DEM 개선을 통한 중소하천 홍수범람지도 정확도 향상 = Enhancement of Digital Elevation Models for Improved Estimation of Small Stream Flood Inundation Mapping

다국어 초록 (Multilingual Abstract)

The accuracy of digital elevation models (DEMs) is crucial for properly estimating flood inundation area. DEM pixel size is especially important when generating flood inundation maps of small streams with a channel width of less than 50 m. In Korea, DEMs with large spatial resolutions of 30 m have been widely applied to generate flood inundation maps, even for small streams. Additionally, when making river master plans, field observations of stream cross-sections, as well as reference points in the middle of the river, have not previously been used to enhance the DEM. In this study, it was graphically demonstrated that high-resolution DEMs can increase the accuracy of flood inundation mapping, especially for small streams. Also, a methodology was proposed to modify the existing low-resolution DEMs by adding additional survey reference points, including river cross-sections, and interpolating them into a high spatial resolution DEM using the inverse distance weighting method. For verification purposes, the modified DEM was applied to Han stream on Jeju Island. The modified DEM showed much better accuracy when describing morphological features near the stream. Moreover, the flood inundation maps were formulated with the original 30 m pixel DEM and the modified 0.1 m pixel DEM using HEC-RAS modeling of the actual flood event of Typhoon Nari, and then compared with the flood history map of Nari. The results clearly indicated that the modified DEM generated a similar inundation area, but a very poor estimate of inundation area was derived from the original low-resolution DEM.

참고문헌 (Reference)

1 이자원, "중·소하천 유역 홍수해 방재의 제도적 체계 구축을 위한 사례 연구" 국토지리학회 48 (48): 177-202, 2014

2 정영훈, "조도계수와 유량의 불확실성이 홍수범람도 구축에 미치는 영향" 대한토목학회 33 (33): 937-945, 2013

3 박기범, "위성사진을 이용한 도시하천 홍수범람도 작성에 관한 연구" 한국환경과학회 20 (20): 199-205, 2011

4 Jung, Y., "Simplified flood inundation mapping based on flood elevation-Discharge rating curves using satellite images in gauged watersheds" 6 (6): 1280-1299, 2014

5 National Geographic Information Institute (NGII), "Offer Free Map Data (DEM)"

6 최천규, "LiDAR 고도자료와 LISFLOOD 모형을 이용한 홍수범람해석" 한국지리정보학회 16 (16): 1-15, 2013

7 Goff, J. A., "Interpolation of fluvial morphology using channel oriented coordinate transformation : A case study from the New Jersey shelf" 36 (36): 643-658, 2004

8 Hong, S., "HEC-Geo RAS also flood flooding using the create practical application method"

9 Ministry of Public Safety and Security (MPSS), "Guideline for Mapping Disaster Map"

10 Ministry of Land, Infrastructure, and Transport (MOLIT), "Guide for Producing the Flood Hazard Map"

11 Lee, J., "Estimation of roughness coefficient using a representative grain diameter for han stream in Jeju Island" Jeju National University Graduate school 2012

12 Korea Institute of Civil Engineering and Building Technology (KICT), "Development of flood hazard mapping method for local streams" 2014

13 Kim, K., "Comparative study on flood inundation according to river terrain modification" 251-255, 2012