A Dynamic Model for Vulnerability Assessment of Regional Water Resources in Arid Areas: A Case Study of Bayingolin, China

Water scarcity is a common problem in many countries, especially those located in arid zones. The vulnerability of water resources due to climate change is an imperative research focus in the field of water resources management. Thus, it is important to carry out a water resources vulnerability assessment to improve water resources management against this background of increasing water demands and global climate change.

The Bayingolin Mongolian Autonomous Prefecture (Bayingolin) is an autonomous prefecture of the Xinjiang Uygur Autonomous Region in the northwest of China. The total water resources of the region are 10.91×10⁸ m³, in which 10.42×10⁸ m³ (95.51%) is surface water. Facing the severe challenges of socioeconomic development and global climate change, the vulnerability of water resources in Bayingolin should be evaluated for the efficient management of its scarce water resources.

To simulate the water supply-and-demand process in Bayingolin and evaluate water resources vulnerability currently as well as in the future, a System Dynamics (SD) model was developed in this study. The model was calibrated and validated using historical data. Three alternative scenarios were designed by changing parameters to test the vulnerability of water resources: 1) increase the wastewater treatment rate by 50%; 2) decrease the irrigation water demand per hectare by 20%; and 3) increase total water supply by 5%.

Results show that the baseline vulnerability of study region is high. The structure of water demand will change in the future, and the ratio of agriculture irrigation water demand will decrease with the use of more efficient water-saving irrigation technology. The different scenarios demonstrated varying levels of vulnerability in the simulation. The relatively lower vulnerability appears in the scenario 2 (decrease the irrigation water demand per hectare), illustrating that one suitable option to solve the problem of water shortages and reduce the water resources vulnerability was to develop and promote water-saving irrigation technology.

The results also demonstrate that SD is a good method to solve the problem in complex water supply and demand system. The paper was published in Water Resources Management in June 2013, 27(8): 3085-3101.