空間篩選方法於自來水管網維修測漏之應用

An application of Spatial Scan Method in Water Distribution Networks Maintenance Leakage Detection

林柏瑋(Bo-Wei Lin)

指導教授 ： 林宏嶽

朝陽科技大學/理工學院/環境工程與管理系/碩士(2010年)

摘要

國內供水系統老舊，無效水量的產生多是因管線漏水。因此必須透過管線測漏與檢修改善上述問題。然而現行檢修漏方法於需要大量人力與時間，因此本研究透過空間篩選方法，探討利用管線維護記錄找出損害顯著之區域，以作為檢修測漏工作之參考。空間篩選方法，主要是將空間資料以視覺化方式呈現，以觀察其空間型態，並利用空間統計和空間分佈處理模式計算區域的標準化機率，比較與觀察值差異，以了解潛在之高風險之區域。本研究選用的空間篩選方法是覆蓋局部案例比例法(Overlapping Local Case Proportions, OLCP)，該方法係利用格點劃定範圍，計算每一個格點鄰近的損害次數，透過數值模擬格點範圍內之損害數，並與實際損害數進行比較，以找出損害數顯著異常區域。由於不同區域的管線損害產生因素不一定相同，為探討差異性，本研究選用台中市中區及北區作為案例區域，透過OLCP方法進行空間分析，並利用不同管線損害機率推估方式進行分析及探討結果。經比較分析結果，經驗公式與區域平均分析結果相似，因此若無法取得管線詳細設置資料時，可透過區域平均損害機率進行推估及分析。而為探討導致管線損害的可能因子，本研究亦透過維護記錄篩選出損害因子(水錘、老化及其他)，並與管線因子(自來水用水量、管線體積、單位體積負荷水量及新舊管線)進行相關性分析。相關性分析結果顯示，中區管線損害主要受到舊管線影響，北區則受單位體積管線負荷水量影響較高。

關鍵字

空間篩選 ； 自來水管線維護點篩選 ； 相關性分析 ； 地理資訊系統 ； 覆蓋局部案例比例

並列摘要

In Taiwan, the pipe leaks because of water distribution network inferiority and aging has resulted in quite significant amount of water loss. However, typical operations of leakage detection maintenance usually need much manpower and time. In this study, spatial Scan method is thus explored to identify the potential regions for further inspection of pipe leaks. Spatial scan method can present spatial information visually intuitive and has statistic functions to test the significance of a distinguish region. In this study the spatial scan method applied is Overlapping Local Case Proportions (OLCP), the approach uses grids to scope the entire area and then simulates the number of maintenance of each grid. The maintenance ratio of each grid is further compared with the observed record and the significance test can be done by statistic functions. Because reasons of pipes may vary between regions, the Central District and North District of Taichung City were analyzed by OLCP respectively to evaluate the difference of local characteristics. Three pipeline damage methods are also discussed in this study, including empirical formula, local maintenance average and global maintenance average, to estimate the probability of pipe damage. After the comparative analysis, empirical formula and local maintenance average have similar results, if detailed information of pipeline is not available, local maintenance average can be used as an alternative. The correlation analysis also reveal that the primary reason of pipe damage may related to the water distribution network aging and water load per unit in Central District and North District, respectively.

並列關鍵字

Spatial scan methods ； Overlapping Local Case Proportions ； Scan of water pipeline maintenance points ； Correlation Analysis ； Geographic Information System

參考文獻

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