Analysis and Prediction of the Lowest Ecological Water Level of the Inland Lake in Arid Region of China

As a key component of the water cycle in arid regions, inland lakes have relatively fragile biological and ecological systems. Once the environment deteriorates, inland lakes in arid regions will be the first to respond accordingly. In view of the lack of ecological water quantity, the continuous decline of lake water level and the insufficient carrying capacity of water resources caused by the changes in precipitation and evaporation, the construction of water replenishment projects and domestic water use for industrial and agricultural production in the inland lake basin in the arid region of China in recent years, the analysis and prediction of the minimum ecological lake water level were carried out. Taking Chenghai Lake as the case study, a comprehensive analysis of the historical water level evolution was conducted using the lowest annual average water level method, the natural water level data method, and the lake morphology data method, and got the current lowest ecological water level of Chenghai Lake was found to be 1495.43 m. And then, taking the year when the legal minimum water level is restored as the boundary for the future, the minimum ecological water level of Chenghai Lake was calculated to be 1499.20m. On this basis, combined with the water replenishment of the existing and under-construction diversion projects in Chenghai Lake, it is predicted that the year when Chenghai Lake will restore its legal minimum ecological water level will be 2025. The research will provide data support and a basis for decision-making for ecosystem restoration, lake area governance and protection, rational development, and utilization of watershed water resources in inland lakes.