The Effect of Climate Change on the Water Supply and Hydraulic Conditions in the Upper Pejibaye River Basin, Cartago, Costa Rica

Abstract

The coNSEquences of climate change have challenged researchers to generate models and projections to understand climate behavior under different scenarios. In Costa Rica, as in other countries, climate-change (CC) models and projections are essential to make decisions about the management of natural resources, mainly water. To understand climate change’s impact on hydraulic parameters such as velocity, depth, and river surface area, we studied the Pejibaye river basin, located in Jiménez in Cartago, Costa Rica. This watershed is characterized by having more than 90% of its surface area covered by forest. We used the precipitation and temperature data from meteorological stations (2000 to 2009) and climate-change scenarios (2000–2099) to predict the response of the basin in different periods. First, we calibrated (NSE = 0.77) and validated (NSE = 0.81) the HBV hydrological model using ten years of daily data from 2000 to 2009. The climate-change data (2000–2099) were incorporated into the calibrated HBV model. This allowed us to determine the impact of CC on the basin water regime for the periods 2040–2059 (CCS1) and 2080–2099 (CCS2). The IBER mathematical model was used to determine the changes in the hydraulic variables of the river flow. For the CCS1, we determined a 10.9% decrease in mean velocity and a 0.1-meter decrease in depth, while for CCS2, the effect will be an 11.3% reduction in mean velocity and a 0.14-meter decrease in depth. The largest decreases in river surface area per kilometer will occur in May (1710 m2) for CCS1 and April (2250 m2) for CCS2.

Quantification and Evaluation of Water Requirements of Oil Palm Cultivation for Different Climate Change Scenarios in the Central Pacific of Costa Rica Using APSIM

“…From the simulations in APSIM under the CCSs, it was established that irrigation works as a solution to mitigate the effects of climate change on oil palm cultivation [20], which in our case requires an average irrigation of 3.13 mm day −1 for CCS1 and 4.31 mm day −1 for CCS2 (January to April). However, both economic and environmental viability should be analyzed, since climate change at the basin level will cause a decrease in water supply [45] and an increase in water demand [46]. This could result in the flows required for irrigation not being available in surface water flows.…”

Editorial to the Special Issue “Hydrological Applications and Cooperation Projects in Developing Countries”

“…Watson-Hernández et al [1] applied hydrological and/or hydraulic models to assess the impact of climate change on the flow regime of the upper Pejibaye river basin in Costa Rica. In the manuscript by Baioni et al [2], an application of a distributed hydrological model is documented for the catchments of the Foro dam in Eritrea, with the aim of quantifying surface runoff and sediment transport in the ungauged basin under investigation.…”