應用遙測偵測鹽水溪上游土地利用改變及其對逕流之影響

Detecting Land Use Change by Remote Sensing and It's Impact on Runoff in the Upstream of Yan-Shoei Creek

10.6574/JPRS.2013.17(1).1

王毓麒(Yu-Chi Wang)；郭俊超(Chun-Chao Kuo)；游保杉(Pao-Shan Yu)

遙感探測 ； 次像元分類 ； 土地利用變遷 ； 水筒模式 ； 降雨－逕流模式 ； Remote Sensing ； Land use change ； Tank model ； Rainfall-runoff model

航測及遙測學刊

17卷1期（2013 / 03 / 01）

1 - 16

繁體中文

臺灣由於經濟發展形成流域內土地都市化嚴重；而都市化對流域內洪水影響程度，是極需探討的主題。本文以鹽水溪流域豐化橋以上集水區為研究區域，探討土地利用改變，對都市化後水文歷線及蓄洪能力之影響。本文利用主題圖切除配合監督式分類之方法，針對1972年Landsat MSS影像及2000年SPOT影像，進行土地利用分類；並發現其中建築面積從1972到2000年增加約1600公頃。因研究區域包含平地及山區，故嘗試加入水筒模式，與過去可合理模擬山區；運動波理論建立之格網型降雨－逕流模式連結。經過12場歷史暴雨事件的率定，證實加入水筒模式可合理模擬降雨－逕流關係；進一步利用此分布型降雨－逕流模式，探討土地利用改變對蓄洪能力之影響程度；結果發現集水區10年重現期距之設計洪水增加約10%，可能增加淹水機率，應提出適當減洪措施以減少損失。

Urbanization is significantly increasing in Taiwan recently because of economic development. The basin Yan-Shoei creek is chosen as the study area to investigate the influence of urbanizing on runoff hydrograph and flood storage ability. 1972 LANDSAT MSS and 2000 SPOT satellite imageries are applied to identify the land use types by using the method that the image was classified by sub-pixel and supervised classification after the thematic maps were first cut off. The results showed building area increases about 1600 acres from 1972 to 2000. Due to the terrain of study area contains flat area and mountains; we tried to connect the tank model for flat area with the grid-based distributed rainfall-runoff model, which is based on kinematic wave approach for hilly area. Calibration from 12 storm events concluded that the model proposed in this work can well simulate the rainfall-runoff relationship. The model is further applied to investigate the impact of land use change on runoff. The return period 10-year flood was found to be increased around 10%, which reveals that changes the probability of flooding. The adaptation measures are necessarily proposed to reduce damage.