基于水资源可利用量的我国水土资源匹配状况分析

Analysis on Spatial Matching Patterns of Available Water Resources and Irrigated Arable Land in China

【目的】评价我国可利用水资源与灌溉耕地资源的匹配状况。【方法】基于流域水资源可利用量和灌溉耕地分布状况,利用单位灌溉耕地面积拥有的水资源可利用量、基尼系数和水土资源匹配相对系数等,定量分析我国主要省区水土资源匹配总体状况、空间分布及变化趋势。【结果】①2009-2019年我国主要省区灌溉耕地面积略有减少,但北方部分省区面积增加显著,灌溉耕地分布有向东北和西北转移的趋势;②我国主要省区水土资源匹配基尼系数在0.40~0.49之间,总体状况为较不匹配,2016年以后有向严重不匹配状况演变的趋势;③水土资源空间分布差异显著,2009-2019年处于不匹配和极不匹配状态的省区从10个增加至11个,主要分布在华北和西北地区,且正在向北扩展。【结论】应遵循“以水定地”原则,通过合理发展后备耕地资源、节水、农业产业结构调整、科学调水等措施提高水土资源匹配状况。

【Background and Objective】The balance between irrigated farmland and water resources for different regions influence agricultural development and food security.The aim of this paper is to evaluate the spatiotemporal balance between available water resources and irrigated farmland in China.【Method】The analysis was based on available water resources and spatial distribution of irrigated farmlands at basin scale.Their balance was calculated using available water resources per unit irrigated farmland and the Gini coefficient.We applied the model to analyze spatial variation in balance between available water resources and irrigated farmlands from 2009 to 2019.【Result】On average,the areas of irrigated farmlands decreased slightly from 2009 to 2019 in China,despite a dramatic increase in several provinces in the north of the country.The Gini coefficients of water resources and land resources varied from to 0.40 to 0.49,suggesting an imbalance,especially from 2016 to 2019.Spatially,there are significant differences in the balance.The number of provinces with imbalance and severe imbalance increased from 10 in 2009 to 11 in 2019,and most of them are in the northwest and north of China.【Conclusion】The imbalance between available water resources and irrigated farmlands,especially in the northwest and north of China,means that future development of arable lands needs to be based on water resources principle.To improve the balance,future efforts should focus on developing reserve arable land resources,saving water,changing agricultural structure and developing water diversion projects.