Assessment Scenarios of Water Resources Management in Arid Areas (Case Study: Birjand Plain, Iran)

Groundwater has often been considered one of the major sources of drinking and agricultural water, particularly in arid and semiarid regions. In this respect, the present study dealt with a combination of numerical models of groundwater and water resource management model. The first conceptual model was prepared to simulate the groundwater table of Birjand plain in South Khorasan province, Iran. Then, the groundwater level was predicted and verified using numerical models. The output of these models was used to investigate the influence of parameters such as climate change and population growth rate on the groundwater level within the WEAP management model. The scenarios discussed in this research included the assessment of the demand rate and saving underground water resources by increasing the rate of population growth, reducing the planting area, and using drip irrigation method instead of traditional irrigation practices until the year 2020. The results showed that by reducing the planting area to 20% by the year 2020 and using drip irrigation with an efficiency of 90% instead of traditional irrigation would reduce water demand by 14% and as a result, an average rate of 8.2 million m3 of water would be saved from 2016 to 2020.