圖書典藏及影音數位平台

「曾文溪水情預警系統檢討規劃建置」委託案保固期間（自101年6月18日至104年6月24日止），執行廠商配合本局需求辦理維護及進駐諮詢服務，經統計共進駐15場事件、時數735.5小時，平均每年5場事件、245小時。進駐人員協助操作水情預警系統，依本局需求進行水情資料蒐集、預估及分析等，提供本局於緊急應變操作參考。 本系統完工將屆3年，系統運算時之基本資料如河川斷面及水庫HAV資料等，均有更新之必要，另氣象預報技術亦有新的推展，可擴充系統模組以提升水情預估準確度。本局為確保緊急應變期間水情掌握及預警推估之準確性，並使預警系統維運工作得以銜接，爰擬辦理本計畫進行水情預警系統資料更新、擴充、維護及進駐諮詢等工作。

The Southern Region Water Resources Office (WRASB) had completed the project “The Planning and Construction for System of Observation and Forecast with Runoff within Tseng-Wen River” in March 2012. Within this dual-structure system, “WRASB Operation Information Platform” provides inflow information for reservoir maintainers to make operation decisions. In this project, the basic data of the system was renewed, including the river bank cross-section, stage-discharge rating curves, warning water levels and reservoir H-A-V curve. The reservoir operation simulation model was also modified with the latest operation directions for reservoir and gates. Furthermore, the input of multiple rainfall information and automatic calculation were built. In the year of 2015, during the period of 6 typhoons, which includes Linfa, Chanhom, Soudelor, Goni, Dujuan and Koppu, 36 information briefings were provided by the technical service team. These briefings summarized the meteorological and hydrological information about the Tsengwen, Agondian and Mudan Reservoirs. The technical service team stationed at WRASB for a total of 69 hours, assisting and operating the system during Linfa, Soudelor and Dujuan typhoon; Review reports were submitted after the 3 events. Through the data of Soudelor and Dujuan typhoon, the forecasted downstream water-levels simulated by measured and forecasted rainfall was compared. The former was generally in line with the trends of measured water level hydrograph, and the latter was influenced by the CWB?s typhoon path prediction inaccuracy. Nevertheless, the simulation error decreased as CWB continuously releasing typhoon path corrections. At the present stage, the rainfall of the watershed of Tsengwen reservoir was estimated by WRASB?s 9 precipitation stations. With the actual inflow, the runoff coefficients of most events were found to be unreasonably larger than 1. By reviewing other precipitation stations in the watershed, differences between WRASB?s and CWB?s nearby precipitation stations often existed. In purpose to increase the accuracy of reservoir inflow estimation, three different combinations of precipitation stations (including: (a) WRASB?s 9 stations; (b) WRASB?s 5 and CWB?s 4 stations; and (c) totally 12 stations) were used in calculating the rainfall of the watershed. The weights of each station in the 3 combinations were calculated through Thiessen?s Polygon Method. The results showed that the runoff coefficients in combination (a) were unreasonably larger than 1, and those in combination (b) and (c) were partly less than 1. Increasing the number of precipitation stations to calculate the rainfall of the watershed is the future direction to ensure the accuracy of reservoir inflow estimation.