The Impact Of Land Use Change On Water Resources In Karst Area

In this paper, Based on TM data on March4,1988, March24,2009and ETMdata on March13,2002in this area and digital elevation model in yunnan province asthe foundation. using the remote sensing software ENVI4.8for the third phase ofimage processing, with the Geographic Information System methods of digitalelevation model, access to the remote sensing and vector data of Bajiang RiverCatchiment upstream, Set up the Bajiang River Catchiment upstream data of landuse/cover, with the previous research results of Karst sample, obtained under variousland use types of basic data, including the meteorological data, vegetations, soilcharacteristics, surface water, groundwater parameters, through the calculation of thecombination of total water resources in this area, analysis of different water resourcesof land use/cover difference.By collecting the basis of field observation data and remote sensing data, usingrelevant extrapolation, hydrogeological parameter match, regression analysis andcorrelation analysis and other methods to get the following results:（1）From1988,2002and2009, the land use change analysis, Bajiang River’supstream22years these dramatic changes have taken place in land use, side reflectsthis22years Bajiang geological environment change and the residents’ social andeconomic development impact on the upstream. River’s upstream the main land typeswere shrub land, followed by the cultivated land, again is the forest land; From1988to2002shrub land decreased2147hm2, shrub land area is stable and little change;Rapid and continuous increase of garden land is the only class, from1988to2009increased by2238hm2; bare land area were increased of333hm2and731hm2;cultivated land increased by2272hm2in22years; from1988to2002constructionland increased by644hm2, to2009increased by1148hm2.Overall, during the periodfrom2002to2009, in addition to the garden land increased dramatically, for varioustypes of land use is development and stability. （2）Area of land use/cover change on the performance of surface runoff isshows: from1988to2002, forest area of change on the influence of the surface watervalue of5.49m, from2002to2009reduced area of change in the surface water of10.38m,2009drought of stone forest and river headwaters forest land has had a hugeimpact;（3）The river’s upstream reaches of land use and the precipitation infiltrationamount is shown as: From1988to2009,precipitation infiltration amount17.11×106m3、18.85×106m3、15.57×106m3in forest land, it is the largest amount ofland use types in the precipitation infiltration; Followed by the shrub land,respectively is11.32×106m3、10.25×106m3,10.24×106m3,three years precipitationinfiltration amount change is not big; the least is bare land, respectively is19.56×106m3、17.75×106m3,15.59×106m3. The smaller the amount of rainfallinfiltration, surface water runoff increase, the storage capacity is reduced,22years ofbare land and cultivated land, go against the cultivation of water catchment areas.（4）Vegetation coverage affects the precipitation infiltration amount is: Thevegetation coverage and precipitation infiltration coefficient correlation index reached0.7189, the correlation coefficient is0.8479, only consider the factors, the vegetationcoverage rate, the lower precipitation infiltration coefficient is smaller, theprecipitation infiltration amount also decrease accordingly, from forest land, shrubland and garden land to cultivated land and bare land、 construction land,thevegetation coverage gradually reduced, there is less rainfall infiltration quantity,performance is construction land <bare land <cultivated land <shrub land<gardenland <forest land.（5）From1988to2009, from cultivated land, garden land, forest land, shrubland to bare land and construction land, the surface water resources in less than a lotof groundwater resources, groundwater resource and natural water resources is reducein turn, There is without groundwater resources in construction land by surfacerunoff.