Janaína Ferreira Guidolini

Inadequate land use planning is one of the main driving forces leading to the occurrence of erosion and environmental degradation. The negative impacts of poor planning influence soil physical quality and fertility, agricultural productivity, water quality and availability, biodiversity and other ecosystem services. In some areas, actual land use is not consistent with potential use. When this occurs, the area is termed as being in environmental land use conflict. Many studies have demonstrated the efficiency of the ruggedness number (RN) method for determining land use potential in watersheds. The RN method is simple and can be carried out using geographic information systems (GIS). However, the absence of potential land use or agricultural land suitability assessments is recurrent in territorial management plans or integrated water resources plans (IWRP), especially for macroscale river basins. Therefore, the aim of this preliminary study is to identify possible environmental land use conflicts at the Rio Grande Basin (BHRG), Brazil, using the Ruggedness Number. The results indicate high agricultural use potential and the predominance of appropriate or acceptable soil use at the BHRG. However, class 1, 2 and 3 environmental conflicts were identified in some Rio Grande sub-basins, suggesting greater environmental degradation risks. The findings clearly indicate that more exhaustive studies on environmental quality (soil capability, water, biodiversity) are required at the BHRG, especially in environmental land use conflict areas. We emphasize that this is an important preliminary study which may be carried out in any other macroscale hydrographic basin.

Water resources are fundamental for the social and economic development of a country and sustainability is the best approach to treat water-related problems. Therefore, sustainability studies of water resources are deemed urgent. Sustainability analysis methods should enable space-temporal monitoring, decision-making, and development of policies necessary for water governance. Furthermore, sustainability analysis methods should also integrate environment and socioeconomic variables into a single system. In this context, this study aimed to assess the water sustainability conditions of the River Grande Basin (BHRG), Brazil, before the implementation of the Integrated Water Resources Plan (IWRP), using the Barometer of Sustainability tool (BS). The River Grande basin was in an “almost unsustainable” condition and under high environmental stress. A significant imbalance between environmental and human well-being in the system was also observed. To achieve an acceptable sustainability condition, it is thus necessary to improve the environmental quality of the area. Among the priority thematic area, native vegetation recovery was the most urgent. Overall, the sustainability study based on the BS not only facilitates comprehension regarding environment and human interrelationships, but also provide references for policy formulations and water management.