Comprehensive Assessment and Analysis of Water Environmental Quality in the Mainstream of the Liaohe River

[Objective] The study aims at evaluating the water environmental quality of the Liaohe River mainstream. [ Method] The water quality of two monitored sections in the mainstream of the Liaohe River from 2004 to 2010 was assessed by the fuzzy comprehensive appraisal combined with weighted average, and some practicable measures were put forward according to the assessment results. [ Result] From 2004 to 2010, the water quality of the Liaohe River mainstream varied from Grade II to III at Zhuershan section, and changed from Grade II to IV at Xing＇an section, becom- ing better on the whole. In addition, the major factor influencing the water quality is the small content of dissolved oxygen （DO） in the water body. Meanwhile, the pollution of the water body mainly results from the discharge of organic matter consuming oxygen largely, and ammonia nitrogen should be paid more attention to. [ Conclusion] The research could provide scientific references for the protection of water environment and its pollu- tion control in the mainstream of the Liaohe River.

Evaluation and Hotspots Identification of Shallow Groundwater Contamination Risk in the Lower Reaches of the Liaohe River Plain

As a prerequisite for groundwater protection and contamination control, evaluation of groundwater con- tamination risk was the extension of groundwater vulnerability assessment. Based on disaster theory and using shallow groundwater of the lower reaches of Liaohe River Plain as the study area, we built an evaluation index system and a contamination index model for groundwater contamination risks from the perspectives of intrinsic vulnerability, external stresses, and functional value. We used data acquisition technology （remote sensing） and spatial analysis technology （GIS） to calculate the value of groundwater contamination risks. The spatial distribution of hotspots was obtained by calculating G index. Results show that groundwater contamination is above a mid-level risk in most of the study area. Areas with extreme high risk account for 37.86%, areas with high risk 32.47%, areas with moderate risk 12.07%, areas with light risk 3.17%, and areas with slight risk 14.43%. Hotspots areas are mainly located in central Shenyang City, northwest of Xinmin City, Beizhen City and Liaozhong County. Coldspots are mainly in Panjin City, Yingkou City, Dashiqiao City, Dawa County and Panshan County. The results reflect the spatial distribution and mechanism of groundwater contamination risk in the study area and provide relative references for land use planning and groundwater resource protection in the lower reaches of the Liaohe River Plain.

Research on Methods of Ecological Security Assessment of the Middle and Lower Reaches of Liaohe River Based on GIS

Ecological security assessment and early warning research possess the attributes of spatiality, non-linearity and randomicity, so we must process much spatial information. Spatial analysis and data management are the advantages of GIS, which can define distribution trend and spatial relations of environmental factors, and show ecological security pattern graphically. Spatial differences of ecological security assessment based on GIS are discussed in this paper, of which the middle and lower reaches of the Liaohe River is taken as a study case. First, to work out pressure-state-response (P-S-R) assessment indicators system, and investigate in person and gather information; second, to digitize the watershed; third, to quantize and calculate by the fuzzy method; last, to construct GIS grid database, and expound spatial differences of ecological security by GIS interpolation and assembly analysis.