Spatial variability of water yield under land use and cover change and rainfall scenarios in the upper basin of the Sauce Chico River, Argentina

Abstract

Land cover changes analysis is important and necessary, it provides the basis for understanding the trends in the processes of degradation, desertification and loss of biodiversity and ecosystem services in a region. The evaluation of the water provisioning ecosystem service due to land use change is crucial in systems with high hydrological vulnerability. The objective of this paper was analyzing the spatial distribution of water yield in relation to land use change (for the years 1997 and 2017) and rainfall scenarios in the upper basin of the Sauce Chico River, Tornquist, Argentina. Using the WY module of InVest®, based on GIS and remote sensing information. We found that agriculture areas occupy 49 % of the basin (185 km²) developed on grazing areas and pastures (64 km²), urban areas and riparian forest occupy < 1 % of the total area of the basin by 2017. The model suggests that the total annual water yield for the basin is 224 943 mm. During the dry scenario (-30% of annual precipitation) water yield decreased to 150 495 mm (39.78%). On the contrary, during the wet scenario (+30% of annual precipitation) water yield increased to 349 940 mm (28.57%). Rocky and urban areas show the highest water yield, followed by agricultural areas. The areas with the highest water regulation correspond to grasslands. The results contribute to the understanding of the hydrological response and provide basic information for decision making and water resource management