The peri-urban interface: hydrological effects of anthropogenic pressure

Abstract

The province of Buenos Aires (Argentina) is one of the main productive areas of the country. In the These days of the province landscape is shaped by a mosaic of rural and urban sectors; here is placed the Cinturón Hortícola Platens integrated by a set of watersheds with different level of anthropogenic modification. The aim of this work was to evaluate how land use covers change process, derived from anthropogenic pressure, affects the hydrological and environmental characteristics of flat land watersheds; for this purpose, it was chosen as case study the peri-urban watershed of El Pesaro Creek, located in Argentina s Pampas region. This watershed has historically presented the least anthropogenic impact, but nowadays shows evident productive and real estate expansion. Land use change was evaluated with satellite images; current land use mainly includes urbanization, cattle raising and intensive agriculture. Surface water chemistry was determined by sampling different sections of the creek, groundwater sampling was based on groundwater monitoring wells distributed along the watershed. Physical-chemical water parameters were determined in situ, major ions were determined in laboratory under standardized methods. Results were compared with hydro chemical previous studies (when the whole watershed was characterized as rural, with extensive livestock farming), allowing to conclude that the most important quantifiable modifications from an ecohydrological perspective are being registered in the upper watershed. In this area is where land use is turning to intensive horticulture (greenhouses), with no planning and minimal precautions about its possible impact on natural resources. Results obtained constitutes a valuable tool for the generation of management strategies not only for this particular watershed, but could also be extrapolated to areas with similar territorial dynamics.