【作者】 石迎春；

【导师】 邵景力； 石建省；

【作者基本信息】 中国地质大学(北京) ， 地下水科学与工程， 2012， 博士

【摘要】 本研究针对砒砂岩地区强烈的沟谷侵蚀问题和国家对于黄河中游多沙粗沙区侵蚀预测预报的需要，总结前人在黄土高原相关研究的经验，采用遥感技术和地理信息系统等手段，分析了砒砂岩典型分布区沟沿线的形态特征变化以及侵蚀形式，建立了研究区的沟沿线及多种影响因素数据库。在基于概率统计的基础上，对研究区内影响因素对沟沿线的变化进行了单因子分析，并利用信息量模型建立了沟沿线分别来自于缓坡和陡壁侵蚀的风险度评价模型。该研究对深化砒砂岩区地形地貌改变的科学认识、制订科学的水土保持规划提供了参考。本研究取得以下主要结论和成果：1．利用面积—高程法分析了研究区内的地貌演化状态。研究区内的斯特拉勒积分值指标S为0.441，说明研究区内的地貌演化正处于壮年期，侵蚀作用将会长时间地存在。2．利用两期遥感数据分析了研究区内沟沿线演化的形态特征和侵蚀形式。缓坡侵蚀引起的沟沿线后退距离大，陡壁侵蚀引起的沟沿线后退距离小，但陡壁侵蚀由于发生频率更高，因此侵蚀产沙量比缓坡侵蚀大。3．分析了地形地貌因素、地表覆盖因素、土地利用因素和谷坡地层结构因素对沟沿线变化的影响：（1）谷坡坡度越陡，沟沿线发生缓坡侵蚀的机率越小，发生重力侵蚀的机率越大；（2）缓坡侵蚀更易于发生在阳坡上，陡壁重力侵蚀更易发生在阴坡上；（3）水流长度越大，沟沿线发生缓坡水力侵蚀机率越大；（4）缓坡面上，最易遭受侵蚀的是风积沙，其次是沙黄土及第三系泥岩，最后是砒砂岩。在陡壁上，沙黄土及砒砂岩，都易发生陡壁重力侵蚀，而风积沙却能防止陡壁重力侵蚀的发生；（5）稀疏的灌木林根本起不到抵抗侵蚀的作用，而且在一定的条件下，中等灌木林都有被继续侵蚀的可能。耕地和天然荒地中出现陡壁侵蚀的比例较高，出现缓坡侵蚀的比例较小；（6）在沟谷地层结构方面，没有泥岩出露的浅沟更容易遭受来自缓坡的水流冲刷，但是泥岩层数的增多越易引起陡壁重力侵蚀的发生。4．以信息量模型为基础建立了研究区内沟沿线分别遭受缓坡水力侵蚀和陡壁重力侵蚀的风险度模型。分别对1987年沟沿线的缓坡侵蚀风险度和陡壁侵蚀风险度进行了分区，并利用该模型对2006年的沟沿线进行了评价。结果表明，相较于1987年沟沿线，2006年沟沿线抵抗缓坡侵蚀的能力大大减弱了，而抵抗陡壁重力侵蚀的能力则有所增强。5．风险度评价方法能为水土保持工作者们提供更具有针对性的水土保持方案，具有一定的适用性。第一是因为考虑的影响因素比较全面，第二是影响因素的获得比较容易，第三是模型的易于操作性。更多还原

【Abstract】 Aimed at the strong gully erosion and the prediction requirement for erosionfeatures in Pisha sandstone area of Middle reaches of Yellow River, based on theresult of gully erosion research on the Loess Plateau, using the Remote sensing andGIS technology, the author analysed characteristics of gully shoulder lines movingbackward and erosion styles in the typical zone of Pisha sandstone, and constructedthe database including shoulder lines and all the effecting factors. Based on theProbability and Statistics theories, the effect factors on the shoulder lines movingbackward were analyzed singlely, and erosion risk modes about the shoulder linesfrom gentle slope surface erosion and from steep slop surface erosion wereconstructed respectively. This research improved the application references on theland features of the Pisha sandstone area, and provided beneficial inquiry for relevantwater and soil conservation rules.The present study came to make important results and achievements as thefollowing.1. Using the method of Area and altitued, the land topographic features of studyarea were analyzed. According to the Strahler integral value S in 0.441, this area wasin the period of maturity phase. This proved that the erosion would last a long time tillPeneplain formed.2. Based on two stages of high spatial resolution remote sensing images, thecharacteristics of gully shoulder lines moving backward and their erosion types in thestudy area were summarized. In the study area, both the frequency and the amount oferosion on the steep slope surface were larger than that of the gentle slope surface.Nevertheless, the erosion occurint on the gentle slope surface makes the shoulderlines move backward for a longer distance.3. Effect of factors, including terrain features, surface soil type, land utilizationtype and gully stratum structures on gully shoulder lines moving backward wereanalyzed. The results were as follows: (1) With the increasement of gully slope, theprobability of gentle slope erosion was smaller, and that of steep slop erosion wasbigger. (2) The gentle slop erosion was inclined to appear on the sunny slopes, but thesteep slop erosion with the gravitational erosion was inclined to appear on the shadyslopes. (3) The flow length determined shoulder lines moving backward for the gentleslope erosion, but for the steep slop erosion, its effect was not distinctly. (4) For thegentle slop surface erosion, the series of soil erodibility is aeolian sand, sandy loessand Pisha sandstone. But the steep slop erosion tended to occur on sandy loess andnaked pisha sandstone fractures, furthermore, the Aeolian sand can prevent theoccurrence of steep slop erosion. (5) Sparse shrubbery cover could not prevent the water and soil loess both for the gentle slope eroion and steep erosion, even under acertain condition, the medium shrubbery cover could not prevent them too. On thecultivate land and natural land, it is earsier to occur the steep slope gravity erosion,and the probability of gentle slope water erosion is small. (6) On the shallow gullieswithout mudstone layer, the probability of gentle slop erosion is high, but more layersof mudstone could increase the probability of steep slop erosion.4. Based on the information mode, modes of erosion risk on shoulder lines forgentle slope erosion and steep slope erosion were constructed separately. According tothese modes, shoulder lines of 1987 and 2006 were all divided to four types of erosionrisks. Comparaing to the erosion riskes of 1987 shoulder lines, the capability of 2006shoulder lines resisting gentle slop erosion decreased, but the capability for steepslope erosion increased.5. The method of risk assessment has certain applicabilities, and can provice"nuts-and-bolts" suggestions for those water and soil conservation rule makers.Because the effecting factors were overall in som extent and they were easily toobtain. Lastely, the mode was easy to construct.更多还原