Emergy-Based Research On Threshold Of Sustainability Evaluation In Human Settlement Construction System

Human settlement environment construction not only brings all kinds of "positive"effects such as more adequate living space, higher quality of life and more convenienttransportation, but also brings some "negative" effects such as rapid consumption innon-renewable resources, environmental pollution and the greenhouse effects. In recentyears, these "negative" effects become more seriously, so finding a healthierdevelopment mode is essential. We find that sustainable development thought is a goodsolution. However, how to evaluate the sustainability of human settlement environmentconstruction deserves to research. There are several drawbacks in recent studies: First,natural resources, public goods and human services are difficult to quantify. Second,dimension is hard to unity. Third, combining the positive part and the negative part toevaluate is a problem. Forth, there are insufficient researches in evaluation threshold.Based on above analysis, this paper tried to break through some disadvantages inregular evaluation, and adapt to the emergy method to assess to human settlementenvironment construction’s sustainability. In addition, I constructed the relatedevaluation indicators, and explore the critical threshold of the evaluation indicator. Thepaper made Chongqing city as the research object, evaluate the sustainability of itshuman settlement environment construction since as municipality directly under thecentral government, and then put forward some proposals on the Chongqing’sconstruction. In theory, it can enrich related research as well. The research framework isas follows:Firstly, this paper comprehensively summarized the existing research results aboutsustainability evaluation method and the threshold especially in the emergy evaluationmethod at home and abroad.Secondly, this paper put forward the development stages’ judgment standard, usethe emergy method, and set up development type, limit type and synthesizing type’shuman settlement environment construction which reflects positive and negative effects.Thirdly, based on the above research result, this paper puts Chongqing’s humansettlement environment construction system as an example, analyzes the material flow,the energy flow and the information flow, researches evaluation standard, makes trendanalysis and put some suggestions on strengthening the sustainability of theChongqing’s human settlement environment construction. The conclusion is as follows:1. Chongqing’s ESI increases from0.58in1997to1.18in2011year by year, in2004, this index brake through the critical threshold value of1.00. Therefore, it reflectsChongqing’s human settlement environment changes form unsustainable developmentstate to sustainable development state. The year of2004is the turning point.2. We discovered from the calculation result of limit type and development type’sevaluation standard that there still exist some unsustainable part in Chongqing’s humansettlement environment construction: greenhouse gas emission and the cycle ofrecycling have been in unsustainable development state.3. Based on above research and conclusion, this paper put forward thecorresponding improvement Suggestions and countermeasures for sustainabledevelopment.