Recognition Of Spatial Framework For Water Quality And Its Relation With Land Use/Cover Change In Ebinur Lake Watershed

In this paper,we select the water samples data of Ebinur Lake Watershed during the rainy season and dry season from 2014 to 2016 and use the self-organizing feature map neural network(SOM)to recognize spatial framework for water quality.On this basis,using the remote sensing image to analysis the characteristics of land use/cover types change in different seasons.Then,analyzed the relationship between the water quality parameters and land use/cover types in different layers.Through establishing the multiple liners regression models to analysis the influence of land use/cover type on water quality in different seasons.According to the situation of LUCC and water quality in Ebinur Lake Watershed,study on the relationship between the LUCC and water quality could provides a quantitative reference of water resources management and optimize the layout of land use/cover.The results as follows:(1)The value of pH are higher in May 2014,which were collected water samples in Kuitun River.The electric conductivity(EC)and mineralization are higher surrounding the Ebinur lake and Akeqisu river.In May 2015,the water quality in JingHe oasis of Ebinur Lake Watershed is poorer.Secondly,surrounding the Ebinur lake and the par of the Kuitun river water quality are affected by a certain degree.In May 2016,the samples surrounding the farmland and Ebinur lake is poorer.Because of there are a number of fish pond and crab pool surrounding the Ebinur lake,which affected by human activity,leading to the uneven distribution of water quality parameters in rainy season.At the same time,in October 2014,water quality situation of Ebinur Lake Watershed is characterized by: Bortala Rive > JingHe oasis > Ebinur lake surrounding > farmland of Wusu.In October 2015,the higher value of TP,TN and NH3+-N are surrounding the Ebinur lake and farmland.The higher value of color in water is in Ganjiahu Haloxylon Forest Nature Reserve and farmland of Wusu.The high value of NUT and suspended solids(SS)are distribute in Ebinur lake and farmland of Wusu.In October 2016,the distribution characteristics of water quality parameters showed a larger difference,and these parameters of high values are higher surround the Ebinur lake.(2)The LULC was classified into 6 categories based on the national land resource classification system,on the field survey that conducted many times to set up interpretation signs and on the actual land use/cover types of Ebinur Lake Watershed:(1)Farmland;(2)Forest-Grass land;(3)Water body;(4)Salinized land;(5)Bare lake bed;(6)Others.In terms of the wholeWatershed,the change of land use/cover types in different season,the others change smaller and accounts for a larger area from 2014 to 2016.Farmland area in May and October showed a larger difference.Water area in May is more than in October,area ratio is less than 5%.The area of forest-grassland,bare lake bed and salinized land in May are less than in October,and the area of bare lake bed and salinized land are less than 2%.(3)In rainy season,clusteringⅠtoⅤunder 100 m buffer,foreat-grass land and salinized land have great influence on some water quality parameters in different clusters.Under 200 m buffer,the area of water body have great influence on water quality from clusterⅠto Ⅳ.Under 300 m buffer,foreat-grass land,water body,bare lake bed and salinized land have certain effects on water quality in each cluster.Under 400 m buffer,mainly for the forest-grass land has great influence on water quality.Overall,water quality mainly in the JingHe oasis is poorer,followed by WuSu farmland.At the same time,along with a few rivers carry pollutants into the Ebinur lake,lead to water quality is affected certainly surround the Ebinur lake.In the Ebinur Lake Watershed,the samples in upstream Bortala river and Jing river are less affected by human activities,the impact on water quality is low.In dry season,under 100 m buffer,the farmland and forest-grass land have great influence on water quality in clusterⅠ,clusterⅡ,cluster Ⅳ and cluster Ⅵ.Under 200 m buffer,farmland have great influence on water quality in each clusters,and the bare lake bed has some correlation with water quality.Under 300 m buffer,farmland,forest-grass land,water body,bare lake bed and salinized land have great affect on water quality.Under 400 m buffer,farmland and grassland have certain relevance with part of the water quality parameters,and the water body,bare lake bed and salinized land have great affect on water quality in cluster Ⅵ.(4)Overall,analysis the relationship between water quality and land use/cover types through the RDA under the different scales and different periods in Ebinur Lake Watershed.In rain season,pH,DO,COD and BOD5 have positively correlated with water body,farmland,salinized land and bare lake bed,the correlation are water body> salinized land >farmland>bare lake bed.In dry season,pH,COD,BOD5,TP and NH3+-N have positively correlated with farmland,bare lake bed,salinized land and others,the correlation are farmland>bare lake bed>bare lake bed>others.Do has positively correlated with water body,and SD also has positively correlated with forest-grass land.(5)Under the optimal scale,established the multiple regression models between the water quality parameters and land use/cover type at different periods.Model has good correlation coefficient,which can predict the impact on water quality with the land use/cover types change in a certain extent.In general,the land use/cover types and water quality of Ebinur Lake Watershed showed evident correlation,the results could provide reference for study on the relationship between land use/cover and water quality in Ebinur Lake watershed.At the same time,it could provide a scientific basis for space development and water environment protection of Ebinur Lake Watershed.