兰州市耕地变化格局与驱动机制分析

An analysis on the changes of farmland pattern and its driving forces in Lanzhou City

以兰州市1999～2008年的统计资料为基础,运用耕地变化景观指数分析了兰州市耕地变化格局特征.通过多元线性回归分析法,对引起兰州市耕地数量变化的驱动力进行了研究.研究表明:兰州市耕地增加的方式有4种,即开发、复垦、整理和农业结构调整.10a间耕地增加最多的方式为土地开发(1 159.75hm2),其次为农业结构调整(159.39hm2),复垦增加为0;兰州市土地减少方式有生态退耕、农业结构调整、灾毁、建设用地等,其中,生态退耕减少15 516.28hm2,建设用地减少3 863.88hm2,灾毁面积1.13hm2,其他原因减少为351.65hm2.兰州市耕地增加的方式单一,优势度相对较高,均匀度低;耕地减少的方式较增加的方式多样,优势度低,均匀度高.经济发展、人口增长和土地生产力是影响兰州市耕地变化的3大驱动力.

Based on the statistical data from 1999 to 2008, the change of farmland landscape characteristics in Lanzhou was analyzed by landscape indexes. And the driving forces that caused the farmland changes of Lanzhou City were studied by using multivariate linear regression. The results indicated that ： the ways of arable land increasing in Lanzhou City were land development（1159.75 hm2） ,agriculture structure adjvst- ment（488. 78 hm2）, land consolidation （159.39 hm2 ）. The ways of arable land reducing were ecological restoration（15516. 28 hm2）, damaged land （1. 13 hm2 ） and the other reasons （351. 65 hm2 ）. The ways of farmland increasing showed single freature, the dominance was high, the evenness was low. The ways of farmland reducing showed more complex freature, the dominance was low, the evenness was high. The eco- nomic development,population growth and land productive force were the three main driving factors that affected the quantitative changes of farmland in Lanzhou City.