| Sihe River Basin crisscrossed rivers, water clouds, has always been belong to population, resources, industry-intensive areas, the rapid development of the economy, capital River provides a valuable resource for Sihe River Basin's rapid economic development, and the basin of the river system natural state has been subjected to different degrees of damage in order to meet human development, Construction of water conservancy project is an important means of river functional development. It could control the flow of water, prevent flood disaster, adjust and distribute water quantity. Although they meeted the needs of human development, they weakened connectivity of the water system. In addition, the changing of climate and rapid development of urbanization, many natural rivers had been destroyed. Specific performances were as follows, large decrease in water area, sharp drop in the number of river network, drying-out of river, river length reduction, disappearing in the end of the river, simple structure of river system; river channel deposition, reduction of water storage, falling on the storage capacity; divided by the road of river system, sluggish in the river internal access; blocked in the water cycle, insufficient flow. Water system structure and connectivity changes made water cycle path seriously blocked. Many factors have different extent affected the basin water system connectivity. Accordingly, they reduced the regulation and storage of water in the river, the water quality purifying and water balance maintaining. Meanwhile, they threatened the safety of flood control and Increased the environmental ecological pressure. The water ecological environment of the river was more serious. The health of river ecosystem and the development of social economy in this area are influenced. Therefore, this study based on existing observational data for many years in the basin and the actual needs of the project to change the law Sihe River Basin Hydrologic preliminary analysis and summary, intended to reveal the regularity; at the same time, combined with the actual situation of the Si River, considering and other urban social and ecological factors, select the relevant indicators to study Sihe River Basin connectivity evaluation and the impact on water dispatching aqueous connectivity to explore for flood mitigation in the watershed and improve water conservancy construction provides technical negative impact on river health support, and draw the following conclusions:1) Changes in precipitation and surface water resources as well as the amount of Sihe River Basin water level, flow, flood and other water regime in closely related genetically linked, and was affected by the dammed-up water project construction and the storage function.2) Sihe River Basin water system connectivity by basin reservoir, sites for blocking effect is obvious, lateral connectivity index was 38.94%, the longitudinal connectivity coefficient is 2.49, the connection rate index was 3.54, the actual index is 0.62, spent connection degree is 1.16, the overall evaluation for inferior quality.3) Water scheduling can effectively use water in the basin upstream abandoned water, water, etc., and simulate the water dispatching in the region maximize in order to maximize the dammed-up water as the goal. It can significantly increase the capacity of regional water supply volume and improve water system connectivity, make water resource allocation more reasonable, in the study area offset caused by water conservancy project construction drainage pattern connectivity becomes poor. It can also improve river connectivity, within the basin water conservancy engineering construction planning, and support the river ecological restoration. |
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