圖書典藏及影音數位平台

本計畫針對鳥嘴潭人工湖上游集水區土砂災害、水源水質等二標的，先蒐集或監測綠覆蓋率、崩蝕率、逕流率、懸浮固體濃度、含砂濃度、污水處理率等資料，再依國內既有土砂生產環境健檢模式，選用崩塌率及綠覆蓋率指標評估集水區土砂環境健康狀況，並針對集水區內非點源污染進行調查分析，有效降低水源污染，強化鳥嘴潭上游水源保護。最後，研擬集水區上游水源保護及策略，以為本局水庫集水區保育、水質優化及防災救援等工作之參考依據，是為本計畫計畫緣起。

Abstract I. Introduction In order to protect the water quality and quantity effectively , this study aims on the soil disaster, water quality and quantity within the watershed of the Naiaozuitan Artificial Lake, , through investigation on the situation of the watershed and evaluating the soil-yielding and water quality environment by the approach of「The Plan of Water Source Conservation Examination on Reservoir Watershed」to provide the basis of the watershed integrity. Via evaluating the soil management and water quality improvement approaches to search and develop countermeasures, in terms of health examination of watershed, watershed, to conducts the control of total-amount of contamination and furthermore, by taking consideration of the needs of human activity and ecosystem to seek the strategy of pollution reduction and cut down on the risk of water pollution. The research results and development of the strategies of upstream watershed can served as a basis of watershed conservation, water quality improvement, disaster prevention and rescuing plan of the management organization. II. Basic data collection of reservoir watershed Niaozueitan Artificial Lake and river barrage are located Kui shan bridge 5 km upstream, the use of Wuxi South Bank land planning - off-slot artificial lake, used to store abundant and dry, with the advantages of stable water supply, simple land use, engineering feasibility and small impact of development environment impact, in order to understand the artificial lake upstream set In the current situation of water quality and quantity in the water area, the basic information of the upper and middle watershed of the artificial lake of the Niaozueitan Artificial Lake will be collected, including (1) geotextutical materials, (2) hydrological data, (3) humanities data, (4) ecological data, (5) The relevant research projects and conservation management work in the past. III. Large-scale environmental monitoring Collecting the analysis from 2009 to 2017, it can be seen that most of the slopes in the watershed are relatively stable. In recent years, the largest new collapse in 2010 has been the largest. The newly added collapse area in the year reached 518.99 hectares, mainly in the previous year which caused by Typhoon Morakot. The large-scale typhoon event in 2013 was only Tianyu Typhoon and Sura Typhoon, and its path had less impact on the mountainous areas of central Taiwan. Therefore, the scale of newly added collapsed land in this year was the smallest, and the newly added collapse area was 95.92 hectares. During 2017 to 2018, there were experienced several large rainfall events, for example: heavy rain on June 1st , June 13th, Oct 11th in 2017 year, and heavy rain on June 13th , June 19th in 2018. However, the area of newly added collapsed areas has decreased by 10.2 hectares. The collapsed land is mainly concentrated in the middle and upper reaches of the sub-watershed, including the north port stream and the upstream slope of Meixi River. The sub- watershed of the downstream of Nangang River, the upper reaches of Nangang River and the upstream slope of Shuichangliu River are occasionally collapsed, and the distribution is sporadic. The change of the re-cultivation site is also like the new collapsed land, mainly concentrated in the northern slopes of Beigangxi and Meixi, and the other sub-catchments are scattered. IV. Reservoir catchment survey The current situation of the watershed is to understand the type, cause, scale and location of the disaster within the scope and to study the soil sand and water quality control measures according to their local characteristics for reference in the conservation implementation plan. According to the plan requirements, on-site investigations were conducted on (1) wild stream and gully survey (2) earth-rock flow potential stream survey (3) collapse land survey (4) road water and soil conservation area survey. Therefore, according to historical data, planning reports, and local visits, the order of the stream flow of the earth-rock flow is mainly based on the M106-3, DF019, and DF247; the collapsed land treatment sequence is the number 4, 15, and 16 of the collapsed land. V. Environmental monitoring of soil sand production in reservoir watershed 1. Soil environmental health check The plan uses the sedimentation rate, the erosion rate, the forest coverage rate, and the sand concentration as the health inspection indicators for the soil sand production environment in the artificial lake watershed of the Niaozueitan Artificial Lake. As for the sedimentation rate, the artificial lake in the Niutan Lake is still in the planning stage, and the relevant measured capacity cannot be obtained. Therefore, the river section measurement result is used as the sedimentation rate. Collecting the data of the section of the Wuxi River section from 2009 to 2013, it was understood that all the river sections are dominated by scouring, and the average section of the river is scoured -0.15 meters. In terms of the rate of collapse, the satellite imagery before and after flood season was used for interpretation in 2018. Since there was no major rainfall event in the watershed in the flood season in 2018, the erosion rate decreased, and the 0.45% before the flood season slightly decreased to 0.43. %, the sub- watershed with the highest erosion rate is the upper reaches of Beigangxi and the middle reaches of Beigangxi. The calculated values before the flood season are 1.3% and 1.25%, respectively, and 1.27% and 1.32% after flood season. In addition, the comparison of the depth of collapse is compared with other major reservoirs in the island of Taiwan. It is found that the artificial lake watershed of the Niutan Lake has a lower collapse depth than the other reservoirs of the island, which is only 0.18 cm. Replaced "green coverage" with "forest cover" to accurately calculate the dense forest coverage within the forest area, rather than orchards and tea gardens, to accurately understand the changes in forestry. The overall forest coverage rate of the artificial lake basin in Nizuitan was 87.1% and 84.2%, respectively, with a slight decline. In terms of sand concentration, the water resources annual report data was used to establish the flow-sand volume rate curve--Wuxi Bridge, Nanbei Tongqiao and Guanyin Bridge to carry out annual sand transport changes. It is found that since 103 years, the sand concentration in each river section has gradually increased. In 106 years, the sand concentration of Wuxi Bridge and the North-South Bridge has reached a maximum of 11.37 Mt/year and 6.73 Mt/year respectively. 2. Soil and sand environmental assessment The annual average soil sand production in the artificial lake watershed of Beimoutan was 2.73±2.10mm (2.86±2.20Mm3). The average daily soil sand output depth in the watershed is 0.007mm/day (0.007Mm3/day), and the average daily soil sand storage depth is 21mm. (22Mm3) or so, belonging to the state of balance of soil and sand. VI. Water quality environmental health check in reservoir watershed The pollution source survey aims to understand the structure of the pollution source and grasp the location of the pollution source as a reference for the reduction strategy. 1.Pollution load inventory The source of river pollution can be divided into point source and non-point source according to the way of river discharge. Point source pollution refers to the location of specific discharge sources such as domestic sewage, industrial wastewater, and livestock wastewater and garbage seepage water. Non-point source pollution, also known as surface pollution, refers to the distribution of storm runoff, agricultural return water and other means. Faceted. The point source pollution load in the upstream watershed of the artificial lake of Nizui Lake is 30,686,635 kg-year, and the non-point source pollution load is 3,383,634 kg-year. 2. Water quality assessment Through the water quality assessment index and RPI, the water quality monitoring data of the Wuxi River Basin of the Environmental Protection Department was used for analysis. Therefore, it has been found that the RPI changes in the water quality stations in the upstream and upper watersheds of the artificial lake in the Niutu Lake have been observed. It is known that most of the dry periods in the upper watershed of the Niuzi Lake are not (slightly) polluted, during the wet season. It is often affected by upstream scouring, and the suspended solids are high, causing the river pollution index (RPI) to be mostly mild or moderately polluted. And due to the monitoring indicators for monitoring water quality and eutrophication are carried out by Carlson single parameter determination and eugenicization standard, the parameters are mainly evaluated by the total phosphorus concentration in river water quality. From the results of monitoring the concentration of total phosphorus, it can be seen that the watershed in the upper watershed of the Niaozueitan Artificial Lake is in a state of poor nutrition. 3. Water quality source The main influence on the water quality of Beigang River is that the suspended solids in the upstream water flow into the river, causing the suspended solids in the river water to rise; and the water quality in the Nangang River is affected by the increase in the number of people in the water. 4. Water quality station Refer to the Environmental Protection Department’s announcement "Setting and Monitoring Guidelines for Water Quality Monitoring Stations", the principle of setting up river water quality monitoring stations, and add water quality stations, Daqiqiao and Beishankeng Bridge. VII. Implementation Strategy and method 1. Conservation Plan During the implementation period, we achieved the goal of reducing soil sand disasters and improving water quality in the upper reaches of the Wuxi River Basin to ensure stable water supply and sustainable use of water resources. The artificial lake in the Niaozueitan Lake is in the form of a trough-type artificial lake. Therefore, the main key issues are focused on water quality improvement and soil sand control, and then four corresponding strategies are developed (monitoring inspection and water conservation, decontamination and weight reduction, hierarchical partition management, and tree planting). Sand control and soil conservation), the planning period is 2019 to 2012, and the estimated expenditure is NTD 984,938,000. 2.LID Demonstration area promotion proposal location The project evaluation and analysis of the characteristics of the water collecting area of the Niaozueitan Artificial Lake, the water and geography factors, the land use, the non-point source pollution area and the current status of the treatment are suitable for promoting the LID location. According to the principle, it is recommended to use Ganfeng Bridge, Yanfeng Bridge Right Bank and Changliu Guoxiao as demonstration areas, and achieved a reduction target of 50% reduction through the LID facility. 3. Point source pollution reduction facilities give priority to promoting areas It is recommended to use double-cold settlements, Beigang settlements, and tortoise settlements in the areas of pollution hotspots, social foundations, community consensus, community friendly environment experience, and exemplary transfer value.