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Tools: Technology

About IHA Download a one-page description of the IHA version 7 software program. (PDF)   Publications - Books Rivers for Life, Sandra Postel and Brian Richter. A Practitioner's Guide to Freshwater Biodiversity Conservation, Nicole Silk and Krisine Ciruna, Eds. Managing Freshwater Inflows to Estuaries - A Methods Guide   Publications - Papers Download PDF copies of various articles and papers relating to the work of the Sustainable Waters Program.   Training Learn more about environmental flows and how to use IHA software at a comprehensive training set for December 18-20, 2007. The Conservancy and its partners organize, sponsor or participate in numerous conferences, workshops and other training opportunities for freshwater stakeholders.

Indicators of Hydrologic Alteration (IHA): Software for Understanding Hydrologic Changes in Ecologically-Relevant Terms

Version 7 Now Available

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, including “A Method for Assessing Hydrologic Alteration Within Ecosystems", and "How Much Water Does A River Need?"

• Obtain IHA Software
• Join the IHA Email Discussion Group
• IHA Application Database
• IHA Online Training Course
• Environmental Flows and IHA Training
   

Flow Restoration Database

This database describes efforts to restore river flow conditions to benefit river ecosystem health. These efforts include modifying dam operations, removing dams, managing ground water pumping, and other strategies to restore river flows. Case Studies from around the world are summarized. Presently, the database lists 855 rivers in 53 countries.

Flow Restoration Database (.pdf, 1.6 MB, updated 6-17-05)

If you know of another project or citation that should be included, please send the appropriate information to sustainablewaters@tnc.org and we will add it to this database. 

Regime Prescription Tool Software

The US Army Corps of Engineers Hydraulic Engineering Center (HEC) and The Nature Conservancy have developed software for hydrologic engineering and planning analysis procedures. The Regime Prescription Tool is available to download online. .

Learn more about the Conservancy's partnership with the Corps - The Sustainable Rivers Project.