Abstract The serious shortage of water resources and the progressive deterioration of downstream water environments restrict development of the agricultural economy. It is necessary to study the optimization method of water allocation from the perspective of sustainable development, considering the real situation of agricultural production and water quality. First, an improved principal component analysis that considers the importance of indicators to the principal components is performed to select evaluation indicators, and the entropy weight method is modified to stably and sensitively determine the weight of the evaluation indicators. Moreover, Dempster–Shafer evidence theory is proposed to obtain the comprehensive weight of the evaluation indicators, taking into account both subjective and objective factors. Second, the model to optimize the planting-raising structure and regulate water quantity and quality is established by combining the evaluation of agricultural water resource carrying capacity (AWRCC). A method of water allocation based on the characteristics of water requirement of crops and livestock is put forward, which can not only avoid imbalanced water supply, but also reduce the dimensions of the model. Finally, our proposed method of optimal allocation of agricultural water resources is applied to the Yang River Basin. The evaluation results show that the AWRCC of the subareas fall between the saturated and the transition state during the years included in this study. The optimization results show that the monthly concentration of ammonia nitrogen and chemical oxygen demand can meet the requirement of water quality of less than 1 mg/L and 20 mg/L, respectively. Meanwhile, economic benefits are increased, and the AWRCC is improved. In conclusion, the proposed method and model can provide a valuable tool to evaluate and promote the coordination between the agricultural economy, water quality safety, and sustainable development of local agricultural water resources.

中文翻译：

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农业水资源承载力评价与种养结构优化

摘要 水资源严重短缺，下游水环境不断恶化，制约着农业经济的发展。有必要从可持续发展的角度，结合农业生产和水质的实际情况，研究水资源配置的优化方法。首先，进行改进的主成分分析，考虑指标对主成分的重要性，选取评价指标，修改熵权法，稳定、灵敏地确定评价指标的权重。此外，提出了 Dempster-Shafer 证据理论来获得评价指标的综合权重，兼顾主客观因素。第二，结合农业水资源承载力评价（AWRCC），建立优化种养结构、调节水量和水质的模型。提出了一种基于农作物和牲畜需水特点的水资源分配方法，既可以避免供水不平衡，又可以降低模型的维数。最后，将我们提出的农业水资源优化配置方法应用于阳河流域。评价结果表明，在本研究纳入的年份中，分区的 AWRCC 处于饱和状态和过渡状态之间。优化结果表明，月氨氮浓度和化学需氧量分别满足小于1mg/L和20mg/L的水质要求。同时，增加了经济效益，改善了AWRCC。总之，所提出的方法和模型可以为评估和促进农业经济、水质安全和当地农业水资源可持续发展之间的协调提供有价值的工具。