汉江水源地土地资源承载力时空格局研究

从粮食、耕地、人口的角度出发，利用土地承载模型、土地承载指数和趋势分析法，借助GIS技术，研究了汉中市县域尺度土地承载力的时空变化特征，并预测了该市2020年耕地资源承载潜力。结果表明:（1）从时间上来看，20世纪90年代汉中市土地承载处于人粮基本平衡状态，2000年以后土地承载指数开始上升，人粮关系出现紧张，截至2010年表现为土地过载现象。（2）空间来看，宁强、略阳、西乡自20世纪90年代始人口就略显超载，山区县由农业生产粗放的经营转为多种因素综合作用下的区域粮食安全隐患。（3）对比2020年全国粮食作物单产为5 370~5 810 kg/hm²，加快农业内部结构调整，加强农业科技投入力度，可在区域范围内保证粮食安全。

Study on Spatiotemporal Variation of Land Carrying Capacity in the Upper Basin of Hanjiang River

Hanzhong was taken as the example. From the view of population, cultivated land and yield of grain, LCC and LCCI were used to study the temporal and spatial variation of land carrying capacity based on the dimension of the county and pre-estimated the production potential of land in 2020. The results showed that: (1) from time perspective, 1990’s LCC of Hanzhong was adequate yield of grain. LCCI of Hanzhong had increased since 2000 and the status quo of LCC was overloaded till 2011; (2) from space perspective, Ningqiang, Lueyang, Xixiang County have been a little of insufficient amount since 1990, extensive production in agriculture was converted into hidden danger of food security under comprehensive effect of many factors in mountainous area; (3) compared to 5 370～5 810 kg/hm² of grain yield in 2020, speeding up the adjustment of agricultural structure, strengthening the agricultural investment in science and technology will ensure food security in this region.