【作者】 王涛；

【导师】 程金花； 王昭艳；

【作者基本信息】 北京林业大学 ， 林业硕士（专业学位）， 2018， 硕士

【摘要】 北京山区近年来多次出现的暴雨灾害体现出北京山区生态安全的欠缺,威胁着北京山区的经济发展和居民的生命安全。水土保持治理是改善北京山区生态环境的重要手段。因此,开展北京山区小流域水土保持生态安全相关研究具有重大意义。本研究以北京山区576条小流域为研究对象,参考已有水土保持生态安全评价方法,应用压力—状态—响应(PSR,pressure-state-response)模型,综合分析北京山区水土保持生态安全影响因素,建立北京山区小流域水土保持生态安全评价指标体系,运用熵权法确定指标权重,基于灰色关联分析法对北京山区小流域生态安全状态进行评价,并选取5条典型小流域对其生态安全指数变化进行分析,研究结果表明:(1)时间尺度上,2012至2016年间,随着北京山区生态清洁小流域治理力度的不断加大,北京山区小流域水土保持生态安全指数也随之上升,虽有部分小流域由于外界扰动原因生态安全指数有所降低,但北京山区小流域水土保持生态安全状态整体呈现上升趋势。北京山区小流域处于较安全及以上等级的比例由2012年的35.76%增长到2016年的52.26%;处于较危险、危险等级的比例由32.12%下降到22.56%。(2)空间尺度上,北京山区各小流域评价等级分布较为复杂,水土保持生态安全评价为危险等级的小流域主要位于密云区东部、门头沟区南部、以及怀柔区中部地区;较危险等级的小流域主要分布于危险等级小流域的周边区域;水土保持生态安全评价等级为一般的小流域于北京山区各区县广泛分布,主要以怀柔区和密云区居多;较安全和安全等级的小流域主要分布于整个山区西部以及延庆区大部分地区。(3)根据北京山区典型小流域水土保持生态安全指数变化可以看出,水土保持安全指数与水土保持治理力度呈显著正相关。生态环境基础较好的地区,经水土保持治理后,水土保持成效显著。生态环境较差的小流域,经水土保持工程建设后,生态安全状况虽有较大改变,但由于抗灾害能力弱,应持续进行水土保持治理。未经治理的小流域生态安全状况受自然灾害影响大,应加强水土保持治理力度。本研究最后根据实际地质灾害发生情况对评价结果进行了验证,研究结果与实际灾害情况基本一致,说明北京山区小流域生态安全评价结果的可靠性较高。更多还原

【Abstract】 In recent years,the occurrence of rainstorm disasters in Beijing mountainous area reflects the lack of ecological security in mountainous area and threatens the economic development and the safety of residents’ lives in Beijing.The treatment of soil and water conservation is an important way to improve the ecological environment in Beijing mountainous area.Therefore,it is of great significance to study the ecological security of small watershed in Beijing mountainous area.In this study,576 small Watersheds in Beijing mountain area are taken as the research object.In reference to the existing ecological safety assessment methods of soil and water conservation,the pressure-state-response(PSR)model is applied to analyze the ecological safety factors of soil and water conservation in the Beijing mountain area,and the evaluation index system of soil and water conservation ecological security of small watershed in mountainous area of Beijing is established.The index weight was determined by entropy weight method,and the ecological security status of small watershed in mountainous area of Beijing was evaluated based on grey relational analysis method.Five typical small watersheds are selected to analyze the change of ecological safety index.The results of this study show that:(1)On the time scale,during the period from 2012 to 2016 the ecological security index of small watershed in mountainous areas of Beijing had also increased with the increasing efforts of ecological clean watershed management in mountainous areas of Beijing.Although the ecological security index of some small watersheds has decreased due to external disturbance,the ecological security status of soil and water conservation in the small watershed of Beijing mountainous area showed an overall upward trend.The proportion of small watershed above the safety level in Beijing mountain area increased from 35.76%up to 52.26%.The proportion of small watershed in the relatively dangerous and dangerous levels decreased from 32.12%to 22.56%.(2)On the spatial scale,the distribution of the evaluation grades of the small watersheds in theBeijing mountainous area is relatively complex.The small watersheds which are in dangerous level in the evaluation of the small watersheds of soil and water conservation and ecological security are distributed in the east of Miyun area,the south of Mentougou and the middle of Huairou.The small watersheds which are in general level are widely distributed in the Beijing mountainous area,mainly in Huairou and Miyun.The small watersheds which are in relatively safe level and safe level are mainly distributed in the western part of the mountainous area and in most areas of Yanqing district.(3)According to the change of ecological safety index of soil and water conservation in small watershed in mountainous area of Beijing,it can be seen that the index of soil and water conservation is positively correlated with the intensity of soil and water conservation management.The work of soil and water conservation has achieved remarkable results after treatment and management in areas with better ecological environment.After the construction of soil and water conservation project,the ecological security situation of the small watershed with poor ecological environment has changed greatly,however,because of its weak ability to resist disasters,the treatment of soil and water conservation should be carried out continuously.The ecological security of untreated small watersheds is greatly affected by natural disasters,so we should strengthen the treatment of soil and water conservation.Finally,the evaluation results are verified according to the actual geological hazards.The results are basically consistent with the actual disasters,which indicates that the reliability of ecological security assessment results of small watershed in Beijing mountainous area is high.更多还原