Regional Hydrological Model with Global Climate Change of Mean Annual Flows of the Santa River Basin, Applying the Fokker–Planck–Kolmogorov Equation

Abstract

Global climate change generates a variation in precipitation and temperature throughout the planet, consequently altering the average, maximum and minimum values of river flows in various parts of the world, causing floods and droughts. Between 1932 and 1994, the glaciers of the tropical Andes in Peru suffered a setback due to the increase in temperature, causing an increase in flow rates. Commonly, hydrological studies applied to the development of hydraulic works consider a stationary hydrological regime; however, with the development and research on global climate change, the need to evaluate the hydrological regime as a non-stationary one arises. This non-stationarity approach can foresee hydraulic projects of maximum and minimum flows not expected determined by current methodologies. The objective of the research was to develop a regional hydrological model of annual mean flows under the influence of global climate change (climate change scenario estimated by SENAMHI for the year 2030) in the Santa River basin. This research used as data the mean annual flow series of the following hydrometric stations: Querococha, Olleros, Quillcay, Chancos, Llanganuco, Parón, Colcas, Los Cedros and Quitaracsa; applying the methodology of linear stochastic models and the Fokker–Planck–Kolmogorov equation, for the development of a regional hydrological model designed to predict future mean annual flows. A regional hydrological model is presented that depends on the basin area with and without snowfall; in addition, it was identified that the model that best describes the stochastic behavior of the mean annual flows is the AR model (1), and that due to the influence of climate change the estimated mean flow decreased by 10%.