圖書典藏及影音數位平台

100 年度水規所辦理「南化水庫上游水資源開發調查規劃」， 針對南化第二水庫壩址地質、築壩材料、集水區崩塌地等進行現 場調查工作。101 年度則以前2 年規劃及調查成果為基礎，就水文 及水源複核、工程佈置研擬、維持庫容規劃、施工計畫、工程用 地及工程費、計畫評價等項目進行更進一步探討，並彙整99~101 年三年之研究調查及評估成果為調查規劃階段之總報告。為賡續 推動南化第二水庫規劃，於本(102)年度辦理「南化水庫上游水資 源開發可行性規劃-工程材料調查與評估及環境現況分析」，針對生 態環境進行初步調查，紀錄現地物種資訊，探討生態課題並研擬 相關後續建議，以利後續規劃進行。 二、

Abstract To continue to promote the Nanhua second reservoir planning, feasibility planning work is carried out this year, mainly divided into engineering materials investigation and assessment, and present environmental situation analysis. I. The investigation and evaluation of engineering materials A huge number of damming materials are in demand. To ensure the feasibility of the project planning, we make an overall review for the material in the neighborhood and go through additional investigations. The results are shown as follows. The existing data are categorized into : (1) those for Nanhua Reservoir construction from 1983 to 1989, (2) Nanhua Reservoir raising planning, (3) Tseng-Wen Reservoir cross-watershed diversion planning, (4) Nanhua Reservoir upstream water resources development survey planning result. The discussions are summarized in Table 1. According to the collected data and summarization of the results, the reserve for the core layer of materials in the feeding areas around the project is about 3,660,000 cubic meters, and 23,672,000 cubic meters for shell layer materials. The reserve for aggregate, filter layer, and riprap in Houku River is about 51,000 cubic meters. The reserve in Qishan River should be sufficient for the damming use. Through their constituent material, thickness, distribution range, and the surrounding outcropping strata state, etc., 19 river terraces were selected, as shown in Fig. 1, a total of approximately 189.2 hectares; The core layer material takes precedence to get from terraces within 7.5 km off the Houku River (excluding cultural relics site). Approximately 974,000 cubic meters are available. In the Beiliao borrow area, about 495,000 cubic meters are available, but it is too far away, so the impact on traffic brings about a poor perception. Shale strength in the inundation area is high and fine-grained material content in the Houku River meandering segment is low, and is not suitable for a material source. Shell material from the Houku River riverbed material takes precedence. Approximately 1,421,000 cubic meters are available. Approximately 4,032,000 cubic meters within 7.5 km off the terraces are available. Dam foundation and structures excavate approximately 1,583,000 cubic meters. On the dip slope on the right bank of the dam site upstream about 300 thousand cubic meters of material are stripped. The filtering layer, riprap, or aggregate are attained from the Qishan River or purchased from the Laonong River as priority. The texture of Houku River riverbed material and sandstone along the bank is poor, inadequate for the material source. According to the results of the “Nanhua 2nd Reservoir Installed at Upstream Survey Planning”, for the Nanhua 2nd Reservoir development scale, the optimal planning project should suggest the crest level EL.260M, full water level EL250M, gross storage capacity 12,000,000 cubic meters and available reservoir capacity 10,000,000 cubic meters. The dam site thereof has been infiltrated permanently because of Nanhua Reservoir. Therefore, in addition to the stability, economy and social & environment effect of the Reservoir, the infiltration by reservoir shall also be taken into consideration when evaluating the dam type. According to the evaluation, the available dam types should include zone filled dam, crushed concrete dam, and complex dam. The project also includes concrete gravity dam into the evaluation. In compliance with preceding proposed dam types, after being assessed in terms of geographical conditions, engineering, security, damming material, economic and other factors, as analyzed and ordinated in Table 2, it is recommended preferably to adopt a crushed concrete dam. It demands 474,000 cubic meters of coarse aggregate, fine aggregate of 249,000 cubic meters, and 25,000 cubic meters of fine-grained material, all of which can be gained from the Qishan River or purchased from the Laonong River. The safety factor is greater than 3.0. Cement, pozzolanic materials, and admixtures employ outsourcing. The amount of material meets demand. Nonetheless, in case of variation of subsequent space-time background or related conditions, dam type should be re-assessed. II. The present environment situation analysis The purpose of the survey is to preliminarily understand the surrounding environmental overview of planning area, to accumulate ecological background information, to assess ecological topics possibly resulting from the newly built reservoir and to give suggestions for improvement. Implement items including terrestrial plants, terrestrial animals, aquatic ecosystems, water quality investigation and cultural sites survey, etc. The project is located in the watershed of the Nanhua Reservoir, i.e. the hill area in the south west side of Taiwan, a low-altitude subtropical zone, where the habitat types primarily include forests, orchards, and agricultural land, with low interruption of people and plentiful animal and plant species. The terrestrial plant survey includes collection of literature and data, formation of plant species and establishment of the plant families in the sampled area, and also rare plant species and quantity of giant trees. The Nanhua 2nd Reservoir survey includes formation of family ties primarily consisting of Longan and Manila. According to the analysis on the tree species and structures in the territory, the Longan structure appears to be J-shape, and the natural regeneration ability of such species appears to be very well in Nanhua Area. The survey on terrestrial animals will be conducted in six major zones in the watershed of Nanhua 2nd Reservoir. One set of line transects and one 1km line transect for bird survey will be installed in each sampled zone. To survey the aquatic ecosystems, two survey samples will be installed in the flooded area of Houku River, and one sample installed at each of the upstream non-flooded area Houku River and Ping Ken River, totaling 4 survey samples with the length of 50M, covering fishes (electric appliances/cast net), shrimp and crab (electric appliances/shrimp cage), aquatic insects (Surber net), planktonic algae and attached algae (sampling), and shellfish (line transect survey). The water quality survey location is identical with the aquatic ecosystems survey location. The survey includes pH value, electric conductivity, water temperature, dissolved oxygen, turbidity, SS, NH3-N, total phosphorus, biochemical oxygen demand and colon bacillus. The water quality for said samples will be evaluated based on the river pollution index (RPI). The Terrestrial plant survey recorded plants of 107 families, 331 genuses and 452 species, including the Red Data Book assessed rare plants of five species (ferns of three species, two species of orchid families) and 3 old trees. The Terrestrial animal survey recorded mammals of 16 families and 23 species, birds of 39 families, 79 species, amphibians of 5 families and 19 species, reptiles of 11 families and 24 species, dragonflies of 7 families and 31 species and butterflies of 5 families and 127 species. The Water ecosystems survey recorded fish of 4 families and 10 species, shrimps of 2 families and 2 species, shellfish of one species, aquatic insects of 10 families, 14 species, attached algae of 13 genera and 24 species and planktonic algae of 18 genera and 30 species. Regarding Water quality survey, the river pollution index (RPI) method was used to assess the water quality of various preceding sampling stations, which show the assessment of impact on water quality grade by suspended solids naturally occurring from mudstone geology in the area. Synthesizing the results, we suggest this project should note the conservation of shallow mountain ecosystem, rare plants, old trees, borrow area bat caves, Fairy Pitta, fireflies, and reduction of deaths caused by roads and environmental changes in fish habitat and others. If the development activity avoids or mitigates impact as the first priority or applies some alternative program, but still produces significant adverse impact to biological diversity, the activity shall take the measure for ecological compensation, in order to achieve such purposes as recovery of the original ecological structure and function ruined by the development activity and maintenance of enhanced ecosystems service. The Draft of Regulations Governing Ecological Compensation promulgated by Environmental Protection Administration suggests that the compensation planning shall comply with the following principles: (1) The territories located within the development base shall be the first priority. (2) Create homozygous habitats (3) At least 1:1 compensation ratio (4) Compensation operations shall be earlier than the implementation of development activity. The project is now under the stage of feasibility study. For the time being, the scope of impact to be produced by the reservoir development still remains uncertain. Therefore, we can only provide suggestions about the compensation against habitats based on the known issues and important habitat types. The details about compensation will be studied in the following “Ecological Compensation Plan”.