Dinâmica do uso da terra e valoração econômica ambiental da Bacia Hidrográfica do Rio Passa-Três, município de Uruaçu, Goiás, Brasil

Abstract

The process of occupation and territorial formation in Goiás has resulted in rapid economic growth, which, together with the migration of large flows to this region, has caused direct implications on the natural environments. Among these implications is the increased demand for water consumption in urban areas. In the northern region of the state, the main source of public supply for the municipality of Uruaçu, the Passa-Três River, has not been able to maintain its supply to the population during periods of drought, due to the environmental problems that the Passa-Três River has been suffering in recent years. One of the reasons related to these problems is due to the aggressive use of natural resources, which occurs because of the consideration of environmental assets as having zero cost, and indicates the need for instruments for the valuation of natural resources. In view of this, the work aimed to analyze the dynamics of land use between the years 1985 and 2021 and identify the negative impacts on the Permanent Preservation Areas (APPs) marginal to the river, to then perform the environmental economic valuation through the Replacement Cost Method (RCM), in order to estimate the total cost for restoration of APPs with inadequate environmental quality. Thus, the first chapter showed the morphopedological and morphometric characterization of the basin area, the history of land use and occupation for the years 1985, 2003 and 2021, and the history of territorial formation of the municipality where the basin is located, followed by the economic characterization. The second chapter dealt with the environmental impacts suffered in the marginal PPAs of the Passa-Tes River as a result of land use and occupation, and the classification of these areas according to their state of environmental quality, being an adequate or inadequate state. In turn, the third chapter, through the Replacement Cost Method, the environmental economic valuation of the Passa-Tes River was carried out, in order to estimate the value necessary for the restoration of the PPAs in an inadequate state. The results showed hat the Passa-Tes river watershed area has soil, relief and slope characteristics that are favorable to the natural occurrence of erosive processes, which were intensified by pasture and griculture, exactly the most predominant land use types in the area. In the same way, pasture areas are also the most predominant type of land use in the APPs, resulting in areas of permanent preservation in an inadequate state, without vegetation and with potential for erosive processes and siltation already existing in several stretches of the channel, demonstrating that the Passa- Tês River is currently in a process of degradation. The Replacement Cost Method resulted in an estimated value of R$ 103.833.805,77 for the restoration of these areas of APP in inadequate state, a value considered to be of high cost, which can be taken into consideration as an incentive for the creation of programs with the objective of protecting or preserving the environment, since repairing is much more expensive than caring for and preserving the environment.