区域生态系统可持续发展的生态价值评价——以宁夏灵武市为例

Assessment with Eco-economic Valuation of Sustainable Development of a Regional Ecosystem:A Case Study of Lingwu City, Ningxia Province

根据我国西部大开发战略 ,从生态经济价值理论出发 ,研究区域生态系统服务功能的价值体系及其基本估价方法。结合我国国情 ,将 Costanza等人单纯自然资本的测算推广到自然、经济、社会综合资本的测算 ,重点突出人类活动干扰下的区域生态系统资本价值结构分析。研究表明 :1 997年灵武市牧草地和水域提供的资本价值约占自然资本总价值的97% ,工矿业消耗的自然资本占自然资本总损耗的 84 %。根据本文的全面测算结果 ,1 990～ 1 997年灵武市生态价值总资本年均递增 4 .5 % ,它将部分抵消该市国民生产总值 1 2 .6 %年均增长率。此外 ,如果用自然资本的增减作为强可持续发展的临界指标 ,1 990～ 1 997年本区域自然总资本以年均 4 %的速度递减 。

Evaluation procedure is an essential component of environmental impact assessment (EIA). The central purpose of evaluation is to help people to make effective, efficient, and environmental sound decisions on the basis of the best obtainable information (D.L.Lawrence, 1993). Environmental impact is any change to the environment, whether adverse or beneficial, wholly or partially resulting from an organization's activities, products or services. In fact, the modern social-economic systems are driven by the positive feedback of exponential growth. The annual percent increase in gross national product (GNP) is taken as every nation's primary indicator of national well-being (W.E.Rees, 1990). There are two ecological problems with these commonplace economic expectations. Firstly, almost all the products or services of organizational activities and the final consumer goods are eventually discharged back into the biosphere as wastes. Secondly, ecological difficulty with the growth-dependent economic systems is that it depends on fixed stocks of natural resources taken by human almost free charge. Therefore, the understanding of systematic value structures of a regional ecosystem with EIA evaluation methods becomes essential necessary. Evaluation is the stage of the EIA process at which all the impact information is brought together and consideration is given to whether the impacts are socially acceptable or not (Richard, 1998). There are two concepts in environmental impact evaluation: the types of values in a regional ecosystem, such as use value, market value, present value, and the methods that could be used in evaluation process. One of the most significant changes in the field of economic valuation since the 1960s has been the move from the use of a comparatively narrow concept of value to a much wider perspective, marked by the introduction of the concept of Total Economic Value (TEV) (Pearce and Turner, 1990). TEV may be broken down into two basic categories of use values and non-use values with several sub-categories. There are two basic approaches to establish the magnitude of the predicted impact: monetary evaluation, e.g., cost-benefit analysis, and scaling weighting evaluation, e.g., ratio-scoring procedure, (Lee, 1982). The first one is mainly considered in this paper because monetary evaluation is more easily accepted by our society in which GNP as an international indicator has been widely applied. Cost-Benefit Analysis (CBA) is now routinely used to evaluate broad questions of environmental policy, but it has limitations. Adams (1996) indicated CBA has three main weaknesses: it attempts the impossible; it is biased; and it entrenches conflict. Without doubt, not all of environmental impacts can be evaluated by CBA but the combination of approaches, such as sales comparison approach, income approach, weighting methods, matrix methods, may be helpful to value complex or hidden impacts. The sales comparison approach is based on the premise that the market value of a property is directly related to the prices of comparable and competitive values. The income approach is based on the property anticipated future income. For the results calculated in this paper, natural capital contributed to total capital was about 1/3 in the regional ecosystem but 84% of natural capital was consumed by local industry in 1997. Natural capital declined 4% each year from 1990 to 1997. Furthermore, the growth rate of total capital per year was 4.5% and not 12.6% calculated with GNP in the city in 1997. This result indicates that Lingwu city was not in a sustainable development during 1990's because the natural capital continually decreased. In fact,the most losses of natural capital were from industry, especially local chemical and steel industries. Therefore, decreased losses of natural capital can be achieved by controlling local heavy industries and promoting agriculture and other industries, such as food processing industry,tourism industry,with sound environmental development. In the future, sustainable development of the regio