Impact Of Land Use And Source-sink Relationship On Pond-river In Urban Region

Pond.as a form of the surface water body is generally between a few squaremeters to several hectares, the depth between a few centimeters to several meters,including naturally pond, artificial pond. Pond has a prominent position in the globalbiodiversity conservation network，they provide ecological stepping-stone for the flowof biological species. Pond is important in water environment protection, rationalmanagement of ponds can be used as convergence meeting of the catchment area ofthe pollutants to improve water quality, unreasonable management tend to makeponds to become source of the pollution of water bodies. Pond, in particular, theartiifcial pond has important production functions and historical and cultural value.Tianhe District, which is widely distributed by pond landscape in southern Chinacity, in this rapidly urbanizing regions, the pond is gradually occupation ordisappeared, Pond which did not disappear became the emissions of waste water,sewage, garbage, pool and dumps", dirty, disorder, and poor "pond landscape is out oftune with the requirements of the Livable City. This thesis is based on the awarenessof the importance of pond, Tianhe District, Guangzhou representative for the studyarea, to carry out the disappearance of the pond landscape processes and the drivingforce, analysis of changes in the pond landscape with surrounding land use, andfurther applications with weighted landscape index of scientific research andmanagement planning process and serve the water environment governance practices.(1)Accordingto the main function of Pond is divided into five types, discussthe number and characteristics of different types of disappeared pond.In this studyarea, from1996to2011，area of pond363011.96m~2reduced to131785.52m~2, theshape also experienced straightening, and gradually the rules until it disappears. Fromthe perspective of land use types，commercial and industrial land has led to thedisappearance of the pond, buffer zone of disappear pond land use from woodlanddominated changes to each land use type of equilibrium.(2)Tested selective sampling concentrations of pollutants on pond water qualityquantitative and qualitative analysis. Spatial from north to south analysis pointed out that water quality in ponds in the watershed index showed”Mn shaped，that meansgood-poor-good-poor-good trend. According to the Statistical Yearbook of theTianhe District data that showed a positive correlation between population, industrialoutput value with water quality index.(3)Based on interpreted the remote sensing data to analyze its land use datacharacteristics and causes. Correlation analysis of ifve water quality indicators of landuse types within the buffer found that the pond exist relative to the strongest negativecorrelation with water quality, followed by relatively weak negative correlation for thegardens, grassland and water land; there are the strongest positive correlation betweenvillages with water quality, followed by cultivated land，commercial and industrialland in residential areas and traiffc areas relatively weak positive correlation. Bycorrelation analysis, compared with the previous findings consistent with it contraryto the results of water quality data in the buffer zone landscape indices.(4)Combined with the chebei river basin and data accessibility, modify theweighted landscape index formula. Chebei river divided into15sub-basin, accordingto the location of water samples will calculate each sub-basin landscape space loadindex. Studies have shown that in each sub-basin gradient trend, weighted landscapeindex and the ifve water quality index showing a relatively strong positive correlation.According to DEM within refinement, chebei river is divided into69sub-basin, thecalculation of the weighted landscape index found that only six sub-basins load indexis less than0in the watershed landscape space, the remaining91.3%of the watershedlandscape space exist non-point source pollution and the risk of increased.Based onthe characteristics of the space distribution of the source-sink landscapes,differentiated the key sub-basins which need space control, included quantity controlmeasures, the space replacement measures for space control, and landscape patternoptimization differentiate，to reduce the discharge of pollutants in the watershed andthe risk of non-point source pollution.