【作者】 尼庆伟；

【导师】 杨凤林；

【作者基本信息】 大连理工大学 ， 环境工程， 2010， 博士

【摘要】 湿地作为地球三大生态系统之一,具有重要的生态服务功能,是一种重要的物质资源和国土资源。长期以来,由于自然因素与人为因素的干扰导致湿地生态系统功能退化与丧失是湿地研究面临的严峻现实。因此,研究湿地生态系统的退化演变机制成为当今湿地科学关注的焦点问题和重要内容,也是对湿地进行科学保护与有效管理和合理开发利用的前提和基础。本文以辽宁省最大的天然内陆型湿地-沈阳卧龙湖湿地省级自然保护区为例,对湿地生态系统的结构与功能首次进行全面分析、评价的基础上,采用定性、定量相结合的方法研究了半干旱内陆型湿地的生态退化机制问题,并提出了相应的保护对策。论文以对新方法的使用为努力和探索的方向,希望为半干旱典型区域的湿地退化研究做出有益的探索。围绕着湿地退化机制的主题本文主要开展了以下相关研究：(1)全面分析了卧龙湖湿地的生态结构及服务功能,计算了湿地的使用价值价值与存在价值,进一步强化了保护卧龙湖湿地的重要意义。依据现代价值论的理论和计算方法对湿地的经济功能、生态功能和社会功能三个方面的共10项使用和非使用价值进行了量化计算,并提出了湿地存在价值的计算方法。计算结果显示,卧龙湖湿地的总价值为Y208.88亿元人民币,其中直接使用价值为￥4.965亿元人民币,非使用价值为￥203.92亿元人民币。(2)考察了自然因素和人为因素变化对卧龙湖湿地退化的影响,建立了湿地脆弱性评价指标体系,采用APH-综合指数法对卧龙湖湿地的生态脆弱性进行了动态评价,在此基础上探讨了湿地生态系统退化的机制问题。评价的结果表明卧龙湖湿地1994年以来的脆弱性呈上升趋势,整体处于严重脆弱的状态。从单因子的权重分析来看,湿地区域的气候因子、蓄水量和水污染程度等指标的权值较高。从湿地的退化机制分析得出,由于卧龙湖湿地地处半干旱的沙漠化区域,区域的气候变化是导致近年来湿地退化的主要原因,人为因素与自然因素的叠加进一步加剧了湿地退化的过程。(3)运用初等突变理论的思想方法,建立了卧龙湖湿地生态系统退化的尖点突变判别模型,以模型描述的方式对卧龙湖湿地的生态退化状态进行了判别。根据卧龙湖湿地地处半干旱地区的实际环境特点,选择以直接影响湿地生态环境状况的蓄水量指标和水环境质量指标作为湿地尖点突变模型的控制变量,以生物多样性指标作为状态变量,湿地的生态功能综合指数作为势函数,分别对卧龙湖湿地1994年、2000年、2002年、2003年、2005年和2006年的退化状态进行了尝试性的模拟判别。结果表明,卧龙湖湿地生态系统于2002年发生了退化突变现象,其结果与湿地实际退化的状况基本吻合,结果还表明,突变理论模型可以对未来的湿地退化趋势进行预测。(4)利用人工智能建模的思想方法,将遗传程序设计(GP)算法应用到卧龙湖湿地的年蓄水量变化趋势的模拟和预测中。在研究所需数据量不足的条件下,对影响湿地生态系统退化的主要控制因素-湿地蓄水量的变化趋势进行了模拟和预测。结合湿地所处半干旱地区的环境特征分析的结论,本文将区域蒸发量和降水量作为模型算法的输入变量,蓄水量作为输出变量,在小数据量条件下模拟了湿地蓄水量的变化,结果表明,GP智能建模的模拟精度较高,适用于半干旱地区的湿地蓄水量变化的模拟,尤其在小数量条件下优于传统的神经网络模型(ANN)和灰色系统模型(GM)。本文还对卧龙湖湿地蓄水量未来的变化趋势进行了预测,结果表明,按照区域降水量持续下降(-0.802mm/a)及蒸发量持续上升的(7.471mm/a)趋势,未来卧龙湖湿地的蓄水量下降趋势明显。(5)针对卧龙湖湿地区域水资源缺乏的现状,结合区域经济发展的中远期规划目标,制定了基于区域生态、经济可持续发展的用水方案,采用多目标模糊规划的方法确定了区域以保护生态为主,兼顾经济效益提高为目标的水资源配置最优方案。最后针对湿地现行管理存在的相关问题提出了相应的保护对策。更多还原

【Abstract】 Wetland ecosystems, being as one of the three important ecosystems on the earth, have been considered as the key important material resource for its various ecological functions and even the key soil resource for its significance in scientific research and supporting the susatainable developmemt of regional ecomomy. The status of degradation and lost of wetland all over the world, owing to the disturbance from natural environment and anthropogenic activities is serious. The researches about the degradation mechanism have, therefore, become the focus and important investigation area, which is considered to be the the premise and basis for scientific protection and effective management of wetlands. Taking the Shenyang Wolonghu Inland-Wetland Natural Conservation, the biggest natural inland-wetland in Liaoning province, this paper presents a case study of degradation mechanism and correspond protecting measures of the wetland based on fully analysis of the structure and functions of the wetland. The purpose of this paper is to make an exploration in application of new methods in research of wetland.The main work of this dissertation is summarized as follows:(1) The ecological functions and the structure of the Wolonghu weltand are fully analyzed. The enormous valuea of the wetland are confirmed, which reveal the key significance of the existence and being worthy of protection of the wetland.10-item function values of use value and non-use value from three main function categories as economic ecological and social functions have been calculated quantitatively according the the modern value theory and its corresponding calculation method. A new method of calculating the existence value of the wetland has been proposed in the paper. The calculation results show that the total value of the Wolonghu wetland is to be 20.822 billion RMB per year, of which the use value is 0.497 billion RMB per year and the non-use value is 20.392 billion RMB per year.(2) Two factors, natural and anthropogenic ones are investigated about impacting the wetland degradation and then the index system of frangibility is set up. Consequently, the frangibility of the wetland has been estimated by means of AHP-integrated index method and followed by the analysis of the degradation mechanism of the wetland. The results of the frangibility estimation show that the frangibility of the wetland is at the serious level with a rising trend since 1994. The precipitation, evaporation, water storage and water quality level factors bear the relatively higher weights. The degradation mechanism of the wetland shows that it is a collective effect from natural factors and anthropogenic activities that result in the wetland degradation, of which the cause of climate changes is dominant.(3) A cusp catastrophic model of Wolonghu wetland has been set up in light of the elementary catastrophe theory for further investigating the degradation process and degradation level of the weltand. The water storage and water quality level are taken as the controlling variables, biodiversity index as the status variable, synthesized index of the wetland ecological functions as the catastrophic function and degradation level of the weltand at 1994,2000,2002,2003,2005,2006 are simulated and estimated, respectively. The results show that the catastrophic phenomenaon of degradation of the wetland was occurring at the year of 2002, which was relative in agreement with the actual facts. Furthermore, the model can be used for prediction of the degradation trend of the wetland.(4) In this paper, based on the condition of small hydrological database, a new artificial inteletgent method of genetic programming (GP) has been proposed for simulating and forecasting the behaiviors of the water strorage of the wetland. The relative controlling factors of the method have been determined after fully analysis of the hydrological conditions of the weltand area. Taking the precipitation and evaporation as the input variables and water storage the output variable, the simulation results from GP show a large agreement with the actual values compared to the popular tools of artifical neural networks (ANN) and grey theory model (GM) under the same condition of small database. The prediction results from the GP evolution model indicate that the water storage in the Wolonghu wetland will sharply reduce in the year of 2015 and 2020 along with the trend of regional precipition and evaporation changes.(5) An optimal water utilization plan has been determined by means of multi-objective fuzzy plan in terms of the principal of sustainable development of regional ecosystem and social economy basing on the condition analysis of regional water resource. Some other protection countermeasures, such as new water resource developing for weltand and management regulations of the wetland, etc. have been put forward.更多还原