西藏地区典型小流域坡面尺度水土保持生态效应评价研究

发布时间：2018-06-19 17:43

本文选题：水土保持 + 生态效应　；参考：《中国水利水电科学研究院》2017年硕士论文

【摘要】：水土流失是制约人类发展和社会进步的重大问题,会对生态环境可持续发展造成严重威胁,是导致生态环境恶化和地区贫困的重要原因。水土流失的危害方式主要包括破坏土壤结构、降低土壤肥力、造成土地沙漠化及石漠化、引发自然灾害等。近年来,由于全球气候变化和人类自然活动的影响,西藏地区生态系统稳定性降低、水土流失问题不断加剧。目前,由于西藏地区水土保持监测站点和监测资料的匮乏,导致有关该区域的水土保持生态效应研究极少。本文以水利部公益性行业科研专项"青藏高原区水土保持生态效应监测与评价技术"为依托,以西藏地区日喀则市的日朗河小流域和拉萨市的茶巴朗小流域为研究区域,对其坡面尺度水土保持生态效应进行全面、科学的评价,构建适用于西藏地区坡面尺度的水土保持生态效应评价指标体系,开展水土保持生态效应的量化评价,为该地区的水土保持生态建设提供规划依据和技术支撑。其主要研究内容及结论如下:(1)首先,通过对研究区水土流失特点和水土保持现状的分析,结合频数统计分析法及专家经验法,初步遴选出14个生态效应评价指标。其次,采用主成分分析法,剔除综合贡献率较低的全磷及土壤有效厚度指标;根据相关性分析结果,剔除与土壤储水量重复性较高的土壤含水率指标;结合指标变异系数和响应程度的计算值,剔除弱敏感性的土壤PH指标。最终,构建了包含土壤储水量、土壤侵蚀模数、最大持水量、土壤容重、有机质、全氮、全钾、植被盖度、生物多样性及土壤固碳量等10个指标的评价体系。(2)针对生态效应评价的特点,采用层次分析法及熵权法计算各个指标的组合权重,其结果为:土壤储水量0.109、土壤侵蚀模数0.251、最大持水量0.059、土壤容重0.021、有机质0.105、全氮0.113、全钾0.024、植被盖度0.113、生物多样性0.041、土壤固碳量0.164。(3)结合各个评价指标的权重和监测资料,计算不同水土保持措施下生态效应的综合评价值。结果表明,水土保持措施区生态效应优于无措施区,说明水土保持措施有助于水土流失治理;针对不同土地利用类型,林地、耕地及石坎梯田的生态效应均优于无措施区,其中,林地生态效应最好,耕地及石坎梯田由于人为扰动多、措施实施时间短等原因,均劣于林地;针对不同水土保持措施,除江孜县卡尔村及曲水县草方格措施外,水土保持措施区生态效应均优于无措施区,这与措施实施时间及研究区气候、土壤条件有关。(4)采用单因素方差分析法对研究区各个单项指标进行对比分析发现,总体而言,除江孜县卡尔村外,随着水土保持措施的实施,措施区各项指标较无措施区域均有所改善。卡尔村出现的异常情况与该区措施实施时间短、人口少、人为扰动少、土壤结皮较厚有关。另外,针对挪村土壤容重及曲水县杨树林土壤侵蚀模数出现异常的原因,还需对研究区进行长期动态监测,进一步研究探讨。
[Abstract]:Soil erosion is a major problem that restricts the development of human and social progress. It will cause serious threat to the sustainable development of the ecological environment. It is an important cause for the deterioration of the ecological environment and the poverty in the region. The damage ways of soil erosion mainly include destroying soil structure, reducing soil fertility, causing land desertification and rocky desertification, and causing nature. In recent years, due to the influence of global climate change and human natural activities, the stability of the ecosystem in Tibet has been reduced and the problem of soil erosion has been aggravated. At present, the lack of monitoring sites and monitoring data on Soil and water conservation in Tibet region has resulted in few studies on the ecological effects of soil and water conservation in this region. Based on the technology of monitoring and evaluating the ecological effects of soil and water conservation in the Qinghai Tibet plateau area, the public welfare industry research project is based on the technology of monitoring and evaluating the ecological effects of soil and water conservation in the Qinghai Tibet plateau area, taking the small catchment of Shigatse in Tibet and the small catchment of tea Barang in Lhasa as the research area. The ecological effects of soil and water conservation on the slope scale are fully and scientifically evaluated, and the construction of the slope is suitable for the slope of the Tibet area. The evaluation index system of soil and water conservation ecological effect of surface scale and the quantitative evaluation of ecological effect of soil and water conservation provide the planning basis and technical support for the ecological construction of soil and water conservation in this area. The main contents and conclusions are as follows: (1) first, through the analysis of the characteristics of water and soil loss and the current situation of soil and water conservation in the study area, the combination frequency 14 ecological effects evaluation indexes were selected by statistical analysis method and expert experience method. Secondly, the principal component analysis method was used to eliminate total phosphorus and soil effective thickness index with low comprehensive contribution rate, and the soil water content index, which was higher in soil water storage, was eliminated according to the correlation analysis results, and the index variation coefficient and the index variation coefficient were eliminated. In the end, the evaluation system of 10 indexes, including soil water storage, soil erosion modulus, maximum water retention, soil bulk density, organic matter, total nitrogen, total nitrogen, total potassium, vegetation coverage, biodiversity and soil carbon sequestration, was constructed. (2) according to the characteristics of ecological effect evaluation, the hierarchical classification was adopted. The method of analysis and entropy weight method is used to calculate the combination weight of each index. The results are as follows: soil water storage 0.109, soil erosion modulus 0.251, maximum water holding capacity 0.059, soil bulk weight 0.021, organic matter 0.105, total nitrogen 0.113, total potassium 0.024, vegetation coverage 0.113, biological diversity 0.041, soil carbon sequestration 0.164. (3) combined with the weight of each evaluation index and monitoring data The comprehensive evaluation of ecological effects under different soil and water conservation measures was calculated. The results showed that the ecological effect of soil and water conservation measures was better than that in the non measure zone, indicating that soil and water conservation measures were helpful for soil erosion control, and the ecological effects of soil conservation measures were better than those in the non measure areas, and the ecological effects of forest land, arable land and sill terrace were all better than those in the non measures area. The effect of soil and water conservation measures is better than that of woodland. In addition to the measures of soil and water conservation, the ecological effects of soil and water conservation measures are superior to those in the non measure areas, in addition to the measures of soil and water conservation in Carle village and Qu Shui county of Jiangzi County, the ecological effects of soil and water conservation measures are all better than those in the non measures areas. (4) the comparison and analysis of the individual indexes of the study area by the single factor ANOVA found that, in general, except the Carle village in Jiangzi County, with the implementation of the measures of soil and water conservation, the indexes of the measure areas were improved more than those in the non measures. The abnormal situation in the village of Carle and the time of the implementation of the measures in this area were short, the population was small, and the human beings were disturbed. In addition, the long-term dynamic monitoring of the soil erosion modulus of the poplar forest in the village of the village and the soil bulk weight of the village and the soil erosion modulus of the poplar forest in the county of Qu Shui county are also needed to be further studied and discussed.
【学位授予单位】：中国水利水电科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157

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