Assessment of current and future land use/cover changes in soil erosion in the Rio da Prata basin (Brazil).

In recent years, the Cerrado biome in Brazil (Brazilian savannah) has faced severe environmental problems due to abrupt changes in land use/cover (LUC), causing increased soil loss, sediment yield and water turbidity. Thus, this study aimed to evaluate the impacts of soil loss and sediment delivery ratio (SDR) over the last 30 years to simulate future scenarios of soil losses from 2050 to 2100 and to investigate an episode of sediment delivery that occurred in the Rio da Prata Basin (RPB) in 2018. In this study, the following were used: an estimation of soil losses for 1986, 1999, 2007 and 2016 using the Revised Universal Soil Loss Equation (RUSLE), an estimation of SDR, sediment export and sediment deposition using the Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model, an association of RUSLE factor C to LUC data for 2050 and 2100 based on the CA-Markov hybrid model, and an estimation of future soil erosion scenarios for 2050 and 2100. The results show that over the last 30 years (1986-2016), there has been a reduction in the areas of highly intense and severe degrees. Future soil erosion scenarios (2050-2100) showed a 13.84% increase in areas of soil loss >10 Mg ha-1 year-1. The results highlighted the importance of assessing the impacts of LUC changes on soil erosion and the export of sediments to agricultural watersheds in the RPB, one of the best ecotourism destinations in Brazil. In addition, the increase in soil loss in the region intensified sediment yield events and increased water turbidity. Furthermore, riparian vegetation, although preserved, was not able to protect the watercourse, showing that it is essential to adopt the best management practices in the agricultural production areas of the basin, especially where ramps are extensive or the slope is greater than 2%, to reduce the runoff velocity and control the movement of sediments on the surface towards the drainage canals. The results of this study are useful for drawing up a soil and water conservation plan for the sustainable production of agriculture and maintenance of ecosystem services in the region.

Identifying priority regions and territorial planning strategies for conserving native vegetation in the Cerrado (Brazil) under different scenarios of land use changes.

The Cerrado biome covers approximately 20% of Brazil and it is crucial for the Water, Food, Energy, and Ecosystems (WFEE) nexus. Thus, in recent years, large areas of the undisturbed Cerrado have been converted into farmland. In this biome, according to the Brazilian Forest Code, farmers need to keep 20% of native vegetation (Legal Reserves - LRs). By exploring combined and isolated impacts of different scenarios of LR and Protected area (PA) arrangements, this study evaluated the importance of complementarity between LR compliance and the amount of PAs (including Conservation Units - CUs and Indigenous Lands - ILs) to reduce deforestation and conserve native vegetation in the Cerrado. Seven scenarios were investigated: a scenario that considers the current PA and the LR values foreseen in the Native Vegetation Protection Law - NVPL; three scenarios focused on production; and three focused on conservation. Considering the trend of the current scenario, the estimated loss of native vegetation will be 30% (30.6 million ha) by 2070. According to the model simulations, for two periods (2050 and 2070), the LR Elimination scenario (LRE) would cause a greater loss of native vegetation than the PA Elimination (PAE), and as expected, the exclusion of both (PALRE) would provide a greater loss of native vegetation. Native vegetation is concentrated mainly on agricultural properties. Taking our conservation-oriented scenarios as an example of conservation strategies, if there were no financial, practical, political, social or personal constraints, there is no doubt that the CPALRI scenario (Creation of Protected Areas and Legal Reserve Increase) is the best trajectory for conserving biodiversity. Therefore, private properties, through LRs, are essential for efficient planning of land use/cover as they ensure security in the WFEE nexus. The resulting projected scenarios are important to help decision makers in territorial planning and how to arbitrate territorial demands aiming at the rational use of the natural resources of the Cerrado.

A computational tool for hydrosedimentological and statistical calculations / Ferramenta computacional para cálculos hidrossedimentológicos e estatísticos

ABSTRACT This paper presents a new computational tool called NH SEDIMENT AND STATISTIC which performs hydrosedimentological and statistical calculations using Visual Basic. This computational tool was developed for studies related to calculations of sediment transport in rivers. The tool includes hydrosedimentological methods for calculating suspension loads, bed loads, and total solid discharge. In addition, it provides the user with the possibility of performing statistical tests such as the Kolmogorov-Smirnov normality test, F test and χ2 test of variance, Student's t-test, non-parametric Wilcoxon test, and statistical parameter calculations. The NH SEDIMENT AND STATISTIC automatically calculates and provides the main results for each of the methods, allowing the user to draw their own conclusions. This proposed computational tool supports hydrosedimentological studies, and is reliable and easy to use, contributing to the reduction of sediment-related problems in the areas of hydraulic engineering, geology, and soil and water conservation. Furthermore, this tool may be used in transdisciplinary scientific areas for complete planning and management of water resources.

RESUMO Este artigo apresenta uma nova ferramenta computacional chamada NH SEDIMENT AND STATISTIC, que realiza cálculos hidrossedimentológicos e estatísticos usando o Visual Basic. Essa ferramenta computacional foi desenvolvida para estudos relacionados a cálculos de transporte de sedimentos em rios. A ferramenta inclui métodos hidrossedimentológicos para calcular cargas de suspensão, cargas de leito e descarga total de sólidos. Além disso, fornece ao usuário a possibilidade de realizar testes estatísticos, como o teste de normalidade Kolmogorov-Smirnov, teste F e teste de variância do χ2, teste T de Student, teste não paramétrico de Wilcoxon e cálculos estatísticos de parâmetros. O NH SEDIMENT AND STATISTIC calcula e fornece automaticamente os principais resultados para cada um dos métodos, permitindo que o usuário tire suas próprias conclusões. Essa ferramenta computacional proposta suporta estudos hidrossedimentológicos e é confiável e fácil de usar, contribuindo para a redução de problemas relacionados a sedimentos nas áreas de engenharia hidráulica, geologia, conservação de solo e água. Além disso, essa ferramenta pode ser usada em áreas científicas transdisciplinares para um planejamento e gerenciamento completos dos recursos hídricos.

The importance of Legal Reserves for protecting the Pantanal biome and preventing agricultural losses.

Considering scenarios of future changes in land use have the potential to support policy-makers in drafting environmental laws to reconcile the demands of multiple land uses. The Pantanal, one of the largest wetlands in the world, has been undergoing rapid land use changes, and does not yet have any integrated environmental legislation on Legal Reserve for entire region (LR - minimum percentage of native vegetation required within private properties). The aim of this paper was to generate future vegetation loss scenarios for the Pantanal based on four LR values: (i) BAU: Business as usual, which considers existing laws: Native Vegetation Protection Law and State Decree; (ii) LRE: LR elimination owing to a bill recently proposed; (iii) LR50: which considers the bill proposing 50% of LR for the Pantanal; and (iv) LR80: our proposed levels of 80% of LR for the lowlands and 35% for the plateau (following values in the Amazon). Based on native vegetation loss from each scenario, we estimated the soil loss and sediment yield to rivers. Our results show that LRE would increase native vegetation loss in the Pantanal by as much as 139% when compared to the BAU, whereas increasing LR levels would reduce conversion values by 29% (LR80). Elimination of the LR would increase soil erosion and sediment production by up to 7% and 10%, respectively, compared to BAU. Based on native vegetation loss from each scenario, we estimated the soil loss and sediment yield to rivers with our data showing more than 90% of the sediment transported to the lowland originating from the plateau. The LR80 indicates a reduction in soil nutrient replacement costs of 10% compared to BAU, while in the LR50 these costs decrease by 1.5%, and in the LRE would increase of 8%. Our results show that abolishing current protections would have substantial impacts on avulsion processes, on several economic activities (tourism, fishery, cattle raising, etc.) and negative impacts for biodiversity conservation and would bring losses to agriculture in the Pantanal. Hence, our study brings clearly evidence of LR importance and need to expand it in this sensitive wetland.