Terrain Classification Index (25 m Grid Data) (WMS Service)

The Terrain Classification Index = (TCIlow) is a dimensionless index in the range of 0-2. It exaggerates the slightest elevation differences, especially in low ranges. Even with the slightest relief differences, clots and flat sinks are recognizable. In the vicinity of anthropogenic structures such as dikes, dams or heaps, residues or artifacts can distort the values. The relief classification index TCIlow is based on the corrected and thinned grid (DGM25) and is calculated from the complex relief parameters height over depth line, catchment area size and modified soil moisture index (BOCK & Böhner & CONRAD & KÖTHE & Ringeler (2007).
BOCK, M. & BÖHNER, J. & CONRAD, O. & KÖTHE, R. & RINGELER, A. (2007): Methods for creating Functional Soil Databases and applying Digital Soil Mapping with SAGA GIS. — In: Hengl, T. et al. (EDS.) Status and prospect of soil information in south-eastern Europe: soil databases, projects and applications. — EUR 22646 EN, 149-163, Scientific and Technical Research series, Office for Official Publications of the European Communities; Luxembourg.

地形分类指数（TCIlow）是取值范围为0至2的无量纲指数。该指数可放大微小的高程差异，尤其在低幅值起伏区间内表现显著。即便地表起伏差异极微，也能清晰辨识出地表斑块与平坦洼地。在堤坝、水坝或堆体等人工构筑物周边，残留物质或人工遗物可能会导致该指数的计算值出现畸变。
地形分类指数TCIlow基于经过校正与抽稀的格网数据（DGM25），由复合地形参数——高程-深度比线、汇水面积以及修正土壤湿度指数计算得到（BOCK等，2007）。
BOCK, M.、BÖHNER, J.、CONRAD, O.、KÖTHE, R.、RINGELER, A.（2007）：《用于构建功能性土壤数据库及应用SAGA GIS开展数字土壤制图的方法》。——收录于：Hengl, T. 等（编者）《东南欧土壤信息的现状与展望：土壤数据库、项目与应用》。——EUR 22646 EN，第149-163页，《科学与技术研究丛书》，欧洲共同体官方出版物办公室；卢森堡。