【作者】 杨平；

【导师】 刘俊民；

【作者基本信息】 西北农林科技大学 ， 水文学及水资源， 2007， 硕士

【摘要】 我国是一个农业大国,又是一个灌溉大国,灌区在社会经济发展和生态环境保护中发挥着重要作用。然而,随着我国社会经济的快速发展和人类活动的加剧,在灌区开发和建设过程中,出现了一系列的生态环境问题,如地下水超采、灌区水质污染、土壤盐渍化等,直接影响了灌区效益的正常发挥。因此,必须重视灌区生态环境问题,了解灌区生态环境质量现状,以便采取适当的治理措施,最终实现经济与环境和谐健康发展的生态型灌区。基于此,本文对灌区生态环境质量进行了分析研究,主要研究成果如下:(1)在对生态环境质量评价的概念、评价标准和方法、评价指标体系系统分析的基础上,结合灌区生态环境的自身特点,提出了灌区生态环境质量和灌区生态环境质量评价的概念。(2)目前灌区生态环境质量评价没有统一的指标体系,在分析灌区建设对生态环境影响的基础上,初步建立了灌区生态环境质量评价指标体系。该指标体系包括气候资源系统、水资源系统、土壤资源系统和生物资源系统,每个子系统又包括了可以反映该系统特征的具体指标。(3)根据灌区生态环境质量评价的特点选用了具有代表性的三种灌区生态环境质量评价模型:模糊层次综合评价法、BP人工神经网络评价法和支持向量机评价法。模糊层次综合评价法是将层次分析法和模糊综合评价法的优点进行了有机融合,该方法提高了评价的效率;BP人工神经网络法是从训练样本中提取每个评价等级样本的规律性特征,然后通过这些规律性特征识别测试样本,该法具有容错性强、自学习、高精度等优点;支持向量机作为一种最新的也是最有效的统计学习方法,该法具有小样本学习、学习效率高和推广性好等优点。由于,这三种方法各有侧重点,同时单一评价方法包含的信息量不够全面,因此造成评价结果不完全一致的问题,本文根据各方法的特点将其按加权平均法进行了综合评价。(4)本文选择有代表性和现实意义的宝鸡峡灌区为例,运用建立的灌区生态环境质量评价指标体系和评价模型进行了典型案例分析,得出了与实际相符合的基本结论,验证了指标体系与评价方法的实用性与可靠性。更多还原

【Abstract】 China is a large agricultural country, also is a big irrigation country. Irrigation Areas plays an important role in the national economic development and eco-environment protection. However, in the wake of the rapid national economic development and human activity intensity, In irrigation development and construction process, a series of ecological problems have appeared, like, excessive extraction of underground water, irrigation water pollution, soil salinization and so on, which directly affected the normal irrigation efficiency . Therefore, attention must be given to irrigation eco-environment, understanding of irrigation eco-environmental quality, in order to take appropriate treatment measures, ultimately achieve economic harmony with the environment and healthy development. For this paper, on the basis of refer to the large number of domestic and foreign research results, study to evaluation of irrigation areas ecological environmental quality, the research results are as follows:(1) On the basis of a systematic analysis of the eco-environmental quality evaluation concept, the evaluation criteria and methods and the evaluation indices system, with the irrigation areas’s own characteristics of eco-environment. Given about the concept of irrigation areas eco-environmental quality and evaluation of irrigation areas eco- environmental quality.(2) Currently, there is no uniform indices system for irrigation areas eco-environmental quality evaluation indices system, on the basis of analysis the impact on the eco- environment form irrigation areas construction. Primarily, establishment the indices system for eco- environmental quality evaluation of irrigation area. The indices system include the climate system resources, water resources, soil resources and biological resources, each subsystem can also include a system to reflect the characteristics.(3) According to the characteristics of irrigation areas eco-environmental quality evaluation, selection of three representative methods, FAHP evaluation, BP ANN evaluation and SVM evaluation. FAHP evaluation is organic integration the merits of AHP and fuzzy comprehensive, which enhanced the efficiency of the evaluation;BP artificial neural network is extracted regular characters of each sample from the training samples, then to recognizes test samples, which have some advantages of strong fault tolerance, self-learning and high accuracy. As a latest and most effective method of statistical learning, in recent years, SVM has become a new hotspot in the field of pattern recognition and machine learning, which has some advantages such as small-sample learning, high efficiency, and easy promotion and so on. However, each of these three methods has its own focus. Single evaluation method included insufficient information, so its assessment results are not completely consistent. The paper made a combination evaluation based on characteristics of above methods according to the weighted average method.(4) The paper chooses Baojixia irrigation area as an example, which has representative and realistic significance. Using the indices system for eco-environmental quality evaluation of irrigation area and the evaluation model for a typical case.The conclusion is match with the fact, the indices system and evaluation model is practicality and reliability.更多还原