Agriculture and Hydropower Generation

Extended Abstract The study La Economía del Cambio Climático en Chile (Economy of Climate Change in Chile) (CEPAL, 2009) shows the impacts of Climate Change in Chile using the results from the GCM model HadCM3, with two GHG scenarios (A2 and B2). As projected in these scenarios, for the near future period it is expected a raise in temperature in Central and South Chile in the order of 1-2°C and a decrease in rainfall in the order of 10% to 20%, depending on the scenario. In terms of impacts in water resources, it can be expected a reduction in streamflow in rivers and a change in their seasonality. The present work develops, through an hydrological and water allocation modeling approach, the climate change impacts of the Maule River Basin highlighting the competence between two economic and water use sectors in this region: hydropower and agriculture. The approach is done using the WEAP (Yates et al, 2005) model that has been extensively used in Climate Change studies in Chile and other regions of the world (Vicuña et al, 2011). The inputs of this model are the projected climate scenarios from three GCMs: ECHAM5-OM (MPI-M), CM2.0 (GFDL) and HadCM3 (UKMO), using two emission scenarios: A1B and B1. Through a statistical downscaling process these scenarios are applied to recreate temperature and precipitation time series, main inputs of the WEAP model. The results of the modeling give information about streamflow, snow melt and accumulation, hydropower generation, allocation of water for the agriculture sector, storage in reservoirs and lakes, among others. The work is centered in the Maule River Basin, located between 35°S and 36°30'S, central Chile. It has an approximate area of 21,054 km 2 , where Maule River is the main water course in the basin. The river originates in the Maule Lake, a water body of 1,570 millions of m 3 , which is the main regulator of the basin, located at 2,170 m above sea level in the Andes. The hydrologic regime of the watershed varies from nival regime in the mountainous area (from 450 – 3,900 m), a mix of pluvial and nival in the middle zone, to a complete pluvial regime in the lower part of the catchment. The watershed' water demand is mainly due to two activities: Agriculture and Hydropower Generation. On one hand, agriculture land use represents 12% of the total area in the basin, and 12% …