1964-1970年盐池荒漠草原村土地利用变化对“以粮为纲”政策的响应

摘要

In order to assess the effect of the "taking grain as the highest priority" policy on land use change in deserting-grazing village and urban landscape pattem change,we used the village of Wanjigou in Yanchi county as an example.By GIS and Fragstats software,this study interpreted and analyzed three aspects of the United States KeyHole satellite image in 1964,1968 and 1970.The results show that grassland,as the matrix of the landscape,was in an absolute dominance (54.92％ ～ 47.57％) in the main types of land use in Wanjigou village from 1964 to 1970.At the same time,cultivated land and abandoned land accounted for about 25 ％ of total area,and sand land was significantly increased (14.68％ ～ 20.51％).Saline area fluctuated with the precipitation.In terms of the number of patches from different types of landscape and fragmentation index,sandy and saline land basically unchanged in the early and late 60 s.by contrast,grassland was reduced by 72 and 0.015,abandoned land by 29 and 0.019,and cultivated land by 35 and 0.066.In conclusion,the "Taking grain as the highest priority" policy in deserting-grazing village caused an excessive land reclamation and ecological problems such as desertification,salinization.%为了解“以粮为纲”政策对荒漠草原地区土地利用及景观格局变化产生的影响,以宁夏盐池县皖记沟村为研究对象,利用GIS和Fragstats软件对1964、1968年和1970年美国KeyHole卫星图像解译和分析.结果表明:1964-1970年主要的土地利用类型中,草地作为景观基质占据绝对优势(占土地利用总面积的54.92％ ～ 47.57％),耕地和撂荒地约占总面积的25％,沙地大幅增加(14.68％～20.51％),盐碱地面积随降水量波动变化.从不同景观类型斑块数量及破碎化指数来看,沙地和盐碱地在60年代初期和末期基本不变,其他类型减少的程度分别为:草地为72和0.015,撂荒地为29和0.019,耕地为35和0.066.研究认为“以粮为纲”政策在荒漠草原地区也实施了土地开垦并造成了沙地边缘的不断扩张,诱发了沙化、盐碱化等生态问题,说明不分地域而实施的一刀切政策,很可能导致严重的生态恶果.