Development of a Rainfall Statistical Analysis Tool for Analytical Probabilistic Models for Urban Stormwater Management Analysis

In this research paper, the frequency analysis of point rainfall data is examined. The emphasis has been placed on the statistical analysis of storm events. The design of urban stormwater management systems based on analytical probabilistic modeling approach depends on the statistical analysis of input meteorology, rainfall. The long-term rainfall record is discretized into independent storm events by defining an inter event time definition (IETD) and each event is characterized by four event characteristics (e.g., rainfall event volume, duration, intensity, interevent time). The time series of discretized storm events representing each of the four characteristics are fitted with probability density functions. The parameters of the PDFs of rainfall characteristics constitute the input to the analytical probabilistic models. As a complement to continuous simulation models (e.g., US EPA SWMM), the computational efficient analytical probabilistic models can use parameters of PDFs as the input to the model for urban stormwater analysis. The objective of this research is to design and build a software utility for engineers and professionals which will perform the aforementioned statistical rainfall analysis. The research methodology is as follows: (1) various sources of freely accessible rainfall records were explored such as (NOAA and NCDC web sites); (2) Class and Relationship diagrams were developed for the overall system architecture (note that the system is separated into a back-end parsing engine, and a series of front-end applications); (3) the Python programming language was selected for development, and the back-end system architecture was implemented; (4) a series of tests were performed to assess the proper functionality of the system; (5) the front-end systems, including a plotting application and a web-based interface, were developed. This tool can be useful for any location in the United States that has a viable rainfall record, and could be used to generate a comprehensive atlas.