which directly influences changes in stream flow, runoff and evapotranspiration (Kundzewicz 2008; Zhang et al. 2012). In addition to climate change, land cover/land change resulting from human activities is considered another factor that directly influences water resources (Ma et al. 2009; Xu et al. 2010). Land cover/land change can alter the hydrological cycle of a region by altering the rates of runoff and infiltration. These changing rates can have a negative impact on the soil water content (He et al. 2009; Dixon and Earls 2012).
Arid climate is one of the five major climate types and can be further classified as semi-arid or desert, based on the Köppen climate classification (Peel et al. 2007; Crosbie et al. 2012). Arid climates currently occupy about 32% of the land area on Earth, which, incidentally, is the largest climate zone. This climate type is associated mostly with the mid-latitude western, wind belts and restricted to the western parts of North America and South America, the northern