都市邊緣地區土地利用變遷之逕流特性研究－以景美溪集水區為例

Runoff Characteristic of Land Use Change in Urban Rim Area - Jing-Mei Watershed

陳文福(Wen-Fu Chen) ； 廖信誠(Hsin-Cheng Liao)

《中華水土保持學報》 27卷4期 (1996/12) Pp. 311-324

https://doi.org/10.29417/JCSWC.199612_27(4).0006

摘要

近廿年來由於人口多往都市集中加上工商經濟之快速發展，平地不敷使用，台北市邊緣之山坡地區遂常被開發，另外大型公共建設如北二高等亦正興建中，致使土地利用／土地覆蓋之型態持續不斷地改變。在土地利用型態變遷下，由於地文條件之改變，集水區降雨所引發之逕流反應即愈趨複雜，而為一不可忽視之問題。本研究利用遙測技術分析不同時期之衛星影像，以取得即時之土地利用型態，並藉地理資訊系統建立集水區水文分析之資料庫，再連結降雨－逕流模式HEC-1之運動波法進行模擬演算，以分析及了解不同時期降雨－逕流物理機制之變化情彤，冀所得經驗能供都市邊緣地區洪流估測理念上之參考。本研究以景美溪集水區進行模擬，經篩選民國75.12及83.10共兩張理想之SPOT衛星影像及其對應之76年與83年各一整年內8場暴雨事件進行檢定與驗證，結果顯示模式之模擬能力良好：針對EQ_P，ET_P、EV三個目標函數而言，已能精確地模擬逕流歷線，且所檢定各場暴雨之EQ_P均在0.1%以下；且由民國76.07.27暴雨經民國76與83年之二組不同時期地文參數代入模式所得之結果顯示：洪峰流量增加約29%，由此可見集水區之水文系統具有時變性之效應且受開發之影響而改變，倘以傳統非時變性之方式來推求集水區水文系統之反應，不易掌握實際狀況。若能循本文之作法，當較能掌握土地利用變遷遽烈之都市邊緣地區集水區逕流之估算。

關鍵字

土地利用變遷 ； 地理資訊系統 ； 遙測 ； HEC-1水文模式

並列摘要

Owing to the increasing concentration of population in city, rapid development of industry along with commercial and economic developments, the population explosion that caused space shortage of plain area in Taipei City during the last twenty years, along with the massive engineering construction of the second freeway in Northern Taiwan which also passes through Taipei City, the patterns of land use/land cover have been continuously changing. These changes in turn convert the physiological conditions, thereby making and make rainfall-runoff relation more complicated and hence leading to an important problem. In this study, we utilized remote sensing technique to analyze the images of different stages in order to monitor the changes in patterns of land use and thereby establish the data base for watershed hydrologic analysis. Further, this data was combined with kinematic wave model of HEC-l to simulate and determine the changes in physical mechanism of rainfall-runoff at different stages. It is believed that the results of this study would be useful to runoff prediction of urban rim area. Two ideal SPOT images of Jing-Mei Chi watershed were used in .this study. These were selected from December 1986 and October 1994 along with their corresponding two annual eight storm events in 1987 and 19940 for calibration and verification. The results indicated that the present model was powerful in simulation, Also, the hydrograph could be simulated precisely to three object functions viz. EQ_P, ET_P and EV, wherein the EQ_P of various storm events is under 0.1 %. Furthermore, form the storm events, obtained form two sets of morphological parameters of 1987 and 1994, we observed that the peak flow increase was 29%. This indicates that the characteristic of the watershed system is belong to time variant and could change easily due to effects of development. Therefore, using classical time invariant approach to predict the response of hydrological system of watershed may not be helpful in controlling the real situation.

並列關鍵字

Land Use Change ； Geographic Information System ； Remote Sensing ； HEC-1 Hydrologic Model