A GIS-based multi-model design rainfall estimation tool for scientists and practitioners.

What is it about?

A GIS-based multi-model design rainfall estimation tool for scientists and practitioners, allowing to compare existing regional rainfall frequency analysis. In this work, a tool named MultiRain is proposed, aimed at providing Intensity-Duration-Frequency (IDF) curves, either related to a point or integrated over an area, adopting multiple existing regional frequency analysis (RFAs). The procedures, accessible both via web-browser and desktop GIS software, are here developed and described for the North-West of Italy.

Featured Image

Photo by Chris Gallagher on Unsplash

Photo by Chris Gallagher on Unsplash

Why is it important?

Spatial analysis of rainfall extremes benefits of scientific advances and continuous data increments, that have led to the development of various methodologies in the last decades. In the field of hydrologic design, due to technical, socio-economic and legislative factors, the availability of new methodologies does not imply the total substitution of the old, consolidated, procedures. This suggests that the hydrologic design is often supported by the opportunity of considering and comparing the results of estimates coming from different estimation methods. The possibility of analyse and compare modern studies, based on more recent historical series and scientific advances, and traditional ones, considered for the design of the infrastructures, allows for a more complete analysis of the hydrological risk. Despite this, merging and harmonizing the information deriving from this wide range of knowledge is not a trivial issue. In particular, problems arise considering the different characteristics of the analysis, the different products and supports (from paper maps to GIS systems) and the methodological approaches that are not always consistent. The development of instruments for fast comparison of results from different studies would allow to solve many issues related to RFA from both the scientific and the operational point of view and to increase the reliability and robustness of the estimates. In this work, a GIS operational tool is presented, aimed at producing concurrent regional rainfall estimates at a point or over an area, using the DDF curves extracted from different existing RFAs.