中国西北旱区农业水土资源利用情景潜力研究

西北旱区水土资源供需矛盾突出,同时作为该区农业生产的瓶颈因素,决定该区经济社会生态可持续发展,因此有必要开展西北旱区农业水土资源相结合的空间情景潜力研究。论文采用水土资源匹配指数计算分析了西北旱区现状年（2010年）农业水土资源的匹配状况,采用农业水土资源利用潜力估算方法计算了西北旱区2020、2030年RCP 8.5和RCP 4.5两种情景下的农业水土资源利用潜力,实现了西北旱区农业水土资源利用潜力的可视化表达。结果表明：2020和2030年RCP 8.5和RCP 4.5排放情景下,相对于2010年,西北旱区各省2020和2030年的总农业水资源量和种植面积均减小。西北旱区6省份2020和2030年两种情景下整体综合效益和整体潜力值均为正,表明各省种植结构整体得到了优化。2020年RCP 8.5和RCP 4.5情景下,西北旱区农业水土资源利用潜力分布范围分别在-0.10×10⁴~0.83×10⁴元/hm²之间和 -1.20×10⁴~0.97×10⁴元/hm²之间;2030年RCP 8.5和RCP 4.5情景下,农业水土资源利用潜力分布范围分别在-0.39×10⁴~2.17×10⁴元/hm²之间和-0.36×10⁴~1.66×10⁴元/hm²之间。

Study on Utilization Potential of Agricultural Soil and Water Resources’ in Northwest Arid Area

Soil and water resources are important factors impacting the productivity of agro-ecosystem in arid and semi-arid areas worldwide. Most studies focused on the aspects of soil and water resources potentials under natural status based on a provincial or larger scale. It is still unknown about the potential’s distributions and matching patterns of soil and water resources in the entire northwest areas of China. Furthermore, with the ever-growing population and urbanization, the contradiction between the supply and the demand in terms of soil and water resources has become much more serious in this region than ever, and has become the bottle-neck factor constraining regional agricultural productivity. To alleviate the contradiction, optimal matching of soil and water potentials and resources plays an important role in the sustainable development of local economy, ecology, and society. To well address the above-mentioned issues, an innovative methodology for calculating the matching index of soil and water resources was developed to analyze the current matching status of soil and water resources in northwest arid area of China. Additionally, a calculation method was also developed to estimate the soil and water resources utilization potential under different climatic scenarios, including the RCP 8.5 and RCP 4.5 scenarios in 2020 and 2030, respectively, in which an accurate and precise equation was developed for visualizing the resource utilization potential. During the base year of 2010, the matching index exhibited a gradual ascending trend from the northwest to the southeast. Total amounts of water resources and planting areas will significantly reduce under the RCP 8.5 and RCP 4.5 scenarios in 2020 and 2030, compared to those in 2010. The integrated economical profits and entire potential values are positive (desirable) under both scenarios in 2020 and 2030, indicating planting structure of the six provinces in northwest arid area can be optimized. The potential values of soil and water resources fall in the range of -0.10×10⁴ to 0.83×10⁴ yuan/hm² and -1.20×10⁴ to 0.97×10⁴ yuan/hm² under RCP 8.5 and RCP 4.5 scenarios in 2020, whereas they fall in the range of -0.39×10⁴ to 2.17×10⁴ yuan/hm² and -0.36×10⁴ to 1.66×10⁴ yuan/hm² under RCP 8.5 and RCP 4.5 scenarios in 2030, respectively. The calculation method in this study provides a new approach for estimating the potential utilization efficiency of soil and water resources in northwest arid area of China, and this methodology can be extended to a wide range of the world with the same environment to capture the great benefit of food security while minimizing the negative impact on soil and water. Our results clearly demonstrated that the soil and water resources can be well matched in a desirable manner in the near future in northwest China if planting structure and areas are well optimized and cropping patterns are well managed.