摘要
通过大量野外调查与遥感数据人机交互式目视解译方法,运用3S技术,解译了日喀则机场周边9县1975年、1990年、2000年和2008年4期遥感数据,分析了风沙化土地的空间分布,以及近34 a风沙化土地的演变趋势。结果表明:2008年日喀则机场周边共有风沙化土地50 053.31 hm2,其中,日喀则市、南木林县、白朗县和仁布县所占比例为51.41%。距离机场40km内风沙化土地面积为21 338.54 hm2,占沙地总面积的42.63%,主要分布在仁布大桥以西、年楚河与雅鲁藏布江交汇处以东,高寒河谷两岸的南木林县和日喀则市江当乡境内的季节性边滩、江心洲和山坡上。1975—2008年间风沙化土地呈缓慢增长趋势,共增长了13.57%,年均增长率为175.94 hm2/a。以1990—1999年风沙化土地扩展最快,2000—2008年增长最慢。气温升高、空气相对湿润程度下降是造成风沙化土地进一步扩展、蔓延的主要原因。
Based on large number of on-the-spot investigation and four sets of remote-sensing data acquired in 1975,1990,2000 and 2008,and the man-machine interaction method,we studied sandy desertification in nine counties near Tibet’s Shigatse Peace Airport,in the middle reaches of the Yarlung Zangbo River Valley.We analyzed the type and distribution of aeolian sandy land and its evolution since 1975 by interpreting Landsat data from 1975,1990,2000 and 2008 using geographic information system（GIS） technology.The purpose is to timely and precisely understand the status,spatial distribution and developmental trend of aeolian sandy land and to provide guidance for future vegetation restoration.The total area of aeolian sandy land in 2008 was 50053.31 hm2,versus 44071.38 hm2 in 1975,46334.59 hm2 in 1990 and 49064.70 hm2 in 2000,representing a 13.57% increase from 1975 to 2008.The areas of aeolian sandy land caused by windblown sediments and wind erosion within 100 km from Shigatse Peace Airport in 2008 totaled 26656.61 hm2 and 8588.06 hm2,respectively,representing 75.63% and 24.37%.The area of aeolian sandy land totaled 21338.54 hm2 within 40 km from the Airport and 14072.70 hm2 between 0 and 20 km from the airport.The area of aeolian sandy land has increased slowly throughout the study period,at a rate of 150.88 hm2/a during 1975-1989,273.01 hm2/a during 1990-1999 and 109.85 hm2/a in the last nine years,representing a gradual slowing.However,the overall rate of expansion since 1990 averaged 175.94 hm2/a.The increased area of aeolian sandy land mainly resulted from the region’s harsh climate and fragile environment,combined with a warmer and drier climate that accelerated the desertification process.
出处
《自然资源学报》
CSSCI
CSCD
北大核心
2011年第7期1148-1155,共8页
Journal of Natural Resources
基金
国家环保公益性行业科研专项(200809010)
关键词
风沙化土地
3S技术
西藏日喀则机场
aeolian sandy land
3S technology
Shigatse Peace Airport of Tibet
