Remote sensing methods as a base for landform and soil maps of the Iranian loess plateau

位于伊朗北方土库曼大草原的伊朗黄土高原，是一个被黄土覆盖的独特景观，至少有70米厚。近年来的沉积学和年代学研究表明，这些黄土沉积物具有很高的第四纪景观演化和气候变化记录价值。此外，这些沉积物提供了东南欧和中亚黄土沉积之间的联系，因此对地层对比非常重要。黄土高原面积约2250平方公里，位于戈尔甘河和阿特雷克河的交汇处，流经北方阿尔博尔兹山脉和科佩达赫山脉的东部。构造抬升、深切侵蚀和河谷下切黄土及下伏地层，造成黄土高原明显的地形起伏。山脊高出谷底约80 m，大部分由黄土组成。频繁出现的黄土威尔斯、陷穴、管道和冲沟反映了地表和地表以下的强烈侵蚀过程。土壤发育与坡向密切相关，因为在北方山坡上，植被保护土壤表面不受侵蚀，并促进形成和保存的雏形土，而在南面的山坡上，土壤可能受到侵蚀，形成了发育较弱的红壤。关于土壤和植被、高原地形特征以及土地利用潜力和问题的空间信息非常有限。对于黄土高原地貌、土地利用和土壤分布的综合记录、分析和解释，遥感可以提供关键的数据和工具。必须考虑到遥感数据的不同来源。在这里，高分辨率立体卫星图像将被用来推导出详细的数字高程模型（1米）的异质景观在两个测试区。此外，其他可用的多光谱和高光谱卫星图像将用于获取整个黄土高原的信息。这些数据将有助于绘制某一地区的地图，其中载有关于地形特征、岩性和土地使用的信息。导出的参数可以进一步用于导出拟议区域的数字土壤图。特别是，将通过与涉及地面激光扫描、差分全球定位系统挖沟和地面实况绘图的实地活动数据进行比较，评价高分辨率遥感数据（1米）对这一特定地形的适用性和准确性。不同数据源的汇编将增强我们对黄土高原地貌特征、岩性单元、土壤和植被的空间分布以及这一偏远地区地貌演化的认识。

The so called Iranian loess plateau, located in the Turkmen steppe of Northern Iran, is a unique landscape covered by loess, up to at least 70 m thick. Recent sedimentological and geochronologcial investigations show that these loess deposits have high value as records of Quaternary landscape evolution and climate change. In addition, these deposits provide a link between loess deposits in Southeastern Europe and Central Asia and are thus of large importance for stratigraphic correlation. The loess plateau covers an area of about 2250 km2 and is located in the interfluve of the rivers Gorgan and Atrek, which drain the Northern Alborz Mountains and the eastern part of the Kopeh Dagh ridges. Tectonic uplift, deep erosion and valley incision into the loess and underlying strata caused the pronounced relief of the loess plateau. The ridges rise to about 80 m above the valley floors and mostly consist of loess. Frequent loess wells, sink holes, pipes and gullies reflect intense erosion processes at the land surface and below. Soil development strongly relates to slope aspect, because on northern slopes vegetation protects the soil surface against erosion and facilitates formation and preservation of a Cambisol, whereas on south-facing slopes soils were probably eroded and weakly developed Entisols formed. Very limited spatial information is available on the soil and plant cover and the relief features of the plateau, as well as on potentials and problems in land use. For the comprehensive documentation, analysis and interpretation of the landform, land use and soil distribution within the loess plateau, remote sensing may provide crucial data and tools. Different sources of remote sensing data must be regarded. Here, high-resolution stereo satellite imagery will be used to derive detailed digital elevation models (1 m) for the heterogeneous landscape in two test areas. Furthermore, other available multi- and hyperspectral satellite imagery will be used to derive information for the entire loess plateau. The data will enable to establish maps of a certain area containing information on landform features, lithology and land use. The derived parameters can be further used for the derivation of digital soil maps of the proposed area. In particular, the applicability and accuracy of high-resolution remote sensing data (1 m) for this specific relief will be evaluated by a comparison to data of a field campaign that involves terrestrial laser scanning, DGPS trenching and ground truth mapping. The compilation of different data sources will enhance our knowledge on the spatial distribution of relief features, lithological units, soils and vegetation in the loess plateau as well as on the geomorphological evolution of this remote region.