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Interaction of Anthropic interventions (rigid structures) with coasts is an essential aspect for understanding their geomorphic evolution and incorporating these data into adequate coastal management. This study analyses the short and long-term behavior (1985 to 2019) of shoreline at Santa Marta Bay (Caribbean - Colombia) and their relationship with coastal protection structures. The shoreline variations were analyzed through aerial photographs and satellite images using DSAS tools. The short-term assessment showed initial intense 1985–1991 erosion, with an average retreat speed rate of − 1.6 m·y− 1. It changed gradually since 2003, due to the construction of rigid structures and beach nourishment, decreasing shoreline retreat and even a progradation rate of 0.2 m·y− 1 was observed. The 2009–2019 period, despite recording a positive average value, exhibited a high percentage of erosion profiles. Therefore, in a decadal or long-term analysis (1985–2019), despite engineering works present positive results in the short term, new interventions are required. The coastal erosion is not uniform along the shoreline, because the area is a closed bay with small sediment inputs, the variations in erosion and accretion rates change with human intervention and the installation of new structures. Therefore, quantifying the scale and rate of shoreline changes and correlating them with anthropogenic structures is an essential step in assessing shoreline vulnerability. [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]

The indicators related to the Regulatory, Provisioning and Cultural Ecosystem Services were mapped, based on semi-structured interviews of owners and Administrators of 32 farms with banana crops, in Quindío Colombia. Three visits were made per site and ethnographic methods were used as a means of data collection, such as dialogue, approach to farmers and their families and semi-structured interviews. Aerial photographs were taken, in order to effect the division of the lots. In these lots, the geospatial position of the SE indicators was considered. The maps were created by means of the Argis 10.1.1 software, a Geographic Information System (GIS) tool. The combination of the participatory mapping of the indicators associated with the ecosystem services, with the GIS tool and the hierarchical analysis of clusters, allowed the grouping of the farms, facilitating the identification of the lots in which both threats and strengths in the generation of said services are presented. [ABSTRACT FROM AUTHOR]

Given their sedimentological, hydrological, and hydraulic characteristics, tropical piedmont rivers create braided courses interwoven with numerous channels that vary in quantity and size in a main riverbed, depending on climatic conditions. This article presents an analysis of the morphodynamical behaviour of a tropical piedmont river in Colombia (the Guatiquía river), as the basis for the evaluation of the susceptibility to flooding of a riverside city (Villavicencio). The study was carried out by (i) analysing historical information consulted in technical reports produced by the Colombian Institute of Hydrology, Meteorology, and Environmental Studies (ideam), the Agustín Codazzi Geographic Institute (igac), and the Colombian Geological Service; (ii) studying hydrological series; (iii) processing and interpreting aerial photographs and multispectral satellite images over a period of 78 years; as well as (iv) by producing the geological and geomorphological cartography with fieldwork controls and support. Thus, it was possible to determine, on the one hand, the dynamic behaviour of the braided courses within the boundaries of the main riverbed of the river system, and, on the other hand, the susceptibility to flooding of the city of Villavicencio, with 64.7 ha in the medium-high category and 17.9 ha in the high category. [ABSTRACT FROM AUTHOR]

Using maps of vegetation cover, aerial photographs and field data, we evaluated the fragmentation status of tropical dry forest at the high basin of river Cauca in southwestern Colombia. The study area had 608992 ha, ranging from northern Cauca to central Risaralda. Forest cover represented 1,76% of the analyzed area, scattered in about 1600 fragments with a mean patch area of 6,03 ha. 75% of the forest fragments were separated by a distance of 500 m or more from its nearest neighbour. Only nine fragments had an extension over 100 ha, most of them with dendritic shapes and up to 17 core areas. This configuration would make them behave more like separate small patches than a continuous large patch. In this landscape, edge effect is expected to greatly influence species composition of dry forest fragments. Evaluation of regional species richness should account for the contribution of other arboreal landscape elements. Bamboo forests and riparian forests are especially important since they increase landscape connectivity. In this context, any conservation or restoration initiative should involve management of the landscape matrix, sugar cane and pastures, in order to make them less resistant to the movement or organisms between landscape elements. [ABSTRACT FROM AUTHOR]

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Alluvial forests are under high pressure from human activities because of their value as agricultural, wildlife, timber and recreational land. Despite this, spatial patterns of alluvial forest deforestation are not well known. We studied forest alterations in a 2800 ha alluvial ecosystem using aerial photographs. During the study period (1939-1997), forests with canopy heights greater than 15 m (high canopy mature forest; HCM forest) decreased by 70-4 per cent while forests with canopy heights less than 15 m (low canopy mature forest; LCM forest) forests decreased by 51 per cent, producing a highly fragmented landscape. Factors responsible for forest change included human activities and river dynamics. Although most of the deforestation was related to human disturbance, almost 27 per cent of forest losses were due to channel migration of the Meta River. HCM forests were the most affected land cover since they are easily accessed, viable for logging and occurred on fertile soils, which are valuable for agriculture LCM forests were less affected since their soil fertilities and inundation regimes were unfavourable to human uses, and thus, less prone to anthropogenic disturbances. [ABSTRACT FROM AUTHOR]

Sibaté is a municipality located in the central region of Colombia, where the first asbestos-cement facility of the country has been in operation since 1942. Both a malignant pleural mesothelioma cluster and landfilled zones with the presence of an underground friable asbestos layer have been identified in Sibaté. There is still limited knowledge regarding the history of the construction of landfilled zones, and what kinds of materials were deposited. The current study aims to improve our understanding of the history and characteristics of the landfilled zones present in Sibaté. Two participatory workshops with inhabitants of Sibaté were conducted to determine when the landfilled zones were built and their location. Information collected in participatory workshops was crossed with both topographic maps and aerial photographs, giving special attention to zones within the urban area of the municipality that in the past were inundated with water from El Muña Reservoir. An opportunistic soil sampling campaign was conducted in suspected landfilled zones that had not been previously sampled, during the replacement of pipelines of the drainage system ordered by the municipality. The analysis of historical topographic maps, combined with the interpretation of aerial photographs, confirmed the disposal of residues in areas that were previously inundated with water from El Muña Reservoir, creating landfilled zones in the urban area of Sibaté. On top of these landfilled zones, a football stadium and a football field with an athletic track were built. The location of landfilled zones identified using geographic analysis was similar to the location identified analyzing maps constructed by inhabitants of Sibaté in participatory workshops. The four soil samples collected during an opportunistic sampling campaign confirmed the presence in new locations of the underground friable asbestos layer discovered in previous studies. Based on the extension of the landfilled zones, the presence of friable asbestos in these areas, and the close proximity to a school and residential dwellings, there could have been major dispersion events of asbestos fibers in the urban area of Sibaté during the disposal of residue materials and the construction of the landfilled zones. Thus, important asbestos exposures may have occurred among residents of Sibaté, which is aggravated by the fact that during those years, more than 50% of the population of Sibaté was 25 years old or younger. Although the results of the current study improved our understanding of the processes and chronology associated with the landfilled zones, the uncertainty regarding their exact location remains significant. It is important to continue investigating the adverse health effects resulting from this potential asbestos exposure source. • An asbestos-cement facility began operations in Sibaté in 1942. • Inundated zones were desiccated and filled with asbestos containing materials. • Sport facilities were built on top of landfilled zones. • Participatory workshops confirmed the general location of the landfilled zones. • The presence of the friable asbestos layer was confirmed in new locations. [ABSTRACT FROM AUTHOR]

Anthropic activities, mainly deforestation, have produced rapid transformation of land cover types in the Urabá region at northwest Colombia. Land cover alterations impact the abundance and composition of the Anophelinae community, affecting malaria transmission dynamics. Therefore, this study used landscape metrics to evaluate the relationship of land cover types with Anophelinae species abundance, composition and diversity in the important malaria endemic Urabá region, in NW Colombia. Orthorectified aerial photographs were used to identify land cover types in four localities of the region. Landscape metrics were obtained and diversity indices were estimated for both, land covers and Anophelinae species collected. The impact of land cover type on the presence and abundance of Anophelinae species was evaluated using a canonical correspondence analysis. Diversity indices showed differences in the Anophelinae community and land covers. The variables with more influence in the Anophelinae community composition were locality, bare soil and the interaction between forest and bare soil covers. The most abundant and dominant species Nyssorhynchus nuneztovari (former Anopheles nuneztovari), related with impacted environments was associated with grass, shrub and bare soil land covers. In conclusion, land covers derived from anthropic activities favored the presence and abundance of the main malaria vectors; but, regardless of differences in landscape, unknown specific factors varying among localities lead to a unique configuration in each site that directly shaped anopheline community composition locally. This information is essential for the development of malaria risk maps and for the design of integrated vector control interventions that include the recognition of the landscape features favoring human-vector contact. Unlabelled Image • Anthropic activities influenced the Anophelinae community composition. • Grass, shrub and bare soil land covers favored the abundance of Ny. nuneztovari. • Landscape fragmentation reduce the Anophelinae community diversity. • A small patch size of bare soil cover influenced the presence of Ny. darlingi. [ABSTRACT FROM AUTHOR]