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1.
Sci Total Environ ; 932: 173107, 2024 Jul 01.
Article in English | MEDLINE | ID: mdl-38729359

ABSTRACT

In the modern urban space, green infrastructures have been gaining increasing relevance due to their positive impacts on sustainability issues, visual appeal, and the well-being of individuals. On the other hand, environmental sustainability has become mandatory in the agenda of governments and organizations. Thus, a systematic analysis on the efficiency and sustainability of green facades and roofs spanning key applications, benefits and implementation constraints is welcome. In this paper, we employed the PRISMA method to investigate how these matters were addressed in the recent literature, comprising articles published in scientific journals indexed to the SCOPUS database. Following the web search, selection, systematization, and analysis of that literature, it was revealed that the efficiency of green facades and roofs has been mostly associated with energy and thermal performance in buildings, which brings unequivocal multiple benefits (e.g., consumption savings, mitigation of urban heat island effects) despite of some barriers (e.g., installation and maintenance costs). Other discussions about green facades and roofs involved their valuable roles in stormwater management, considering their retention capacity, and in the treatment of wastewater for reuse in non-potable applications, considering their filtering capacity. It was also discovered the need to improve green infrastructures through the use of cleaner technologies and recycled materials, selection of plants that are appropriate for the local climate, and minimization of construction, transportation, disposal and maintenance costs. Efficiency and sustainability in these cases was prognosed to succeed if the costs were minimized throughout the entire life cycle, and complemented with incentive policies (e.g., tax reduction, agile administrative processes) and collaboration among multidisciplinary teams comprising designers, builders, municipality planners and the academic and market worlds.

2.
Sci Total Environ ; 923: 171437, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38447735

ABSTRACT

Human actions can damage the ecosystems and affect the services depending on them, with ample detrimental consequences. In earlier studies, the Conservation Use Potential (PCU) framework proved useful in assessing the capacity for aquifer recharge, suitable land uses and resistance to erosion at the river basin scale. On the other hand, the joint analysis of PCU and land uses allowed identifying the adequacy of current uses in relation to suitability (natural uses) in various basins. This was especially useful from the management perspective in basins with environmental conflicts, where current uses differed from suitability, because the PCU indicated how and where the conflicts should be mitigated. Besides the use as management tool, the PCU has potential to shed light over environmental issues such as ecosystem services, but that was not tempted so far. The aim of this work was therefore to bridge that knowledge gap and frame the PCU's application from the standpoint of Ecosystem Services (ES) assessment. We demonstrated how the PCU could be used to improve provision (recharge), support (sustainable agriculture) and regulation (resistance to erosion) services in a specific basin with land use conflicts (the Upper Rio das Velhas basin, located in Minas Gerais, Brazil), through the planning of suitable uses. It was noted that the studied basin is mostly composed of Very Low, Low and Medium potentials. These classes occur because steep slopes, fragile soils and lithologies with high denudation potential and low nutrient supply dominate in the basin. On the other hand, urban sprawl has a negative impact on all ES, while maintaining agricultural areas with appropriate management can effectively regulate erosion. As per the current results, the premise of using the PCU as joint management-environmental tool was fully accomplished, and is recommended a basis for public policy design and implementation in Brazil and elsewhere.

3.
Sci Total Environ ; 954: 176355, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39306136

ABSTRACT

Soil conservation adheres to various United Nations Sustainable Development Goals while in Brazil is a constitutional obligation. To attain the goals and fulfil the obligation, laws, policies, governance and science must be imbricated to deliver suitable conservation solutions for the long term, namely appropriate to positively influence other downstream chains such as the food chain. However, in Brazil, a major world producer and exporter of food, weaknesses were recently diagnosed by judicial authorities concerning soil governance and coordinated land use policies. Integrated scientific assessments on soil conservation and mitigation of degraded soil are also lacking in this country. This was enough motivation and the purpose to present here a holistic view over the soil conservation agenda and promoting policies in Brazil, based on a literature review that followed the guidelines and criteria of PRISMA approach. We termed this analysis a review hinged on "edge-to-edge" science contributions for two reasons. Firstly, the intent of retrieving from the recently published literature solely papers centered on a relevant soil conservation topic (e.g., soil characterization, here called an "edge") but with complementary analyses over boundary topics (frontier "edges", such as soil degradation). Secondly, the intent of underlining the urgency to assist decision-makers with scientific evidence in all dimensions of the soil conservation agenda ("edge-to-edge" science), namely soil characterization (e.g., quality reference values), soil degradation assessment (e.g., anthropogenic-related soil erosion or contamination), soil degradation consequences focused on the carbon cycle (e.g., net CO2 emissions and climate warming), sustainable management practices and production systems (e.g., no-tillage agriculture and integrated crop-livestock-forestry systems), and scientific evaluation of existing laws as well as of governance and policy programs with potential implications on soil quality (e.g., the Forest Code). Thus, this literature review addressed all these topics following a multidisciplinary discourse, which produced an extensive but comprehensive document about soil conservation in Brazil.

4.
Sci Total Environ ; 912: 169136, 2024 Feb 20.
Article in English | MEDLINE | ID: mdl-38072273

ABSTRACT

The use of tailings dams in the mining industry is recurrent and a matter of concern given the risk of collapse. The planning of tailings dam's emplacement usually attends construction design criteria and site geotechnical properties, but often neglects the risk of installing the depositional facilities in potentially unstable landscapes, namely those characterized by steep slopes and(or) high drainage densities. In order to help bridging this gap, the present study developed a framework model whereby geomorphologic vulnerability is assessed by a set of morphometric parameters (e.g., drainage density; relief ratio; roughness coefficient). Using the Ribeirão Ferro-Carvão micro-basin (3265.16 ha) as test site, where six dams currently receive tailings from the mining of iron-ore deposits in the Brumadinho region (Minas Gerais, Brazil) and one has collapsed in 25 January 2019 (the B1 dam of Córrego do Feijão mine of Vale, S.A.), the risk of dam instability derived from geomorphologic vulnerability was assessed and alternative suitable locations were highlighted when applicable. The results made evident the location of five dams (including the collapsed B1) in high-risk regions and two in low-risk regions, which is preoccupying. The alternative locations represent 58 % of Ribeirão Ferro-Carvão micro-basin, which is a reasonable and workable share. Overall, the study exposed the fragility related with tailings dams' geography, which is not restricted to the studied micro-basin, because dozens of active tailings dams exist in the parent basin (the Paraopeba River basin) that can also be vulnerable to geomorphologically-dependent hydrologic hazards such as intensive erosion, valley incision or flash floods. Attention to this issue is therefore urgent to prevent future tragedies related with tailings dams' breaks, in the Paraopeba River basin or elsewhere, using the proposed framework model as guide.

5.
Sci Total Environ ; 949: 174970, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39059671

ABSTRACT

Tailings dams' disasters begin a stage of river water contamination with no endpoint at first sight. But when the river was formerly used for public water supply and the use was suspended as consequence of a dam break, a time window for safe suspension lift must be anticipated to help water managers. The purpose of this study was to seek for that moment in the case of Brumadinho dam disaster which occurred in 2019 and injected millions of cubic meters of iron- and manganese-rich tailings into the Paraopeba River, leading to the suspension of public water supply to Belo Horizonte metropolitan region with this resource, until now. To accomplish the proposed goal, an assemblage of artificial intelligence and socio-economic development models were used to anticipate precipitation, river discharge and metal concentrations (iron, manganese) until 2033. Then, the ratios of metal concentrations between impacted and non-impacted sites were determined and values representing extreme events of river discharge were selected for further assessment. A ratio ≈1 generally indicates a similarity between impacted and non-impacted areas or, put another way, a return of impacted areas to a pre-rupture condition. Moreover, when the ratio is estimated under the influence of peak flows, then a value of ≈1 indicates a return to pre-rupture conditions under the most unfavorable hydrologic regimes, thus a safe return. So, the extreme ratios were plotted against time and fitted to a straight line with intercept-x representing the requested safe time. The results pointed to 6.57 years after the accident, while using iron as contaminant indicator, or 8.71 years when manganese was considered. Despite of being a relatively low-risk timeframe, the suspension lift should be implemented in phases and monitored for precaution of potential sporadic contamination events, while dredging of the tailings from impacted areas should continue and be accelerated.

6.
Sci Total Environ ; 937: 173407, 2024 Aug 10.
Article in English | MEDLINE | ID: mdl-38797427

ABSTRACT

Following the B1 dam collapse at Córrego do Feijão Mine, actions were taken to address environmental damage and enhance the quality of water in the Paraopeba River. Natural processes in the river involve gradual reduction of contamination through dispersion and downstream transportation of tailings-a slow, nature-driven process. Dredging, a human intervention, aimed to expedite recovery. Hence, this study aimed to explore dredging's role in reducing contamination in the impacted Paraopeba River zone. Analysis revealed a direct link between dredging and post-collapse turbidity, though recent trends suggest a lessening impact on pre-collapse conditions. Distinct seasonal variations were observed in iron and manganese concentrations, peaking during wet seasons and displaying notable upstream-downstream disparities. An analysis of ratios (downstream/upstream) was conducted to understand and even predict the return to pre-collapse conditions. Wet season averages for iron and manganese decreased by around 90 % over time, with standard deviations reducing by about 48 % and 58 %, respectively. In the dry season, the averages decreased by over 100 %, indicating water quality improvements surpassing pre-collapse levels. Standard deviations also decreased significantly, by approximately 67 % and 79 %, respectively. Employing an exponential decay model revealed that the contribution of dredging in the dry period is negligible, but in the wet period the contribution can be estimated at 28.6 % in the case of iron and 25 % in the case of manganese. While the models performed well based on extensive data, some limitations occur in estimating dredging contribution rates. The model's sensitivity might overlook influential factors, underscoring the importance of considering sediment nature and dredged area extent in understanding water quality dynamics. Despite these potential limitations, this investigation provides crucial insights into the intricate relationship between dredging and water quality in the Paraopeba River. These findings pave the way for future studies aimed at deeper exploration and more accurate assessments of this association.

7.
Sci Total Environ ; 949: 174971, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39069187

ABSTRACT

The B1 tailings dam of Córrego do Feijão iron-ore mine owned by Vale, S.A. company collapsed in 25 January 2019 releasing to the Ferro-Carvão stream watershed (32.6 km2) as much as 11.7 Mm3 of mine waste. A major share (8.9 Mm3) has been deposited along the stream channel and margins forming a 2.7 km2 patch. The main purpose of this study was to question whether the tailings deposit impacted the local water cycle and how. Using the Soil and Water Assessment Tool (SWAT) hydrologic model, the water balance components of 36 hydrologic response units (HRU) were calculated for pre- (S1) and post- (S2) B1 dam rupture scenarios represented by appropriate soil, land use and tailings cover. The results revealed an increase of evapotranspiration from S1 to S2, related to the sudden removal of vegetation from the stream valley and replacement with a blanket of mud, which raised the exposure of Earth's surface to sunlight and hence soil evaporation. For 11 HRU (10.3 km2) located around the tailings deposit, a decrease in lateral flow was observed, accompanied by an increase in percolation and a slight increase in groundwater flow. In this case, the water balance changes observed between S1 and S2 reflected a barrier effect imposed to the lateral flows by the tailings, which shifted the flows towards the vertical direction (percolation). Thus, the water followed an easier vertical route until reaching the shallow aquifer and being converted into groundwater flow. As per the modelling outcomes, the hydrologic impacts of B1 dam rupture are relevant because they affected 1/3 of Ferro-Carvão stream watershed, and hence claim for the complete removal of the tailings.

8.
Sci Total Environ ; 949: 175026, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39097022

ABSTRACT

Tailings dams' breaks are environmental disasters with direct and intense degradation of soil. This study analyzed the impacts of B1 tailings dam rupture occurred in the Ribeirão Ferro-Carvão watershed (Brumadinho, Brazil) in January 25, 2019. Soil organic carbon (SOC) approached environmental degradation. The analysis encompassed wetlands (high-SOC pools) located in the so-called Zones of Decreasing Destructive Capacity (DCZ5 to DCZ1) defined along the Ferro-Carvão's stream bed and banks after the disaster. Remote sensed water indices were extracted from Landsat 8 and Sentinel-2 satellite images spanning the 2017-2021 period and used to distinguish the wetlands from other land covers. The annual SOC was extracted from the MapBiomas repository inside and outside the DCZs in the same period, and assessed in the field in 2023. Before the dam collapse, the DCZs maintained stable levels of SOC, while afterwards they decreased substantially reaching minimum values in 2023. The reductions were abrupt: for example, in the DCZ3 the decrease was from 51.28 ton/ha in 2017 to 4.19 ton/ha in 2023. Besides, the SOC increased from DCZs located near to DCZs located farther from the dam site, a result attributed to differences in the percentages of clay and silt in the tailings, which also increased in the same direction. The Ferro-Carvão stream watershed as whole also experienced a slight reduction in the average SOC levels after the dam collapse, from nearly 43 ton/ha in 2017 to 38 ton/ha in 2021. This result was attributed to land use changes related with the management of tailings, namely opening of accesses to remove them from the stream valley, creation of spaces for temporary deposits, among others. Overall, the study highlighted the footprints of tailings dams' accidents on SOC, which affect not only the areas impacted with the mudflow but systemically the surrounding watersheds. This is noteworthy.

9.
Sci Total Environ ; 899: 165639, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37478951

ABSTRACT

The Payment for Environmental Services (PES) is often conceived through complex schemes without a clear definition of all concepts involved. This study presents the results of a systematic literature review on PES schemes in Brazil, accompanied by a critical assessment of their efficacy for potential environmental gains. The PES approaches were grouped into six categories based on the research focus, and those that were focused on PES policies were identified as the most studied. A particular emphasis has been given to the Amazon and Atlantic Forest biomes, where the ecosystem services studied were mostly centered on issues related to carbon and water, respectively. Approximately one-third of all schemes provided no clear definition of which ecosystem services are proposed for payment. In addition, the review showed no consensus among studies on the definition of services in similar schemes. Most schemes presented no payment system conditioned on the provision of environmental services. Furthermore, the review showed that the absence of clarity in the application of concepts may hinder the development of public policies to properly implement PES in Brazil. The conclusion is that standardizing terms used in the literature and in PES schemes is critical; therefore, the use of the Common International Classification of Ecosystem Services (CICES) as a reference is recommended to ensure clarity, objectivity and, more importantly, the expected environmental efficacy.

10.
Sci Total Environ ; 873: 162303, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36805064

ABSTRACT

Water security is an expression of resilience. In the recent past, scientists and public organizations have built considerable work around this concept launched in 2013 by the United Nations as "the capacity of a population to safeguard sustainable access to adequate quantities of acceptable quality water for sustaining livelihoods, human well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability". In the 27th Conference of the Parties (COP27), held in Sharm El-Sheikh (Egypt) in last November, water security was considered a priority in the climate agenda, especially in the adaption and loss and damage axes. This discussion paper represents the authors' opinion about how the conference coped with water security and what challenges remain to attend. As discussion paper, it had the purpose to stimulate further discussion in a broader scientific forum.

11.
Sci Total Environ ; 891: 164426, 2023 Sep 15.
Article in English | MEDLINE | ID: mdl-37236470

ABSTRACT

The collapse of B1 dam at the Córrego do Feijão mine of Vale, S.A., located in the Ferro-Carvão stream watershed (Brazil), released 11.7 Mm3 of tailings rich in iron and manganese, and 2.8 Mm3 entered the Paraopeba River 10 km downstream. Seeking to predict the evolution of environmental deterioration in the river since the dam break on January 25, 2019, the present study generated exploratory and normative scenarios based on predictive statistical models, and proposed mitigating measures and subsides to ongoing monitoring plans. The scenarios segmented the Paraopeba into three sectors: "anomalous" for distances ≤63.3 km from the B1 dam site, "transition" (63.3-155.3 km), and "natural" (meaning unimpacted by the mine tailings in 2019; >155.3 km). The exploratory scenarios predicted a spread of the tailings until reaching the "natural" sector in the rainy season of 2021, and their containment behind the weir of Igarapé thermoelectric plant located in the "anomalous" sector, in the dry season. Besides, they predicted the deterioration of water quality and changes to the vigor of riparian forests (NDVI index) along the Paraopeba River, in the rainy season, and a restriction of these impacts to the "anomalous" sector in the dry season. The normative scenarios indicated exceedances of chlorophyll-a in the period January 2019-January 2022, but not exclusively caused by the rupture of B1 dam as they also occurred in areas not affected by the accident. Conversely, the manganese exceedances clearly flagged the dam failure, and persist. The most effective mitigating measure is likely the dredging of the tailings in the "anomalous" sector, but currently it represents solely 4.6 % of what has entered the river. Monitoring is paramount to update the scenarios until the system enters a route towards rewilding, and must include water and sediments, the vigor of riparian vegetation, and the dredging.

12.
MethodsX ; 9: 101766, 2022.
Article in English | MEDLINE | ID: mdl-35800984

ABSTRACT

Starting with a log-linear relationship between groundwater discharge per unit drainage area (Q/A b), hydraulic turnover time (t) and aquifer mobile storage (z), this study builds a groundwater security method at catchment scale. The method embeds previously published approaches to calculate Q/A b, t and z, and relies solely on stream flow discharges and watershed areas. The ability to build a method on a couple of variables is remarkable. The method recasts the calculated variables as aquifer security indicators (S Q, S t and S z), relating S Q with yield capacity, S t with self-depuration capacity and S z with resilience. Groundwater security is the weighted product of S Q, S t and S z. The method is validated with stream flow discharges and drainage areas concerning 294 hydrometric stations and their watersheds, located in continental Portugal. The results revealed a majority of moderately to highly secure watersheds, especially as regards S t (> 62%), while 7-10% were classified as very highly secured in general (S Q-S t-S z). The least secured basins are located in the more arid regions of continental Portugal (Northeast and south regions), as expected. The method can be easily transposed to any other region worldwide, with the necessary adaptions to regional climate, geological and topographic settings. • Compile stream flow discharge data and organize them as natural logarithms and logarithmic variations as function of time, to estimate Q, t and z; • Recast the Q, t and z values as S Q, S t and S z ratings, respectively, using the appropriate reclassification scales, and estimate watershed security levels, namely average security or customized (weighted) securities that highlight the contributions of Q/A b (watershed yield), t (aquifer's self-depuration capacity) or z (aquifer's resilience); • Use the results to draw illustrative diagrams and spatial distribution maps.

13.
Sci Total Environ ; 834: 155285, 2022 Aug 15.
Article in English | MEDLINE | ID: mdl-35447180

ABSTRACT

The rupture of mine-tailings dams can severely contaminate rivers, because released tailings can interact with water for years keeping contaminant concentrations high. The general purpose of this study was to examine the rupture of B1 tailings dam in Ferro-Carvão stream (municipality of Brumadinho, state of Minas Gerais, Brazil), which occurred in 25 January 2019 and contaminated the main water course (Paraopeba River) with 2.8 Mm3 of metal-rich tailings. The specific purpose was to assess the percentage of non-conforming concentrations following the event, considering the Normative Deliberation COPAM/CERH-MG no. 1. The results showed non-conforming aluminum, iron, manganese, lead, phosphorus and turbidity concentrations, clearly above pre-rupture averages, especially in the rainy period. The catastrophe triggered the suspension of Paraopeba River as drinking water source to the Metropolitan Region of Belo Horizonte (BHMR; 6 million people). Since then, the supply to the BHMR became an everyday challenge to water management authorities, because the Paraopeba source represented a 30% share. Mitigation measures are therefore urgently needed. As complementary objective to this study, we aimed to verify the possibility to restore drinking water supply through conventional treatment. The treatability of Paraopeba River water was assessed by the Raw Water Quality Index considering the rainy and dry periods in separate. The results suggested the possibility to lift up the suspension in the dry period, improving the regional water security. Considering the huge dataset on which this study is standing, our results are generalizable to similar events with sparser information.


Subject(s)
Drinking Water , Water Pollutants, Chemical , Brazil , Environmental Monitoring , Humans , Rivers , Water Pollutants, Chemical/analysis , Water Supply
14.
Sci Total Environ ; 851(Pt 1): 158248, 2022 Dec 10.
Article in English | MEDLINE | ID: mdl-36028023

ABSTRACT

The present study aimed to investigate the rupture of B1 tailings dam of Córrego do Feijão mine, which drastically affected the region of Brumadinho (Minas Gerais, Brazil). The contamination of water resources reached 155.3 km from the dam site. In the river channel, high concentrations of Mn, Al, As and Fe were detected and correlated to the spillage of the tailings in the river. The presence of the tailings also affected the chlorophyll-a content in the water, as well as the reflectance of riparian forests. With the increase of metal(oid) concentrations above permitted levels, water management authorities suspended the use of Paraopeba River as resource in the impacted areas, namely the drinking water supply to the Metropolitan region of Belo Horizonte. This study aimed to evaluate possible links between tailings distribution, river water quality, and environmental degradation, which worked as latent variables in partial least squares regression models. The latent variables were represented by numerous physical and chemical parameters of water and sediment, measured four times in 22 locations during the rainy season of 2019, in addition to stream flow and to NDVI evaluated in satellite images processed daily. The modeling results suggested a relationship between river flow turbulence and increased arsenic release from sand fractions, as well as desorption of Mn from metal oxides, both representing causes of water quality reduction. They also revealed increasing iron concentrations affecting the forest NDVI (greening), which was interpreted as environmental degradation. The increase of chlorophyll-a concentrations (related with turbidity decreases), as well as the increase of river flows (responsible for dilution effects), seemed to work out as attenuators of degradation. Although applied to a specific site, our modeling approach can be transposed to equivalent dam failures and climate contexts, helping water resource management authorities to decide upon appropriate recovery solutions.


Subject(s)
Arsenic , Drinking Water , Water Pollutants, Chemical , Arsenic/analysis , Brazil , Chlorophyll , Environmental Monitoring , Iron , Least-Squares Analysis , Rivers/chemistry , Sand , Seasons , Water Pollutants, Chemical/analysis
15.
MethodsX ; 9: 101858, 2022.
Article in English | MEDLINE | ID: mdl-36164431

ABSTRACT

The method presented in this study assesses groundwater contamination risk using a L-Matrix system approach. The L-Matrix in this case is a cartesian diagram where the XX-axis represents aquifer vulnerability (0≤V≤1) determined by the well-known DRASTIC model, and the YY-axis represents the potential hazardousness (0≤H≤1) of an activity (infrastructural development, industrial activities, livestock and agriculture) measured by a European Commission approach. The diagram is divided into four regions, the boundaries of which are set to V = 0.5 and H = 0.5. Watersheds are represented in this diagram considering their V and H indices, and assigned a potential contamination risk if groundwater sites located within their limits show contaminant concentrations above legal limits for a given use. Depending on the region the watershed falls in the L-Matrix diagram, different management or contamination prevention actions are highlighted: activity development, activity monitoring, activity planning or activity inspecting. Watersheds located in the inspecting region and simultaneously evidencing contamination risk require immediate action, namely conditioning or even suspension of use. The method is tested in the Paraopeba River basin (Minas Gerais, Brazil), a densely industrialized basin that was recently affected by an iron-ore mine tailings dam break.•The L-Matrix diagram highlights different groundwater susceptibility realities experienced by watersheds with different combinations of aquifer vulnerability and activity hazardousness, namely possibility for potential expansion of new hazardous activities but also the necessity to periodically inspect and eventually condition or suspend others.•The L-Matrix diagram is likely a better approach to implement contamination prevention measures in watersheds, than the integrated contamination risk index used by most methods.

16.
Sci Total Environ ; 776: 146019, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-33652307

ABSTRACT

The inadequate management of soils and the absence of conservation practices favor the degradation of pastures and can trigger adverse environmental alterations and damage under the terms of Brazilian Federal Law no. 6.938/1981. Based on this premise, this study aimed to estimate soil losses caused by water erosion in pasture areas using the brightness index (BI) from the annual series of Landsat 8 images in different geological formations. A specifically prepared Google Earth Engine (GEE) script automatically extracted the BI from the images. The study occurred in the Environmental Protection Area (EPA) of Uberaba River basin (Minas Gerais, Brazil). To accomplish the goal, 180 digital 500-wide random buffers were selected from 3 geologic types (60 points per type), and then analyzed for zonal statistics of USLE (Universal Soil Loss Equation) soil loss and BI in a Geographic Information System. The regression models BI versus USLE soil loss allowed estimating BI soil losses over the pastures of EPA. The model fittings were remarkable. The validation of soil loss maps in the EPA occurred in pasture phytophysiognomies through the probing of penetration resistance in 37 randomly selected locations. The results were satisfactory, mostly those based on the BI. The BI losses increased for greater resistances. Amplified losses also occurred in regions exposed to environmental land use conflicts (actual uses that deviate from land capability or natural use). Overall, the BI approach proved efficient to accurately track soil losses and pasture degradation over large areas, with the advantage of standing on a single parameter easily accessed through remote sensed data. From an environmental standpoint, this is an important result, because the accurate diagnosis and prognosis of degraded pastures is paramount to implement mitigation measures following the "polluter pays principle", even more in Brazil where the areas occupied by degraded pastures are enormous.

17.
Sci Total Environ ; 759: 143905, 2021 Mar 10.
Article in English | MEDLINE | ID: mdl-33340864

ABSTRACT

Water management is a crucial tool for addressing the increasing uncertainties caused by climate change, biodiversity loss and the conditions of socioeconomic limits. The multiple factors affecting water resources need to be successfully managed to achieve optimal governance and thus move towards water security. This study seeks to obtain a holistic vision of the various threats that affect the ecological integrity of the basins that form the hydrological district of Galicia-Costa, through the method of partial least squares path modelling (PLS-PM). The data is analysed overall for the hydrological years from 2009 to 2015. The independent latent variables are "Anthropogenic" (comprising the percentage of water bodies with edges alongside artificial surfaces, the percentage connected to artificial land use patches, the edge density of artificial surfaces and population density) and "Nature" (edge density of forestry land uses, edge length of land water bodies alongside forested areas and the percentage of land occupied by the largest patch of forest). The dependent latent variables are "SWP", which represents surface water parameters (biological oxygen demand, chlorides, conductivity and dissolved iron) and "Ecological Integrity" (METI Bioindicator). The connections between latent variables are uantified through path coefficients (ß). From an overall perspective, the PLS-PM results reveal that 69.0% of "SWP" is predicted by the independent variables (R2 = 0.690), "Anthropogenic" contributes by increasing SWP (ß = 0.471), while "Nature" decreases the concentration of SWP (ß = -0.523), which indicates the polluting parameters in the water. The variables "Anthropogenic" (ß = -0.351) and "SWP" (ß = -0.265) lower the quality of "Ecological Integrity". This variable must be managed through soil conservation measures for the benefit of water security. This study has been able to identify and quantify the variables that increase contaminant concentration and decrease ecological integrity, providing a promising methodology that facilitates protection and correction measures to guarantee water safety.

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