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我国冻融侵蚀现状及防治对策 总被引：1，自引：1，他引：1
冻融侵蚀普查是水利普查中水土流失普查的重要内容之一。在冻融侵蚀普查工作中,采用我国自主建立的冻融侵蚀评价模型和评价指标体系,获得了全国冻融侵蚀强度、面积和空间分布情况数据,揭示了我国冻融侵蚀的空间分布特征。成果显示:我国冻融侵蚀区总面积为172.48万km2,其中轻度以上冻融侵蚀面积为66.096万km2,分别占我国陆地国土面积的17.97%和6.89%。在冻融侵蚀分布的8个省(区)中,西藏的冻融侵蚀面积最大,约占全国冻融侵蚀面积的48.90%,其余省(区)冻融侵蚀面积由大到小依次为青海、新疆、四川、甘肃、内蒙古、黑龙江、云南。 相似文献
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基于多源地空耦合数据的青藏高原冻融侵蚀强度评价 总被引：2，自引：1，他引：1
[目的]分析和探讨青藏高原冻融侵蚀成因及其空间分布格局,为研究区水土保持研究和生态环境保护提供数据支撑和决策参考。[方法]引入冻融侵蚀动力因子(冻融期降雨侵蚀力和冻融期风场强度)和冻融期降水量(表征冻融期土壤相变水量)构建冻融侵蚀评价模型,进而对青藏高原冻融侵蚀状况开展了定量评价和空间格局分析。[结果]构建的冻融侵蚀评价模型在青藏高原地区具有较高的适用性,总体评价精度为92%;青藏高原冻融侵蚀面积分布广泛,占总面积的63.68%,而非冻融侵蚀区则主要分布于柴达木盆地、雅鲁藏布江流域下游以及横断山区;冻融侵蚀强度随着坡度的上升而增加,15°~24°和≥24°坡度带上冻融侵蚀剧烈,而≤3°坡度带冻融侵蚀强度相对较小;不同植被类型区的冻融侵蚀强度空间分布格局差异显著,其中草甸的冻融侵蚀强度最小。[结论]青藏高原冻融侵蚀状况总体上属于中度侵蚀,其空间分布格局受地形、植被类型和气候影响显著。 相似文献
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西藏冻融侵蚀空间分布规律 总被引：6，自引：0，他引：6
西藏是我国冻融侵蚀最主要的分布区,也是受冻融侵蚀危害最为严重的区域。以影响冻融侵蚀主要因子为指标所建立的评价模型对西藏冻融侵蚀进行分级评价所得出的结果为依据,分析了西藏冻融侵蚀的空间分布规律。分析结果表明：（1）西藏冻融侵蚀分布范围广大,冻融侵蚀总面积达664 317.4 km^2,占该区国土面积的55.3%;（2）西藏冻融侵蚀的区域分异明显,不仅不同强度冻融侵蚀具有不同的区域分布特征,而且冻融侵蚀地区分布差异明显,每个地区都有不同于其他地区的冻融侵蚀空间分布特点;（3）西藏冻融侵蚀垂直分异明显,不同强度冻融侵蚀的百分比构成随海拔高度的升高而呈现有规律的变化,冻融侵蚀在垂向上的分布具有在海拔较低区域和较高区域分布面积小、强度大,中间区域分布面积大、侵蚀强度小的特点。 相似文献
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对国内冻融侵蚀相关研究成果及相关工作做了分类与归纳。冻融作用对土壤水分、土壤结构及土壤养分的影响具有双向性,众多学者多采用室内模拟的方法研究冻融侵蚀。介绍了目前我国部分省已开展的冻融侵蚀预测与监测的相关经验以及待解决的问题。 相似文献
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基于GIS的三江源区冻融侵蚀评价与分析 总被引：3，自引：1，他引：3
三江源区由于其高海拔、高纬度和低气温的气候特点而成为冻融侵蚀较严重的区域,因此开展其冻融侵蚀强度的研究对区域合理的生态环境规划和生态环境保护方案制定具有积极作用。该文采用归一化方法和冻融评价模型,利用影响冻融侵蚀的主要因子气温年较差、降水量、坡度、植被盖度和太阳辐射进行定量研究与分析,结果表明:三江源区冻融侵蚀区分布面积较广,占源区总面积的75.7%,其中长江源区的冻融区面积比最大,其次是澜沧江源区和黄河源区。3个流域的冻融侵蚀均以中度侵蚀为主,但它们在侵蚀强度等级构成和不同强度等级所占比例均存在显著差异,总体而言长江流域的冻融侵蚀相对最严重。相同强度冻融侵蚀区在空间上积聚,不同强度冻融侵蚀空间分异明显,呈现出由东向西的低-高-低-高侵蚀的带状分布特征。尽管该区域内存在多个高值和低值区交叉分布的现象,但它们的主要影响因素存在一定的差异,其中西部地区以植被覆盖和太阳辐射为主,而东部地区以降水、坡度和太阳辐射为主。 相似文献
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我国冻融侵蚀的调查方法 总被引：4，自引：0，他引：4
冻融侵蚀是我国仅次于水蚀和风蚀的第3大土壤侵蚀类型,也是第1次全国水利普查水土保持情况普查的土壤侵蚀类型之一,其普查方法的制定和正确运用对普查结果有重要影响.通过介绍冻融侵蚀范围的确定方法和冻融侵蚀强度评价方法,阐述冻融侵蚀分级评价中涉及到的年冻融日循环时间、日均冻融相变水量、年均降水量、坡度、坡向和植被盖度等6个因子的计算流程、赋值标准和权重,以及普查过程中各个环节的质量控制措施.研究结果对于完善我国冻融侵蚀的调查方法以及科学评价冻融侵蚀的现状、发展趋势和预测预报等具有重要意义. 相似文献
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Vegetation significantly influences human health in the Yellow River basin and the plant cover is vulnerable to people. Typical types of erosion in the Yellow River basin include that caused by water, wind and freeze–thaw. In this paper, vegetation cover change from 1982 to 2006 was studied for a number of different erosion regions. The Global Inventory Monitoring and Modeling Studies Normalized Difference Vegetation Index (GIMMS NDVI) data were employed, while climatic data were also used for analysis of other influencing factors. It was shown that: (1) generally the vegetation cover in different erosion regions displayed similar increasing trends; (2) spatially the vegetation cover was highest in the water erosion region, the second highest was in the freeze–thaw region and the lowest in the wind erosion region; and (3) vegetation cover in the Yellow River basin is influenced by climate factors, especially by temperature. In water erosion regions, the temporal change of vegetation cover seemed complicated by comprehensive climatic and human influences. In wind erosion regions, the vegetation cover had close relations to precipitation. In freeze–thaw erosion regions, the vegetation cover was primarily altered by temperature. In all the three erosion regions, significant change of the vegetation cover occurred from 2000 just after the ‘Grain for Green’ (GFG) programme was implemented throughout China. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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《国际水土保持研究(英文)》2023,11(1):86-96
The southeastern Tibetan Plateau, which profoundly affects East Asia by helping to maintain the stability of climate systems, biological diversity and clean water, is one of the regions most vulnerable to water erosion, wind erosion, tillage erosion, freeze–thaw erosion and overgrazing under global climate changes and intensive human activities. Spatial variations in soil erosion in terraced farmland (TL), sloping farmland (SL) and grassland (GL) were determined by the 137Cs tracing method and compared with spatial variations in soil organic carbon (SOC) and total nitrogen (total N). The 137Cs concentration in the GL was higher in the 0–0.03 m soil layer than in the other soil layers due to weak migration and diffusion under low precipitation and temperature conditions, while the 137Cs concentration in the soil layer of the SL was generally uniform in the 0–0.18 m soil layer due to tillage-induced mixing. Low 137Cs inventories appeared at the summit and toe slope positions in the SL due to soil loss by tillage erosion and water erosion, respectively, while the highest 137Cs inventories appeared at the middle slope positions due to soil accumulation under relatively flat landform conditions. In the GL, the 137Cs data showed that higher soil erosion rates appeared at the summit due to freeze–thaw erosion and steep slope gradients and at the toe slope position due to wind erosion, gully erosion, freeze–thaw erosion and overgrazing. The 137Cs inventory generally increased from upper to lower slope positions within each terrace (except the lowest terrace). The 137Cs data along the terrace toposequence showed abrupt changes in soil erosion rates between the lower part of the upper terrace and the upper part of the immediate terrace over a short distance and net deposition on the lower and toe terraces. Hence, tillage erosion played an important role in the soil loss at the summit slope positions of each terrace, while water erosion dominantly transported soil from the upper terrace to the lower terrace and resulted in net soil deposition on the flat lower terrace. The SOC inventories showed similar spatial patterns to the 137Cs inventories in the SL, TL and GL, and significant correlations were found between the SOC and 137Cs inventories in these slope landscapes. The total N inventories showed similar spatial patterns to the inventories of 137Cs and SOC, and significant correlations were also found between the total N and 137Cs inventories in the SL, TL and GL. Therefore, 137Cs can successfully be used for tracing soil, SOC and total N dynamics within slope landscapes in the southeastern Tibetan Plateau. 相似文献
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黄河中游,尤其是以黄土丘陵沟壑区为代表的那些多沙区的侵蚀产沙是引起黄河下游河道严重淤积的主要原因。在这些地区,水力侵蚀、风力侵蚀、冻融侵蚀是其主要的外侵蚀因素。其中水力侵蚀已经得到比较深入的研究,风力侵蚀也已引起人们的空前重视,而对该区的冻融侵蚀的关注却相对薄弱。实际上,冻融侵蚀对这些地区沟道的作用非常显著。从黄河中游丘陵沟壑区冻融侵蚀的环境背景、作用机理和表现方式等方面展开论述,并根据沟道的岩性特点、沟道侵蚀量大小及对一些实测资料对比,初步认为砒沙岩区的冻融侵蚀量可以达到沟道产沙量的一半左右,最大可达流域侵蚀量的1/3左右。 相似文献
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辽宁省冻融侵蚀发生的气候环境条件分析 总被引：2，自引：1，他引：2
利用辽宁省1961-2006年的气温、降水等资料,分析了近46a来辽宁地区气温和降水变化对冻融作用与冻融侵蚀的影响.结果表明:辽宁地区气候变化主要表现在年平均气温的波动上升且十分显著,而降水呈波动下降趋势;年内冬、春季节平均气温增加率较高,以2-4月比较强烈;冬季降水基本不变,其它季节降水均减少.在气温和降水变化的情况下,辽宁地区土壤冻结期有推后的趋势,解冻期有提前的趋势,所以冻融期有所缩短,土壤化通期有所提前.此外,土壤冻结深度有减小的趋势;随着初春(3月)温度的显著上升,冻融侵蚀有加剧的趋势. 相似文献
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秃尾河流域暴雨洪水产沙特性的研究 总被引：13，自引：3，他引：13
用秃尾河流域实测降雨洪水泥沙资料 ,对流域的暴雨洪水泥沙特性做了较为全面系统的分析 ,阐明了秃尾河流域泥沙来源 ,揭示了冻融侵蚀、风蚀和水蚀的共同作用是导致高含沙水流发生的机理 ,以及次暴雨洪水泥沙输移比小于 1的特性 ,为多沙粗沙区流域治理提供了科学依据 相似文献
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未完全解冻层对黑土坡面降雨侵蚀的影响 总被引：2，自引：1，他引：2
春季解冻期土壤侵蚀受未完全解冻层影响较大,以东北黑土为研究对象,通过室内降雨模拟试验,分析未完全解冻层对土壤侵蚀总量及侵蚀速率的影响.结果表明:在所选水平内,低含水率黑土侵蚀总量随着初始解冻深度增加而减少;高含水率黑土在h=10mm水平上侵蚀总量最大;侵蚀速率均呈现先增大后减小的变化趋势,在20min降雨时间内,总会出现一个侵蚀速率峰值,不同初始解冻深度峰值出现时间并不完全相同;当h=5mm和h=10 mm时,未完全解冻层阻水作用都比较明显,侵蚀量差异主要在试验初始阶段,也就是说,土壤含水率只是在试验最初阶段起着一定作用,随着入渗量增多,土壤逐渐达到饱和,二水平之间侵蚀量差异较小,相反这一阶段未完全解冻层隔离作用被充分体现. 相似文献
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以我国东北草甸土为研究对象,采用人工模拟降雨方法,分析试验区冻融环境及春季解冻期室外降雨侵蚀过程。结果表明:温度大体经历了降温、稳定和升温3个阶段,对应地表土壤经历了冻结、稳定冻结和融化3个过程;表层土壤在冻结和融化的两个过程中都经历了冻融作用,其中10月末至12月初和2月中下旬至3月上中旬均是地表土壤经受冻融交替作用强烈的时期,特别是融化阶段是控制春季解冻期土壤侵蚀的关键时期;冻融前后土壤含水率减小19%、土壤容重减小8.9%;整体土壤侵蚀速率表现为增加趋势;小雨强解冻深度浅的处理,侵蚀速率增加幅度不大,坡面细沟以宽浅型为主;大雨强侵蚀速率波动性增强。 相似文献
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春季解冻期白浆土融雪侵蚀模拟研究 总被引：1，自引：0，他引：1
采用室内人工模拟融雪水冲刷试验,研究了春季解冻期冻融温差、循环次数、土壤初始含水率、融雪水流量和解冻深度这5个控制因子对白浆土侵蚀的影响。结果表明,影响土壤侵蚀的首要因素为融雪水流量。春季解冻期土壤发生侵蚀主要集中在前15次冻融循环过程中,之后即使冻融循环次数增加,侵蚀量增幅也不明显。土壤含水率变化与侵蚀量之间线型关系不明显,初始含水率较小的土壤侵蚀量大于初始含水率较大的侵蚀量。在径流冲刷过程中,融雪流量的大小和土壤冻层的存在,共同影响解冻深度与侵蚀量大小之间的关系。当融雪流量较小时,土壤解冻深度越小侵蚀量越大,二者间呈负相关关系;反之,当融雪流量较大时,土壤解冻深度与侵蚀量之间呈正相关关系。 相似文献
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Haoming Fan Yujia Liu Min Wu Lili Zhou 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2017,67(6):510-517
Snowmelt-induced rill erosion could bring serious harm for soil quality and agricultural productive conditions of slope farmland in the black soil zone of Northeast China. In this study, we conducted laboratory experiments to investigate the effects of the freeze-thaw (FT) temperature, number of FT cycles, water content, flow rate, and thaw depth on rill morphology and erosion amount in two common soil (black soil and albic soil). The thaw depth obtained the maximum range, which was the primary factor for the width-to-depth ratio of rills in the black soil; whereas, the flow rate obtained the maximum range as the primary factor for rill erosion in black soil and albic soil. The number of FT cycles had a minor effect on rill erosion in the two soils. Under the same conditions, the rill morphology showed a large difference between the two soils, and higher rill erosion occurred in albic soil than black soil. Rill erosion was relatively high in black soil and albic soil when the FT temperature fluctuated around 0°C during freezing-thawing. The water content exhibited a greater effect on rill erosion in black soil than in albic soil. The unthawed frozen layer could promote rill erosion during snowmelt period to some extent. The results could provide some reference for future study snowmelt-induced rill erosion mechanism and preventive measures. 相似文献
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草甸土近地表解冻深度对坡面降雨侵蚀影响研究 总被引：2，自引：0，他引：2
采用室外人工模拟降雨实验,研究了春季解冻期近地表草甸土解冻深度对该时期坡面降雨侵蚀过程的影响。结果表明:土壤解冻深度对入渗、产流以及侵蚀量有较大影响。由于降雨过程中冻土层逐渐向下移动,解冻土层厚度增加,坡面产流和入渗也随之经历着此消彼长的过程。对同一降雨强度,解冻深度愈小,坡面初始产流时间愈早,前期侵蚀率愈大,土壤侵蚀总量也愈大,但降雨后期侵蚀率增幅减小。随着降雨时间的延长,坡面随解冻深度不同发生不同程度的细沟侵蚀。降雨前期解冻深度越小,降雨过程中发展为细沟侵蚀的时间越早,侵蚀强度也越严重,降雨过程中侵蚀率大小的变化也受到细沟发育程度的影响。 相似文献