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黄土高原地质灾害发生规律 总被引：2，自引：0，他引：2
《山地学报》2019,(5)
我国每年约有30%地质灾害发生在约占国土面积6%黄土高原地区,灾害数量多、危害严重、机理复杂,然而由于对黄土灾害的发生规律仍然不明晰,长期以来制约了区内大型工程建设、移民搬迁选址等工作。依托1:5万黄土高原区地质灾害调查数据,通过专题要素图件编制和数理统计等手段,重点分析11680处地质灾害,总结了灾害时空分布规律。结果表明,1)在区域地质构造抬升的背景下,黄土高原地形破碎,地貌沟壑纵横,具有滑坡、崩塌、泥石流等地质灾害多发的特点。2)地质灾害具有明显的时空发生规律,在整个黄土高原区域尺度上,地貌演化与斜坡结构控制地质灾害空间分布和斜坡破坏模式;在流域尺度上,老年期、壮年期、幼年期等沟谷发育期控制着地质灾害变形破坏模式及危害程度;在具体斜坡点上,坡型、坡度、坡高等坡体几何形态控制地质灾害的类型和失稳概率;在时间上,降雨及冻融作用控制年内地质灾害的分布。 相似文献
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黄土高原侵蚀期研究 总被引：22，自引：12，他引：10
黄土高原在沉积的同时也存在着侵蚀,主要是流水、重力等因素造成的。这种侵蚀会受到气候、构造运动以及人类活动控制。资料显示,黄土高原存在3种基本的侵蚀期,一是气候侵蚀期,二是构造侵蚀期,三是人为因素侵蚀期。此外还有气候与构造共同作用产生的侵蚀期和构造与人类共同作用产生的侵蚀期。温湿期风尘堆积少,降水量增多,流水动力增强,是黄土高原理论上的侵蚀期。构造抬升引起侵蚀基准面下降,进而导致黄土高原加快侵蚀,出现构造侵蚀期。人类活动破坏了黄土高原的植被和土层结构,导致黄土高原侵蚀加剧,从而出现了人类因素引起的现代侵蚀加速期。在黄土发育的冷干期,由于植被稀疏,侵蚀量大于温湿期,但堆积量远大于侵蚀量。要改变现代侵蚀状况,就应当加强黄土高原生态环境治理。 相似文献
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黄土高原现代侵蚀强度的空间差异早就为人们所知,有关方面的科学家已作了黄土高原的侵蚀分区(参考文献省略)。随着时间的推移和资料的局限,现行的黄土高原侵蚀分区已不能完全适应当前生产和水土保持工作的需要。为了适应新的形势,急需以新 相似文献
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黄土高原分形沟网研究 总被引：10，自引：1，他引：10
推测认为黄土高源沟网具有分形性。根据Hoton定律推导沟网分维计算式，确定沟网分形结构，分形理论求算得小流域沟网的分维D＝1．9接近于平面空间时的D＝2理论值。统计分析发现流域边界周长、长轴、短轴、长短轴比、汇合角等地貌指标随流域面积的变化。从而证明黄土高源流域的自相似性。 相似文献
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硬化地面与黄土高原水土流失 总被引：3，自引：2，他引：1
在界定硬化地面概念的基础上,进一步将硬化地面分为道路、城镇街区、农家场院三大类。并利用黄土高原400~600mm集流能力试验公式,对甘肃省陇东黄土高原沟壑区不同硬化地面的集流能力、侵蚀量进行分类实例分析研究,发现硬化地面集流能力远大于自然地面,因此城镇、道路、村庄附近的土壤侵蚀尤其严重。在黄土高原地区,不仅与之相关的沟壑的形成和发育,而且相关沟谷和河流的溯源侵蚀之力度大小也要受其影响。随着人口的增加,硬化地面面积越来越大,受其影响水土流失更加严重,这是历史时期黄土高原水土流失日益加剧的重要原因之一。今后黄土高原的水土保持工作,须将防治水土流失与解决水资源紧缺有机结合起来。其最佳解决途径,就是用硬化地面所集中的雨水,作为工农业生产和生活用水,以解决黄土高原水资源之不足。 相似文献
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Conversion of cropland to forestry and grassland is an important method to reduce soil erosion and improve the biophysical environment in the Loess Plateau. The feasibility, methods, and environmental effects of cropland conversion were studied based on 11 typical watersheds of national experimental bases instead of different geographic areas of the Loess Plateau. Between 1986 and 2000, cropland, sloping cropland and non-agricultural land decreased by 8%, 92.5% and 8% respectively, while forestry increased by 15.7%. The land use change not only decreased annual soil erosion by 74%, but also increased vegetation coverage by 100% and improved the soil condition and biodiversity. This can be achieved by building basic farmland, increasing capital and scientific input, and planting trees and grasses according to the natural biophysical restrictions. 相似文献
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WANG Fei LI Rui JIAO Feng YANG Qingke TIAN Junliang 《地理学报(英文版)》2005,15(4):484-490
1 Introduction The soilerosion in Loess Plateau is mostserious on the globe mainly due to the destroying of naturalvegetation and cultivation on slope land overextensive areas(Yang and Yu,1992;Jiang, 1997).To convertsloping cropland (cropped land on slope… 相似文献
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The spatio-temporal characteristics of net primary productivity (NPP) since implementation of the Grain to Green Program (GTGP) are important for understanding ecological restoration of the Loess Plateau in China. Here, we conduct spatio-temporal analysis of NPP using MODIS datasets (500 m, 8-day intervals) and VPM (Vegetation Photosynthesis Model) from 2000-2015. We found that NPP on the Loess Plateau increased significantly from 2000 to 2015 (p<0.05). Significant increases in NPP were observed in core areas of the GTGP, including northern Shaanxi and Lüliang Mountain in Shanxi. NPP in alluvial plains decreased due to urban expansion into cropland. Significant increases in NPP from 2006-2010 were located north of the area of change in 2000-2005. NPP increased across three vegetation types and four slope gradients. In hilly-gully regions prone to soil erosion, such as central and southeastern parts of the Loess Plateau, obvious vegetation restoration was detected. 相似文献
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Developing an effective approach to rapidly assess the effects of restoration projects on soil erosion intensity and their extensive spatial and temporal dynamics is important for regional ecosystem management and the development of soil conservation strategies in the future. This study applied a model that was developed at the pixel scale using water soil erosion indicators (land use, vegetation coverage and slope) to assess the soil erosion intensity in the Loess Plateau, China. Landsat TM/ETM+ images in 2000, 2005 and 2010 were used to produce land use maps based on the object-oriented classification method. The MODIS product MOD13Q1 was adopted to derive the vegetation coverage maps. The slope gradient maps were calculated based on data from the digital elevation model. The area of water soil-eroded land was classified into six grades by integrating slope gradients, land use and vegetation coverage. Results show that the Grain-To-Green Project in the Loess Plateau worked based on the land use changes from 2000 to 2010 and enhanced vegetation restoration and ecological conservation. These projects effectively prevented soil erosion. During this period, lands with moderate, severe, more severe and extremely severe soil erosion intensities significantly decreased and changed into less severe levels, respectively. Lands with slight and light soil erosion intensities increased. However, the total soil-eroded area in the Loess Plateau was reduced. The contributions of the seven provinces to the total soil-eroded area in the Loess Plateau and the composition of the soil erosion intensity level in each province are different. Lands with severe, more severe and extremely severe soil erosion intensities are mainly distributed in Qinghai, Ningxia, Gansu and Inner Mongolia. These areas, although relatively small, must be prioritised and preferentially treated. 相似文献
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Evaluation of the ecological effects of eco-compensation policies helps analyze policy rationality and feasibility and provides scientific and practical bases for perfecting eco-compensation systems. Taking the key ecological function area of the Loess Plateau, China as a case study, we have evaluated ecosystem responses to the Grain-for-Green Project that commenced in 1999. Six indicators were selected to assess changes in ecosystem structure, quality and function. The results showed that implementation of the Grain-for-Green Project has reduced sloping cropland by 1571 km2 and increased ecological land by 1337 km2. The increase in ecological land alters ecosystem structures across the study area and the decline in sloping cropland reduces farming activity interference; both of these are conducive to the restoration of natural vegetation. From 2000 to 2010, the vegetation cover of grassland, desert and forest ecosystems increased 10.89%, 8.34% and 4.24% respectively and average NPP rose 51%, with an average annual growth rate of around 5%. This indicates that eco-compensation has promoted the improvement of ecosystem quality. Total biomass of ecosystems increased two times on average from 2000 to 2010, meaning that the carbon sequestration capacity of ecosystems also increased. The reduction in the area of water loss and soil erosion and the increase in retained runoff by forests indicate an improvement in ecosystem function and services on the Loess Plateau. 相似文献
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黄土丘陵沟壑区典型小流域土地持续利用案例研究 总被引：24，自引：5，他引：24
本文选择我国水土流失最为严重的黄土丘陵沟壑区作为研究地区,通过野外调查、土地利用填图,结合区域国民经济发展规划提出了4种基本土地利用规划方案附加2种保护性耕作措施;开展了生态适宜性、经济可行性和社会可接受性评价。提出:在得到大量外部经济支持的前提下,应积极实行15°以上的坡耕地全部退耕还林还草的方案,其中在中等坡度的地区(15°-25°)应发展果园和经济林;若缺少外部强有力的经济支持,该区土地利用调整应逐步开展,短期内(约0-5年),建议坡度大于25°的坡耕地逐步退耕还林还草,其中,坡度大于25°,地形条件较好的地区应种植果园和经济林;中期(约5-10年),坡度大于20°的黄土地区应逐步退耕还林还草,其中坡度介于20°-25°之间的地区应转变为果园和经济林;10年之后,建议大于15°的坡耕地全部转变为其他用途,其中坡度介于15°-25°的黄土地区应转变为果园和经济林,坡度大于25°的地区转变为林地/灌丛和草地 相似文献
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黄土高原水土流失区生态退耕对粮食安全的影响 总被引：11，自引：0，他引：11
退耕还林是黄土高原水土流失区改善生态环境的一种有效途径,但在一定程度上必然会影响到区域的粮食安全,其中最直接最主要的影响便是退耕带来耕地面积减少,引发粮食总产量的降低。根据黄土高原水土流失区的生态退耕规划,对退耕还林还草可能对当地造成的粮食生产影响进行分析。利用具有显著科学性和可操作性的最小人均耕地面积和耕地压力指数模型,对该区各亚区进行了粮食安全评价,并以此为基础提出了黄土高原水土流失区各亚区退耕还林还草与粮食安全的协调途径。 相似文献
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本文利用遥感技术通过典型区的分析,对黄土高原土地退化现状及其成因过程进行了深入研究。结果表明,黄土高原地区由于特殊的自然条件,加以长期人类活动影响,土地退化十分严重,并处于不断发展之中,主要表现为水土流失和土地沙化等。 相似文献
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黄土高原典型地区土壤侵蚀共性与特点 总被引：19，自引：1，他引：19
通过对黄土高原典型地区土壤侵蚀以往的研究结论进行综合分析，在比较土壤侵蚀相似性和差异性的基础上，对这些典型地区土壤侵蚀的共性与特点进行了研究，结果表明：1、黄土高原典型地区土壤侵蚀影响因素有降雨、地形及土地利用；2、黄土高原各典型地区主要侵蚀类型为水蚀及重力侵蚀；主要侵蚀发生时间为汛期；主要侵蚀空间分布特征为具有垂直分带性；3、绥德地区侵蚀产沙强烈，天水地区侵蚀相对轻微，安塞地区各种侵蚀特征典型。西峰地区土壤侵蚀特殊。 相似文献
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基于遥感调查数据集定量分析了1990—2015年中国黄土高原地区耕地的时空变化特征和口粮绝对安全最小耕地保障面积的数量变化。结果表明：黄土高原耕地面积从1990年的192 529.65 km2至2015年的182 688.50 km2，净减少了9 841.14 km2，幅度达5.11%，其中2000—2010年的减幅最大，净减少8
483.00 km2；较大的耕地动态变化图斑主要分布于中部和西部区域，细碎的变化图斑广泛分布；耕地地类转出面积（31 875.82 km2）大于转入面积（21 815.25 km2），耕地面积的增加主要由草地和林地转化而来，主要分布在灌溉农业区和东南部平原区，减少的耕地主要转化为草地和林地，主要分布在中部沟壑区的雨养农业区。此外，该时期耕地转化为建筑用地和交通用地等人工表面的面积逐渐增加，主要分布在东南部低海拔平原地区；黄土高原口粮绝对安全所需最小耕地保障面积呈明显减少特征（从1990年的70 913.37 km2下降到2015年的33 981.64 km2），占该区耕地总面积比例呈明显缩减态势（从1990年的36.83%缩减到2015年的18.60%），目前耕地总量的净减少未对口粮绝对安全的耕地保障数量造成大的影响。 相似文献