Search

Water resource management in Brazil is constantly evolving, and greater knowledge about this resource allows better planning and more sustainable uses. In Brazil, the improvement of water resource management faces the difficulty of implementing the instruments of the National Water Resources Policy, such as classification of water bodies. Thus, to help improve the water management instruments in the country's northern region, the objective of the present study was to diagnose the influence of land use and occupation on the water quality of the Igarapé Nazaré microbasin. For this purpose, indirect methods of landscape analysis were applied based on the processing of remote sensing images in a GIS. For the water quality analysis, 10 collection points were selected in the watershed, with samples collected at each one in four periods (high water; HW/LW transition; low water; LW/HW transition). In the collected samples, 14 parameters were analyzed, namely: temperature, pH, electrical conductivity; turbidity; water transparency and depth; dissolved oxygen; chlorophyll a, ammonia, nitrite, nitrate, total phosphorus and dissolved phosphorus; total coliforms and E. coli. The spatial analysis showed that the microbasin has about 84-% anthropized territory, with emphasis on agriculture, and sources of pollution from industries, fish farming and domestic sewage. Parameter analyses showed high values of total phosphorus (0.005-27.55-mg.L-1), total coliforms (4,103-1,09,106 CFU) and E. coli (0-5.8,105 CFU), and low DO concentration (0.0-8.33-mg.L-1), below the official limit established in all periods analyzed The water quality of the Igarapé Nazaré microbasin was found to suffer strong anthropic interference, requiring improvement of the sanitary infrastructure of city of Ji-Paraná, for maintenance of the watershed in class 2. [ABSTRACT FROM AUTHOR]

The sudden increase in Amazon fires early in the 2019 fire season made global headlines. While it has been heavily speculated that the fires were caused by deliberate human ignitions or human-induced landscape changes, there have also been suggestions that meteorological conditions could have played a role. Here, we ask two questions: were the 2019 fires in the Amazon unprecedented in the historical record, and did the meteorological conditions contribute to the increased burning? To answer this, we take advantage of a recently developed modelling framework which optimises a simple fire model against observations of burnt area and whose outputs are described as probability densities. This allowed us to test the probability of the 2019 fire season occurring due to meteorological conditions alone. The observations show that the burnt area was higher than in previous years in regions where there is already substantial deforestation activity in the Amazon. Overall, 11 % of the area recorded the highest early season (June–August) burnt area since the start of our observational record, with areas in Brazil's central arc of deforestation recording the highest ever monthly burnt area in August. However, areas outside of the regions of widespread deforestation show less burnt area than the historical average, and the optimised model shows that this low burnt area would have extended over much of the eastern Amazon region, including in Brazil's central arc of deforestation with high fire occurrence in 2019. We show that there is a 9 % likelihood of the observed August fires being caused by meteorological conditions alone, decreasing to 6 %–7 % along the agricultural–humid forest interface in Brazil's central states and 8 % in Paraguay and Bolivia dry forests. Our results suggest that changes in land use, cover or management are the likely drivers of the substantial increase in the 2019 early fire season burnt area, especially in Brazil. Burnt area for September in the arc of deforestation had a 14 %–26 % probability of being caused by meteorological conditions, potentially coinciding with a shift in fire-related policy from South American governments. [ABSTRACT FROM AUTHOR]

The information survey and the land use and land cover (LULC) change monitoring are essential to understand the changes in the landscape and their impacts on the environment. The Brazilian savanna (Cerrado) constitutes the second largest biome in Brazil and is highly relevant because of its rich biodiversity. The Cerrado in the Maranhão State is facing a high conversion rate of its natural vegetation into agricultural systems because of the agricultural development policies. This article aims to analyze and quantify the LULCC in the Chapadinha microregion, Maranhão State, Brazil, by comparing Landsat satellite images from 2000, 2009, and 2019. The Chapadinha microregion covers an area of more than 14,000 km2 and, since 2000, presents significant spatial transformations related to agricultural expansion. The goal of this expansion is the economic development based on agricultural commodities (mainly soybean monoculture) for exportation. The study area is the third microregion in terms of agricultural production in Maranhão. The satellite image interpretation showed a reduction of more than 800 km2 of natural vegetation. [ABSTRACT FROM AUTHOR]

The Território Quilombola Kalunga de Goiás (TKG) was established by law nº. 11,409/GO, and was federally regularized as territory in 2009. Its total area covers three Municipalities of Goiás: Monte Alegre de Goiás, Teresina de Goiás and Cavalcante. There live remaining communities of quilombolas. The present work aims to evaluate the recurrence of fires in this Territory and in its surroundings, doing relationships between land use and land cover and burned areas. For this purpose, were used data generated from satellite images, made available in public databases, and procedures in GIS. During the annualized time, the frequency of fires was moderate. Grassland had the largest proportion of burned areas. [ABSTRACT FROM AUTHOR]

The factors that contribute to land use change in the municipality of Gaúcha do Norte - MT, are entirely linked to the economic process and agricultural production. This process has left Brazil in a state of alert due to the process of deforestation and loss of tropical forests. From 2000 to 2010, the forest areas converted into agriculture accounted for 13.3%, the main factor that directly potentiated with deforestation was the cultivation of soybeans, which in turn was occupying places previously occupied by livestock and pushing the livestock forest inside. The phenomena of land use change and land cover start from multidimensional issues in the environmental and economic context. The use of environmental modeling through cellular automata to analyze land use change phenomena and reproduce the trajectory through future land use simulations and evolution establishes an integration associated by mathematical models and flow integration systems. That predict the trajectory of land use change, thus generating a dynamic model capable of predicting future land use changes by replicating possible patterns of landscape evolution and enabling assessments of future ecological implications for the environment. [ABSTRACT FROM AUTHOR]

Pastures are complex land covers with a variety of land use systems. This land cover occupies large areas in the globe and is mainly used for livestock production. Brazil is one of the largest livestock producers and has extensive pasture areas. We analyzed the pasture land cover change of the São Paulo State between the years 2000 to 2015. São Paulo was chosen as study case due to its large industrial and agricultural importance and its expressive land cover changes over past decades. It was analyzed land covers databases generated by the Brazilian Annual Land Use and Land Cover Mapping Project (MapBiomas Project) – Collection 4. Transition matrix was generated to analyze the land cover change during the period. Gain, loss, total change, net change and swap were calculated in terms of area. Total pasture area decreased but continues the largest land cover of the São Paulo State; with 79.5% of persistence in the area. Main changes were from losses of pastures and gains in agriculture. Most of the changes to pasture came from other non vegetated areas and grassland categories. These results demonstrated the relevance of pastures areas in land cover change dynamics to address land use policy and plan future land use scenarios. [ABSTRACT FROM AUTHOR]

The Brazilian savanna (Cerrado) is one of the most important biodiversity hotspots in the world. Being a fire-dependent biome, its structure and vegetation dynamics are shaped by and rely on the natural occurring fire regime. Over the last decades, Cerrado has been increasingly threatened by accelerated land cover changes, namely the uncontrolled and intense use of fire for land expansion. This is particularly seen in Brazil's new agricultural frontier in northeastern Cerrado: the MATOPIBA region. Changes in MATOPIBA's fire regime resulting from this rapid expansion are still poorly understood. Here we use satellite-derived datasets to analyze burned area patterns in MATOPIBA over the last 18 years, at the microregions level. We further evaluate the role of climate and land use in spatial and temporal burned area variability and assess their trends in the last two decades. Results show an increased contribution of MATOPIBA to Cerrado's total burned area over the last few years: Maranhão and Tocantins present the highest values of total burned area with some microregions burning more than twice its area over the study period. Climate is shown to play a relevant role in MATOPIBA's fire activity, explaining 52% of the interannual variance, whereas land use and burned area were found to have more complex interactions that are highly dependent on the regional context. Lastly, climate and land use drivers are found to have an overall increasing trend over the last two decades, whereas burned area trends show much heterogeneity within MATOPIBA. [ABSTRACT FROM AUTHOR]

Farmland expansion in the Brazilian Cerrado, considered one of the largest agricultural frontiers in the world, has the potential to alter water fluxes on different spatial scales. Despite some large-scale studies being developed, there are still few investigations in experimental sites in this region. Here, we investigate the water balance components in experimental plots and the groundwater table fluctuation in different land covers: wooded Cerrado, sugarcane, pasture and bare soil. Furthermore, we identify possible water balance trade-offs due to the different land covers. This study was developed between 2012 and 2016 in the central region of the state of São Paulo in southern Brazil. Hydrometeorological variables, groundwater table, surface runoff and other water balance components were monitored inside experimental plots containing different land covers; the datasets were analyzed using statistical parameters; and the water balance components uncertainties were computed. Replacing wooded Cerrado by pastureland and sugarcane shifts the overland flow (up to 42 mm yr -1) and the water balance residual (up to 504 mm yr -1) and may affect groundwater table behavior. This fact suggests significant changes in the water partitioning in a transient land cover and land use (LCLU) system, as the evapotranspiration is lower (up to 719 mm yr -1) in agricultural land covers than in the undisturbed Cerrado. We recommend long-term observations for continuing the evaluations initiated in this study, mainly because there are few basic studies on tropical environments at the hillslope scale and more assessments are needed for a better understanding of the real field conditions. Such efforts should be made to reduce uncertainties, validate the water balance hypothesis and catch the variability of hydrological processes. [ABSTRACT FROM AUTHOR]

Land surface models are excellent tools for studying how climate change and land use affect surface hydrology. However, in order to assess the impacts of Earth processes on river flows, simulated changes in runoff need to be routed through the landscape. In this technical note, we describe the integration of the Ecosystem Demography (ED2) model with a hydrological routing scheme. The purpose of the study was to create a tool capable of incorporating to hydrological predictions the terrestrial ecosystem responses to climate, carbon dioxide, and land-use change, as simulated with terrestrial biosphere models. The resulting ED2+R model calculates the lateral routing of surface and subsurface runoff resulting from the terrestrial biosphere models' vertical water balance in order to determine spatiotemporal patterns of river flows within the simulated region. We evaluated the ED2+R model in the Tapajós, a 476674km² river basin in the southeastern Amazon, Brazil. The results showed that the integration of ED2 with the lateral routing scheme results in an adequate representation (Nash-Sutcliffe efficiency up to 0.76, Kling-Gupta efficiency up to 0.86, Pearson's R up to 0.88, and volume ratio up to 1.06) of daily to decadal river flow dynamics in the Tapajós. These results are a consistent step forward with respect to the "no river representation" common among terrestrial biosphere models, such as the initial version of ED2. [ABSTRACT FROM AUTHOR]

This study aims to analyse the dynamics of land-use and land-cover (LULC) in a selected southern Amazonian area (Brazil), monitoring and distinguishing trajectories in NDVI (Normalized Difference Vegetation Index) variations for the last three decades. The area, with a total of 17336 km², has been subject to significant LULC changes associated with deforestation progress and use of fire. Considering available Landsat time series, it was selected an image per year from 1984 to 2013 (path/row -231/66), at a particular period of year, atmospherically corrected using LEDAPS tools. NDVIs values were generated for each selected image. Furthermore, the images of 1984 and 2010 still underwent a classification of LULC differentiate five categories: water, forest, secondary/degraded forest, savannah/pasture and crop/bare soil. The trajectories in NDVI variation values were analysed by R software, considering intersections of classified categories. The pixels identified as forests on the images of 1984 and 2010 displayed stable trajectories of NDVI values, with average value 0.824 and coefficient of variation 3.9%. While the pixels of savannah/pasture, which was periodically affected by fire, had an average NDVI value 0.585 and coefficient of variation 15,1%. The main regressive trajectory was the transition "forest to crop/bare soil", identifying 1999 as the starting point in the drop in NDVI values, associated with an increase of the deforested areas. Therefore, the results show distinct trajectories associated with NDVIs and LULC changes that assist in better understanding the dynamics of ecological processes and the human impacts operating in the area. [ABSTRACT FROM AUTHOR]

In this paper soil carbon, nitrogen and phosphorus concentrations and related elemental ratios, as well as and nitrogen and phosphorus stocks were investigated in 17 paired sites and in a regional survey encompassing more than 100 pasture soils in the Cerrado, Atlantic Forest, and Pampa, the three important biomes of Brazil. In the paired sites, elemental soil concentrations and stocks were determined in native vegetation, pastures and crop-livestock systems (CPS). Overall, there were significant differences in soil element concentrations and ratios between different land uses, especially in the surface soil layers. Carbon and nitrogen contents were lower, while phosphorus contents were higher in the pasture and CPS soils than in forest soils. Additionally, soil stoichiometry has changed with changes in land use. The soil C:N ratio was lower in the forest than in the pasture and CPS soils; and the carbon and nitrogen to available phosphorus ratio (PME) decreased from the forest to the pasture to the CPS soils. The average native vegetation soil nitrogen stocks at 0-10, 0-30 and 0- 60 cm soil depth layers were equal to approximately 2.3, 5.2, 7.3Mgha-1, respectively. 15 In the paired sites, nitrogen loss in the CPS systems and pasture soils were similar and equal to 0.6, 1.3 and 1.5Mgha-1 at 0-10, 0-30 and 0-60 cm soil depths, respectively. In the regional pasture soil survey, nitrogen soil stocks at 0-10 and 0-30 soil layers were equal to 1.6 and 3.9Mgha-1, respectively, and lower than the stocks found in the native vegetation of paired sites. On the other hand, the soil phosphorus stocks 20 were higher in the CPS and pasture of the paired sites than in the soil of the original vegetation. The original vegetation soil phosphorus stocks were equal to 11, 22, and 43 kg ha-1 in the three soil depths, respectively. The soil phosphorus stocks increased in the CPS systems to 30, 50, and 63 kg ha-, respectively, and in the pasture pair sites to 22, 47, and 68 kg ha-1, respectively. In the regional pasture survey, the soil phosphorus stocks were lower than in the native vegetation, and equal to 9 and 15 kg ha-1 at 0-10 and 0-30 depth layer. The findings of this paper illustrate that land-use changes that are currently common in Brazil alter soil concentrations, stocks and elemental ratios of carbon, nitrogen and phosphorus. These changes could have an impact on the subsequent vegetation, decreasing soil carbon, increasing nitrogen limitation, but alleviating soil phosphorus deficiency. [ABSTRACT FROM AUTHOR]

Approximately 57% of the Brazilian northeast region is recognized as semi-arid land and has been undergoing intense land use processes in the last decades, which have resulted in severe degradation of its natural assets. Therefore, the objective of this study is to identify the areas that are susceptible to desertification in this region based on the 11 influencing factors of desertification (pedology, geology, geomorphology, topography data, land use and land cover change, aridity index, livestock density, rural population density, fire hot spot density, human development index, conservation units) which were simulated for two different periods: 2000 and 2010. Each indicator were assigned weights ranging from 1 to 2 (representing the best and the worst conditions), representing classes indicating low, moderate and high susceptibility to desertification. The results indicate that 94% of the Brazilian northeast region is under moderate to high susceptibility to desertification. The areas that were susceptible to soil desertification increased by approximately 4.6% (83.4 km²) from 2000 to 2010. The implementation of the methodology provides the technical basis for decisionmaking that involves mitigating actions and the first comprehensive national assessment within the United Nations Convention to Combat Desertification framework. [ABSTRACT FROM AUTHOR]

Latest studies estimate land use intensity of wind-powered electricity around 0.3–1.3 m2 MWh-1 [1]. This is significantly lower compared to biomass-powered electricity, which land use intensity is estimated around 450-800 m2 MWh-1 [1]. Hence, the significant contribution of biomass energy to land-use change, particularly in countries like Brazil, is widely known. In contrary, low land use intensity of wind-powered electricity suggests that contribution of its infrastructure to land-use change is minor. However, some studies point out the potential restriction of land use for human settlements, negative impact on biodiversity [1] and occurring land conflicts [2] due to wind-powered electricity infrastructure. Better knowledge of wind-powered electricity infrastructure impact on land use change require investigation of related land cover patterns. For discovering those patterns, we focus on two major questions:- What land cover is favourable for VRES infrastructure deployment?- What land-use changes follow the VRES infrastructure deployment?Our case study focuses on wind parks deployed during past 25 years in Brazil. For spatiotemporal analysis of land cover patterns in Brazil, we combine annual land-use and land cover time series – available from 1985 to 2017 – with locations of wind generation infrastructure, transmission grids and transportation network [3].Land cover patterns related to wind parks deployment will improve our understanding of its role in current land use change, and allow the assessment of future land use change in case of extensive wind parks deployment. [1] Uwe R. Fritsche et al. „Energy and Land Use". Global Land Outlook Working Paper (2017).[2] C. Brannstrom, A. Gorayeb, J. S. Mendes, C. Loureiro, A. J. A. Meireles, E. V. Silva, A. L. R. Freitas, R.F. Oliveira. Is Brazilian wind power development sustainable? Insights from a review of conflicts in Ceará state. Renewable and Sustainable Energy Reviews (2017), 67, p. 62-71. https://doi.org/10.1016/j.rser.2016.08.047[3] MapBiomas Project - Collection v.3.0 of the Annual Land Use Land Cover Maps of Brazil: http://mapbiomas.org/map#coverage [ABSTRACT FROM AUTHOR]