Water resources management by simulation under virtual water scenario in agricultural sector, case study: Hirmand catchment, Iran.

Abstract

Due to the frequent drought periods, water consumption increase, and competition of different water-using sectors, the Hirmand catchment is in a critical water status in the Sistan region. This threat has been intensified in recent years. To cope with this problem, we must pay more attention to different types of water use such as virtual water as a water saving method. The present study calculates virtual water demand of agricultural products in the Sistan region in the cropping year of 2013-2014 using water evaluation and planning (WEAP) system. Furthermore, impacts of the implementation of the virtual water scenarios are predicted on water resources and consumption over the 2015-2030 period. Results show that tomato and alfalfa have less virtual water demand despite their high water requirements due to their high production yield. Furthermore, wheat and barley have the highest virtual water demand. Also, the results of the WEAP model reveal that in the virtual water scenario, the mean annual water demand is lower than the current account (61% for net efficiency, 17% for current efficiency). Consequently, unmet demand will be reduced about 383 million m3. Therefore, given the prevalence of drought in the region, it is appropriate to implement this scenario to protect water resources. Hence, it is highly recommended to orient planning and investment in agricultural development projects of the Sistan region with the concept of virtual water.