| Luke lake catchment is located in Delingha in Hercynian Mongolian Tibetan autonomous prefecture in Qinghai province.It is located inside of the Delingha alluvial basin,which is the secondary northern Qaidam basin.Luke lake catchment is the region with the most abundant biodiversity in Qaidam basin and has an important role to sustain eastern Qaidam basin and its surrounding ecological environment security.The research of Luke lake's vegetation and lakes has important significance to the protection of the ecology.In this paper,the spatial and temporal variations of vegetation and the lake area are studied with ArcGIS software by using the data of remote sensing,meteorology,and land utilization,etc.The normalized difference vegetation index(NDVI),vegetation coverage,and vegetation net primary productivity(NPP)are included when study the vegetation.Furthermore,the correlation between the main meteorological factors-precipitation as well as temperature and vegetation as well as lake area is studied.There are several results for this research.On the first place,the NDVI of the most vegetation are between 0.05?0.3 in the research area in the past 11 years(2001-2011),which have the annual change rate between-0.04-0.04.It's indicated that the regional vegetation variation basically shows a normally distribution,which means that the deterioration rate and the good development rate are almost same,the overall distribution,however,stay at a very low state.On the second place,after the comprehensive quantitative analysis to NDVI and NPP of the research area,it shows that the terrestrial vegetation ecosystem remains a constant steady state in Luke lake catchment,but the maximum NPP value is lower than that of global land.It is illustrated that this stability is very fragile,and it is vulnerable to the land use change.Thirdly,the area of Luke lake almost has no change in resent ten years,the area of Tuosu lake,however,has an increasing trend.Fourthly,the correlation between vegetation index and rainfall as well as temperature is not good,but the correlation of NDVI and the year before rainfall is better than with the correlation of the rainfall of this year.Fifthly,The correlation between vegetation net primary productivity and the temperature is not obvious,but basically has a positive correlation.NPP is positively correlated with rainfall.Sixthly,It's shown that the human activity is the main influence factor to the change of lake area and followed by natural factor according to the analysis of the influence factors of the lake area.The analysis and research of this paper will provide important reference basis to ecological environment system protection and reasonable development and utilization of water resources in the region of Luke lake catchment. |
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