A Study On Structure Characters Of Surface Drainage System In Karst Areas Of Guizhou Province

The particularity of geology, landform, physiognomy in karst areas leads to the formation of a development of river basin water system also has its typical characteristics. This paper discusses the surface water system in karst area of Guizhou province, the study of this problem based on two questions: first, the structure of the surface water system of the karst area of the internal parameters characteristics and its development; Second, the scale effect of surface water structures in karst area. In order to investigate the structure of the internal parameters of surface water system characteristics and development regularity of karst regions, based on the map of Xifeng county as a typical landscape in Guizhou karst, in Leishan county as the normal landform areas, corresponding on the 1:50 000 topographic maps to extract the water system, its internal structure parameters are calculated respectively, and comparative analyzed. As for the scale effect of karst region water system structure research, we selected Houhe river basin and Xiaoluwo river basin in map of Xifeng county as the research object, and extracted the same basin in different scales of water systemin 1:10 000 and 1:50 000 topographic map, and then we can get the differences of the drainage structure in different scales. Based on ArcGiS platform and its statistical features, in combination with Horton- Strahler classification principles to extract data, and using the Excel software to analyze data, using quantitative methods to look for the characteristics of the surface water system structure of the karst area. The results show that:(1) In karst area, the drainage form varied. Development of dendritic drainage, not only convergence drainage pattern, but also in the negative areas development a significant part of the star system. In the surface water system, there are quite a part of the lower surface drainage downwards into the underground water system, one of them to 4 are part of the channel into the underground, to form the underground water system.(2) The waterway system developed in Karst area is more sparse, and the waterway were performed in the channel frequency and water channel density characteristic value is less than normal landscape area, karst area respectively is 6.21 / km2 and 2.75 km/km2; Normal landform areas respectively 21/km2 and 6.86km/km2. Results further demonstrated that karst area drainage network is sparse, lack of surface water resources is the conclusion.(3) Downscaling, there is not much impact on the overall shape drainage network, but it is a change of the internal details. With the downscaling, it will increase the degree of bending waterways, to form a more meandering river. And at the edge of drainage network, it will lower neonatal many waterways.(4) Pushed down as the scale, the drainage network structure characteristic value were increased, and the drainage structure with regional scale effect, the terrain is more complex, relative elevation difference larger basin, scale effect more apparent, difference is bigger. Height of the terrain is relatively simple, relatively small watershed, scale effect is not obvious...