GIS的黄土高原典型小流域地貌发育定量化分析

选取黄土高原典型小流域作为研究对象,黄河的泥沙主要来源于黄土高原腹部陕北黄土高原,面积高程积分常常用来判定侵蚀地貌区域地貌发育阶段,面积高程积分作为揭示流域活动性重要指标之一,在流域地貌发育宏观定量研究中起重要作用。根据Davis侵蚀循环学说,把流域地貌发育划分为幼年期、壮年期和老年期,流域地貌演化越长侵蚀越严重,面积高程曲线也从最初的凸形到S形直至最后的凹形,面积高程积分值也从0.6到0.35.文章在回顾了地貌发育历史和地貌发育定量研究基础上,利用面积高程积分去定量化描述黄土高原典型小流域地貌发育阶段,并且提出新的研究方法并加以验证。根据不同阶段对地貌发育的判定,结合不同学者的研究成果,利用地理信息系统技术,尝试通过地理信息系统技术判定流域地貌发育阶段,结合地貌学,地理学,以ARCGIS和EXCEL作为技术平台,对流域地貌发育加以分析并且提出改进方法。利用面积高程积分可以很明确的确定流域地貌属于地貌发育青年期,侵蚀比较严重,利用体积高程积分替代面积高程积分,分析结果具有一致性。面积高程积分在研究地貌发育定量研究中,虽比较准确,但是体积高程积分具有形象直观,计算快速,计算结果和实际比较符合等优点,不失为研究地貌发育阶段的一种可靠方法。

Quantitative analysis of landform development in the typical small watershed in Loess Plateau Based on Geographic Information System

The Yellow River sediments mainly come from north shaanxi Loess Plateau, this paper chose typical small watersheds in Loess Plateau as research object. Hypsometric Integral is often used to reflect the landform erode stage and evolution process. As one of the important indicator of watershed evolution characteristics, Hypsometric Integral plays an important role in macroscopic quantitative analysis of land- form evolution in watershed scale. On the basis of Davis＇ theory of erosion cycle, landform evolution in watershed can be divided into young stage, mature stage and old stage. The longer the evolution, the se- vere the erosion, and the shape of Hypsometric curve changed from initial convex to ＂S＂ and finally to concave, the Integral value is also ranged from 0.6 to 0.35. Based on the review of landform evolution and its quantitative research, this paper quantitatively described the development stage of landform evolution of typical small watershed in Loess Plateau by the use of Hypsometric Integral. In addition, a new method is proposed and tested, on the basis of different stages of landform evolution and achievements of several scholars, this paper tried to determine and analysis the development stage of watershed landform by the combine use of Geographic Information System, Geomorphology and geography, and ArcGIS and Excel as technology platform, the result shows that the watersheds are in mature stage, and erosion is rel- atively serious. Instead of Hypsometric Integral, volume elevation integral has similar results in experi- ment. although Hypsometric Integral is relatively accurate, volume elevation integral is more intuitive and visual, and faster in computation. In addition,its results are closer to actual fact, and it will be a reliable method to study the development stages of landform.