Vegetation fractional coverage change in a typical oasis region in Tarim River Watershed based on remote sensing  

作　　者：Fei ZHANG Tashpolat TIYIP JianLi DING Mamat SAWUT Verner Carl JOHNSON NigaraTASHPOLAT DongWei GUI 

机构地区：[1]College of Resources and Environment Science, Xinjiang University, Urumqi 830046, China [2]Key Laboratory of Oasis Ecology, Xinjiang University, Urumqi 830046, China [3]Department of Physical and Environmental Sciences, Colorado Mesa University Grand Junction, Colorado 81501, USA [4]Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Urumqi 830011, China [5]Cele National Station of Observation & Research for Desert-Grassland Ecosystem in Xinjiang, Cele 848300, China

出　　处：《Journal of Arid Land》2013年第1期89-101,共13页干旱区科学（英文版）

基　　金：supported by the National Basic Research Program of China (2009CB421302);the Joint Fundsof the National Natural Science Foundation of China(U1138303);the National Natural Science Foundation of China(41261090,41161063);the Open Foundation of State Key Laboratory of Resources and Environment Information Systems (2010KF0003SA);Scientific Research Foundation for Doctor (BS110125);Xinjiang Natural Science Foundation for Young Scholars (2012211B04);Research Fund for Training Young Teachers (XJEDU2012S03)

摘　　要：Vegetation fractional coverage （VFC） is an important index to describe and evaluate the ecological system. The vegetation index is widely used to monitor vegetation coverage in the field of remote sensing （RS）. In this paper, the author conducted a case study of the delta oasis of Weigan and Kuqa rivers, which is a typical saline area in the Tarim River Watershed. The current study was based on the TM/ETM＋ images of 1989, 2001, and 2006, and supported by Geographic Information System （GIS） spatial analysis, vegetation index, and dimidiate pixel model. In addition, VBSl （vegetation, bare soil and shadow indices） suitable for TM/ETM＋ irrlages, constructed with FCD （forest canopy density） model principle and put forward by ITTO （International Tropical Timber Organization）, was used, and it was applied to estimate the VFC. The estimation accuracy was later prow^n to be up to 83.52%. Further, the study analyzed and appraised the changes in vegetation patterns and revealed a pattern of spatial change in the vegetation coverage of the study area by producing the map of VFC levels in the delta oasis. Forest, grassland, and farmland were the three main land-use types with high and extremely-high coverage, and they played an important role in maintaining the vegetation. The forest area determined the changes of the coverage area, whereas the other two land types affected the directions of change. Therefore, planting trees, protecting grasslands, reclaiming farmlands, and controlling unused lands should be included in a long-term program because of their importance in keeping regional vegetation coverage. Finally, the dynamic variation of VFC in the study area was evaluated according to the quantity and spatial distribution rendered by plant cover diigital images to deeply analyze the reason behind the variation.Vegetation fractional coverage （VFC） is an important index to describe and evaluate the ecological system. The vegetation index is widely used to monitor vegetation coverage in the field of remote sensing （RS）. In this paper, the author conducted a case study of the delta oasis of Weigan and Kuqa rivers, which is a typical saline area in the Tarim River Watershed. The current study was based on the TM/ETM＋ images of 1989, 2001, and 2006, and supported by Geographic Information System （GIS） spatial analysis, vegetation index, and dimidiate pixel model. In addition, VBSl （vegetation, bare soil and shadow indices） suitable for TM/ETM＋ irrlages, constructed with FCD （forest canopy density） model principle and put forward by ITTO （International Tropical Timber Organization）, was used, and it was applied to estimate the VFC. The estimation accuracy was later prow^n to be up to 83.52%. Further, the study analyzed and appraised the changes in vegetation patterns and revealed a pattern of spatial change in the vegetation coverage of the study area by producing the map of VFC levels in the delta oasis. Forest, grassland, and farmland were the three main land-use types with high and extremely-high coverage, and they played an important role in maintaining the vegetation. The forest area determined the changes of the coverage area, whereas the other two land types affected the directions of change. Therefore, planting trees, protecting grasslands, reclaiming farmlands, and controlling unused lands should be included in a long-term program because of their importance in keeping regional vegetation coverage. Finally, the dynamic variation of VFC in the study area was evaluated according to the quantity and spatial distribution rendered by plant cover diigital images to deeply analyze the reason behind the variation.

关 键 词：vegetation fractional coverage （VFC） VBSI （vegetation  bare soil and shadow indices） dimidiate pixel model delta oasis of Weigan and Kuqa rivers 

分 类 号：S157.1[农业科学—土壤学] TV213.4[农业科学—农业基础科学]