Estudos socioambientais na microbacia do Rio Chafariz (PB) como ferramenta para gestão.

Abstract

Environmental planning is an important tool for the processes of environmental management. This work aimed to identify some factors which have a negative influence on the environmental quality of a watershed such as deforestation, agriculture and farming, mining activities, river discharge. Degradation can be caused by these activities and also by the misuse of natural resources which increases the process of soil erosion, which is worsened by run-off; proper soil management and conservation are important practices which contribute for environment preservation. At the Chafariz river microbasin, which has an area of 215,6 km2, it is observed intense mining activity as well as cattle-raising, agriculture, sand extraction. Morphometrically, it is characterized as the compactness index (Kc) a value of 1,57; the shape factor (Kf) 0,39 and the circularity index 0,4, showing that its form tends to be stretched. These parameters indicate that the area is not susceptible to floods and presents low run-off, factor which helps drain density. It was observed that anthropic actions are changing this profile, since the extraction of vermiculite discharges its residues in the open air, so in the raining season, they are carried and placed in the water bodies, silting them, resulting in overflow and reduction of the time water resides in the watershed. Regarding water potability, it was total coliform and Escherichia coli or thermotolerant infested, making it unfit for human consumption in natura. Salinity varied from mean to very high, sodicity varied from low to mean, jeopardizing its use on agriculture due to the risk of salinization of soils. In economic terms, it was identified demotivation to produce and sell agricultural products. According to all accounts, production and final prices are very low, making the whole activity not worthy. Other limiting factors are: small area to plant; limitations regarding water availability; lack of Governmental rural technical assistance which guide them in regard to agricultural practices in order to promote productivity. These factors result in socioeconomic imbalance, rural exodus and all the impacts resulting from this situation.