International Center for Integrated Regional Analysis Frequency Tool (ICI-RAFT)

Purpose: Regional frequency analysis of hydro-meteorological data
Developer: U.S. Army Corps of Engineers International Center for Integrated Water Resources (USACE IWR)
Key Features: Trading time for space, import data using excel
Latest Release: 2013, Version 1.1
OS Platform: Windows
Cost: Free
Related Software:
Website: ICI-RAFT Web Page

Introduction

ICI-RAFT, developed in 2013, uses meteorological data from similar sites to compile a lengthier meteorological record than can be obtained from individual sites. The software is based on the book by Hosking and Wallace entitled “Regional Frequency Analysis Using L- Moments”. The ICI-RAFT program employs the following four steps to develop the extended meteorological record: 1) locate sites with similar characteristics where only 20 is required; 2) perform a clustering algorithm to determine relevant sites; 3) select a frequency distribution along with associated weights; and 4) perform a frequency analysis to extend the record length. The program applies L-Moments to determine drought durations and flood event frequencies.

ICI-RAFT has several key features, including the ability to extend gage record data where the data is limited, and the ability to import data into the program using MS Excel. The program was developed by the United States Army Corp of Engineers and is supported on the Microsoft Windows operating system.

Advantages and Limitations

Advantages Limitations
  • Data can be exported to non-gaged sites
  • L-Moments are more robust than conventional moments
  • Does not perform other types of regional frequency analysis
  • Assumes stationary (no major changes in the watershed and no impact from climate change)
  • No technical reference manual

Illustrative Screens

Sample Applications

Africa East Asia and the Pacific Europe & Central Asia Latin America & the Caribbean Middle East and North Africa South Asia
Flow Frequency Curves, Lower Tisza River, Hungary
 Calculation of precipitation return periods, Brazil Return periods for discharge, Karun basin, Iran

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