Extracting operation rule of cascade reservoirs using a novel framework considering hydrometeorological spatiotemporal information based on artificial intelligence models

Abstract

The scientific operation of cascade reservoirs is of great significance for completely utilizing water resources and maximizing their comprehensive benefits. The extraction of reservoir operation rules from massive historical operational data still remains a challenge. Therefore, a novel framework for extracting the operation rules of cascade reservoirs was proposed in this study based on artificial intelligence models by considering hydrometeorological spatiotemporal information. First, the observed precipitation was obtained by merging multi-source precipitation products through a convolutional long-short-term memory (ConvLSTM) network. Second, a novel extraction model by considering hydrometeorological spatiotemporal information was established, comprising a process of capturing the spatiotemporal information of interval precipitation using ConvLSTM and a feature aggregation process of aggregating precipitation and reservoir historical operation information using an LSTM network. Finally, three different extraction strategies (recursive, direct, and multi-input multi-output (MIMO) strategies) for cascade reservoir operation rules were developed and compared, and the influence of future multi-step forecast information was analyzed. Considering the example of Yalong River, the results are as follows: (1) the proposed extraction model has excellent fitting performance with a Nash-Sutcliffe model efficiency coefficient (NSE) of more than 0.95 and mean relative error (MRE) of less than 10 %, especially in reservoirs with large regulation capacity; (2) according to the regulation capacity of the reservoirs and reliability of forecast precipitation, appropriately adding multi-step forecast information can improve the performance of the extraction models; (3) each reservoir's NSE when using the three strategies is above 0.9, indicating that they can all be used to extract the operation rules of the cascade reservoir. Among them, the direct strategy is optimal.