An interval bilateral regulation framework of water resources supply and demand in irrigation area under water sources uncertainty

Abstract

Climate change and human activities have diminished the stability of the water resources system, leading to multiple uncertainties in the prediction of incoming water, reservoir operation optimization on the water supply side, and adaptive adjustments of the water-use structure on the water demand side. In response to quantify uncertainty and match the water supply-demand in water resources regulation, we developed a novel "ensemble inflow prediction—reserve operation strategy—interval bilateral regulation—water supply risk analysis" framework by coupling the interval prediction methods of incoming water, the bilayer model of reservoir multi-objective optimal operation, and the optimization model of planting structure in irrigation area. In the proposed framework, the NGBoost and Bootstrap methods were employed to assess the uncertainty of runoff and groundwater based on the varying sample sizes. A bilayer model of reservoir multi-objective operation was proposed under uncertain runoff to optimize reservoir operation rules for different sequences of reservoir water storage and supply. An interval bilateral regulation model of water supply and demand was developed to optimize crop planting structures for adapting to uncertain water supply scenarios. We applied this framework to the Baojixia Irrigation Area (BIA) of Northwest China. The results show that the NGboost model achieves satisfactory prediction results for the monthly runoff. The reservoir group, following the sequence of water storage [II, III, IV, V, VI] and the sequence of water supply [VI, V, IV, III, II], can reduce water supply risks under uncertain runoff. Compared to the current scenario, annual average economic benefit has been increased by 19.6 %-24.9 %, irrigation water has been reduced by 10.3 %-12.5 %, and water shortage rates have been reduced to 2.1 %-2.9 % under water supply scenarios A-W, A-N, A-D, and A-E in the interval bilateral regulation framework. This study provides a new perspective to address the interaction of water supply-demand and multiple uncertainties.