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The Araguaia River floodplain is an important biogeographic boundary between the two largest South American biomes: the Cerrado (Brazilian Savanna) and the Amazon rainforest. The large-scale degradation due to land use conversion experienced in the Araguaia River watershed represents a potential source of mercury (Hg) transport to aquatic ecosystems. However, more information is needed about the dynamics of Hg distribution in savanna floodplains, including the Araguaia River floodplain. We analyzed total mercury (THg) concentrations in the bottom sediments of 30 lakes connected to the Araguaia River and four tributaries, aiming to evaluate the environment's integrity based on the geoaccumulation index (I geo) and the ecological risk index (ERI). The principal component analysis was applied to examine associations between Hg concentrations, environmental conditions, and land use intensity among lakes associated with different river systems. We used indicator cokriging to identify areas with a greater probability of Hg pollution and ecological risk associated with land use intensity. The land use data showed the predominance of areas used for pasture in the Araguaia River basin. THg concentrations in the sediments varied between 22.6 and 81.9 ng g−1 (mean: 46.5 ± 17.7 ng g−1). Sediments showed no significant pollution (I geo : 1.35 - 0.50; Classes 1 and 2) and low to considerable ecological risks (ERI: 23.5–85.1; Classes 1 to 3). THg in bottom sediments was associated with land use, water turbidity and electrical conductivity, and sediment organic matter. The indicator cokriging indicates a moderate to strong spatial dependence between land use intensity and Hg, confirming the contribution of anthropic sources to the increment of ecological risk but also the influence of extrinsic factors (such as environmental conditions, geology, and hydrology). Integrating sediment assessment and land use indices with geostatistical methods proved a valuable tool for identifying priority areas for Hg accumulation at a regional scale. • [THg] were determined in the bottom sediments of 30 savanna floodplain lakes. • [THg] in bottom sediments is related to land use intensity and organic matter. • The lakes present no significant pollution and low to moderate ecological risks. • A moderate to strong spatial dependence exists between Hg and land use intensity. • Indicator cokriging is an efficient method for identifying [THg] regional hotspots. [ABSTRACT FROM AUTHOR]

Forest fires cause many environmental impacts, including air pollution. Brazil is a very fire-prone region where few studies have investigated the impact of wildfires on air quality and health. We proposed to test two hypotheses in this study: i) the wildfires in Brazil have increased the levels of air pollution and posed a health hazard in 2003–2018, and ii) the magnitude of this phenomenon depends on the type of land use and land cover (e.g., forest area, agricultural area, etc.). Satellite and ensemble models derived data were used as input in our analyses. Wildfire events were retrieved from Fire Information for Resource Management System (FIRMS), provided by NASA; air pollution data from the Copernicus Atmosphere Monitoring Service (CAMS); meteorological variables from the ERA-Interim model; and land use/cover data were derived from pixel-based classification of Landsat satellite images by MapBiomas. We used a framework that infers the "wildfire penalty" by accounting for differences in linear pollutant annual trends (β) between two models to test these hypotheses. The first model was adjusted for Wildfire-related Land Use activities (WLU), considered as an adjusted model. In the second model, defined as an unadjusted model, we removed the wildfire variable (WLU). Both models were controlled by meteorological variables. We used a generalized additive approach to fit these two models. To estimate mortality associated with wildfire penalties, we applied health impact function. Our findings suggest that wildfire events between 2003 and 2018 have increased the levels of air pollution and posed a significant health hazard in Brazil, supporting our first hypothesis. For example, in the Pampa biome, we estimated an annual wildfire penalty of 0.005 μg/m3 (95%CI: 0.001; 0.009) on PM 2.5. Our results also confirm the second hypothesis. We observed that the greatest impact of wildfires on PM 2.5 concentrations occurred in soybean areas in the Amazon biome. During the 16 years of the study period, wildfires originating from soybean areas in the Amazon biome were associated with a total penalty of 0.64 μg/m3 (95%CI: 0.32; 0.96) on PM 2.5 , causing an estimated 3872 (95%CI: 2560; 5168) excess deaths. Sugarcane crops were also a driver of deforestation-related wildfires in Brazil, mainly in Cerrado and Atlantic Forest biomes. Our findings suggest that between 2003 and 2018, fires originating from sugarcane crops were associated with a total penalty of 0.134 μg/m3 (95%CI: 0.037; 0.232) on PM 2.5 in Atlantic Forest biome, resulting in an estimated 7600 (95%CI: 4400; 10,800) excess deaths during the study period, and 0.096 μg/m3 (95%CI: 0.048; 0.144) on PM 2.5 in Cerrado biome, resulting in an estimated 1632 (95%CI: 1152; 2112) excess deaths during the study period. Considering that the wildfire penalties observed during our study period may continue to be a challenge in the future, this study should be of interest to policymakers to prepare future strategies related to forest protection, land use management, agricultural activities, environmental health, climate change, and sources of air pollution. • Effects of wildfires on air pollution and health in Brazil varies across land use. • Greatest effect of wildfires on PM 2.5 occurred in soybean areas in the Amazon. • Soybean in the Amazon was linked with a penalty of 0.72 μg/m3 on PM 2.5. • Wildfires from soybean areas caused 3872 excess deaths. • Sugarcane crops area driver of deforestation-related wildfires in Brazil. [ABSTRACT FROM AUTHOR]

Assessing the relative contribution of Land Use and Cover Changes (LUCC) and climate changes on runoff still represents a great challenge for water resources management. This issue is particularly critical for the Upper Paraná River Basin (UPRB), one of the most important basins in South America and responsible for most of the production of food, ethanol, and electricity generation in Brazil. In this paper, we used the Soil and Water Assessment Tool (SWAT) to quantitatively assess the relative contribution of both forcings. The simulation period included a time of great importance for climate studies, known as the 1970s global climate shift, and of great impact on river discharge within the UPRB. Three land use and cover scenarios were assigned to the 1961–1990 period of simulations, representing land use and cover during a pristine period (around the Year 1500), 1960, and 1985. Thirteen years of precipitation before and after the climate shift (considered to be the period 1974–1977) were analyzed and compared. Results showed a precipitation increase for the basin in general after the climate shift. The increase in rainfall reached up to 15% in many northern areas and more than 20% in the southern parts of the basin. By comparing all simulations, results indicate that both LUCC and precipitation increase due to the climate shift had a significant effect on the changes in annual discharge of the largest rivers of the UPRB. However, the results suggest that the impact of the precipitation increase on the discharge exceeded that of the LUCC. Between 1960 and 1985 the LUCC accounts for about 16% of the increase of the median annual discharge, whereas climate shift accounts for an increase of about 32%. These findings, suggesting a more relevant role for the climate, are consistent with two recent water crisis experienced by the country in the last decades, caused by prolonged below-normal rainfall throughout 2001/2002 and again in 2014/2015. [Display omitted] • We simulated land use and cover from a pristine period (Year 1500), 1960, and 1985. • We evaluated the effects of precipitation change on discharge from 1961 to 1990. • Natural vegetation fell by more than half of the original area up to 1985. • Precipitation increased by more than 20% after the 1970s global climate shift. • Results suggest that climate shift is the main driver in increasing annual discharge. [ABSTRACT FROM AUTHOR]

In Brazil, agriculture expansion is taking place primarily in the Cerrado ecosystems. With the aim of supporting policy development and protecting the natural environment at relevant hotspots, a scenario study was conducted that concerned not only land-use change, but also the resulting effects on erosion and deposition. This coupled approach helped to evaluate potential landscape impacts of the land-use scenarios. In the study area, the Balsas sub-basin in Maranhão State, a model chain was used to model plausible future soybean expansion locations (CLUE-S model) and resulting sediment mobilization patterns (LAPSUS model) for a business-as-usual scenario. In the scenario, more erosion occurred in areas where the conversion of natural vegetation into soybean cultivation is likely to take place, but the generated sediments tended to accumulate mainly within the conversion areas, thus limiting the offsite effects of the increased erosion. These results indicated that when agricultural expansion is kept away from rivers, Cerrado conversion will have only a limited impact on the sediment loads of local rivers. Where land-use changes are most concentrated are coincident with areas where more new sediments are generated (higher erosion) and where more sediments are re-deposited. [Copyright &y& Elsevier]

Mercury (Hg) contamination of riparian communities and of environmental compartments of the Amazon can be directly related to the occupation of the territory. The objective of this study was to identify the characteristics of aquatic environments that are associated with high levels of Hg in ichthyofauna. Our research aimed at determining the influence of variables related to fish ecology, types of aquatic environment, fishing activities by local riparian populations, and watershed use on the levels of contamination of ichthyofauna. Six sites were sampled during two distinct periods of the hydrological cycle: at the beginning of descending waters and during low waters. We focused on ten dominant fish species representing four trophic levels: Curimata inornata, Geophagus proximus, Schizodon vittatum, Leporinus fasciatus, Anostomoides laticeps, Hemiodus unimaculatus, Caenotropus labyrinthicus, Hoplias malabaricus, Plagioscion squamosissimus, Acestrorhynchus falcirostris. The study sites, which included lotic and lentic habitats, are exploited year-round by local riparian communities. Spatial variations in Hg contamination in ichthyofauna were determined by factorial analysis of variance taking into account fish diets, seasons, and sampling sites. Multiple regressions were used to check the influence of ecological and anthropogenic variables and variables related to watershed uses, on Hg levels in key species representing the four trophic groups. Each variable was checked independently. Next, multiple regressions were used to verify the concomitant influence of selected variables. Independently of the study site and the phase of the hydrologic cycle, fish Hg contamination followed the trend piscivores>omnivores>herbivores>detritivores. In all the aquatic study sites, Hg levels measured in predatory species were often higher than the 500ng/g fresh weight threshold. Mean Hg levels in key species were significantly higher during descending waters in lotic environments, and during low waters in lentic environments. Data from this study demonstrated that simple models based on watershed use and on easily obtained variables such as the suspended particulate matter (SPM) load and SPM Hg concentrations, number of inhabitants, habitat types, and the stage in the hydrological cycle enable very good prediction of Hg levels in fish. Our cartographical data clearly showed that the watershed site with the highest aquatic vegetation cover (6% of the open water body) and with the lowest forest cover (62% of the land) corresponded to the highest Hg concentrations in fish. Conversely, the watershed site with 94% forest cover and 1% aquatic vegetation corresponded to the lowest levels Hg concentrations in fish. These results suggest that land uses of watersheds play a key role in the level of Hg contamination of local ichthyofauna. [Copyright &y& Elsevier]

Assessing management effectiveness in protected areas is a fundamental instrument to achieve socio-biodiversity protection goals. This study aimed to analyze the management effectiveness of Cunhambebe State Park (from now on, "PEC") in the State of Rio de Janeiro in Brazil, from the perception of stakeholders and the multi-temporal analysis of land use and land cover between 1998 and 2018. We used the Rapid Assessment and Prioritization of Protected Area Management method for a participatory approach. Seventy-two indicators were used and applied to assess the perception of stakeholders related to the Advisory Council. The management effectiveness of PEC was classified as moderately satisfactory (63.41%). Indicators of "Legal security", "Vulnerability", "Site design and planning" and "Financial resources" revealed the weaknesses and threats of management and what should be the priority projects for better effectiveness. Through the multi-temporal analysis, we identified that the advances of pasture and urban areas are the highest pressures and threats, as perceived by stakeholders. In our case study, we provide evidence of actions that must be performed by the PEC management team. These actions must consider the weaknesses and threats presented by the SWOT analysis. Finally, we recommend some political and management measures: 1) Financial resources for the land regularization of areas overlapping with PEC, 2) Guidelines about PEC areas must be included in the Master Plans of municipalities that cover PEC limits, 3) Technical assistance to improve land management, and 4) Strengthen environmental education initiatives at all school levels. Image 1 • Stakeholders' perception potentially influences the management effectiveness of protected areas. • Multidisciplinary approach helps in the assessment of socio-biodiversity protection. • Participatory workshop allows a more authentic analysis of management effectiveness. • Mapping of land use enables the understanding of conservation planning conflicts. [ABSTRACT FROM AUTHOR]

Rapid population growth coupled with climate change has been putting pressure on natural resources worldwide, especially on water resources. The Paracatu basin located in Brazil is a basin which has been showing a reduction in its water availability for many years due to the growing demand for irrigation in the region. Therefore, the objective of the present work was to analyze the trends in the flow and precipitation data for the Paracatu basin and correlate them with land use between the years 1980 and 2019, and thus make a projection of flows through the year 2030 based on these results. The projections of future flows in the fluviometric stations analyzed were obtained using the WEAP model, considering the projected increase in the irrigated area for the region and the future climate data from the IPCC for the RCP 4.5 scenario. The results of the analyzes indicated a tendency towards a reduction in flows in all the analyzed fluviometric stations, both in the monthly and annual series, whereas the total annual precipitation did not show a trend in the analyzed period. Future flows showed a downward trend, as well as flows observed in the period from 1980 to 2019, reinforcing that activities such as irrigated agriculture without planning can negatively affect the sustainability of water resources, intensifying conflicts and tensions which already exist in the basin. This type of analysis proved to have great potential to contribute to the solution of water resource management challenges in several hydrographic basins around the world which are in a situation of scarcity and conflict. • The seasonality in the precipitations were not determinant in the flow data trends • There was a tendency to reduce the annual minimum flow in all fluviometric stations • Behavior of the stream flows are associated with the increased demand for water use • Future flows showed a downward trend, as well as flows observed • This method has great potential to the solution of water resource management [ABSTRACT FROM AUTHOR]

Brazil contains the largest volume of freshwater of any nation in the world; however, this essential natural resource is threatened by rapid increases in water consumption and water quality degradation, mainly as a result of anthropogenic pressures. Declining water quality has become an increasingly more significant global concern as economic activities and human populations expand and climate change markedly alters hydrological cycles. Changes in land-use/land-cover (LULC) pattern have been recognized as a major driver of water quality degradation, however different LULC types and intensities affect water quality in different ways. In addition, the relationships between LULC and water quality may differ for different spatial and temporal scales. The increase in deforestation, agricultural expansion, and urban sprawl in Brazil highlights the need for water quality protection to ensure immediate human needs and to maintain the quality of water supplies in the long-term. Thus, this manuscript provides an overview of the relationships between LULC and water quality in Brazil, aiming at understanding the effects of different LULC types on water quality, how spatial and temporal scales contribute to these effects, and how such knowledge can improve watershed management and future projections. In general, agriculture and urban areas are the main LULCs responsible for water quality degradation in Brazil. However, although representing a small percentage of the territory, mining has a high impact on water quality. Water quality variables respond differently at different spatial scales, so spatial extent is an important aspect to be considered in studies and management. LULC impacts on water quality also vary seasonally and lag effects mean they take time to occur. Forest restoration can improve water quality and multicriteria evaluation has been applied to identify priority areas for forest restoration and conservation aiming at protecting water quality, but both need further exploration. Watershed modelling has been applied to simulate future impacts of LULC change on water quality, but data availability must be improved to increase the number, locations and duration of studies. Because of the international nature of watersheds and the consistent relationships between land use and water quality in Brazil, we believe our results will also aid water management in other countries. Image 1 • Agriculture, urbanization and mining are major sources of water quality degradation in Brazil. • Water quality variables respond differently to pressures at different spatial scales. • LULC impacts on water quality vary seasonally and with varying time lags. • Watershed planning and modelling help support decisions but must be improved. • Science-based polices and decisions are necessary to protect water quality in Brazil. [ABSTRACT FROM AUTHOR]