The Analysis Of Temporal And Spatial Variation Of Major Land-cover In Shehong County Based On RS And GIS

Land resource, as an important production resource, is the foundationof human survival and development, and is an irreplaceable human society wealth aswell. In recent years, series of problems such as the increase in population,environmental pollution, climate change are increasingly aggravating.The global landresources is undergoing dramatic changes, and seriously hampered the survival andsustainable development of human society. Therefore, accurate understanding of landcover and change information is quite significant for promoting the sustainabledevelopment of land resources timely.In this paper, we choose Landsat TM images and HJ-CCD images as data source,and then apply remote sensing and geographic information system technology todiscuss the extraction methods of information about water bodies and vegetationcover, which revealed the spatial and temporal variation characteristics of the waterbodies and vegetation cover connecting with the meteorological data. Through theresearch, we explore the method of how to use Landsat TM images and HJ-CCDimages to study the space distribution and variation characteristics of the water bodiesand vegetation cover information. Firstly, we choose the major land cover types forsampling, and analysis the spectral characteristics of the main land cover types.In thisway, we build the information extraction model of water bodies and vegetation, andextract the results for accuracy evaluation; then we study the water bodies andvegetation information of Shehong county during the year and interannual variability;futhermore we study the interannual variability in-depth analysis of the townshipvegetation coverage in Shehong county. By studying, we reach to the following mainconclusions:(1) We investigate the water bodies and vegetation cover information extraction model which is suitable for the Shehong County, then we can portray the spatialdistribution characteristics of water bodies and vegetation cover information duringthe year (2009,2010), and the years in the same month (May, August and October) inShehong County.(2) We analyze the temporal and spatial variation of water bodies in2009and2010of Shehong County. The change about water bodies is obvious in2009and2010of Shehong County. Compare2009data for the year shows that June2009coveredthe largest surface area of67.72square kilometers, the minimum surface area coveredin February2009, only33.46square kilometers. Compared with2010data showedthat the surface cover area of water bodies in September,2010, is the largest of67.83square kilometers, the minimum surface area covered by March2010, only37.45square kilometers.The rate of area change about water bodies is2.29%in February–June,2009, and in March–September,2010is2.03%.(3) We analyze interannual variability characteristics of the water bodies in May,August and October of Shehong County. Studies show that water interannual changeis larger in May and the rate is1.04%, but, the interannual variability in August andOctober is small and the change rate is0.58%and0.17%, respectively.(4) We analyze the temporal and spatial changes of vegetation cover informationin2009and2010of Shehong County, and study the major towns of the vegetationcover in Shehong County. Studies have shown that in2009and2010the situation ofvegetation cover is better, and change more obvious during the year. The vegetationcoverage area in February–June,2009is accounting for26.45%of the county area;and in March–September,2010is approximately30.79%, which is more obvious.(5) We analyze the interannual variability of vegetation characteristics inShehong County, and study the township vegetation cover in Shehong County. Studiesshow that in May2000-May2010vegetation cover area is changing more obvious,accounting for about-23%of the county area; in August, the interannual variability issmall, only accounting for4.74%of the county area; in October, the interannualvariability is also small, accounting for4.59%of the county area. The town of Jinhuacovers the highest interannual vegetation coverage area, and the town of Fuhe andQingdi covers the lowest interannual vegetation coverage area.