Based On Dem Spatial Differentiation Of Surface Drainage Density And Its Tectonic Significance

The relationship between surface water system in plain area and tectonic activity domain problem, which has been widespread concern of geomorphology, sedimentology, structural geology and hydrology, water resources. In the plain, basin, thick layer of loose sediment distribution area, part exists as an insidious form of active faults can be used as the seismogenic structure leads to a potential strong earthquakes occurred even great earthquakes. In North China, population is most concentrated, industrial and agricultural production as one of the most developed regions. The northern Zhangjiakou-Bohai tectonic zone(Zhang Bodai) was established in 1980 s, has been the subject of extensive attention of seismologists and geologists. Zhang Bo area is an important economic development zone in our country large and medium-sized city, Beijing, Tianjin, Tangshan occupies an important position in the Bohai economic circle, especially the emerging industrial zone developed in recent years, Tianjin Binhai New Area of Hebei Caofeidian planning area, Nanpu oil field to make the region to further enhance the economic status, occupies an important position in the national economy and social development, there is a higher requirement for the prediction of seismic damage and seismic fortification level.This paper is based on the ASTER GDEM resolution 30*30m data, combined with RIVER TOOLS3.0, ARCGIS10.0 and SURFER8.0 and other related software, water extraction of large area in North China, and the regional water system to do the statistical analysis, the automatic extraction of drainage density within the region 2 class above water by RiverTools3.0, the drainage density value of the input Surfer8.0 to generate the water density map of North China area. Through the drainage density grid map and Arcgis10.0 interpolation calculation to generate the region comparison, attest to credibility by Rivertools3.0 extract water and related water features. The results show: because the water density in generation process, two kinds of software selected different scales, leading to its water density value range is also changed accordingly, but from a macro can be seen: the water density map generation two methods, high value anomaly in the north area of each basin are concentrated and distributed in the in North China, and along the edge of the basin parallel distribution. While low value anomaly distribution is concentrated in Yanshan, Taihang Mountain uplift and the west of the Loess Plateau, namely Hebei plain edge.Finally, the stream density results of FIG North China, with regional geophysical data corresponding to analyze the distribution pattern density in North River North concealed base structure, Bouguer gravity anomaly, response mode geothermal field seismic zone and the Bohai Bay Basin, and summarizes The main results of this study, as well as shortcomings of the paper, to be further improved.(1) The density map of the response Bohai Bay River sediment thickness in: Depression in the Bohai Bay sediment thickness is large, the deposition thickness of the raised areas are relatively small. Also in the north Zhuoxian, Baoding south side, there is a large river system density and deposition thickness uniformity; mostly in high stream density values at the boundary of the turning point of the Bohai Bay Basin. The deposition thickness of the space density changes and there is a big river consistency, reflecting the North China obviously inherited tectonic movement.(2) Drainage Density Bouguer gravity anomaly in North China’s response: depositing a layer thickness of the horizontal distribution of gravity anomalies with good shape corresponding to the Bohai Bay Basin gravity high anomalies corresponding to the stream density high values, corresponding to the gravity low anomaly area River low density area. In the water system density map with the general outline of the situation better consistency southeast of Beijing, Tianjin northwest side, ningjin term County area, city of Cangzhou and other places near the river density contrast gravity Bouguer anomaly and appears opposite sign.(3) the Bohai Bay Basin geothermal gradient is high, a larger range. Geothermal gradient and the level of their structural position in which the related relationships with regional tectonic very close. In the western Bohai Bay Basin, geothermal gradient contour large river system density map corresponds exactly to the NNE high gradient zone. Taihang Mountains are located along a ridge in Jizhong Depression, Linqing Depression edge, at the junction with the region and raised areas, ground temperature distribution and stream density anomaly distribution, basically in line with the response stream density on the base structure.(4)Quaternary tectonic activity is very active in North China, the Bohai Bay Basin is the most intense seismic activity in North China region. History has repeatedly catastrophic earthquake. River North area density control can be seen: in North China at the earthquake-prone parts of the river just in the corner with a density gradient and the transfer of parts of both extending direction, the conclusion of earthquake prediction, the foothills of the North China Plain to the deposition earthquake prediction disaster is very important.