Using GIS to determine forest and land loss around water springs administered by rural aqueducts in the Northern Zone of Costa Rica

Abstract

In Costa Rica, the water supply for rural population is mainly provided by the Rural Water Management Boards (ASADAS).
With the location of the water springs, calculations are performed to determine forest and soil loss by using Puyravaud formula (2003) and Revised Universal Soil Loss Equation (RUSLE) during the period 1997 to 2012. This process was conducted within 200 meter radius from the water spring. With these processes it was determined the erosion on the surface surrounding the water spring and reinforced its functions as a buffer zone to natural and manmade phenomena.
In the water spring called Caimitos and San Francisco in the 1997 coverage in the 200 meter radius, was a deforested area, with 12.3 hectares, which remained in the same condition to the year 2012, this condition generates important soil losses for the water spring calculated in 12.28 tons per hectare per year. This amount is classified as slight erosion; however there are emerging areas that show moderate, severe and very severe erosion.
The determination of forest loss and erosion along with mapping, also using geographic information systems (GIS), allow setting the behavior of the forest and erosion through spatial modeling.