Response Relationship Study Based On The Watershed Spatial Properties Of The Water Environment

Based on the developing experience of water resources management in theforeign countries, it reveals that the implementation of basin-based water resourcesmanagement is the development trend and inevitable requirement of China, while weare facing many problems, such as the extraction and collection of watershedenvironmental data and the analysis of watershed environmental situation, etc. Thispaper is focusing on the first two problems.This paper explores the suitable method for China to extract the watershedspatial attribute data in the following steps. First, choose a single flow method whichuses the ArcHydro tools to generate the Songhuajiang River basin river networkstructure and coding system. Second, apply ArcGIS tools to cut the watershedproperty based on the basin river network and extract data in a batch way. Third,according to the CN value balance equation, select the hydrological monitoring dataof Songhuajiang River basin to fit the recession coefficient, snowmelt factor, CNvalues for different land types and other important hydrological parameters, then usethese hydrological parameters to estimate the average annual runoff depth and theaverage annual flow of sub-basins. And at last achieve the division conversing fromcounty-based to basin-based of the non-point source emission data using NANIplug-ins.Many statistical methods, such as description the statistics, correlation analysis,factor analysis, and time series analysis are selected in this paper to analyze theSonghua River Basin Water Environment conditions based on a large data set,including13parameters monitoring at25sites from2005to2009. The results showthat water quality of Songhuajiang River is generally lower than the national Class IIIwater standards, in which the average level of permanganate index, BOD, totalnitrogen, total phosphorus, oil and other indicators are lower than Class III standard,the level of ammonia nitrogen is lower than Class IV standard, while the averagelevel of chemical oxygen demand below Class V, the worst of all. The organic chemical oxygen demand and total nitrogen are the two representative pamameters ofwater pollution in Songhuajiang River Basin. The relationships between theparameters show that the dissolved oxygen, oxygen consumption of organic matterand total nitrogen exist a significant negative correlation, while the correlationbetween the total nitrogen and oxygen consumption of organic matter is higher thanwhich between the total phosphorus and oxygen consumption of organic matter. FAidentified three factors capturing52.18%,19.97%and11.64%of the total variance,respectively. Factor1had strong positive loadings on the total nitrogen and oxygenconsumption of organic matter and strong negative loading on the dissolved oxygen,this factor may be interpreted as the dominant pollutants characterization factor.Factor2had strong positive loadings on mercury, lead and zinc, mainly representedthe heavy metal pollution. Factor3is correlated with pH and explained asbackground factor. The dominant pollutions of Songhuajiang River are total nitrogenand oxygen consumption of organic matter, lead to seasonal time series analysis ofammonia nitrogen and COD and the result indicated that the COD with a inflectionpoint in2007occurred downward trend in recent years while the NH3-N has notimproved markedly.SPARROW model is used in this paper to simulate the total nitrogen pollution.The model input variables, which are under the consideration of our state situation,are using the Levenberg-Marquardt algorithm for nonlinear optimization. With theunderstanding of model structure and the experience of foreign applications, themodel results are acceptable for the study area. Values of R2for the final TN modelsare0.79, and contaminant sources are included point sources, applied fertilizers foragricultural land, livestock wastes and aquiculture wastes. Coefficients estimated inthe model for temperature, land slope, precipitation and stream density arestatistically significant while the first in-stream decay is the most important processfor the total nitrogen transport.The model results showed that there were63%reaches of Songhuajiang Riverbelow Class III as the ratio below Class V was47%. The worst stream reaches mainlylocated in Harbin included Mudanjiang River, Yitong River, Yinma River, HulanRiver, Lalin River, Tangwang River, etc. and the sub-basins with high yield were Nenjiang River eastern tributaries, Hulan River as well as its tributaries and LalinRiver. The application of SPARROW model on Songhuajiang River gave the sourceidentification of this watershed. The share of non-point agricultural source is thehighest,51.5%, the point source contributed approximately28.8%, aquiculture wastesoccupied14.0%and the share of livestock wastes was only5.7%, while the decaypercent in main stream is lower than which in tributaries among sub-basins.