Storm Event Characteristics Based on IETD for Different Climatic Regions within United States

Given the climate variability and change throughout the world, local level continuous assessment of storm event characteristics is critical for analyzing adequacy of existing urban drainage infrastructures and for updating the critical rainfall information for future hydrologic designs. Given such new information, it is instructive to analyze this key input to the most of the stormwater management planning, analysis, design, and operation. Based on the Inter-event Time Definition (i.e., minimum dry period between storm events, or IETD), a long-term point rainfall record can be analyzed for different storm event characteristics such as event volume, event duration, event average intensity, and inter-event time. Such analysis will provide valuable information to our engineers, water resources professionals, and regulatory authorities about the change in storm event characteristics (i.e., storm event volume for different durations) over time at a specific location. This study evaluates storm event characteristics based on varying IETDS for different climatological regions within the United States. The available long-term hourly rainfall records at the representative stations within each of the climatic regions have been employed to conduct the analysis. The analysis will provide the storm event characteristics, particularly event volume and duration over time and their statistical analysis and spatial variability in a region and across different climatic zones. Such information is very useful for volume-based hydrology for managing urban stormwater management systems. The paper presents preliminary results of an ongoing study.