Study On Spatial Distribution Characteristics Of Karast Hyporheic Zone In Typical River Basin Based On RS And GIS

The karst Hyporheic Zone is in the karst fissure development area,where the surface water interacts with groundwater,and playing an important ecological protection role.Karst hyporheic zone widely distributed in China.However,due to its relatively insufficient research,and protection measures are not in place,Karst hyporheic zone pollution is increasing,which seriously threatens the water quality and the health of the surrounding ecosystem.It is important to study the distribution characteristics of Karast Hyporheic Zone,which is of great significance for the study of mechanism and migration law of karst hyporheic zone.Based on the previous studies on the karst hyporheic zone and the basic characteristics of karst hyporheic zone,according to the corresponding meteorological phenomena in the karst hyporheic zone,applied RS and GIS techniques to identify and analysis the distribution characteristics of karst hyporheic zone.In this paper,the distribution of karst water in Jinan,the typical river basin-Sanchuan basin(Jinxiu Chuan,Jinyun Chuan,Jinyang Chuan,collectively known as Sanchuan)as the study area.Based on a basic overview of location,topography and hydrogeology information,Respectively using spectral classification to superimposed with DWT model?LWP model?GgLWP model to identify potential distribution of karst hyporheic zone.Selected the wet period(September 2015)and the dry season(March2016)two seasons of GF-1 remote sensing data to pretreatment,.Using the supervised classification method to interpret the land use type,combined with the change characteristics of biomass index,the karst hyporheic zone distribution is divided into high,medium and low three grades.Three kinds of humidity models were established based on GIS,including DWT model,LWP model,GgLWP model.Then the classification result respectively superimposed with sensing spectra analysis,divided karst hyporheic potential distribution level.According to the results of field vegetation surveyfield and sampling to verify the accuracy of karst hyporheic zone potential distribution by remote sensing spectral classification superimposed with DWT model,LWP model,GgLWP model results.The results show that the method of LWP model superimposed with remote sensing spectral classification has high reliability and can accurately reflect the distribution of karst hyporheic zone.And the reliability of the high,medium and low three types is 86.5%,61.7% and 78.3% respectively by remote sensing spectral classification superimposed with LWP model.The proportions of high,medium and low grade of the study area were 10.3%,31.9% and 57.8% respectively.Karst hyporheic zone is more distributed in the river,reservoir river bed,river bank buffer zone,spring exposed area.Among them,the eastern part of the higher degree of development,the western region less developed.The distribution range of karst hyporheic zone in Wohushan reservoir area is the most,and the distribution range of the upper reaches of Jinxiuchuan is the smallest.The distribution range of karst hyporheic zone in Jinyangchuan watershed is the largest in the three main rivers,followed by Jinxiuchuan,and the distribution range of Jinyunchuan is the smallest.Based on the results of remote sensing spectral classification and superposition LWP model,analyzed the spatial basic factors of karst hyporheic zone,and analyzed the spatial evolution of karst hyporheic zone distribution by variational function method.The results show that the spatial variability of karst hyporheic zone is the largest in the east-west direction,the northwest-southeast direction is the second,the spatial variation scale in the northeast-southwest direction is the smallest,and the main variation direction of the karst hyporheic zone is in the east-direction.Accor-ding to the results of remote sensing interpretation and spatial analysis,discussed the influence factors of spatial variability of karst hyporheic zone by correlation analysis.The results show that the distribution of karst hyporheic zone is related to NDVI,NDWI and topography.The possibility of karst hyporheic zone is higher in high NDVI and NDWI areas and in areas with high NDVI and NDWI after drought period.The higher the slope,the greater the possibility of karst hyporheic zone,and the higher the distribution level of karst hyporheic zone.