Capacidade de uso da terra, aspectos socioeconômicos e ambientais no município de Várzea, PB

Abstract

The depletion of natural resources due to the growing demand for agricultural and forestry products combined with the use of land without considering its potentialities and limitations has led to the degradation of vegetation, soil and water. The study of land use capacity becomes important for the proper management of the soil, and the knowledge of the vulnerability to which the populations are exposed, are an essential element for the evaluation of the impacts thereof. The objective of the study was to analyze the land use capacity and the social, economic, environmental and drought vulnerabilities in the Caatinga area of the Seridó Paraíba. The survey was carried out at Fazenda Cachoeira de São Porfírio, located in the Meso-region of Borborema, Microregion of Seridó Ocidental, municipality of Várzea, PB. In order to evaluate the soil use capacity, the property was divided into five areas (Natural Pasture (PN), Caatinga Hyperxerófila (CAH), Caatinga Hyperxerófila and Pastejo CAHP), Pastejo (PJ) and Caatinga Nativa (CAN) with its limits of altitude and the features of the different stages of succession. Soil characteristics, soil color, effective depth, soil texture, permeability, declivity, susceptibility to erosion, stoniness, fertility and current use were computed in order to compose the maximum formula (in the form of alphanumeric notations) and to determine the classes of soil use capacity, for all areas, except for the native Caatinga area that field observations were made. The socioeconomic, environmental and drought diagnosis was carried out with visits in the rural area of the municipality of Várzea, PB, where a survey of the families was carried out and 47 questionnaires, subdivided into variables identified by codes, considering the following factors: social vulnerability; technological vulnerability; vulnerability to droughts. The data were analyzed using the modal, maximum and minimum values of each variable, and the percentages of degradation of each factor were calculated by means of the equation of the line. It was observed that the inadequate management of the areas contributed to the increase of the erosive processes in all the areas, with the appearance of gullies in the CAH and CAHP areas. The PN area is suitable for agricultural cultivation, since the PJ area presented lower depth and limitation for agricultural exploitation, making conservation practices necessary. Five classes of capacity utilization, II, VII, VI, IV and VIII, were identified for PN, CAH, CAHP, PJ and CAN areas, respectively. There was high socioeconomic vulnerability and droughts in the rural area of Várzea, PB, and an environmental vulnerability slightly above that accepted by the methodology. Maximum vulnerability was observed in the variable machinery and industrialization, which increased the technological vulnerability. Thus the characteristics found in the survey allowed to distinguish the land use class and to identify the real property conditions and to allow a conservationist planning for rational use. The study of socioeconomic, environmental and drought vulnerabilities indicates high rates that compromise the quality of life of families in the rural area of Várzea, PB.