New Methodology to Develop Future Flood Frequency under Changing Climate by Means of Physically Based Numerical Atmospheric-Hydrologic Modeling

Current issues in and an emerging method for flood frequency analysis under changing climate

“…Comparison of the model-simulated (control run) and the empirical (from flow record) (obs) flood frequency curves at the outlet of the CCW using observed annual maximum flow data and the model-simulated annual maximum flow data from the downscaling of the control runs from two selected GCMs (Trinh et al, 2016) Figure 2. Flood frequency curves for two consecutive 45-year non-overlapping time windows obtained from the ensemble of all flow projections during 21st century at the outlet of the CCW (Trinh et al, 2016) strated by a numerical application to a target watershed. This new approach to flood frequency analysis is based on the dynamical downscaling of the projections of the 21st century climate by global climate models to the region of study.…”

“…This section explains a recently developed method (Trinh et al, 2016) to estimate the 100-and 200-year return period floods without any frequency curve extrapolation under changing climate as aforementioned. This method utilizes future climate projections produced by multiple GCMs/ ESMs based on multiple future climate scenarios.…”

“…The aforementioned method was demonstrated by Trinh et al (2016) over the Cache Creek watershed (CCW) in California, the United States. The CCW is located in the Coastal Range of California with an area of approximately 3,000 km 2 .…”

“…As a physically-based hydro-climate model, Trinh et al (2016) utilized the Watershed Environmental Hydrology Hydro-Climate Model (WEHY-HCM, Kavvas et al, 2013;Kure et al, 2013). The WEHY-HCM was developed by integrating a regional atmospheric model with a physicallybased hydrologic model, the Watershed Environmental Hydrology Model (WEHY, Chen et al, 2004aChen et al, , 2004bKavvas et al, 2004Kavvas et al, , 2006 through the atmospheric boundary layer.…”

Physically based maximum precipitation estimation under future climate change conditions

“…Several new approaches have been developed with the dynamical downscaling technique in order to address the aforementioned issues in the traditional approaches for the extreme flood/precipitation estimation. Trinh et al () developed a new methodology to obtain the future flood frequency at a watershed under a changing climate by means of the dynamical downscaling technique with future climate projections. Although this methodology solved the aforementioned issues in the traditional FFA, another new approach was developed to estimate the extreme precipitation over a target watershed by means of a regional atmospheric model (Ishida et al, , ; Ishida, Ohara, Kavvas, Chen, & Anderson, ; Ohara et al, ), which can be considered as an alternative to the traditional PMP approach.…”