锡林郭勒盟乌拉盖流域生态风险评价

发布时间：2018-04-10 15:35

本文选题：乌拉盖流域 + 生态环境状况　；参考：《内蒙古师范大学》2015年硕士论文

【摘要】：锡林郭勒盟乌拉盖流域位于内蒙古自治区锡林郭勒盟东北部,是锡林郭勒盟面向东北地区的重要出口和生态屏障。作为乌珠穆沁草原主要组成部分的乌拉盖河是内蒙古自治区境内最大的内陆河,对乌珠穆沁草原的生存有着重要决定影响。本文考虑生态风险的典型性,将乌拉盖流域作为研究对象,以五期T M遥感影像(199 0年、2000年、2005年、201 0年、2013年)为主要数据源,结合遥感、GIS技术等现代技术及Exc el、S PS S等软件工具和数理统计方法,从引起生态风险的自然因素方面入手,进行风险识别,并建立风险评价指标体系,对乌拉盖流域进行生态风险评价,得出乌拉盖流域五期(1990年、200 0年、200 5年、201 0年、201 3年)的生态风险指数及区域等级,为探讨和制定相应的生态风险治理对策提供科学的依据。总体上看乌拉盖流域在199 0-2013年期间的五个时期生态环境状况风险级别一直为低,在199 0年至200 5年期间生态环境状况呈现逐年减少趋势,但变化并不明显,这说明了乌拉盖流域的生态环境状况是比较稳定的。在2005年至2 0 1 3年期间生态环境(△E I)呈增长的趋势,这说明该地区生态环境状况略微变好。且生态环境状况指数(E I)均大于7 5,因此,乌拉盖流域是一个植被覆盖度高,生物多样性丰富,生态系统稳定,特别适合人类生存的地区。从整体来分析,乌拉盖流域的生态环境优良且稳定,但不同年份的评价指数在数值上还是有一些差别。通过乌拉盖流域不同土地利用类型的“易损性”可以看出:在整个研究区,不同等级风险区没有过于明显的界线,但在时间序列上,呈现降低趋势,这说明乌拉盖流域生态环境状态有所好转。其中高风险区主要分布在西南部及东北部,但其分布较为分散,高风险区的土地利用类型主要是耕地和未利用土地。较高风险区主要分布在高风险区的周边地区,而在西北部也有零星分布。较高风险区的土地利用类型主要是低覆盖度草地和中覆盖度草地。中等风险区遍布整个乌拉盖流域,面积较大,但主要还是分布在西北部地区。中等风险区的土地利用类型主要是高覆盖度草地。较低风险区主要分布于低风险区的周围,较低风险区的土地利用类型主要是部分灌木林地。低风险区主要分布在南部及东南部地区,尤其是西乌珠穆沁旗东南部地区,除此之外,中部及北部地区也有零星的分布。其土地利用类型主要有水域和有林地等。
[Abstract]:Located in the northeast of the Xilingol League of Inner Mongolia Autonomous region, the Wulagai Valley of the Xilingol League is an important export and ecological barrier to the Northeast region of the Xilingol League.As the main component of Uzhimuqin grassland, the Ulagai River is the largest inland river in Inner Mongolia Autonomous region, which has an important influence on the survival of Uzhoumuqin grassland.In this paper, considering the typicality of ecological risk, the Wulagei basin is taken as the main data source, with five phases of TM remote sensing images in 1990, 2000, 2005 and 201 years, 2013) as the main data sources.Combining with modern technology such as remote sensing and GIS technology and software tools such as Exc Elton PS S and mathematical statistics method, risk identification and risk evaluation index system are established from natural factors that cause ecological risk.The ecological risk index and regional grade of the Wulagai watershed were obtained in the fifth period of the Wulagai watershed (from 1990 to 2005-201 years to 2013 years), which provided a scientific basis for the discussion and formulation of the corresponding countermeasures for ecological risk management.On the whole, the risk level of ecological environment condition in the five periods of 1990-2013 has been low, and the ecological environment state has been decreasing year by year from 1990 to 2005.But the change is not obvious.This shows that the ecological environment of the Wulagei basin is relatively stable.From 2005 to 2003, the ecological environment (ei) showed an increasing trend, which indicated that the ecological environment in this area had improved slightly.The Eco-environmental index (E I) is higher than 7.5. Therefore, the Wulagai watershed is a region with high vegetation coverage, rich biodiversity and stable ecosystem, which is especially suitable for human survival.From the overall analysis, the ecological environment of the Wulagai basin is good and stable, but the evaluation index in different years is still different in numerical value.Through the "vulnerability" of different land use types in the Wulagei basin, it can be seen that, in the whole study area, there is no obvious boundary between the different grade risk areas, but in the time series, there is a decreasing trend.This shows that the state of the ecological environment of the Wulagai basin has improved.The high risk areas are mainly distributed in the southwest and northeast, but they are scattered. The land use types in the high risk areas are mainly cultivated land and unused land.The higher risk areas are mainly located in the peripheral areas of the high risk areas, and are scattered in the northwest.The main types of land use in high risk areas are low coverage grassland and middle coverage grassland.The middle risk area covers the whole Wulagai basin, but it is mainly distributed in the northwest area.The main land use type in middle risk area is high coverage grassland.The low risk area mainly distributes around the low risk area, and the land use type in the lower risk area is mainly part of shrub land.The low risk areas are mainly distributed in the south and southeast, especially in the southeast of West Uzhoum Banner. In addition, there are also scattered distribution in the central and northern regions.Its land use type mainly has the water area and the woodland and so on.
【学位授予单位】：内蒙古师范大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X826

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