Integrating Environmental, Geographical and Social Data to Assess Sustainability in Hydrographic Basins: The ESI Approach

The elaboration of environmental sustainability indexes (ESI) aims to describe the complexity between social, environmental and ecological health. These indexes play a crucial role by helping stakeholders during the decision-making process and by identifying possible sites that require practical sustainable actions. In this study, we aim to elaborate an ESI for hydrographic basins. We use three factors to build the index: land use; vulnerability to soil degradation and topographic land attributes; and human development. The human development factor includes the dimensions of education, sanitation, longevity and income. These three factors are recommended by the Organization for Economic Cooperation and Development and reflect the pressure-state-impact assessment model. To verify the effectiveness of the proposed ESI, we applied it in a hydrographic basin located in southern Brazil. The sustainability level variation in the basin was classified into five groups: very low (0%), low (17%), intermediate (72%), high (11%) and very high (0%). The predominance of the intermediate sustainability level was found to mainly owe to the extent of agricultural land and the high degree of susceptibility to soil erosion in areas with low environmental conservation. In areas with native vegetation, environmental sustainability was found to be higher than in areas with other land use types. The resulting ESI will help facilitate future studies in environmental, economic or social dimensions in any hydrographic basin.