牧区水-土-草-畜平衡调控模型建立与应用

针对牧区水资源短缺、水土资源不匹配、草畜平衡矛盾突出及生态环境脆弱的问题,该文在分析现有研究对牧区水-土-草-畜平衡调控研究不适应的基础上,构建经济效益与生态效益统一度量的牧区水-土-草-畜平衡调控模型,并在内蒙古自治区鄂托克前旗进行实例应用,以牲畜饲养过程中灌溉人工草地和天然草地耦合比例建立调控方案集,分析水土草资源开发与经济生态综合效益响应关系,结果表明随牲畜补舍饲时间增加灌溉人工草地种植面积增加,区域发展限制因素逐渐由天然草地限制过渡为水资源限制,研究区土地资源丰富,水资源是控制区域水-土-草-畜平衡发展的关键因子。到2030年鄂托克前旗水-土-草-畜平衡调控阈值主要指标为水资源开发利用量控制在2.66亿m~3,灌溉面积控制在4.24～4.31万hm~2之间,灌溉人工草地开发规模控制在3.04～3.42万hm2之间,牲畜饲养量控制在113.54～118.85万羊单位之间。模型为定量化研究牧区水-土-草-畜平衡调控阈值提供一种新的思路与手段。

Regulation model and application for water-land-forage-livestock balance in pastoral areas

Abstract: Most of the pastoral areas in China are located in arid and semi-arid regions, where water resources are short, water and land resources are not matched, and forage and livestock conditions are not balanced. In consequence grassland degradation and serious desertification have been induced. Overgrazing and agricultural development are the main man-induced factors for ecological system degradation in pastoral areas. With the development of research, alleviating ecological degradation has been evolved gradually from achieving the balance between forage and livestock to achieving the balance among water, land, forage, and livestock. Therefore, the water-land-forage-livestock balance regulation is the key to solve this problem. In this paper, the existing researches on the adaptation of water-land-forage-stock balance regulation in pastoral areas have been analyzed. Under this premise, converting the value of grassland ecological services into acceptable grassland ecological benefits is incorporated into the regulation of water-land-forage-livestock balance in pastoral areas. And the water- land- forage- livestock balance regulation model with uniform measure of economic benefits and ecological benefits have also been built. The regulation model was constructed by the multi-objective programming method. The genetic algorithm (GA) which evaluates individual fitness based on target sorting matrix was used to solve the model, and FORTRAN language was used for programming and data processing. The calculation program is developed as a new method and thought for the quantitative study of the water-land-forage-livestock balance regulation threshold. Taking Etuokeqian banner as an example, a set of control schemes for irrigating artificial grassland and natural grassland coupling ratio during livestock rearing have been established. Based on this, the relationship between development of water and land resources and its response in economic and ecological benefits under different schemes have been analyzed. The results showed that the area of irrigated artificial grassland was increased with the increase of livestock feeding time, and the limiting factor of regional development gradually shifted from the natural grassland to the limitation of water resources. The study area has rich land resources. Thus, water resources are the key factors in controlling the balanced development of the regional water-land-forage-livestock. By 2020, there will be 4 main indicators of water-land-forage-livestock balanced control threshold in Etuokeqian Banner. The development and utilization of water resources should be controlled at 1.66 hundred million m3, the irrigated area should be controlled at 3.28 to 3.38 ten thousand hm2, the development scale of irrigated artificial grassland should be controlled between 2.16 to 2.51 ten thousand hm2, and the amount of livestock keeping should be controlled in 89.43 to 100.46 ten thousand sheep units. By 2030, the development and utilization of water resources should be controlled at 2.66 hundred million m3, the irrigated area should be controlled at 4.24 to 4.31 ten thousand hm2. The development scale of irrigated artificial grassland should be controlled between 3.04 to 3.42 ten thousand hm2, and the amount of livestock keeping should be controlled in 113.54 to 118.85 ten thousand sheep units.