Research On The Groundwater Vulnerability Assessment Of The Lower Liaohe River Plain

Groundwater vulnerability, which is also called groundwater environment vulnerability, reflects the relative potential possibility and tendency of groundwater system to be polluted. The results of groundwater vulnerability research can provide an important reference to the long-term plan perspective of the city development, the arrangement of the industry and agriculture and the determination of water resources development pattern, which also can provide the base for the rational exploitation and protection of the groundwater resources. They can also help the pubic know more about groundwater environment pollution risk and have the thought of the prevention taking priority in groundwater protection.At present, there are four major classes of groundwater vulnerability assessment methods: overlay and index methods, employing process-based simulation models, statistical methods and fuzzy mathematics methods. The above four classes of methods all have every range with particular emphasis in applying, so they have their own advantages and disadvantages.Using the research experiences gained from home and abroad for reference, groundwater vulnerability is systematically studied further in this paper. Taking the lower Liaohe river plain area as the study area and based on the specific conditions of the study area, eleven parameters such as depth to groundwater, etc , were selected to form the vulnerability assessment factor system, groundwater vulnerability assessment model based on the fuzzy mathematics methods is developed, which has been successfully applied in the comprehensive vulnerability assessment in the lower Liaohe river plain area. The model has been based on the fuzzy mathematics methods theoretically and the rating system of eleven parameters has been obtained according to the specific conditions of the study area and the assessment standard of the DRASTIC model. The assessment model employs four major classes of groundwater vulnerability assessment methods that are used together to overcome the shortcomings of the single class of methods and to strengthen the objective and scientific foundation of the assessment results.On this basis, groundwater vulnerability assessment was conducted by the method of fuzzy pattern recognition in this area. Compared the assessment results with the measured situation, the comparing result showed that the assessment system and method are scientific to a certain extent, so it is an effective method for evaluating groundwater vulnerability.