黄土高原土地利用变化对土壤侵蚀影响研究

发布时间：2019-03-11 10:14

【摘要】：土壤侵蚀是备受关注的全球环境问题之一,也是土地利用变化引起的环境效应之一,研究土地利用变化对土壤侵蚀的影响已成为土地利用变化和土壤侵蚀研究领域的重点。黄土高原是中国乃至全球水土流失最为严重的地区之一,随着三北防护林体系建设、退耕还林还草、封山禁牧等一系列生态措施的采用,黄土高原的土地利用格局已经发生了显著变化,并且对土壤侵蚀产生了重大影响,因此有必要深入研究黄土高原土地利用变化对土壤侵蚀影响的时空分异规律。研究基于中国科学院遥感与数字地球研究所等单位建立的1:10万比例尺长时间序列中国土地利用变化及土壤侵蚀动态数据库,综合运用土壤侵蚀严重程度指数、强度转类指数、土壤侵蚀变化率等,整体评价了1980年代末至2000年、2000-2005年、2005-2010年黄土高原土壤侵蚀的时间演变规律,分析了《黄土高原地区综合治理规划大纲(2010-2030年)》中六大综合治理分区的土壤侵蚀区域差异,并进一步分析了土地利用变化对土壤侵蚀的影响。结果表明:(1)2010年黄土高原依然是土壤侵蚀的高发区,其中黄土丘陵沟壑区是黄土高原水蚀最严重的分区,沙地和沙漠区是风蚀最严重的分区。2010年黄土高原土壤侵蚀严重程度指数为4.04,其中黄土丘陵沟壑区是黄土高原水蚀最严重的分区,土壤侵蚀严重程度指数为7.63,沙地和沙漠区的风蚀最严重,黄土高塬沟壑区、农灌区、土石山区的严重程度指数依次降低,河谷平原区最低,为1.06。(2)黄土高原2000年前土壤侵蚀加剧,之后有减轻趋势。1980年代末至2000年期间黄土高原水蚀强度平均上升0.88级,2000年至2010年期间水蚀情况不断好转,强度平均下降1级左右。1980年代末至2000年间,黄土高原风蚀强度平均下降0.39级,2000至2005年间,风蚀强度平均上升0.67级,2005至2010年间,风蚀强度平均下降0.87级。此外,各治理分区成片发生土壤侵蚀加剧的面积越来越小,尤其是到了2005年之后,各分区的整体侵蚀强度均在减轻。(3)黄土高原不同治理分区影响土壤侵蚀的主要土地利用变化方式不尽相同,但是草地的动态对于各分区的影响都比较大。黄土高塬沟壑区、河谷平原区、土石山区和农灌区以草地开垦为耕地为主,沙地和沙漠区以草地退化为未利用地为主,黄土丘陵沟壑区以未利用地变草地及退耕还林还草为主,各区中以黄土丘陵沟壑区退耕还林还草的面积与成效最为显著。(4)黄土高原影响土壤侵蚀的土地利用变化方式在2000年前以草地变未利用地及草地变耕地为主,2000年后以耕地变林地为主。1980年代末至2000年间,存在较多开垦荒地草地以及草地退化为未利用地的现象;2000至2005年期间,造成土壤侵蚀变化的土地利用变化主要有退耕还林、草地退化为未利用地、草地变林地;2005至2010年影响土壤侵蚀的则以退耕还林、未利用地变草地、城镇扩张为主。(5)一般来说,黄土高原土地利用类型间按土壤侵蚀强度从轻到重依次为水域、城乡工矿居民用地、林地、草地、耕地、未利用土地,土壤侵蚀是否减轻与土地利用方式的变化方向有关。耕地减少一般都能减轻土壤侵蚀强度,但耕地退化为未利用地对土壤侵蚀的加剧作用却是巨大的;林地开垦为耕地、林地退化会加剧土壤侵蚀,林地被开发为城乡工矿居民用地则使得侵蚀强度平均下降1级左右;开垦草地和植被退化加剧了土壤侵蚀,草地开荒为城乡工矿居民用地则使得土壤侵蚀强度平均降低1至2级;水域减少通常会使得土壤侵蚀强度加剧,与之相反,未利用地减少总能够较好地减轻土壤侵蚀。
[Abstract]:Soil erosion is one of the most important global environmental problems, and is one of the environmental effects caused by land-use change. The study of the impact of land-use change on soil erosion has become the key in the field of land-use change and soil erosion research. The loess plateau is one of the most serious soil and water loss in China and even the whole world, and with the adoption of a series of ecological measures such as the construction of the three-north protection forest system, the conversion of the farmland to the forest and the grass and the ban of the mountain, the land-use pattern of the Loess Plateau has changed significantly. Moreover, it is necessary to study the spatial and temporal differentiation of land-use change on soil erosion in the Loess Plateau. Based on the 1: 100,000 scale long-time series of land use change and the dynamic database of soil erosion, which is based on the remote sensing and digital earth research institute of Chinese Academy of Sciences, the soil erosion severity index, the intensity index, the rate of change of soil erosion, etc. are comprehensively used. The temporal evolution of soil erosion in the Loess Plateau from the late 1980s to the year 2000,2000-2005 and 2005-2010 was evaluated, and the regional differences of soil erosion in the comprehensive treatment planning program of the Loess Plateau (2010-2030) were analyzed. The effect of land-use change on soil erosion is further analyzed. The results show that: (1) The loess plateau in the Loess Plateau is the most serious area of water erosion in the Loess Plateau in 2010, and the sand and desert areas are the most serious areas of the wind erosion. The severity index of soil erosion in the Loess Plateau in 2010 is 4.04, The soil erosion is the most serious in the Loess Plateau, the severity index of the soil erosion is 7.63, the wind erosion in the sand and the desert area is the most serious, the severity index of the loess high-gully region, the non-agricultural irrigation area and the soil-stone mountain area is decreased in turn, and the lowest in the valley plain area is 1.06. (2) The water erosion intensity of the Loess Plateau increased by 0.88 at the end of the 1980s to the end of the year 2000, and the intensity of the water erosion in the Loess Plateau from the end of the 1980s to the end of the year 2000 was improved, and the average intensity of the water decreased by about 1. Between the end of the 1980s and the end of 2000, The average wind erosion intensity of the loess plateau decreased by 0.39, and the average wind erosion intensity increased by 0.67 for 2000 to 2005, and the average wind erosion intensity decreased by 0.87 in 2005 to 2010. In addition, the area of increased soil erosion in each of the management zones is becoming smaller and smaller, especially after 2005, the overall erosion intensity of each zone is reduced. (3) The main land-use change way of soil erosion is different from different treatment zones on the Loess Plateau, but the dynamics of the grassland are relatively large for each zone. The grassland in the high-gully region of the loess, the plain area of the valley, the mountainous area of the soil and the non-agricultural irrigation area are mainly cultivated as cultivated land, and the grassland in the sandy land and the desert area is the main part of the unutilized land. The area and effect of returning farmland to forest in the loess hilly and gully region are the most significant. (4) The land-use change of soil erosion in the Loess Plateau was mainly based on the non-use of land and grassland in the Loess Plateau, and the land was changed to forest land after 2000. In the end of the 1980s to 2000, there existed more and more wasteland and grassland degradation as the unutilized land. During the period from 2000 to 2005, the land-use change that caused the change of soil erosion mainly has the conversion of farmland to forest, and the grassland is degraded to the unutilized land and the grassland is changed into forest land; in the period of 2005 to 2010, the soil erosion is affected by the conversion of the farmland to the forest, the grassland in the land is not used, and the urban expansion is the main. (5) In general, the soil erosion intensity between the land use types of the Loess Plateau is from light to weight to the water area, and the land, the forest land, the grassland, the cultivated land, the unused land and the soil erosion of the urban and rural industrial and mining areas are related to the change direction of the land use mode. The reduction of cultivated land can generally reduce the intensity of soil erosion, but the degradation of the cultivated land is not the use of land to increase the soil erosion, and the forest land is cultivated as the cultivated land, and the degradation of the forest land will aggravate the soil erosion. The development of the forest land as the land for urban and rural industrial and mining residents has resulted in an average erosion intensity of around 1 grade, and the degradation of the cultivated grassland and the vegetation has increased the soil erosion, and the land reclamation of the grassland is the land for the urban and rural industrial and mining residents, so that the intensity of the soil erosion is reduced by an average of 1 to 2; The decrease in water area will often result in an increase in the intensity of soil erosion, which, in contrast, has not been used to reduce the total soil erosion better.
【学位授予单位】：中国科学院大学(中国科学院遥感与数字地球研究所)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S157

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