摘要
近50年来的统计资料显示,吉林省耕地面积的数量变化在建国后先增加后不断下降,渐趋于平缓,从1993年开始,耕地面积开始稍有增加。重点根据1986年和2000年TM影像解译后得到的土地利用图,分析了吉林省近15年来耕地的变化、转移及其空间分布。分析表明,耕地面积变化表现为其他土地利用类型转化为耕地的面积大于耕地转化为其它类型的面积。耕地的转移变化类型主要发生在耕地、林地和草地之间;变化发生的空间主要发生在吉林省西部的白城和松原两个地区。耕地在空间上的移动和转化也带来了质量的变化:耕地质量的变化主要是由于优质耕地被占用,新开垦的耕地主要为肥力较差的土壤,导致了全省土地质量下降;通过构建的空间分布质心模型,分别计算了近15年来的耕地分布质心和粮食生产质心偏移,计算结果表明:耕地的分布重心朝西北方向移动,而粮食生产质心并没有同样的变化趋势,也间接说明了耕地质量的降低。进一步分析对粮食生产的影响,讨论了今后吉林省粮食生产的对策。
The quantity and quality changes of cropland in Jilin province are analyzed by combining the statistics from 1949 to 1999 and land-use maps interpreted from TM images in 1986 and in 2000. In general, the decreasing trend of the cropland in Jilin province is derived from the statistic data in 1949～1999. Since 1983, the cropland area has increased slightly, because the land area converted from other land-use types to cropland is larger than the cropland to other land-use types. From the overlaying function of GIS, we can get the sources of the newly increased cropland where they come and the destination of the newly decreased cropland where they go, and the spatial distribution of the conversion. It shows that the net increased cropland is about 43.40×10~4 hm^2, in which the newly decreased is 11.95×10~4hm^2 and the newly increased land area is 55.45×10~4hm^2. While the quality change of the cropland can be seen from that the change is mainly caused by the conversion from forestland, grassland to cropland and the change has mainly took place in the west, where has fragile eco-environment. According to the spatial distribution model, the centroid' moves of the cropland and the grain producing are calculated, whose directions are not consistent. The centroid of the cropland moves toward northwest by 8.13km, while the centroid of grain production in the corresponding period moves toward northeast by 5.8km. The spatial change of the cropland does not bring about the consistent spatial change of the grain production, which shows the comparatively low benefit of the reclamation to the west. Furthermore, we can see that the decrease of the cropland in the west is the largest in the whole province, and the decreased cropland has mainly converted to forestland and grassland, one of the reasons for which is that the benefit of farming is so low that the restoration of the ecological environment is the natural evolvement. The impact of the dynamic change of the cropland on food security is further analyzed, and the sugge
出处
《资源科学》
CSSCI
CSCD
北大核心
2004年第4期119-125,共7页
Resources Science
基金
中国科学院知识创新重大项目"东北地区农业水土资源优化调控机制与技术研究"(编号:kzcx1-sw-19)
