Error in digital network and basin area delineation using d8 method: A case study in a sub-basin of the Ganga
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- 作者：Brijesh Kumar ; Kanhu Charan Patra…
- 刊名：Journal of the Geological Society of India
- 出版年：2017
- 出版时间：January 2017
- 年：2017
- 卷：89
- 期：1
- 页码：65-70
- 全文大小：
- 刊物类别：Earth and Environmental Science
- 刊物主题：Geology; Hydrogeology;
- 出版者：Geological Society of India
- ISSN：0974-6889
- 卷排序：89
文摘
Digital elevation model (DEM) is one of the input data derived from different satellite sensors for hydrologic and hydraulic modelings. Two prime questions could be answered before using these DEMs. First, the acceptability of datasets for our use and second appropriate resolution of the dataset. Three widely used DEMs SRTM 30m, ASTER 30m and SRTM 90m are analyzed to evaluate their suitability to delineate river network and basin boundary area. The hydrology tool of spatial analyst extension inbuilt in ArcGIS 10.2 (which uses the D8 method for calculation of flow direction) has been used for the delineation of both river networks and basin boundary. The assessment of river network alignment and boundary delineation is carried out in the seven sub-catchments of Gandak river basin having different morphological characteristics. The automatically delineated boundary area for all the three DEMs reflects a significant difference when compared with the digitized basin area from the Ganga flood control commission (GFCC) map. The maximum boundary area delineation error is 39137.20 km2 forASTER 30m, and minimum delineation error of 13239.28 km2 for SRTM 90m. In the stream network, delineation accuracy is good for SRTM 90m while, except Gandak trunk, ASTER 30m DEM shows better delineation accuracy indicated by mean absolute error (MAE) and standard deviation (SD).