Calculation Of Resources Value For Constructed Wetland And A Case Study

As a natural sewage processing technology, the constructed wetland has the benefits of low-cost, strong effluent biosafety, obvious environmental benefits. It can also turn the wastewater to resources. This technology has more and more application. In recent years, the constructed wetland in the foreign countries becomes the main technology in the sewage processing of the small and the medium-sized cities. It also suits for the situation in our country. There are few environmental evaluations at home and abroad. Although the environmental economics has developed a lot, it is not mature enough to quantify the environmental economic value. The research on the wetland value concentrates on the summarization and the qualitative aspects. It is popular to do quantifying research at abroad. But there is few research on the total evaluation on the constructed wetland. It can promote the development of constructed wetland in our country to do the resources value evaluation of the constructed wetland.China now is under to way to research on the green GDP. The high economic growth in our country is based on the high resources consumption and ecological destruction in a long time. The growth path is an extensive way. It hampers our economy and society sustainable development. Therefore, the research on resources and environment value is important for the green GDP.This paper mainly research on: 1. construct the resources evaluation model; 2. form the constructed wetland resources evaluation model; 3. quantify the environment value weight using the environmental economics methods; 4. for the preference coefficient through questionnaires; 5. do the case study on the Maguanqiao constructed wetland in Shenyang.The second part mainly includes the environmental value evaluating methods and the environmental value evaluation models. The environmental value evaluating methods include: the direct market evaluation, revealing preferences method, contingency evaluation method. The direct market evaluation method includes does-response method, productivity changes, the cost of disease method, the human capital law and the opportunity cost method. The revealing preference method includes the content of asset pricing law and travel costs method. The contingency evaluation method includes tender evaluation and the comparison of Game Theory method. Environmental resources value evaluation model is the main theoretical innovation of this paper. Based on the multiple, dynamic and the regional characteristics of the environmental resources, the writer puts forward the preference coefficient concept and includes it into the total value evaluation model. Compared to the traditional resources value evaluation model, this model makes the environmental resources value become dynamic and regional obviously. Including the preference into the evaluation model, it can strengthen the extent of recognition of the public. It demonstrates the multiple, dynamic and regional of the environmental resources.The third part summarizes the constructed wetland first. It includes the basic concept of the constructed wetland, the development of the constructed wetland at home and abroad. It introduces the three types of constructed wetland in details: the Surface-flow wetland, the undercurrent of wetlands and vertical flow wetland. Based on this it constructs the value of the constructed wetland. The total value of the constructed wetland equals to the environmental economy value minus the costs. The environmental economy value includes environmental capacity value, resources value and the social value. The environmental capacity value means the maximum capacity the constructed wetland can contain the pollutants. The resources value means the products of the constructed wetland (mainly plants) and the effluent value. The social value means the Landscape and aesthetic value of Popular Science. The cost can be quantified directly. It includes the maintaining cost and the constructed cost. The maintaining cost means the cost of normal function of the constructed wetland. The constructed cost means the inputs for the constructed wetland. This paper uses the contingency evaluation method and the questionnaires to quantify the value weight. The concrete evaluation process includes the market hypothesis, the questionnaires designing and the data-processing. Based on this it constructs the resources value evaluation model of the constructed wetland.The fourth part is the case study. It takes the Maguanqiao wetland in Shenyang as an example. Maguanqiao constructed wetland locates in the Dongling District in Shenyang. It covers 6.3hm2. It designs to be capable to process 30,000 thousands t/d sewage while the real capacity is 20,000 thousands t/d. Through the questionnaires on the environmental economy value evaluation of the constructed wetland and the constructed wetland type preference, the paper quantifies the environmental value weight and the preference coefficient. Based on the questionnaires the writer analyzes the data, including the correlation analysis, randomness analysis and the error analysis. Finally it concludes that the total value of the Maguanqiao constructed wetland in Shenyang is 990,850 thousands yuan. The ratio of the cost and benefit is 1:2.62. It gives the total evaluation on the final results.The fifth part is the conclusion. The total value of the Maguanqiao constructed wetland in Shenyang is 990,850 thousands yuan. The ratio of the cost and benefit is 1:2.62. Through research we find that the constructed wetland has good social, environmental and economical benefits. As a sewage processing technology it is suitable for large-scale promotion in our country.The research of this paper is a good attempt for the resources value evaluation. It is of great significance to promote the development of the resources value evaluation and the green GDP.