Effect of land use and buffer zones range on the quality of the Itapetininga River: the use of biomonitoring technology

Abstract

The municipality of Itapetininga, located in the state of São Paulo, is a reference in agricultural production. The main source used for irrigation, watering, manufacturing processes, and other uses is the Itapetininga river. The river is approximately 180 km long, passing through four municipalities, it is one of the main ones in the Alto Paranapanema basin, but studies in its microbasin are still scarce, whether related to the quality of the river or its surroundings. Disorderly urban growth and the expansion of agricultural activities in the region with unsustainable practices are threats to the resource. The use of benthic macroinvertebrates can be of great value in analyzing the quality of aquatic ecosystems. In addition, it is known that land use and deforestation, especially in watershed protection areas, usually reflect negative impacts on watercourses. This work is based on the hypothesis that changes in land use along the river, as well as the suppression of arboreal shrubby vegetation in the APP zone, are factors that impact the quality of the Itapetininga river and can be detected by expedited analysis of the macroinvertebrate community benthic. The objective of this work is to determine the quality of the watercourse in different stretches and relate it to the land uses and extension of the APP strip. For this purpose, collections will be carried out in the dry and rainy seasons along the river at ten sampling points, seeking to cover different land uses and degrees of preservation of APP. Sediment samples will be collected for analysis of benthic macroinvertebrates, considering groups of rapid identification and analysis frequently pointed out as good indicators. Analyzes of transparency, turbidity, pH, nitrite, nitrate, ammonia, phosphate, dissolved oxygen, BOD, total coliforms, and E. coli will also be carried out. In addition, through field visits and satellite images, the width of the APP band, land uses, and how these affect these variables will be measured. The relationships between variables and land use and APP bandwidth will be determined by Canonical Correspondence Analysis and double-entry Analysis of Variance. (AU)