Calculating agricultural water-saving potential in arid areas using system dynamic model

【Objective】Agriculture is the main water consumer in many countries and regions, and improving agricultural water use efficiency is critical to sustainable development in these regions. A prerequisite for this is to understand the potential for water saving in the agricultural sector. This paper presents a method to evaluate agricultural water-saving potential in arid regions.【Method】The method considered the influence of desertification, soil erosion, and other environmental factors on water conservation. A total of 30 key factors, including agricultural water consumption, irrigated land area, irrigation water use efficiency, grain-to-economy ratio, and soil and water conservation rate, were considered in the evaluation. Using the Vensim PLE software, a system dynamic flow diagram model was developed to calculate agricultural water-saving potential. The model was applied to Inner Mongolia (excluding Dongsimeng City) to evaluate its agricultural water-saving potential at regional scales, in both the short term (up to 2035) and the long term (up to 2050).【Result】① Agricultural water-saving potential in Inner Mongolia was estimated to be 2.518 billion m3 in the short term (up to 2035) and 2.958 billion m3 in the long term (up to 2050). Among all areas in the province, Bayannur had the highest water-saving potential, while Wuhai had the least. ② Engineering water-saving projects contributed the most to the water-saving potential (approximately 52.83%), while technical water-saving measures contributed the least (approximately 16.91%). The contribution of engineering water-saving projects to water savings is expected to increase over time.【Conclusion】Our results demonstrate that the system dynamic model can be used to estimate agricultural water-saving potential. The results obtained using this model are reliable and provide valuable technical support for formulating agricultural water-saving policies in arid regions.