| 其他摘要 | Guizhou province is located in the center of a widespread karst region in southwest of China, which is the largest one in the world. In recent years, because the rapid growth of population and economy，irrational destruction of the environment and the predatory use of resources accelerated the deterioration of the fragile karst environment. Rocky desertification problem is becoming more pronounced and growing, it not only put a threat to local people's living environment and economic development, but also restricts the sustainable development of Southwest China and South China as a major obstacle to building a harmonious society and sustainable development. The hazards of rocky desertification have been understood,and afforestation, soil conservation, ecological protection and other rocky desertification control works have been carried out. However, there is not a strong sense that rocky desertification occurred in the case of distribution pattern of the match ecosystems and geological structural features, What's more, small watershed is the basic hydrogeological units in the karst area, it is a complex binary three-dimensional geological body, constituting a relatively independent ecosystem. Only match the characteristics of the geological structure with ecological restoration and reconstruction measures that can achieve more effective government effect. However, due to differences in geomorphology, topography, climate and other environmental factors, a variety of small watershed ecosystems have formed. The watershed classification becomes particularly urgent. Taking ArcGis? as a platform and Guizhou as study area, borrowing Erdas?、Excel?、Spss? software, utilizing with karst watershed automatic extraction technology， The relationship between the spatial distribution of drainage network and the master of natural elements has been analysised quantitativly in Guizhou province. Taking small watershed as research unit, the main natural factors affecting the the classification of small watershed has been discussed. Basing on geomorphic unit, focusing on the lithology analysis, characteristics of small watershed factors have been analysised and cardinged to present classification system of landform+ lithology+ average slope. The following conclusions are drawn from the analysis： I. The drainage network is137678 km long，per square kilometer is 0.78 km in Guizhou province. Because difference of rainfall is not very significant, the drainage density is not increasing with rainfall; their spatial distribution is not entirely consistent. Due to affected by tectonic movement, terrain was uplifted tipsily, along with the river showing that the eastern is dense and the western is sparse. The drainage network density of South China fold system is the largest in Southeastern, the second is Sichuan Taiwan depression, 993.66 m/km2, Weining North West tectonic deformation zone is least which is 574.31 m/km2. The drainage network density of others distributes between 500 m/km2 to 900 m/km2, difference of drainage network is very large in different tectonic, impacted by the structure. In vertical space, slope has big influence on drainage network density. When the slope is ≤2°, and with slope increasing, the drainage network decreases constantly; When the slope is flat relatively (≤ 10 °), with the increase of slope, the drainage network density decreases rapidly, when the slope is large (≥ 30 °), the drainage network density is smaller, the change is slow relatively. Slope is one of the most important factors to Guizhou drainage network distribution in the vertical direction. II. Drainage network density and lithology in spatial distribution have a good coupling relationship, but the geomorphic types have little impact on it in karst. Non-carbonate rock drainage network is 66710 km long, drainage network density is 1000.04m/km2 and the carbonate area drainage network is 70968km long, drainage network density is 648.65 m/km2. the limestone area is 597.16 m/km2, the dolomite area is 779.41 m/km2, Coupling relationship of the river |
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