Indicators of Hydrologic Alteration (IHA): Software for Understanding Hydrologic Changes in Ecologically-Relevant Terms
The Indicators of Hydrologic Alteration (IHA) is a software program
that provides useful information for those trying to understand the
hydrologic impacts of human activities or trying to develop
environmental flow recommendations for water managers. Nearly 2,000
water resource managers, hydrologists, ecologists, researchers and
policy makers from around the world have used this program to assess how
rivers, lakes, and groundwater basins have been affected by human
activities over time, or to evaluate future water management scenarios.
This
program was developed by scientists at the Nature Conservancy to
facilitate hydrologic analysis in an ecologically-meaningful manner.
This software program assesses 67 ecologically-relevant statistics
derived from daily hydrologic data. For instance, the IHA software can
calculate the timing and maximum flow of each year's largest flood or
lowest flows, then calculates the mean and variance of these values over
some period of time. Comparative analysis can then help statistically
describe how these patterns have changed for a particular river or lake,
due to abrupt impacts such as dam construction, or more gradual trends
associated with land- and water-use changes. The IHA software is
described in a number of
scientific papers.
Disclaimer
Because software is inherently
complex and may not be completely free of errors, it is your
responsibility to verify your work and make backup copies, and TNC will
not be responsible for your failure to do so. In no event will TNC be
liable for indirect, special, incidental, or consequential damages
arising from use of or inability to use this product, including, without
limitation, damages or costs relating to the loss of profits, business
goodwill, data or computer programs, even if advised of the possibility
of such damages. The foregoing limitations shall not apply to claims
relating to death or personal injury which arise out of products deemed
to be consumer goods under applicable law. Some states do not allow the
exclusion or limitation of implies warranties of limitation of liability
for incidental or consequential damages, so the above exclusion or
limitation may not apply to you.
Any commercial use of this software is prohibited without the express, written consent of TNC
