Ecosystem Services Demand Management Under Climate Change Scenarios: Use of WEAP Software in Case of Water Demand in Ziz Basin, Morocco

Introduction

Arid and semi-arid ecosystems provide several goods and services. Water ecosystem service is the most important element that supports the human well-being. Climate change is a real challenge in the dry areas that affect some extreme events such as drought, which increases and complicates the management groundwater reserves. The change in precipitation influences the flows of the rivers, which forces local population to use groundwater to meet the increasing demand. Several studies have shown that it is important to include the effects of climate change in local water planning (Schimmelpfennig, 1996). Risbey (1998),seeking to link present-day planning decisions to uncertain future climate projections. More recently, researchers have used integrated water resource planning models to evaluate the impact of climate perturbations on the performance of current water management systems (Brekke et al., 2004; Vicuna et al., 2007; Zhu et al., 2005; Karmaoui et al., 2018; 2016; 2015).

The trend toward a global warming of the Earth’s atmosphere is an important environmental force with significant implication for the state of groundwater ecosystems. The Earth’s surface temperature during the last two decades has increased by about 0.5° C and an ongoing rise with similar amplitude is expected up to 2025 (IPCC, 2001; IPCC, 2007). The global warmth in 2001 was unusually high and is considered to be a consequence of anthropogenic greenhouse gases (Hansen et al., 2002).

Since 1970s, Morocco has experienced a general rainfall decline and temperature increase (Driouech, Déqué & Mokssit, 2009) that causes a decreasing trend in water resources. The Ziz-Gheris catchment in the south of Morocco is a concrete example of climate change impact on water resources and groundwater specially.

In this chapter, Water Evaluation and Planning (WEAP) software was used to evaluate and trace the trend of water demand. This model was applied in case of Ziz basin in order to simulate and analyze the situation of water (reservoir and groundwater) under different scenarios.