Current Browsing: terrain


1:250000 DEM map of the middle reaches of Heihe River (2005-2007)

DEM (digital elevation model) is the abbreviation of digital elevation model, which is an important original data for watershed terrain and feature recognition. The principle of DEM is to divide the watershed into M rows and N columns of quadrilateral (cell), calculate the average elevation of each quadrilateral, and then store the elevation in a two-dimensional matrix. Because DEM data can reflect the local terrain features of a certain resolution, a large amount of surface morphology information can be extracted by DEM, which includes the slope, slope direction and the relationship between cells of watershed grid unit [7]. At the same time, the surface water flow path, river network and watershed boundary can be determined by certain algorithm. Therefore, to extract basin features from DEM, a good basin structure model is the premise and key of the design algorithm.

2020-07-28

Topography of the Heihe River Basin

"Heihe River Basin Ecological hydrological comprehensive atlas" is supported by the key project of Heihe River Basin Ecological hydrological process integration research. It aims at data arrangement and service of Heihe River Basin Ecological hydrological process integration research. The atlas will provide researchers with a comprehensive and detailed background introduction and basic data set of Heihe River Basin. The topographic map of Heihe River Basin is one of the basic geographic part of the atlas, with a scale of 1:2500000, positive axis isometric conic projection, and a shading map made of 90m SRTM DEM data. Data source: 90 m SRTM DEM, 1 million administrative data of Heihe River Basin in 2008, road distribution data of Heihe River Basin in 2010, residential area distribution data in 2009, and 100000 River distribution data in 2009.

2020-03-05