the eastern flank show a dependence on elevation (R2 = 0.90, 0.82, and 0.65, respectively). In stark contrast, the stable isotope compositions of neither precipitation nor plant waxes from the western flank correlate with elevation (R2 < 0.23), on top of a negligible (p‐value >0.05) correlation between δ2Hwax and δ2Hp. In general, δ2Hwax values along the eastern flank of the Eastern Cordillera seem to follow the trend of a simple Rayleigh distillation process that is consistent with studies elsewhere on the eastern side of the Andes in South America. Neither δ2Hp nor δ18Op, and therefore δ2Hwax, offer reliable estimates of past elevations in the western flank, due perhaps to water vapor source mixing, evaporation overprint, contrasting plant communities, and/or differences in evapotranspiration. Thus, δ2Hwax is only reliable for paleohydrology and paleoaltimetry reconstructions on the eastern flank of the Andes, whereas interpretations based on δ2Hp and/or δ18Op west of the highest point of the Eastern Cordillera need to consider mixing of moisture sources in addition to precipitation amount. Plain Language Summary: As air rises over mountainous terrain, heavy isotopes of hydrogen and oxygen preferentially enter the condensate and rain out during ascent leaving remaining vapor depleted in the heavy isotopes. Previous studies have shown that stable isotope values of both precipitation and plant waxes correlate with elevation, and therefore, can be used to reconstruct past surface elevations. This correlation with elevation is clear on the eastern flank of the Eastern Cordillera of Colombia in the northern tropical Andes. On the western flank, however, no correlation was found for either precipitation or plant waxes. Complex atmospheric circulation and the topographic configuration of inter‐Andean valleys pose a challenge for simple isotope signals. It follows that geologists carrying out paleoaltimetry and paleohydrology studies using stable isotopes should be wary of mixed moisture sources and/or complex evaporation paths and be more confident in paleoelevation and paleoclimate estimates if moisture sources are simple. Key Points: The stable isotope composition of precipitation and plant waxes in the eastern flank of the Eastern Cordillera record an elevation‐dependent signalThe stable isotope composition of neither precipitation nor plant waxes from the western flank correlate with elevationStable isotopes are unreliable paleoaltimeters when multiple water vapor sources and/or evaporation overprint simple Rayleigh distillation [ABSTRACT FROM AUTHOR]

Given the importance of climate change and the increase of its severity under extreme weather events, we analyze the main drivers of high food prices in Colombia between 1985 and 2020 focusing on extreme weather shocks like a strong El Niño. We estimate a non‐stationary extreme value model for Colombian food prices. Our findings suggest that perishable foods are more exposed to extreme weather conditions in comparison to processed foods. In fact, an extremely low precipitation level explains only high prices in perishable foods. The risk of high perishable food prices is significantly larger for low rainfall levels (dry seasons) compared to high precipitation levels (rainy seasons). This risk gradually results in higher perishable food prices. It is nonlinear and is also significantly larger than the risk related to changes in the US dollar‐Colombian peso exchange rate and fuel prices. Those covariates also explain high prices for both perishable and processed foods. Finally, we find that the events associated with the strongest El Niño in 1988 and 2016 are expected to reoccur once every 50 years. [ABSTRACT FROM AUTHOR]

The large-scale integration of variable renewable energy sources into the energy system presents techno–economic challenges. Long–term energy system optimization models fail to adequately capture these challenges because of the low temporal resolution of these tools. This limitation has often been addressed either by direct improvements within the long–term models or by coupling them to higher resolution power system models. In this study, a combined approach is proposed to capitalize on the advantages and overcome the disadvantages of both methods. First, the temporal resolution of an energy model was enhanced by approximating the joint probability of the electricity load and the supply of intermittent sources. Second, the projected electricity mix was simulated by a power model at an hourly resolution. This framework was used to analyze mid–century deep decarbonization trajectories for Colombia, subject to future uncertainties of hydroclimatic variability and the development of the bioeconomy. The direct integration method is found to consistently reduce the overestimation of the feasible penetration of VRES. However, its impact is marginal because of its inability to assess the short–term operation of the power system in detail. When combined with the soft–linking method, the reliable operation of the power system is shown to incur an additional overhead of 12–17% investment in flexible generation capacity, 2–5% of the annual energy system cost, and a 15–27% shortfall in achieving the aspired GHG mitigation target. The results obtained by combining both methods are found to be closer to the global optimum solution than using either of these methods individually. [ABSTRACT FROM AUTHOR]

Background: Previous studies suggest a relationship between precipitation and ocular toxoplasmosis (OT) reactivation and congenital toxoplasmosis infection. We aimed to investigate the relationship between precipitation and the frequency of new OT cases in Colombia from 2015 to 2019. Methodology: This retrospective cohort study analyzed data obtained from a claims-based database created by the Colombian Ministry of Health and national registries of precipitation of the Institute of Hydrology, Meteorology, and Environmental Studies. We estimated the daily number of OT cases, interpolating data from the average number of annual cases from 2015 to 2019. Then, we compared exposures (mean daily precipitation) in the case period in which the events (interpolated OT new cases) occurred by a quasi-Poisson regression, combined with a distributed lag non-linear model to estimate the non-linear and lag–response curve. Principal findings: In the 5-year analysis, there were 1,741 new OT cases. Most of the cases occurred in 2019, followed by 2015 and 2018. New OT cases among departments were significantly different (P< 0.01). The cumulative exposure-response curve was decreasing for most departments. Nevertheless, in Chocó, Bogotá, Cesar, Cauca, and Guajira, when a certain amount of precipitation accumulates, the relative risk (RR) increases, which was contrary to the pattern observed in the other regions. The response curves to the one-day lag showed that precipitation influences the RR; however, the trends vary by department. Finally, an increasing trend in the number of cases was directly proportional to precipitation in Guajira, Atlántico, Norte de Santander, Santander, Caquetá and Quindío (r = 0.84; P< 0.05). Conclusions: Precipitation influenced the RR for new OT cases. However, varying trends among geographical regions (departments) lead us to hypothesize that other sociodemographic, behavioral, and environmental variables, such as wind and water contamination, could influence the RR. Author summary: We analyzed data obtained from the Colombian Ministry of Health and the national meteorology center to determine the effect of precipitation on the new cases of ocular toxoplasmosis (OT). The number of interpolated daily cases was estimated and compared with the exposure (precipitation) by a quasi-Poisson regression, combined with a distributed lag non-linear model to estimate the lag, non-linear response curve, and a Pearson correlation test. In the 5-year study period, 1,741 new cases of OT were reported. We found significant differences in the trends among all departments, with most departments showing decreasing cumulative exposure-response curves. However, in Chocó, Bogotá, Cesar, Cauca, and Guajira, when a certain amount of precipitation accumulates, the relative risk (RR) increases, contrary to the pattern observed in the rest of the country. The response curves at one-day lag showed that precipitation influences the RR; however, trends vary by department. We found a positive correlation between the number of cases and precipitation (β = 0.03; P< 0.05), indicating that precipitation affects the RR of new cases of OT. However, inconsistent trends exist across geographical regions, leading us to hypothesize that other sociodemographic, behavioral, and environmental variables, such as wind and water contamination, might influence the RR. [ABSTRACT FROM AUTHOR]

Fire is a process of disturbance of natural ecosystems that can be used for land management and soil preparation for agricultural purposes, but can also drastically affect biodiversity and the distribution and abundance of species by changing land use and altering the microclimate. The analysis of data on thermal anomalies has become a valuable tool for the study of places with low monitoring of the occurrence of fires. In this study, information from the MODIS sensor was used to analyze the spatio-temporal distribution of fires in the five natural regions of Colombia (Caribbean, Andean, Pacific, Orinoquia, and Amazon) in the period of 2000–2020. Nevertheless, MODIS fire hotspots present some difficulties in estimating the magnitude of fire activity, due the relations between active fires and burned areas, which are not constant in space and time. The method used in this work consisted to performance an inter-annual and intra-annual analysis of thermal anomalies data and identifying the incidence of temperature in the occurrence of fires. The fire density (defined as the number of fires per unit area) and the fire trends over the study period were also analyzed. Inter-annual fire peaks were recorded in 2004 (8.21%) and 2007 (8.04%), and three main fire hotspots were identified in the Orinoquia, Andean, and Caribbean regions. Moreover, 87% of fire peaks were observed in the dry season (December–March). On the other hand, the highest incidence of thermal anomalies occurred in the Orinoquia region (83409 ± 185 fires), and the highest incidence of fires per unit area was recorded in the Andean region (0.162 ± 0.086 fires-km2-year). Fire activities varied strongly according to region and year over the study period. Significant correlations were observed between temperature and fire density in the Andean (Rho = 0.7506), Pacific (Rho = 0.7364), and Caribbean (Rho = 0.5571) regions. Thus, temperature seem to be a driver of fire density in these regions. [ABSTRACT FROM AUTHOR]

Texture is a fundamental soil property for multiple applications in environmental and earth sciences. Knowing its spatial distribution allows a better understanding of the response of soil conditions to changes in the environment, such as land use. This paper describes the technical development of Colombia's first texture maps, obtained via a spatial ensemble of national and global digital soil mapping products. This work compiles a new database with 4203 soil profiles, which were harmonized at five standard depths (0–5, 5–15, 15–30, 30–60, and 60–100 cm) and standardized with additive log ratio (ALR) transformation. A compilation of 83 covariates was developed and harmonized at 1 km 2 of spatial resolution. Ensemble machine learning (EML) algorithms (MACHISPLIN and landmap) were trained to predict the distribution of soil particle size fractions (PSFs) (clay, sand, and silt), and a comparison with SoilGrids (SG) products was performed. Finally, a spatial ensemble function was created to identify the smallest prediction errors between EML and SG. Our results are the first effort to build a national texture map (clay, sand, and silt fractions) based on digital soil mapping in Colombia. The results of EML algorithms showed that their accuracies were very similar at each standard depth, and were more accurate than SG. The largest improvement with the spatial ensemble was found at the first layer (0–5 cm). EML predictions were frequently selected for each PSF and depth in the total area; however, SG predictions were better when increasing soil depth in some specific regions. The final error distribution in the study area showed that sand presented higher absolute error values than clay and silt fractions, specifically in eastern Colombia. The spatial distribution of soil texture in Colombia is a potential tool to provide information for water-related applications, ecosystem services, and agricultural and crop modeling. However, future efforts need to improve aspects such as treating abrupt changes in the texture between depths and unbalanced data. Our results and the compiled database (10.6073/pasta/3f91778c2f6ad46c3cc70b61f02532db, , 10.6073/pasta/d6c0bf5847aa40836b42dcc3e0ea874e,) provide new insights to solve some of the aforementioned issues. [ABSTRACT FROM AUTHOR]

Mangroves are important ecosystems of tropical and subtropical shorelines. Anthropogenic activity decreases their habitat quality, affecting structural and functional trophic features. We hypothesized that higher levels of anthropogenic intervention generate diversity loss and modify the trophic structure of tropical mangrove fish communities. We compared the taxonomic and isotopic (δ13C/δ15N) composition, abundance, trophic position, and isotopic niche of fish communities from three mangrove systems with different anthropogenic intervention levels in the Colombian Pacific. Non-parametric statistical tests and a Bayesian approach were used to analyze data. A total of 1254 specimens belonging to 23 families, 25 genera, and 30 species were identified, presenting higher abundance (821) in moderate anthropogenic intervention level mangrove (Moderate-AIL), with high dominance of one species (Lile stolifera). The low anthropogenic intervention level mangrove (Low-AIL) was the second in abundance (291) but exhibited a greater number of species (23), while the high anthropogenic intervention level mangrove (High-AIL) presented the least abundance (142) and species number (17). The isotopic composition ​​reveals that Moderate and High-AIL mangroves presented enriched 13C and 15 N compared to Low-AIL (~ 2 to 4 ‰). Mean trophic position (TP) of communities was slightly higher in the more intervened systems (~ 1 to 2 orders of magnitude), as well as in specific species (Centropomus spp.). Isotopic niche width (TA and SEAc) was greater in High-AIL (41.1 and 9.2), more than doubled compared to Moderate-AIL (33.0 and 4.1). In High-AIL isotopic niche width increased, indicating lesser availability of prey and basal resources. The results obtained in this study support the proposed hypothesis and, suggest that anthropogenic intervention modifies diversity and food webs dynamics, affecting the transfer of matter and energy from macrotidal tropical mangroves to coastal ecosystems. However, it is recommended to be careful concluding differences based exclusively on the anthropogenic intervention level, since it is widely documented that mangrove settings also influence the analyzed trophic parameters. [ABSTRACT FROM AUTHOR]

Glaciated Andean mountains have experienced several decades of shrinkage in their transition to non-glaciated regimes. This study analyses the period of hydrologic transition from 1956 to 2020 in a watershed of the Sierra Nevada del Cocuy (SNC), which is the most extensive remaining tropical glacier in Colombia. Using ground hydrometeorological data, remote sensing products, a metric of extreme flow regulation, and decadal flow duration curves, the study shows how the combined effect of continuous glacier shrinkage, highly variable precipitation regimes and increasing human extractions have altered the hydrological capacity of the watershed to regulate high, low, and mean flows. The alteration is noticeable since the 2000s, when communities have effectively benefited from the surplus of baseflow provided by the shrinking glacier to the limit, creating an unsustainable dependency with potential restrictions of use in the short run and major implications for water security of humans and the environment in the forthcoming decades. [ABSTRACT FROM AUTHOR]

The Tumaco multivariate index (TMI) is a multidecadal monthly index constructed with unique time series of sea surface temperature, surface air temperature and rain measured at Tumaco bay, in the southern Pacific coast of Colombia, and available since 1961. In this work, this index is re‐evaluated after the addition of in situ sea level data, and its properties for different standardization periods are compared against oceanic El Niño–Southern Oscillation (ENSO) and other derived indices. In particular, we propose a modified TMI, hereinafter referred as TMI4, whose potential to identify the expected sign and the amount of future variations of rain induced by ENSO events in Colombia is analysed for selected extreme episodes. Results indicate that after the inclusion of sea level data, TMI4 can anticipate the development of El Niño events before the ENSO 3 and some other sea surface temperature‐based regional indices, although its predictability depends on the ENSO type (canonical or Modoki). The explanation is that sea level includes new information into TMI4 on the onset of El Niño events. In particular, the signal of intraseasonal sea level anomalies carried by downwelling Kelvin waves is detected at Tumaco tide‐gauge. Moreover, the analysis of the differences, both in magnitude and spatial distribution, of rainfall anomalies induced by positive (El Niño) and negative (La Niña) ENSO events characterized by TMI4 are regionally presented. As a result, we find that TMI4 is especially suited for extensive northern and western areas of mainland Colombia. For completeness, in the appendix we briefly introduce the semi‐automated implementation of TMI4, including a visual interface, which is currently being tested by personnel within the operational oceanography area at Centro de Investigaciones Oceanográficas e Hidrográficas del Pacífico (Dimar‐CCCP). [ABSTRACT FROM AUTHOR]

This study extends knowledge of the evolution of glacier shrinkage in the Cocuy‐Güican Mountains since the maximum glacier extent of the Little Ice Age (LIA). Mass balance data for the Ritacuba Glacier since 2009 were acquired and compared with available data for the Conejeras Glacier (Los Nevados National Park). This study also investigated the hydrological significance of Colombian glaciers, which is still largely unknown because the available information is very limited. Glaciers in the Cocuy‐Güican Mountains covered 13.2 km2 in 2019 compared with 127.8 km2 during the maximum LIA, representing a shrinkage of 89.7%. Analysis of glacier cover observations made in 1955, 1994, 2010, and 2019 revealed that the rate of ice loss was greatest from 1994 to 2010 (0.59 km2 yr−1), and was then almost halved from 2010 to 2019 (0.34 km2 yr−1). This slowing of glacier retreat is consistent with the moderate negative mass balance measured for 2009–2019, and an accumulated loss of 1766 mm w.e. (mm water equivalent). The progressive confinement of glaciers to higher elevations, ice accumulation in topographic locations providing shelter from solar radiation, and an absence of recent marked climatic anomalies could explain why the Cocuy‐Güican glaciers have temporally reached a near equilibrium state conditions. This contrasts with the Conejeras Glacier, where 47,000 mm w.e. has been lost in the same period. The available data on runoff and isotope tracers of streamflow and precipitation suggest that precipitation rather than glacier melt water exerts primary control over the hydrological variability at high elevation sites. [ABSTRACT FROM AUTHOR]

Background: Colombia has one of the highest burdens of arboviruses in South America. The country was in a state of hyperendemicity between 2014 and 2016, with co-circulation of several Aedes-borne viruses, including a syndemic of dengue, chikungunya, and Zika in 2015. Methodology/Principal findings: We analyzed the cases of dengue, chikungunya, and Zika notified in Colombia from January 2014 to December 2018 by municipality and week. The trajectory and velocity of spread was studied using trend surface analysis, and spatio-temporal high-risk clusters for each disease in separate and for the three diseases simultaneously (multivariate) were identified using Kulldorff's scan statistics. During the study period, there were 366,628, 77,345 and 74,793 cases of dengue, chikungunya, and Zika, respectively, in Colombia. The spread patterns for chikungunya and Zika were similar, although Zika's spread was accelerated. Both chikungunya and Zika mainly spread from the regions on the Atlantic coast and the south-west to the rest of the country. We identified 21, 16, and 13 spatio-temporal clusters of dengue, chikungunya and Zika, respectively, and, from the multivariate analysis, 20 spatio-temporal clusters, among which 7 were simultaneous for the three diseases. For all disease-specific analyses and the multivariate analysis, the most-likely cluster was identified in the south-western region of Colombia, including the Valle del Cauca department. Conclusions/Significance: The results further our understanding of emerging Aedes-borne diseases in Colombia by providing useful evidence on their potential site of entry and spread trajectory within the country, and identifying spatio-temporal disease-specific and multivariate high-risk clusters of dengue, chikungunya, and Zika, information that can be used to target interventions. Author summary: Dengue, chikungunya, and Zika are diseases transmitted to humans by the bite of infected Aedes mosquitoes. Between 2014 and 2016 chikungunya and Zika viruses started causing outbreaks in Colombia, one of the countries historically most affected by dengue. We used case counts of the diseases by municipality and week to study the spread trajectory of chikungunya and Zika within Colombia's territory, and to identify space-time high-risk clusters, i.e., the areas and time periods that dengue, chikungunya, and Zika were more present. Chikungunya and Zika spred similarly in Colombia, but Zika spread was faster. The Atlantic coast, a famous touristic destination in the country, was likely the place of entry of chikungunya and Zika in Colombia. The south-western region was identified as a high-risk cluster for all three diseases in separate and simultaneously. This region has a favorable climate for the Aedes mosquitoes and other characteristics that facilitate the diseases' transmission, such as social deprivation and high population mobility. Our results provide useful information on the locations that should be prioritized for interventions to prevent the entry of new diseases transmitted by Aedes and to reduce the burden of dengue, chikungunya and Zika where they are established. [ABSTRACT FROM AUTHOR]

This study assessed the precipitation recycling and moisture sources in the Colombian Pacific region between 1980–2017, based on the monitoring of moisture in the atmosphere through the Eulerian Water Accounting Model-2 layer (WAM2 layer) and the delimitation of the area contributing to terrestrial and oceanic moisture in the region is performed using the "precipitationshed" approach. The results indicate a unimodal precipitation recycling ratio for the North and Central Pacific and Patía-Mira regions, with the highest percentages between March and April, reaching 30% and 34%, respectively, and the lowest between September and October (between 19% and 21%). Moreover, monthly changes in the circulation of the region promote a remarkable variability of the sources that contribute to the precipitation of the study area and the spatial dynamics of the precipitationshed. From December to April, the main contributions come from continental sources in eastern Colombia and Venezuela, the tropical North Atlantic, and the Caribbean Sea, a period of high activity of the Orinoco Low-Level jet. In September, the moisture source region is located over the Pacific Ocean, where a southwesterly cross-equatorial circulation predominates, converging in western Colombia, known as the Choco Jet (CJ), decreasing the continental contribution. An intensified Caribbean Low-Level Jet inhibits moisture sources from the north between June and August, strengthening a southerly cross-equatorial flow from the Amazon River basin and the southeastern tropical Pacific. The March–April (September–October) season of higher (lower) recycling of continental precipitation is related to the weakening (strengthening) of the CJ in the first (second) half of the year, which decreases (increases) the contribution of moisture from the Pacific Ocean to the region, increasing (decreasing) the influence of land-based sources in the study area. [ABSTRACT FROM AUTHOR]

Colombia's lightning climatology was studied using 16 years of high-resolution data from the Tropical Rainfall Measuring Mission Lightning Imaging Sensor (TRMM LIS). The findings present the climatology of the country organized in two ways: where lightning occurs and when lightning occurs. The authors sorted data using Colombia's six natural regions and conditional mean values for day, month, quarter, and year for frequency occurrence. The findings show a high mean flash rate density (FRD) around 70 fl km - 2 year - 1 in 15 % of the territory. Most of this activity concentrates in the northern part of the country between latitude 7 ∘ N and 11 ∘ N. Regarding time patterns, lightning reaches its maximum in most of the territory two times a year with a transition period marked by a steep fall. But, the areas with higher activity seem to have a single lightning season, with a maximum around August. These findings confirm the need to consider lightning activity based on regional contexts. During the day, activity is more probable from afternoon to evening in the southern part of the country; meanwhile, it tends to go from afternoon to early morning in northern regions. [ABSTRACT FROM AUTHOR]

Landslides typify one of the most hazardous natural phenomena fostering economic and even human losses worldwide. Several countries like Colombia, in South America, are hotspots for fatal landslides. In this contribution, we thoroughly reviewed four available databases, articles, grey literature and web resources, in order to build up a new catalogue of fatal landslides in Colombia. We gathered a catalogue of 2351 individual fatal landslides which caused about 37,959 deaths. Of these, we found 11 fatal events in historical times (pre-twentieth century). In modern times (1912–2020), we analysed landslides' spatial and temporal distribution, finding that in central-western Colombia, particularly in the departments of Caldas, Risaralda, Quindío and Antioquia, these kinds of events are more frequent. Upward trends in these areas and a nationwide increase in the number of events in the last 20 years suggest that fatal landslides are far from being effectively mitigated. Our findings also show a strong correlation between the climate variability phenomenon known as El Niño Southern Oscillation (ENSO) and fatal landslides, particularly during those years when strong La Niña (cold phase of ENSO) events occur. Despite rainfall being the most common trigger for fatal landslides, we observed an increasing trend in anthropogenically related events in the last decade. Finally, we obtained multiple socio-economic indices and ran a statistical analysis at the departmental level in order to assess whether impoverished and vulnerable people are more affected by fatal landslides. We propose that in most cases, departments with low income, high levels of corruption and inequality are usually more affected. [ABSTRACT FROM AUTHOR]

In tropical regions, deep convective systems are associated with extreme rainfall storms that usually detonate flash floods and landslides in the Andean Colombian region. Several studies have used satellite data to address the structure and formation of tropical convective storms. However, there is a local gap in the characterization, which is essential for a better understanding of flash floods and preparedness, filling a gap in a region with scarce information regarding extreme events. In this work, we assess the deep convective storms in a mountainous region of Colombia using meteorological radar observations between 2014 and 2017. We start by identifying convective and stratiform formations. We refine the convective identification by classifying convective systems into enveloped (contained in a stratiform system) and unenveloped (not contained). Then, we analyze the systems' temporal and spatial distributions and contrast them with the watersheds' features. According to our results, unenveloped convective systems have higher reflectivity and hence higher rainfall intensities. Moreover, they also have a well-defined spatial and temporal distribution and are likely to occur in watersheds with elevation gradients of around 2000 m and an aspect contrary to the wind direction. Our assessment of the convective storms is of significant value for the hydrologic community working on flash floods. Moreover, the spatiotemporal description is highly relevant for stakeholders and future local analysis. [ABSTRACT FROM AUTHOR]

An increasing frequency of extreme atmospheric events is challenging our basic knowledge about the resilience mechanisms that mediate the response of small mountainous watersheds (SMW) to landslides, including production of water-derived ecosystem services (WES). We hypothesized that the demand for WES increases the connectivity between lowland and upland regions, and decreases the heterogeneity of SMW. Focusing on four watersheds in the Central Andes of Colombia and combining "site-specific knowledge", historic land cover maps (1970s and 1980s), and open, analysis-ready remotely sensed data (GLAD Landsat ARD; 1990–2000), we addressed three questions. Over roughly 120 years, the site-specific data revealed an increasing demand for diverse WES, as well as variation among the watersheds in the supply of WES. At watershed-scales, variation in the water balances—a surrogate for water-derived ES flows—exhibited complex relationships with forest cover. Fractional forest cover (pi) and forest aggregation (AIi) varied between the historic and current data sets, but in general showed non-linear relationships with elevation and slope. In the current data set (1990–2000), differences in the number of significant, linear models explaining variation in pi with time, suggest that slope may play a more important role than elevation in land cover change. We found ample evidence for a combined effect of slope and elevation on the two land cover metrics, which would be consistent with strategies directed to mitigate site-specific landslide-associated risks. Overall, our work shows strong feedbacks between lowland and upland areas, raising questions about the sustainable production of WES. [ABSTRACT FROM AUTHOR]

Climate change includes the change of the long-term average values and the change of the tails of probability density functions, where the extreme events are located. However, obtaining average values are more straightforward than the high temporal resolution information necessary to catch the extreme events on those tails. Such information is difficult to get in areas lacking sufficient rain stations. Thanks to the development of Satellite Precipitation Estimates with a daily resolution, this problem has been overcome, so Extreme Precipitation Indices (EPI) can be calculated for the entire Colombian territory. However, Colombia is strongly affected by the ENSO (El Niño—Southern Oscillation) phenomenon. Therefore, it is pertinent to ask if the EPI's long-term change due to climate change is more critical than the anomalies due to climate variability induced by the warm and cold phases of ENSO (El Niño and La Niña, respectively). In this work, we built EPI annual time series at each grid-point of the selected Satellite Precipitation Estimate (CHIRPSv2) over Colombia to answer the previous question. Then, the Mann-Whitney-Wilcoxon test was used to compare the samples drawn in each case (i.e., change tests due to both long-term and climatic variability). After performing the analyses, we realized that the importance of the change depends on the region analyzed and the considered EPI. However, some general conclusions became evident: during El Niño years (La Niña), EPI's anomaly follows the general trend of reduction -drier conditions- (increase; -wetter conditions-) observed in Colombian annual precipitation amount, but only on the Pacific, the Caribbean, and the Andean region. In the Eastern plains of Colombia (Orinoquía and Amazonian region), EPI show a certain insensitivity to change due to climatic variability. On the other hand, EPI's long-term changes in the Pacific, the Caribbean, and the Andean region are spatially scattered. Still, long-term changes in the eastern plains have a moderate spatial consistency with statistical significance. [ABSTRACT FROM AUTHOR]

The hydroclimatology of Northern South America responds to the coupling between the Pacific and Atlantic oceans, the Amazon–Andes interactions, and the orographic barrier of the regional Andes. The relative contributions of oceanic and terrestrial moisture sources have been mostly evaluated in modelling studies, with limited observational data for validation. We combine observations from stable isotopes in precipitation and output from the Lagrangian moisture trajectory tracking model FLEXPART to characterize and contrast the relative contribution of oceanic (from the Atlantic and the Pacific) and terrestrial (from different regions in the continent) moisture sources to mean monthly precipitation in the Andes and Caribbean regions of Colombia. Our results indicate that most moisture becoming rain in the region has an atmospheric residence time that deviates from commonly assumed 10 days. These residence times vary between source and sink regions from 1 day in the case of recycling to more than 10 days in Andean precipitation originating in the Atlantic Ocean. Common integration times for both regions from all sources are commonly in the order of three to 7 days. Most precipitation in the region comes from terrestrial sources including moisture recycling from the same region (>30% for all months), the Orinoco River basin (up to 28% in April), and the northern Amazon basin (up to 17% in June, July, and August); followed by individually considered oceanic sources including the Tropical South Pacific (up to 30% monthly in October, November and December) and Tropical North Atlantic (up to 30% monthly for January). The fact that a significant proportion of rainfall is recycled highlights that water availability in the Andean and Caribbean regions of Colombia could potentially be altered by current widespread and pervasive changes in vegetation cover. More generally, our results highlight the need to assess the hydrological consequences of land cover change in South America, particularly in a country like Colombia where water, food, and energy security all depend directly on precipitation. [ABSTRACT FROM AUTHOR]

Soil waterlogging is an environmental limitation that is promoted by changes in rainfall patterns and negatively affects plant physiology, growth, and development, coffee production, and exports in Colombia. The objective of this research was to evaluate responses in growth, water status, and chlorophyll fluorescence parameters for plants under different waterlogging conditions. The evaluations were carried out on six-month-old "Cenicafé 1" variety seedlings that were suitable for establishment in the field. The seedlings were subjected to different waterlogging periods: 4, 8, 12, and 16 days, using a completely randomized block experiment design with 30 replicates. Total dry mass (TDM), total leaf area (TLA), and the total number of leaves (TNL) were performed, and growth indices were calculated. The leaf water potential (Ψpd and Ψmd), maximum efficiency of photosystem II-FV/Fm, and electron transport rate (ETR) were also measured. Waterlogging for 16 days caused a 57% reduction for TDM, which was significant starting at 4 days. Statistical differences in the TLA were detected after 12 days, with decreases of 29%. The Ψpd, Ψmd, Fv/Fm, and ETR were sensitive to waterlogging, which decreased noticeably after 8 days. The results indicated the physiological performance and growth of the coffee cv. "Cenicafé 1" plants were significantly affected by waterlogging conditions after eight days. [ABSTRACT FROM AUTHOR]

Oceanic biogeographic barriers disrupt population connectivity and are produced by currents, changes in sea surface temperature, geomorphology, upwelling and resource availability, among others. Their impacts can vary in magnitude depending on their duration and degree of obstruction. Knowing the effects of biogeographic barriers on genetic connectivity has important implications in management and species conservation. To estimate the effects on the genetic connectivity of marine fishes, Sparisoma aurofrenatum was chosen as our model to test the influence of three different barriers in the southern Caribbean as listed: the Panamá-Colombia countercurrent, the Magdalena freshwater outlet, and la Guajira coastal upwelling. This species of parrotfish plays an important ecological role, helping to maintain the balance between corals and macroalgae, and facilitating recruitment and coral growth. Mitochondrial DNA (control region) was used in 88 individuals sampled between July and October 2015, along four localities across the putative barriers in the southern Caribbean. Our results point to discrete populations connected by an asymmetrical east to west unidirectional flow, a high effective population size with a population expansion during the last glacial period. Thus, the three southern Caribbean barriers in this species appear to be effective in isolating populations, but permeable to immigration. [ABSTRACT FROM AUTHOR]

Anthropogenic climate change is a global trend, hitherto incontrovertible, causing immense social and economic damage. Although the this is evident at the global level, at the local level, there is still debate about the most appropriate analyses to support this fact. This debate is particularly relevant in developing countries, such as Colombia, where there is a significant lack of data at the local level that require analysis and interpretation. Consequently, studies are often superficially conducted to support climate change theory at the local level. However, such studies are then used to design hydraulic infrastructure, with potential catastrophic errors for human and environmental health. In this study, we sought evidence of climate change through an analysis of a series of data on temperature (maximum, mean and minimum), as well as total annual and maximum rainfall in 24 h registered at the Rafael Nuñez Airport station in the city of Cartagena, Colombia, from 1941 to 2015. The hypotheses of homogeneity, trend, stationarity and non-stationarity were analyzed. Problems of non-homogeneity and the presence of periodicity in the analyzed series were found, showing a trend and apparent non-stationarity in the original series. This could be associated with the effects of climate change. In this case, no correlation was found between temperatures and rainfall. Spectral analysis was performed for all series, and residual series were generated by extracting the harmonics of greatest significance. It was found that the series data generated from the third harmonic are generally stationary and without trend. Therefore, the trend and non-stationarity of the original series are due to problems of non-homogeneity and periodicity in the series. In the results of the stationarity test conducted according to the Phillips–Perron criterion, all series were non-stationary. For the two additional criteria of stationarity tests, 40% were shown to be stationary, and 60% were non-stationary. Specifically, non-homogeneity problems and apparent trends associated with climate change could have negative implications for the design of drainage systems. [ABSTRACT FROM AUTHOR]

Despite great advances in remote sensing technologies, accurate satellite information is sometimes challenged in tropical regions where dense vegetation prevents the instruments from retrieving reliable readings. In this work, we introduce a satellite-based landslide rainfall threshold for the country of Colombia by studying 4 years of rainfall measurements from The Climate Hazards Group Infrared Precipitation with Stations (CHIRPS) for 346 rainfall-triggered landslide events (the dataset). We isolate the two successive rainy/dry periods leading to each landslide to create variables that simulate the dynamics of antecedent wetness and dryness. We test the performance of the derived variables (Rainfall Period 1 (PR1), Rainfall Sum 1 (RS1), Rainfall Period 2 (PR2), Rainfall Sum 2 (RS2), and Dry Period (DT)) in a logistic regression that includes three (3) static parameters (Soil Type (ST), Landcover (LC), and Slope angle). Results from the logistic model describe the influence of each variable in landslide occurrence with an accuracy of 73%. Subsequently, we use these dynamic variables to model a landslide threshold that, in the absence of satellite antecedent soil moisture data, helps describe the interactions between the dynamic variables and the slope angle. We name it the Landslide Triggering Factor—LTF. Subsequently, with a training dataset (65%) and one for testing (35%) we evaluate the LTF threshold performance and compare it to the well-known event duration (E-D) threshold. Results demonstrate that The LTF performs better than the E-D threshold for the training and testing datasets at 71% and 81% respectively. [ABSTRACT FROM AUTHOR]

Previous soil moisture conditions play an important role in the design of hydraulic structures because they are directly related to the runoff threshold associated with a return period. These represent one of the main determinants of the runoff response of a drainage basin. One of the main difficulties facing hydrologists in Colombia lies in the time spent gathering and analyzing information related to the selection of antecedent moisture conditions. In this study, complete records from 19 rainfall stations located in the Atlántico region, Colombia, were used to analyze the cumulative precipitation during the 5 days prior to the annual maximum daily precipitation associated with different return periods using the Gev, Gumbel, Pearson Type III and Log Pearson Type III probability distributions. Different interpolation methods (IDW, kriging and spline) were applied to evaluate the spatial distribution of the antecedent moisture conditions. The main contribution of this research is establishing, using a probabilistic approach, the behavior of antecedent moisture conditions in a particular region, which can be used by engineers and designers to plan water infrastructure. This probabilistic approach was applied to a case study of the Atlántico region, Colombia, where the spatial distribution of antecedent moisture conditions was calculated for several return periods. The results indicate that the better results were obtained with the IDW interpolation method, and the Pearson Type III and Gumbel distributions also showed the best fits based on the Akaike criterion. [ABSTRACT FROM AUTHOR]

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Atmospheric deep convection in equatorial continental regions is not homogeneously distributed in space or time, primarily due to surface inhomogeneities such as elevated topography and coastlines. This is the case in northwestern South America, which has particularly complex topography which, together with its geographical location, is responsible for some of the most prominent precipitation features around the globe. Although some of these features have been previously investigated in detail, others have not yet been studied, and some not even documented in the literature. The diverse atmospheric convective activity that takes place in this region constitutes a natural laboratory that can provide important insights into fundamental questions relevant for global climate. We use seven years of infrared brightness temperature data in 30 min intervals from the GOES‐13 geostationary satellite to estimate the spatial, seasonal and diurnal distributions of deep convective events in this region. By doing so, we bring forward several relevant features, providing a starting point for future investigations. For example, we find that deep convective events have a bimodal seasonal distribution throughout most of the Colombian Orinoco and Amazon basins, where precipitation is known to have a unimodal distribution. Furthermore, deep convective events in this region tend to be comparable in size to those offshore the Colombian Pacific coast or over the Magdalena river valley, but with significantly shorter lifetimes. On the other hand, nocturnal convection dominates at several continental locations; one of these, the middle‐lower Magdalena river valley, has been previously identified as one of the most active lightning hotspots on Earth, but its convective mechanisms have not yet been fully investigated. Another such location worth investigating is the middle Magdalena river valley, which may have strong similarities with the Maracaibo Lake area. [ABSTRACT FROM AUTHOR]

Ortiz Royero, J.C.; Henriquez Cera, S., and Gomes, H., 2022. Coastal meteo-marine parameters of Hurricane Matthew along the Colombian Caribbean coast: Establishing a baseline of knowledge. Journal of Coastal Research, 38(1), 66–76. Coconut Creek (Florida), ISSN 0749-0208. The hurricanes on the Colombian continental coast have been lower in intensity and number than in other areas of the Caribbean Sea. Thus, given the lack of knowledge about the hurricane parameters in this area, the protocols to deal with a hurricane emergency on the Columbian continental coast are not clear. This work analyzes the meteo-marine parameters caused in Colombia by the passage of Hurricane Matthew to establish a baseline of knowledge. Further progress in understanding the effects the hurricane may have had on several coastal areas, particularly in the areas of hydrology, morphological changes, storm surge, and flood, is expected in future work. The results show that the most significant meteo-marine parameter was the swell generated by the hurricane; although it followed a NW trajectory toward the coast, the swell reached up to 4.5 m of significant wave height and a peak period of 14 seconds. Also, the accumulated rainfall in only 3 days significantly exceeded the average monthly values of October (the rainiest month of the year). This effect is of particular interest given that recent modeling studies established an increase in precipitation rates associated with tropical hurricanes. The wind was not significant with respect to typical values in the zone. [ABSTRACT FROM AUTHOR]

The tropical dry forest (TDF) ecosystem is characterised by strong seasonality exasperated periodically by the El Niño/southern oscillation (ENSO). The environment produced by this event could constrain the survival of small organisms, such as insects. Carabid beetles were collected in a TDF in Armero, Colombia, during wet and dry seasons in both El Niño and non-El Niño periods. A series of traits linked to desiccation resistance were measured to characterise their adaptation to the TDF environment and to investigate changes experienced by carabid beetles during both episodes in quantitative (assemblage) and qualitative (traits) parameters. We found no difference in the presence of traits between El Niño and non-El Niño episodes, but carabid assemblages changed significantly in composition and assemblage structure between these episodes. During both periods, small-sized and nocturnal species dominated the assemblages, but in terms of number of individuals, medium and large-sized, and visual hunter species dominated. Calosoma alternans and Megacephala affinis were the most abundant species with high dispersal capacity. Carabid beetles exhibited morphological traits well-adapted to drought experienced in TDF, including when it is exasperated by ENSO. However, long-term studies can help to elucidate the real effects of ENSO and to confirm the adaptation of carabid beetles to cope with this extreme environment. [ABSTRACT FROM AUTHOR]

We derive and solve a linear stochastic model for the evolution of discharge and runoff in an order-one watershed. The system is forced by a statistically stationary compound Poisson process of instantaneous rainfall events. The relevant time scales are hourly or larger, and for large times, we show that the discharge approaches a limiting invariant distribution. Hence any of its properties are with regard to a rainfall-runoff system in hydrological equilibrium. We give an explicit formula for the Laplace transform of the invariant density of discharge in terms of the catchment area, the residence times of water in the channel and the hillslopes, and the mean frequency and the probability distribution of rainfall inputs. As a study case, we consider a watershed under a stationary rainfall regime in the tropical Andes of Colombia and test the probability distribution predicted by the model against the corresponding seasonal statistics. A mathematical analysis of the invariant distribution is performed yielding formulas for the invariant moments of discharge in terms of those of the rainfall. The asymptotic behavior of the probabilities of extreme discharge events is explicitly derived for heavy-tailed and light-tailed families of distributions of rainfall inputs. The scaling structure of discharge is asymptotically characterized in terms of the parameters of the model and under the assumption of wide sense scaling for the precipitation amounts and the inverse of the residence time in the channel. Our results give insights into the conversion of uncertainty inherent to the rainfall-runoff dynamics and the roles played by different geophysical variables, with the ratio between the mean frequency of rainfall events to the residence time along the hillslopes largely determining the qualitative properties of the distribution of discharge. [ABSTRACT FROM AUTHOR]

Cumulative and synergistic impacts from environmental pressures, particularly in low-lying tropical coastal regions, present challenges for the governance of ecosystems, which provide natural resource-based livelihoods for communities. Here, we seek to understand the relationship between responses to the impacts of El Niño and La Niña events and the vulnerability of mangrove-dependent communities in the Caribbean region of Colombia. Using two case study sites, we show how communities are impacted by, and undertake reactive short-term responses to, El Niño and La Niña events, and how such responses can affect their adaptive capacity to progressive environmental deterioration. We show that certain coping measures to climate variability currently deliver maladaptive outcomes, resulting in circumstances that could contribute to system 'lock-in' and engender undesirable ecological states, exacerbating future livelihood vulnerabilities. We highlight the significant role of social barriers on vulnerabilities within the region, including perceptions of state abandonment, mistrust and conflicts with authorities. Opportunities to reduce vulnerability include enhancing the communities' capacity to adopt more positive and preventative responses based on demonstrable experiential learning capacity. However, these will require close cooperation between formal and informal organisations at different levels, and the development of shared coherent adaptation strategies to manage the complexity of multiple interacting environmental and climatic pressures. [ABSTRACT FROM AUTHOR]