Influence of land use on the static levels in wells in La Carreta river microbasin, San Juan de Cinco Pinos, Chinandega, Nicaragua

Abstract

Groundwater is a vital resource that constitutes the largest reserve of accessible freshwater, so guaranteeing its availability is a priority action for the well-being of rural communities. The objective of this study is to demonstrate the importance of vegetation cover and its influence on the availability of water resources by monitoring the variations of static groundwater levels in wells in the La Carreta River micro-basin, in San Juan de Cinco Pinos, Chinandega. The depth of the water mirror of the wells was measured with a Solinst Water Level Model 102 water level indicator during February, March, April, September, October, November and December of 2018. The ANUDEM model was used to generate maps of the static levels of groundwater of the microbasin from the interpolation of the measurements considering its topography. The climatic conditions of 2018 caused the variations in groundwater levels to be more marked, presenting values ​​greater than six meters deep from the static level during the dry period, in clay soils with little vegetation cover associated with agricultural uses, in contrast to the rainy period, where it remained less than four meters deep in much of the micro-basin. The variation of static levels in April to November in wells surrounded by agricultural crops and pastures is lower compared to wells surrounded by broadleaf forests, evidencing the notable incidence of forest cover in the recovery of the static level. It is concluded that land use influences the variation of static groundwater levels, with uses that have greater forest cover being those that favor the water surface of the wells to be closer to the ground surface.