圖書典藏及影音數位平台

塔羅灣溪治理計畫於99年公告至今已14年，其時空背景及土地利用、水文、環境、地形等條件已變遷，且今年遭逢卡努、海葵颱風豪雨重創後，原治理計畫擬定之計畫保護標準、治理管理對策及水道治理計畫與用地範圍線..等有必要重新加以檢討修訂。

Taluowan River is one of the important tributaries of Jhuoshuei River. After the Fourth River Management Branch, Water Resources Agency, and Ministry of Economic Affairs took over river management in 2007, they completed the river management plan from 2008 to 2009 and announced the river management plan in 2010. , however, because in 2012 the Nantou County Government announced the hot spring area management plan (abolition of the Lushan Hot Spring Area), it has been more than 13 years, and after being hit hard by heavy rains from typhoons such as Kanu and Haikui in 2023, its temporal and spatial environmental background, land use , hydrology, topography and other conditions have changed. It is necessary to review and revise the planning protection standards, treatment and management countermeasures, waterway treatment plan and land use boundary lines drawn up in the original 2010 announced treatment plan, and promote the announcement of the treatment plan. procedures to provide the basis for the implementation of subsequent river governance and management plans.The Taluowan River basin is located on the western slope of the Central Mountains, within the two villages of Renai Township, Jingping and Hehe. The basin has the Hualien River basin to the east, the upper reach of the Jhuoshuei River to the north and west, and the Wanda River basin to the south. The mountains in the basin are highly undulating, and most of the tributaries are cut into narrow valleys. There are also sporadic terrain surfaces on the tops of steep valleys. The flat terrains are the most developed at 2,200 to 2,400 meters. They may be relics on the flat surfaces of high mountains. There are more continuous terrains in the Lushan area. The Jiaojiao steps extend northward to Weishangshan area. In terms of terrain slope, DEM classifies the terrain slope of the basin. The total area occupied by slopes 1 to 7 is 7433.81 hectares, of which the area occupied by slopes above grade 5 is about 92.87%. The length of the main stream is about 18.20 kilometers, the height difference of the basin is about 2,331 meters, and the average slope is about 1/8. The main stream of the tributary Mahaipu River is about 12.2 kilometers long. The altitude difference in the mountainous area where it originates is about 1,905 meters, and the slope is 1/6.In terms of flood disasters, the Taluowan River is a mountainous river. Flood disaster losses are mostly concentrated in the losses of crops in the downstream. Previous floods have often caused soil and sand deposition in the river channel. In recent years, the Kanu typhoon has caused more than 1,000 millimeters of heavy rain in Renai Township, and about 600,000 cubic meters of soil and sand have been silted. Buildings on both sides of the road have been submerged, landslides have broken out, roads have been buried or roadbeds have been hollowed out and interrupted, leaving residents trapped in Renai Township; Haikui Typhoon Due to more than 400 millimeters of rainfall in the upper reaches, nearly 100,000 cubic meters of earth and rock were deposited; both sides of the river below the Lushan Suspension Bridge were once again engulfed by floods due to the Kemi typhoon, and the water level was also approaching the Lushan Suspension Bridge and Steel Bridge. It was initially estimated that nearly 400,000 cubic meters of earth and rock were deposited. ruler. The main causes of disasters are mostly poor geological and hydrological conditions in the basin and insufficient sand transport capacity of local river channels. In addition, both sides of the river are affected by man-made development, and the river channels for water and sand transport have become narrower, forming a high disaster risk area.In recent years, affected by Typhoons Kanu and Anemone in 2012 and Typhoon Kemi in 2013, the Taluowan River has often surged and heavy rains have exceeded the warning standards for landslides, causing buildings on both sides to be submerged, landslides to break out, roads to be buried, or roadbeds to be hollowed out. break. According to interviews and surveys, the main targets for flood control and preservation are that the Nantou County Government announced the abolition of the Lushan Hot Spring Area in May 2011, and many areas along the route have been designated as protected areas, prohibiting any form of development activities. As of August 2013, the Lushan Hot Spring Area has not yet been There are 4 illegal hot spring operators and 14 operating shops, but they are all outside the river area line. Therefore, after inventory, there are currently no preservation objects (such as shops, restaurants and homes) within the land area.Based on the hydrological analysis results of this plan, the 113-year cross-section measurement results, and the results of river bed quality sampling and analysis results of this plan review, simulations were carried out in conjunction with the flood peak flow rate at each return period of each control point in this analysis. The outlet refers to the water level of Taluowan River Section 13-1 in the Jhuoshuei River System Large Section Measurement Plan in 108 of the Republic of China as the starting water level, and the Manning roughness coefficient was affected by river dredging and disturbance of the river bed before sampling, so the sampling results may be inconsistent. Due to the concern of underestimation, it was adjusted to 0.04 with reference to the Manning n value table of the river course to calculate the flood carrying capacity of each section of the Taluowan River. It has been calculated that the flood carrying capacity of Taluowan River section 5~8-2 in the Lushan Hot Spring Area has mostly failed to meet the 2-year return period standard, and the river conditions (water level, flow rate) are extremely unstable.The soil and sand production volume of the Taluowan River Basin is 8.8 million cubic meters, of which approximately 6.4 million cubic meters will be transported downstream with floods or landslides, while 2.4 million cubic meters of soil and sand will be trapped within the basin. , showing that there is still a large amount of soil and sand left in the basin. When a flood event occurs in the future, the remaining large amount of soil and sand may move downstream with the stream water, which may harm the downstream preservation objects. Therefore, how to avoid a one-time downward movement of soil and sand, causing serious soil and sand disasters downstream. , is an important issue currently encountered.The comprehensive water control strategy in this basin is not a simple flood treatment strategy. It must integrate water, soil and forest to develop the best flood prevention and disaster reduction plan, and take the Benxi River boundary point (1 km upstream of the Lushan Suspension Bridge) as the upper and lower Downstream demarcation. Looking at the current flood control projects, there are no protection objects on both sides of most river sections, and their flood discharge capacity can still meet the planned flow rate; only the river sections with obvious protection targets have been protected by Typhoon Kanu and Typhoon Haikui in 112 of the Republic of China. The facility project was buried by a large amount of soil and sand. However, due to the efforts of the Fourth River Management Branch, Water Resources Agency, and Ministry of Economic Affairs, the deep channels of the main river channels have been initially dredged. However, in the 113th year of the Republic of China, Typhoon Kemi and Typhoon Santoer occurred. It also carried part of the slope soil and sand, and accumulated more than 200,000 cubic meters. Therefore, from a general perspective, there is no need for improvements such as flood diversion and dredging in Benxi. We only need to consider the use of river channel sand to contain floods, dredging, river channel arrangement, soil and rock removal, and hillside management and other management measures.The treatment measures revised this time take into account that the local residents are far away from the river terrace land and there are no preservation objects, so the adjustment is to use river area line management (cooperating with dredging operations, concentrating water and sand to strengthen the basic flood drainage capacity and sand discharge capacity) , subject to maintaining the natural stability of the river; therefore, there is no addition or reconstruction of river defense structures, and there is no economic evaluation of related project costs, construction sequence, and physical improvement projects. However, the current river environment, riverside landscape improvement, improvement of life quality and community economy Taking other considerations into account, dredging, vegetation removal, or river channel adjustment should still be carried out from time to time based on the river sedimentation situation to maintain the river’s flood capacity. In addition, Section 05 to Section 08 are sections of the river that are constricted, fast-flowing, and have high scour potential. It is necessary to strengthen flow rate and large-section detection. In addition to increasing water gauges and monitoring systems to strengthen monitoring, the Fourth River Branch of the Department should conduct structural inspections and detect river bed erosion and siltation every year, maintain necessary flood clearance space, and ensure surrounding preservation objects. safety, and through riverbank construction and green beautification, the role and intangible value of Benxi’s blue-green connection in the urban area will be enhanced.The overall flood control infrastructure (low-water bank protection) of the Taluowan River is generally complete. Considering that there are currently no protection objects (residents and businesses) on both sides of the river section, after previous discussions, there is no addition or reconstruction of river protection structures in this revision, so there is no project. Expenses and program costs, and related benefits. Although this plan does not have an economic evaluation of the physical improvement project, considering the current river environment, riverside landscape improvement, improvement of life quality and community economy, it is still necessary to conduct dredging, vegetation removal or river arrangement from time to time depending on the river sedimentation situation to maintain the River flood capacity. In addition, in view of the overall low-water bank protection in key river sections such as Section 05 to Section 8, there have been few floods in the past years that have attacked the infrastructure of facilities on both sides of the river. In addition to increasing water gauges and strengthening monitoring by the surveillance system, the Fourth River Branch of the Department should conduct annual Structural inspection and detection of river bed erosion and siltation conditions, maintaining necessary flood clearance space, and ensuring the safety of surrounding preservation objects.