近30年西藏耕地面积时空变化特征  

Spatial-temporal characteristics of cultivated land in Tibet in recent 30 years

作　　者：杨春艳[1,3] 沈渭寿[2] 王涛[1,2] 

机构地区：[1]南京信息工程大学,南京210044 [2]环境保护部南京环境科学研究所,南京210042 [3]江苏省大气环境与装备技术协同创新中心,南京210044

出　　处：《农业工程学报》2015年第1期264-271,共8页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家环保公益性行业科研专项(201209032);江苏省2013年度普通高校研究生科研创新计划项目(CXLX13_499)

摘　　要：耕地对保障粮食安全、促进社会经济发展起着至关重要的作用。西藏生态环境脆弱，深入了解西藏耕地分布及其变化过程，可以为指导西藏农业发展、保障生态安全提供参考。本研究以4期遥感资料为数据源，采用土地利用动态度、土地利用区位指数和土地区域差异模型，对1980－2010年西藏耕地面积时空变化特征进行研究。结果表明：1）近30 a西藏耕地面积总体呈增长趋势，从3252 km2增加到3703 km2，占西藏土地总面积的比例从0.27%上升到0.31%，年变化量15.37 km2，年变化率0.46%。2）西藏耕地主要分布在日喀则、拉萨、山南、昌都4个地区，海拔〉3800-4200 m之间，28°-30°N地区，其中拉萨、海拔〉3800-4000 m、28°-29°N是耕地最为集中的地区。3）近30 a西藏耕地相对增加较快的是昌都地区、海拔3200 m以下和4200 m以上地区、30°-33°N地带，西藏耕地的变化表现出向高、低海拔地区、纬度较高地区扩展的趋势。近30 a西藏耕地的时空变化特征是气候等自然地理条件与人类活动综合作用的结果。Cultivated land plays a vital role in ensuring food safety and promoting social and economic development. At the same time, ecological environment in Tibet is fragile. Therefore, an in-depth understanding of the changing process of cultivated land will provide reference information for agricultural development and ecological security in Tibet. In this paper, based on remote sensing images of four periods and other related data, the temporal-spatial characteristics of cultivated land area in Tibet from 1980 to 2010 was analyzed. By using ERDAS IMAGE9.3 software, the remote sensing images were registered and geometrical corrected based on topographic maps of 1：100000 scale. According to the remote sensing image shape, texture and color, combined with land use status data, remote sensing interpreting marks were established. The supervised classification of automatic interpretation method was used to gain interpretation result, from which data of cultivated land were extracted. After correcting the interpretation cultivated land results combined with field investigation data and visual interpretation of remote sensing images, cultivated land area’s identifiable information of four periods were gotten. In order to preferably understand the temporal and spatial changes of cultivated land, the study period was evenly divided into three time periods：the first stage was 1980-1990, the second stage was 1990-2000, and the third stage was 2000-2010;and the units including administrative region, interval of altitude as well as latitude were divided. By using dynamic degree of land use, location index of land use, the temporal-spatial characteristics of cultivated land area were analyzed. Analysis of different conversion types showed that the increase of cultivated land was mainly from grassland and forest land, while the decreased cultivated land mainly was converted to grassland, forest land and construction land. From the climatic conditions, the period of 1990-2010 was beneficial to expand the cultivated land, and cu

关 键 词：遥感 土地利用 动态 耕地 时空变化 西藏 

分 类 号：F301.2[经济管理—产业经济]