陇东黄土高原耕地变化趋势及驱动因子分析

利用1986—2002年陇东地区耕地统计资料,对该区耕地资源利用与变化的基本特征、耕地数量变化的基本过程、空间差异、耕地流向以及耕地数量变化的主要驱动机制进行了分析。结果表明:(1)16 a来陇东地区耕地数量呈明显的波动减少趋势,经历了缓慢减少—急剧减少—缓慢减少的变化过程。(2)耕地的主要流向是工矿用地、居民点和各类交通用地以及果园;耕地的增加主要是未利用土地的开垦。(3)经济发展、人口增长和政策是耕地面积减少的主要宏观驱动因子,耕地变化过程中的明显突变与国家宏观政策背景相关联,耕地快速减少在发生时间上与经济的快速增长基本同步,在空间分布上与地区经济发展速度水平的差异相一致。

Trend and Driving Factors of Cultivated Land Use Change in Longdong Loess Plateau

The characteristics of arable-land resources and utilization,the basic processes and regional differences of changes in arable-land areas were revealed according to the statistics data of arable-land areas from 1986 to 2002 and the detailed investigation of land use in the recent 5 years.Also,the driving mechanism for the changes in the cultivated land areas was discussed.The main conclusions were as follows.(1) There was a trend of obvious fluctuant decrease in arable-land areas in the past 20 odd years.The changes of arable-lands underwent the process from a gentle decrease to a sharp decrease,then to a slow decrease.(2) The decreased arable-lands were mainly inverted to project and mine lands,residential areas,various traffic lands and orchards.The increased arable-lands mainly came from the exploitation and reclamation of non-utilized lands and the arrangement and resumption of project and mine lands.(3) The economic development,population growth and policies were the dominant macro-driving factors for the decrease in cultivated land areas.The obvious break in the change process of arable-lands was related to the national macro-policies.The rapid decrease of cultivated land areas coincided in time with the overheated economic growth resulting from the direct investment in fixed assets.Spatial distribution of the decrease in arable-lands matched the differences in speed and scale of economic growth in different regions of the Longdong Loess Pleteau.