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1.
黄土地区土壤重力侵蚀灰色系统模型研究   总被引:1,自引:0,他引:1  
傅炜 《地理科学》1997,17(2):176-182
介绍了黄土丘陵沟壑区土壤区土壤重力侵蚀灰色系统预测模型的构造原理和方法,并用灰色关联度的方法来反映模型的预测值与山西离石王家沟流域重力观测数据之间的关联性,用以分析模型的预测精度。同时反映了土壤重力侵蚀系统的动态变化规律,引入了残差辨识的理论和方法,以提高模型的预报水平。  相似文献   

2.
黄土高原流域地貌系统的地貌演化特征十分复杂,尚有诸多科学问题有待进一步深入研究。以往研究大多集中在流域地貌演化的侵蚀和发育特征等某一方面,缺乏从流域地貌系统及其势能信息熵的视角深入剖析野外多岩土层黄土小流域地貌演化特征的研究。为此,基于系统论的观点和方法,构建多岩土层黄土小流域地貌系统及其势能信息熵的数学模型,并以辛店沟小流域为例,对其地貌演化特征进行研究。结果表明:(1)构建的野外多岩土层黄土小流域地貌系统的概念模型及其势能信息熵的数学模型能够有效对辛店沟小流域进行数值模拟。(2)以黄土侵蚀作用为主的辛店沟小流域从2000—2019年的地貌演化过程是其势能信息熵的熵减过程和黄土地貌不断侵蚀的过程。(3)辛店沟小流域的势能信息熵能较好地反映该小流域的地貌演化阶段和地貌侵蚀过程。  相似文献   

3.
黄土丘陵区沟谷发育及其稳定性评价   总被引:6,自引:1,他引:5  
本研究选择黄土高原北部丘陵区无定河两个支流米脂河,金鸡河,在对其流域系统河道级数,冲沟和坳沟发育时期进行划分与判断的基础上,计算了各级沟谷及坳沟的“宽深比”,并对其进行了对比分析。研究表明黄土沟谷发育中冲沟发育阶段是沟谷稳定性最差的阶段,而坳沟阶段是沟谷发展的稳定阶段,稳定性的差异可由沟谷W/D值来定量化,据此可预测黄土丘陵区尚有数十万年的沟谷不稳定时期即强水土流失期。  相似文献   

4.
XU Feng  GUO Suoyan 《地理学报》2002,12(4):435-442
This paper discussed the spatial distribution of soil erosion in China at the end of the 20th century based on the second national soil erosion survey. The result indicated soil erosion is still the prime environmental problem in China. Soil erosion mainly occurs in the western regions of China, and the slight erosion type, ion the whole, exerts the greatest impact on soil erosion pattern. The distribution of water erosion shows the impact of landforms: slight water erosion mainly in mountainous and hilly areas, and half of violent water erosion on the loess landforms. Farmland, forestland and grassland are the major land use types of slight hydraulic erosion distribution, while the serious hydraulic erosion and slight wind erosion mainly occur on grassland. Thus, the conservation of the grassland is the key to either hydraulic and wind erosion control. The huangmian soil (a major type of cultivated soil developed from loess mother material) is the one facing the most serious threat from soil erosion in Chinas soil resources. Further discussion on the soil erosion distribution still needs more research on the method and relevant data analysis.  相似文献   

5.
This paper discussed the spatial distribution of soil erosion in China at the end of the 20th century based on the second national soil erosion survey. The result indicated soil erosion is still the prime environmental problem in China. Soil erosion mainly occurs in the western regions of China, and the slight erosion type, ion the whole, exerts the greatest impact on soil erosion pattern. The distribution of water erosion shows the impact of landforms: slight water erosion mainly in mountainous and hilly areas, and half of violent water erosion on the loess landforms. Farmland, forestland and grassland are the major land use types of slight hydraulic erosion distribution, while the serious hydraulic erosion and slight wind erosion mainly occur on grassland. Thus, the conservation of the grassland is the key to either hydraulic and wind erosion control. The huangmian soil (a major type of cultivated soil developed from loess mother material) is the one facing the most serious threat from soil erosion in Chinas soil resources. Further discussion on the soil erosion distribution still needs more research on the method and relevant data analysis.  相似文献   

6.
威连滩冲沟砂黄土的风蚀与降雨侵蚀模拟实验   总被引:3,自引:0,他引:3  
 通过风洞与模拟降雨实验,研究了风力与降雨对青海省贵南县威连滩冲沟砂黄土的复合侵蚀作用。实验得出:①风蚀后的降雨使砂黄土表面在风干过程中形成了一层较为坚硬的结壳,增大了土壤的抗蚀性,降低了第二次风洞实验后期的风蚀率;②土壤水分与人为扰动是影响土壤风蚀的两个重要因素。当土壤水分较小时,风蚀率受人为扰动影响巨大;当土壤水分较大时,人为扰动对土壤风蚀的影响较小;③在持续降雨的实验条件下,砂黄土的产流、产沙量随着雨强的变化而改变。这种变化与表土的侵蚀率、可蚀性物质的多少、土壤水分以及土壤的入渗率等都有很大的关系。  相似文献   

7.
黄土丘陵区坡面形态和植被组合的土壤侵蚀效应研究   总被引:7,自引:0,他引:7  
陈利顶  贾福岩  汪亚峰 《地理科学》2015,35(9):1176-1182
以位于陕北黄土丘陵区的羊圈沟流域为重点研究区,针对不同坡面类型(坡长、坡形、坡度)和植被组合进行野外土壤采样,利用137Cs元素示踪方法评估坡面的土壤侵蚀效应。研究发现:① 坡面形态对土壤侵蚀具有重要影响。自坡顶至坡脚,“直-凹”组合的坡型一般具有相对较低的土壤侵蚀模数,整体上起到“汇”的作用;但“凹-直/凸”组合的坡型具有相对较高的土壤侵蚀模数,在土壤侵蚀方面起到“源”的作用;其他坡型,如直坡、凸坡、“直-凸”和复杂性坡型的土壤侵蚀模数介于两者之间。② 坡面不同植被空间配置对土壤侵蚀的影响具有明显差异。研究发现,坡面植被组合(自坡顶至坡脚)为荒草地-果园、有林地-其他植被类型组合和荒草地-其他植被类型的坡面具有相对较低的土壤侵蚀模数,起到了一定“汇”的功能,但人为干扰较为强烈的景观坡面(无水土保持措施)具有相对较高的土壤侵蚀模数,整体上表现为土壤侵蚀的“源”区。  相似文献   

8.
中国土壤风力侵蚀空间格局及驱动因子分析   总被引:51,自引:2,他引:51  
利用遥感与地理信息系统方法对全国土壤风力侵蚀状况进行了宏观调查,建立了全国1:10万土壤风力侵蚀数据库,对导致土风力侵蚀的原因进行分析,指出风速,土壤干燥度,地表植被指数,土培质地和坡度是土壤风力侵蚀的重要驱动因子,分析了这些因子与土壤侵蚀的空间关系,利用主成份分析方法,建立风力侵蚀动力指数模型,模型输出的风力侵蚀动力指数与全国土壤风力侵蚀遥感调查的结果有较好的一致性,表明土壤风力侵蚀动力指数可以较好地反映地区土壤风力侵蚀过程,并对沙漠化治理有指导意义。  相似文献   

9.
黄土高原地区坡面土壤侵蚀具有明显的垂直分带性,溅蚀片蚀带是坡面侵蚀的最上方地带,研究片蚀过程含沙量变化有助于阐明坡面侵蚀规律。本文采用人工模拟降雨试验方法研究了黄土坡面片蚀稳定含沙量及其影响因素;试验处理包括2种质地的黄土(塿土和黑垆土),2个雨强(90和120 mm/h)和4个坡度(10°、15°、20°和25°)。结果表明:在不同质地黄土、降雨强度和坡度条件下,水流含沙量均呈现先减小后平稳的规律;稳定含沙量与土壤颗粒体积分形维数、降雨强度和坡度呈幂函数关系,稳定含沙量随土壤颗粒体积分形维数的增大而减小,随降雨强度和坡度的增大而增大,影响程度依次为土壤颗粒体积分形维数、降雨强度和坡度;所分析的水动力学指标中单位水流功率与稳定含沙量关系最密切,降雨强度对稳定含沙量的影响大于单位水流功率。  相似文献   

10.
This paper analyzes the spatial variation in soil erosion in the loess hilly-gully region of northern Shaanxi Province, China. It sums up existing research, describes the factors that drive soil erosion, and uses geodetection to investigate the factors individually and in pairs.Our results show that soil erosion in the loess hilly-gully region of northern Shaanxi is mainly hydraulic erosion. There are significant spatial differences in the severity of soil erosion in the region. Generally, it is more severe in the north and west and less severe in the south and east. Individual factor detection results show that the major risk factors affecting soil erosion are human population distribution, precipitation, land-use type, elevation, and soil type. Interactive detection results show that interacting factors play much bigger roles in soil erosion than do individual factors. Based on forced detection results from different periods of time, we can see that forest and grass coverage, urbanization, and economic development in the study area all clearly inhibit soil erosion.  相似文献   

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