The Response Of Land Use Change To Moisture And Temperature Of Land Surface In Xiangjiang River Basin

Land use and cover change (LUCC) has become one of the main methods which humanactivities impact on global change. Since1990s, experts have done many researches onLUCC from the aspect of process, pattern, mechanism and environmental response whichacquires significant progress on the global or large regional scale, while the case study on thelocal scale still need to be deepened further. Xiangjiang River Basin is the major industrialand agriculture production bases in our country and is also the rapid urbanization and rock-ribbed flood and drought disaster. Recent years, urbanization and replacing farmland withforest accelerate the changes of land use in the areas. Studying the mechanism with thesechanges effect moisture and temperature of land surface, it has significance for keeping landresources of Xiangjiang River Basin sustainable and deepening the theory and method ofLUCC.Based on TM remote sensing data, meteorological data, a variety of socioeconomicstatistical data and other data sources, this paper firstly analysis the temporal and spatialvariation of land use in Xiangjiang River Basin through the aspects of quantity, structure andmorphology. And then, retrieving the land surface moisture (LSM) and land surfacetemperature (LST) from the remote sensing dada, selecting normalized difference vegetationindex (NDVI), modified normalized difference vegetation index (MNDWI), normalizeddifference built-up index (NDBI) and normalized difference bare index (NDBaI) asquantitative indicators of land use types, to analysis the relationship among land use types,LSM and LST, and the impact of land use change on land surface thermal and hydriaenvironments. The results show that:During the research period, the trend of land-use change in Xiangjiang River Basin isthat the area of cultivated land, forest and grass land and unused land decreased, while thearea of construction land and waters land increased. Meanwhile, the area of cultivated land isdecreasing and construction land is increasing, which become the main trend of the land usechange. The changing areas of land use in Xiangjiang River covers602174.44hm2,6.94%ofthe total. The three main kinds of changes whose area was60.25%of the total changes werechanging from grassland to forest landed, from cultivated land to grassland, and fromcultivate land to construction land. The rural-urban fringes of Chang-Zhu-Tan, Hengyang andYongzhou are the main changed areas. The competitive dynamic degree of land-use is on therise and the order of dynamical degree of land-use types as follows: unused land>constructionland>waters land>cultivated land>forest and grass land. On the land-use structure, theconnection of landscape in Xiangjiang River Basin is increasing, the complication of landscape shape is decreasing and the landscape pattern is developed into diversification andhomogenization. On the land-use morphology, fractal dimensions reduced generally and SIincreased generally, it show that the landscape structure in Xiangjiang River Basin has thevariation trend which from fragmentation to integration.From1985to2007, on the local-scale of Chang-Zhu-Tan, Hengyang and Yongzhou,NDBI and NDBaI produce positive effects on LST, while NDVI and MNDWI do the negativeeffects. By the end of the study period, the relationships among LST band and remote sensingindex bands have been improved. Among which, the correlation of NDBI and LST issignificant and steady. On the type-scale, NDBI and MNDWI are not affected so much by thedifferent intervals of values, but for NDVI and NDBI. LUCC will change the surfacetemperature, and there have significant differences among the different land use types of theLST. It reflects in construction land which keeps the highest LST, lowest in water area and thesame current land use type also will be different for the changing process information ofTupu.During1985-2007, there was obvious multiple linear relationships among the soilmoisture, normalized difference vegetation index (NDVI), modified normalized differencevegetation index (MNDWI), normalized difference built-up index (NDBI) and normalizeddifference bare index (NDBaI), and the R remains on an upward trend. On the aspect of soilmoisture, cultivated land non-agriculture is the main cause for affecting the soil moisture inurban areas and the suburbs, yet returning farmland to forests do the positive effects to soilmoisture recovering. NDMI are infected most by vegetation distribution and growth vigor. Inthe terms of land use types, different types of Tupu have different influences to surfacemoisture environment. It mainly shows that the quantitative indicators on nature landscape ofLSM higher than man-made landscape, and the forest and grass land is higher than cultivatedland.There may be following innovation in this paper:(1)Established a new model of geo-information atlas, which including the processinformation of the land use change.(2)Analyze the relationships among the land use types, land surface moisture and landsurface temperature based on geo-information atlas.(3)As an exploratory study, this paper analyzes the scale effects of the relationshipbetween remote sensing indexes and LST.