圖書典藏及影音數位平台

國內自民國88年921地震後，流域土砂問題已成為流域重要災害成因，為疏解此複合性災害所引發二次災害，水利署擬推動新思維土砂經理策略，擬以流域整體治理考量推動，維護流域河川水流正常機能(防洪安全)、土砂運移連續性、水庫庫容、海岸線、生物多樣性保育，避免人為開發衍生流域土砂之問題(土砂生產、運移、沉積失衡)，以減輕國內之土砂災害，推動流域土砂經理有其必要性及迫切性。

Taiwan is located at the junction belt between the Eurasian Plate and the Philippine Sea continental Plate with characteristics of fragile geology, steep slopes, and rapid river flow. During the summer and autumn seasons there are frequent typhoon and storm events that result in severe sediment erosion and transport. The planing of sediment management at a basin mainly belongs to 3 government departments in Taiwan, which are the “Water Resources Agency”, the “Soil and Water Conservation Bureau”, and the “Forestry Bureau.” The new interface of sediment movement also generated because of the different purpose of sediment management in several. In recent years, the Taiwan Government promoted the intergrated plan of sediment managemet at the river-basin scale. Sediment yield and runoff in river basins of Taiwan with a characteristic of high unsteady and non-uniform that caused dramatic changes of erosion and sedimentation in river and seacoast. So the objective of sediment management in Taiwan should maintain the stabilization of topography in the downstream river and seacoast. Basically, the objective is set up an allowance variation range of topography. A plan of sediment management can be made after the management objective finished. To analyze each plan by using field monitor, numerical model and hydraulic model then choose the best one. Specific method for sediment management could refer to the control strategy of Yellow River in China that is using the existing reservoirs to execute the management of water and sediment transport. Some river basins may refer to the Abe River Basin in Japan which is to spread the sediment control into all major tributaries under the condition of no reservoir. There is no standard model on sediment management of river basin, some may have the same but the others are different that requires own effort to achieve. Strengthen the desilting facilities of reservoirs, adjust the strategy of operation on desilting and flushing of reservoirs, control the outflow of water and sediment, and the particle size may correspond the stable condition in the downstream river and seacoast. Integrated multi-reservoirs operation combined with all tributaries on the downstream of reservoirs might be good way for consideration as the water and sediment control strategy in Yellow River. It needs to spread the control works of water and sediment to all major tributaries and its watershed if the major river with no reservoirs. By using different soil and water conservation methods to distribute management each sediment product and flow out. The control items are the water and sediment discharge, density and particle size, such as the Integrated Sediment Management Plan of Abe River Basin in Japan.