摘要
退耕还林是目前黄土高原恢复生态环境和控制水土流失的主要政策。为搞清政策驱动下黄土高原生态退耕的基本情景,以安塞县为例,利用2000年土地利用图和地形坡度图,以地形坡度15o、20o和25o为退耕界限,借助GIS空间分析技术,模拟和分析了安塞县生态退耕的规模、空间分异特点及退耕补贴需求和对农业的影响。研究结果表明:安塞县合理的退耕坡度界限应在20o-25o之间,北部的镰刀湾、王家湾、化子坪、坪桥、郝树坪和南部的楼坪6乡镇可考虑退耕20o以上的坡地,其他8乡镇宜退耕25o以上坡地。
Returning land for farming to forestry is the central policy adopted at present to control soil erosion and restore ecological environment of the Loess Plateau. In order to make clear the policy-driven ecological de-farming scenarios, taking Ansai County as an example, using the land use map and the topographic slope map in 2000 and taking the topographic slope gradient 15°, 20°and 25° as the de-farming thresholds, assisted by spatial analysis techniques of GIS, this paper simulates and analyzes the scale and spatial difference characteristics of ecological de-farming of Ansai County, the subsidy demand for de-farming and the influences of de-farming on agricultural development. The research results are as follows： （1） The area of de-farming slope land with a gradient of more than 25° in Ansai County amounts to 3451.05 hm^2, the de-farming index is 3.14%, and the total subsidy demand for de-farming land is 6884.84×10^4 yuan （RMB）. The food reduction resulted from de-farming is 2132.62 t in the harvest year, 955.17 t in the usual year, and 620.35 t in the drought year. （2） The area of de-farming slope land with a gradient of more than 20° in Ansai County adds up to 36281.61 hm^2, the de-farming index is 32.96%, and the total subsidy demand for de-farming land is 72381.81 × 10^4 yuan （RMB）. The food reduction resulted from de-farming is 22420.71 t in the harvest year, 10041.9 t in the usual year, and 6521.86 t in the drought year. （3） The area of de-farming slope land with a gradient of more than 15^ in Ansai County adds up to 101807.99 hm^2, the de-farming index is 92.49%, and the total subsidy demand for de-farming land is 203106.94 × 104 yuan （RMB）. The food reduction resulted from de-farming is 62913.62 t in the harvest year, 28178.06 t in the usual year, and 18300.65 t in the drought year. （4） The reasonable de-farming slope gradient in Ansai County should be in the range of 20° to 25°. The five countryside towns （i.e. Liandaowan, Wangjiawan, Huaziping, Pingqiao, Haoshuping） in the northern part of Ansai County, together with the town of Louping which lies in the southern part can de-farm the slope land with a gradient of more than 20°; and the other eight countryside towns should de-farm slope land with a gradient of more than 25°.
出处
《地理学报》
EI
CSCD
北大核心
2006年第4期369-377,共9页
Acta Geographica Sinica
基金
国家自然科学基金项目(40371051)~~
关键词
生态退耕情景
政策
农业
安塞县
ecological de-farming scenarios
policy
agriculture
Ansai County
