陕西黄土高原台塬区土地利用的人地关系透视

Prospective of Man-Earth Relationship of Land-use in Shaanxi Loess Tableland Region

基于RS和GIS,采用土地资源承载指数、土地生态风险综合指数,分析陕西黄土高原台塬区的城市化、粮食安全与生态安全对土地需求的博弈。结果表明,1985—2010年,研究区的建设用地增加25 888.8 hm2,25 a中扩张了32.37%,但普遍存在土地城市化快于人口城市化,城市扩张需求与低效的土地利用并存;耕地减少12 850.1hm2,土地资源承载指数由0.88增长为1.12,区域人—粮关系由"平衡有余"转为"临界超载";生态用地减少13 003.1 hm2,比1985年降低6.98%,土地生态风险综合指数由0.47增大为0.67,且高生态风险区域明显扩大。城市化在土地利用变化中起引擎作用,城市化、粮食安全与生态安全对土地需求的矛盾更为突出,区域人地关系日趋紧张。

Based on RS and GIS,this paper used land resource carrying index and land ecological risk index,analyzed the land demand change of urbanization,food security and ecological safety in Shaanxi Loess tableland region. The result as the followings： From 1985 to 2010,the construction land enlarged 25 888. 8 hm^2,expanded32. 37% compared to 1985. Land urbanization was faster than the population urbanization. Urban expansion demand and inefficient land use exist at the same time. Arable land reduced 12 850. 1 hm^2. Land resource carrying index increased from 0. 88 to 1. 12. The relationship of people-food from balanced to critical overload. Ecological land reduced 13 003. 1 hm^2,of which was 6. 98% lower than that in 1985. Land ecological risk index increased from 0. 47 to 0. 67,and the high ecological risk areas significantly increased. It is concluded that urbanization plays a role of engine in the land use change,and the conflicts of the land demand among utilization,food safety and ecological safety has become more serious. Such land-use change mode lead to the man-earth relationship in Shaanxi Loess tableland region became increasingly nervous.