Impact of Climate Change on Water Balance Components and Droughts in the Guajoyo River Basin (El Salvador)

Abstract

This study assessed how changes in terms of temperature and precipitation might translate into changes in water availability and droughts in an area in a developing country with environmental interest. The hydrological model Soil and Water Assessment Tool (SWAT) was applied to analyze the impacts of climate change on water resources of the Guajoyo River Basin in El Salvador. El Salvador is in one of the most vulnerable regions in Latin America to the effects of climate change. The predicted future climate change by two climate change scenarios (RCP 4.5 and RCP 8.5) and five general circulation models (GCMs) were considered. A statistical analysis was performed to identify which GCM was better in terms of goodness of fit to variation in means and standard deviations of the historical series. A significant decreasing trend in precipitation and a significant increase in annual average temperatures were projected by the middle and the end of the twenty–first century. The results indicated a decreasing trend of the amount of water available and more severe droughts for future climate scenarios with respect to the base period (1975–2004). These findings will provide local water management authorities useful information in the face of climate change to help decision making.

Evaluating the Potential of GloFAS-ERA5 River Discharge Reanalysis Data for Calibrating the SWAT Model in the Grande San Miguel River Basin (El Salvador)

“…This region's climate is tropical, with high annual precipitation rates. However, the intra-annual distribution is uneven, with 90% of precipitation falling during the rainy season between May and October and scattered showers occurring during the dry season between November and April [36,42]. According to weather station measurements, the average annual precipitation is 1700 mm.…”

“…Central America is an area in which remotely sensed data can be highly useful for hydrological modelling to improve estimates of water resources [36]. Tan et al (2021) [37] reviewed 123 articles regarding the use of alternative climate products in SWAT modelling.…”

Impacts of Water Resources Allocation on Water Environmental Capacity under Climate Change

“…The function of the water availability estimation module is estimating the water availability under historical and future scenarios. As the outputs of the General Circulation Model (GCM) have been widely used across the world for projecting the future climate [30,31], they are inputted into Soil and Water Assessment Tool (SWAT) hydrological model for predicting the water availability in the future. In order to adjust the outputs of large scale GCM for satisfying the inputs of the small-scale SWAT model, an effective statistical downscaling method (i.e., Daily Bias Correction (DBC) method) is adopted in this module [32].…”

Impact of climate change on hydro-meteorological drought over the Be River Basin, Vietnam

“…In recent years, many studies have been conducted to assess the impact of climate change on hydrometeorological drought at the regional scale using hydrologic modeling tools. For instances, Blanco-Gómez et al (2019) have assessed the impact of changing climate on drought in the Guajoyo River Basin (El Salvador) under five general circulation models (GCMs) using the SWAT (Soil and Water Assessment Tool); and they found that the drought duration and intensity have upward trends in the future. Zhao et al (2019) used the SWAT model together with Stream Drought Index (SDI) to prognosticate the effect of changing climate on hydrological drought in the Weihe River Basin (China) and inferred the rises in frequency, duration, and intensity of hydrological drought in the future.…”