Nguyen Thanh Hung
Hochiminh City University for Natural Resources and Environment. HoChiMinh, Vietnam
Tran Thi Tham
Vietnam National Forestry University. Hanoi, Vietnam

Abstract

The study shows the effective application of sentinel-2 images in analyzing the current state of urban surface water drainage in Bien Hoa city. The extraction of each component of water, vegetation and impervious surface based on NDVI, MNDWI and NDBI indexes has contributed very effectively in the formation of the composite cover map. Overall classification accuracy T = 0.92, Kappa coefficient = 0.87. Asymptotic analysis with the QGIS tool was used to determine the minimum distance from any point in the urban area to the natural permeable surface. The isolation of urban cover surface helps to determine the ratio of impervious surface and natural permeable surface within Bien Hoa city wards. The results of asymptotic analysis have shown that the central wards of Bien Hoa have 3-5 times higher access distance to the natural permeable surface than the suburban wards, corresponding to the ratio of impervious surface area/natural permeable surface between them. The coefficient of variation according to the statistical results of asymptotic distance is an important basis for evaluating the degree of interlacing of areas with impervious surfaces with areas with natural permeable surfaces. Research results have located the spatial distribution and characteristics of areas with high potential for flooding in Bien Hoa city, those are the downtown areas with an impervious surface ratio >60% and the access distance to the naturally permeable surface >120m. This result will be very useful in sustainable urban drainage planning.

 Keywords: Sustainable urban drainage; Sentinel-2; GIS; Urban planning; Drainage system.