基于水足迹的河套灌区多目标种植结构优化调整与评价

针对黄河水量逐年减少和农业面源污染日趋严重等因素导致内蒙古河套灌区农业用水短缺、生态环境不断恶化的问题,本文将水足迹概念（蓝水足迹、绿水足迹、灰水足迹）引入多目标优化模型和多目标决策评价模型,对灌区有限的水资源进行合理配置。以河套灌区为例,本文选取小麦、玉米、葵花、瓜类、番茄5种典型作物,从经济、社会、资源以及生态4个角度对作物的种植结构进行优化,并耦合模糊层次分析和TOPSIS法对多种优化方案（多目标优化方案、单目标优化方案、现状情景方案）进行评估优选。结果表明,在保障粮食作物产量的基本需求下,减少粮食作物小麦、玉米的种植面积,增加经济作物葵花、番茄和瓜类的种植面积,可以达到增加经济收入、保证社会公平性、提高水资源利用效率及减少粮食生产过程中给环境带来负面效应的目的。并且,评价结果表明多目标优化方案兼顾经济、社会、资源和生态多方面,优化结果优于单目标优化结果和现状情景。研究可为河套灌区及类似地区作物种植结构调整提供相应的理论依据和决策支持,助力灌区可持续发展。

Optimization and Evaluation of Multi-objective Planting Structure in Hetao Irrigation District Based on Water Footprint

Agricultural water shortage is serious and ecological environment becomes deteriorating continuously due to the reducing available Yellow River water resources and serious agricultural non-point source pollution in Hetao Irrigation District, Inner Mongolia. Based on these problems, the footprint concept was introduced into the multi-objective optimization model and multi-objectives decision evaluation model to allocate the limited water resources rationally. Taking Hetao Irrigation District as an example, the optimal planting structures of five main crops (wheat, corn, sunflowers, tomatoes and melons) were obtained considering the aspects of economy, society, resources and ecology. Meanwhile, multiple optimization schemes (multi-objective condition, single-objective condition and current condition) were evaluated and selected by integrating the FAHP model and TOPSIS model. Results showed that under the basic premise of food crop yield, reducing the planting area of wheat and corn, and increasing the cash crops (sunflowers, tomatoes and melons) were recommended. It can increase economic income, ensure social equity, improve irrigation water use efficiency and reduce the negative environmental effects simultaneously. Furthermore, the evaluation results showed that the multi-objective optimization scheme, taking into account the tradeoffs amongst economic, social, resources and environmental aspects, was better than both the single-objective condition and the current condition. The research result can provide theoretical decision support and promote sustainable development to Hetao Irrigation District and similar irrigation areas.