Urban Flood Analysis in Ungauged Drainage Basin Using Short-Term and High-Resolution Remotely Sensed Rainfall Records

Abstract

Analyzing flooding in urban areas is a great challenge due to the lack of long-term rainfall records. This study hereby seeks to propose a modeling framework for urban flood analysis in ungauged drainage basins. A platform called “RainyDay” combined with a nine-year record of hourly, 0.1° remotely sensed rainfall data are used to generate extreme rainfall events. These events are used as inputs to a hydrological model. The comprehensive characteristics of urban flooding are reflected through the projection pursuit method. We simulate runoff for different return periods for a typical urban drainage basin. The combination of RainyDay and short-record remotely sensed rainfall can reproduce recent observed rainfall frequencies, which are relatively close to the design rainfall calculated by the intensity-duration-frequency formula. More specifically, the design rainfall is closer at high (higher than 20-yr) return period or long duration (longer than 6 h). Contrasting with the flood-simulated results under different return periods, RainyDay-based estimates may underestimate the flood characteristics under low return period or short duration scenarios, but they can reflect the characteristics with increasing duration or return period. The proposed modeling framework provides an alternative way to estimate the ensemble spread of rainfall and flood estimates rather than a single estimate value.

Using Remote Sensing Techniques to Improve Hydrological Predictions in a Rapidly Changing World

“…Moreover, the authors pointed out the need to carefully transfer hydrological parameters, since the locally derived hydrodynamic parameters may not be applicable to mesoscale areas. Zhu et al [12] proposed a modelling framework for the urban flood analysis in ungauged catchments using short-term and high-resolution rainfall data. The framework includes three steps.…”

Evaluation of eco-environmental quality for the coal-mining region using multi-source data

“…The projection pursuit model projects the high-dimensional data onto the low-dimensional space, constructs the objective projection function, and finds the best projection that can reflect the structure or features of the original high-dimensional data 24 . This method avoids subjective factors and masses of missing pieces, by which objective results can be obtained, and has achieved great application effect in water resource evaluation 25 , land use evaluation 26 and watershed flood analysis 27 . Driving force analysis of evaluation results is also an important part of the eco-environment assessment.…”