Impacts of Climate Change and Land Use on Projections of Erosion and Sediment Production in the Jequetepeque River Basin in the Peruvian Andes

Peru is one of the most vulnerable countries to the effects of climate change. The projected increase in erosion and sediment production in the Andean region is of particular concern. This study examines the impact of climate change scenarios in the upstream area of the Gallito Ciego reservoir, and it investigates whether the implementation of green policies can mitigate the expected trends compared to the no-action scenario. Using the SWAT model, historical conditions (1981-2010) in the study area were analyzed. The results show an average annual flow of 30 m³/s and a sediment concentration of 1.0 g/L at the calibration station. Erosion and sediment production rates were estimated at 16.1 and 12.6 tons/ha/year, respectively, while the observed sedimentation rate was 3.72 hm³/year (1988-2017). Climate change scenarios (SSP2-4.5 and SSP5-8.5) and land use scenarios [three green measures scenarios (GMSs) and one trend scenario] were simulated for the period 2021-2080. The projection of the average annual flow remains unaltered by variations in land use, with an average increase of 43%. However, other variables show contrasting trends. The trend scenario predicts an average increase of 69% in annual sediment concentration, while the GMSs show an average increase of 41%. Erosion and sediment yield rates project average increases of 137% and 122% in the trend scenario compared to 99% and 93% in the GMSs. These findings underscore the urgent need for measures to mitigate the impacts of climate change in the Andean region.