自然资源学报 ›› 2014, Vol. 29 ›› Issue (4): 623-632.doi: 10.11849/zrzyxb.2014.04.007

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近35 a西藏拉萨河流域耕地时空变化趋势

摆万奇1, 姚丽娜1,2, 张镱锂1, 王春连3   

  1. 1. 中国科学院地理科学与资源研究所, 北京100101;
    2. 中国科学院大学, 北京100049;
    3. 北京大学建筑与景观设计学院, 北京100871
  • 收稿日期:2013-02-07 修回日期:2013-05-25 出版日期:2014-04-20 发布日期:2014-04-20
  • 作者简介:摆万奇(1963-),男,河南南阳人,博士,副研究员,主要从事土地利用/土地覆被变化研究。E-mail:baiwq@igsnrr.ac.cn
  • 基金资助:

    国家重点基础研究发展计划项目(2010CB951704);国家科技支撑计划项目(2013BAC04B01)。

Spatial-temporal Dynamics of Cultivated Land in Recent 35 Years in the Lhasa River Basin of Tibet

BAI Wan-qi1, YAO Li-na1,2, ZHANG Yi-li1, WANG Chun-lian3   

  1. 1. Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. College of Architecture and Landscape Architecture, Peking University, Beijing 100871, China
  • Received:2013-02-07 Revised:2013-05-25 Online:2014-04-20 Published:2014-04-20
  • About author:10.11849/zrzyxb.2014.04.007

摘要:

利用4 期卫星遥感资料,分析了1976—2011 年西藏拉萨河流域耕地时空变化趋势。结果表明:①近35 a 拉萨河流域耕地从5.63×104 hm2增加到6.56×104 hm2,占流域总面积比例从1.71%上升到2.00%。其中,1976—1988 年为缓慢增长期,年增长率为0.09%,1988—2006 年为快速增长期,年增长率为0.59%,2006—2011 年为急速增长期,年增长率达0.86%。耕地增加主要来自草地,耕地减少则主要源于建设用地扩张。②耕地聚集度从下游到上游不断减少,其中拉萨市耕地聚集度最高但下降最快。耕地空间变化表现为中游以耕地增加为主,下游以耕地减少为主。中游的墨竹工卡县具有最高的耕地相对变化率,因而区域差异度最大。③耕地扩张不断向更高海拔和更大坡度的范围推进,其中4 000~4 200 m海拔高度和5°~10°坡度范围的耕地净增加量最多。

关键词: 地形因子, 耕地, 拉萨河流域

Abstract:

Lhasa River Basin, with an area of 3.29×104 km2, is the key agriculture and agropastoral interlaced region of Tibet Autonomous Region, and cultivated land has been sustaining regional economy and eco-environment. Therefore, an in-depth understanding of the process of changing cultivated land will provide scientific basis and database for agricultural development and ecological security in the region. Based on satellite remote-sensing images of 1976, 1988, 2006 and 2011, and DEM data with a resolution of 30 m, the spatial-temporal dynamics of cultivated land in recent 35 years in the Lhasa River Basin of Tibet has been analyzed with GIS and models of dynamic index, location index and regional difference. The results show that: 1) Between 1976 and 2011 cultivated land increased from 5.63×104 hm2 to 6.56×104 hm2, and its proportion to the total area of the Lhasa River Basin increased from 1.71% to 2.00% . The process of cultivated land expansion within 35 years can be divided into three periods with slow (1976-1988), fast (1988-2006) and radical (2006-2011) increasing, and the average annual increasing rates are respectively 0.09%, 0.59%, and 0.86%. The increased cultivated land is mainly from grassland, and the decreased mostly resulted from construction land expansion. 2) From downstream to upstream in the Lhasa River Basin, there is a decreasing level of cultivated land aggregation, and the cultivated land in Lhasa city has the highest but fastest declining aggregation. The spatial dynamics in cultivated land has been on the trend of increasing in the middle reaches and decreasing in the lower reaches. Maizhokunggar County which is located in the middle reaches owns the highest relative changing rate, and thus with maximum regional difference. 3) Cultivated land expansion has been reaching to higher altitude with greater slope, of which 4000-4200 m altitude and 5°-10° slope have the greatest net increase in area of cultivated land.

Key words: cultivated land, Lhasa River Basin, landform factors

中图分类号: 

  • F301.2