甘肃省近30a来耕地空间动态变化与驱动力分析

Spatial dynamic variation and driving forces of cultivated land use in Gansu Province during the past 30 years

通过采用主成分分析法与GM(1,1)模型,分析了近30 a来甘肃省耕地变化的总体趋势、空间差异、耕地复种指数的动态变化与耕地变化驱动力,并对未来耕地变化趋势进行了预测,结果表明:1978年以来,甘肃省耕地面积时增时减,总体呈递减趋势;各市(州)与全省耕地变化相比存在明显空间差异;耕地复种指数呈波动性上升,虽然总体水平在上升,但是耕地复种指数并不高,耕地利用程度有待提高;经济发展水平、人口因素、农业产业结构调整和农业现代化水平是耕地变化的主要驱动力;GM(1,1)预测分析表明在今后一段时间内,在影响因子不变的前提下,耕地面积将持续减少。

According to the statistical and survey data from 1978 to 2005 from Gansu YearBook and Gansu Rural YearBook, the overall tendency, spatial differences and multiple cropping index of cultivated land changes of Gansu Provnce were analyzed, and its driving forces were also discussed and evaluated by SPSS software. Furthermore, the trend of cultivated land changes in the future was also predicted with GM （1,1） model. The results of analysis can be found as follows： Firstly, the total areas of cultivated land are reducing; Secondly, taking advantage of the formula Of the relative change index and with support of GIS aided spatial analysis, the relative change index of the cultivated land of some regions in Gansu can be indicated on the map, from which the spatial distribution of the changing area of cultivated land can be determined and compared very clearly ; Thirdly, the multiple cropping index of cultivated land in Gansu is increasing, the general level is improving, but it is still low, there still is a gap between the theoretical potential values, the use degree of cultivated land should be improved; Fourthly, with the method of principal component analysis, twelve driving forces which play an important role in the changing of the cultivated land are classified into four types, which are the development of economy, the pressure of population, the adjustments of agricultural structure and the improvement of agricultural technology ; Fifthly, the results of the GM （1,1） model indicated the cultivated land would keep decreasing with all driving factors kept invariable in a coming period;Finally, in order to ensure food security, several measures for cultivated land protection are put forward to prevent the reducing of cultivated land. In the all, cultivated land is important to the development of human and the limited cultivated lands must be protected. The results of this study could provide scientific basis for sustainable development of cultivated land in Gansu Province.