Definition of Priority Areas for Recovery and Environmental Conservation in Water Supply Catchment Areas According to Land Use and Management Capability

Environmental policies and programs have an important role in stimulating the provision of ecosystem services, reconciling environmental, socioeconomic and cultural issues. In a context of public sector budget constraints, the definition of priority areas for conservation or environmental recovery in watersheds is crucial for the implementation of such policies and programs. This research aims to contribute to this discussion through the analysis of land use and vegetation cover in relation to potential soil use capacity, considering effective soil depth, internal drainage characteristics of soils, slope and susceptibility to erosion as limiting factors. The study is carried out in the catchment area of the Serra Azul reservoir, which is an important source of drinking water for the Metropolitan Region of Belo Horizonte (MRBH), Brazil. The catchment has a surface of 248 km² and the reservoir provides around 2.3 m³/s, which represent about 10% of the total MRBH drinking water system provision, supplying water for about 270.000 people.

Land use, vegetation cover, soil type and rainfall regime in the study area were obtained through remote sensing imagery, secondary data and field visits. Areas of urban expansion, farms, mining and agricultural activities comprise the land use mosaic in the catchment. Nevertheless, the catchment keeps an expressive percentage (66%) of native vegetation cover. The method for defining the prioritization for the protection and recovery areas in the catchment included those that are legally protected, such as riparian areas and areas surrounding water springs, and areas particularly susceptible to environmental degradation.

The results of the research highlight that, on the one hand, some legally protected areas are already impacted by urban expansion and economic activities appointing lack of effective control by the public sector. This intensive use of sensible areas may lead to high risks of soil degradation. On the other hand, we identified areas which would allow a more intensive use of the soil, with greater gains in productivity. This analysis has the potential to assist in decision-making processes regarding the prioritization of investments in environmental conservation, recovery and restoration, especially in catchments that are sources of drinking water and where to reconcile conflicting land and water uses is a requirement. Furthermore, it also brings elements for implementing compensation schemes for the provision of ecosystem services, with the creation of mechanisms to encourage the maintenance of native vegetation cover and, in the case of agricultural interests, the adoption of soil and water conservation measures.