i-Tree Hydro (Beta)

Application Overview

i-Tree Hydro is currently in the final stages of development and expected to be released as a beta test version near the end of winter in 2010. Here are a few answers to some frequently asked questions regarding i-Tree Hydro.

What is Hydro?

Hydro is a stand alone application designed to simulate the effects of changes in tree and impervious cover characteristics within a watershed on stream flow and water quality. It was designed specifically to handle urban vegetation effects so urban forest managers and urban planners can quantify the impacts of changes in tree and impervious cover on local hydrology to aid in management and planning decisions.

It is also designed for ease of use, utilizing available data sets as inputs to the model. Hydro is a combination of two modules. A base module designed to simulate hourly changes in stream flow due to changes in urban tree and impervious cover characteristics and a water quality module that uses outputs from the base program to simulate changes in water quality.

What will Hydro tell me?

Given various changes in tree and impervious cover characteristics provided by the users, Hydro will quantify and illustrate hourly and total changes in stream flow and water quality. Data will be presented in tabular summaries as well as through graphs (hydrographs) that illustrate the changes between the base case (conditions as they are now) and a future case specified by the user.

Why is the information produced by Hydro important?

Urbanization significantly alters stream flows and water quality due to increased impervious surfaces, increased pollutants emitted from various sources and decreases in natural vegetation cover. These changes lead to increased runoff and flashiness of stream flow after storms, potential flooding issues, and poorer water quality that affect human health and well-being.

Through the Clean Water Act, the U.S. Environmental Protection Agency has designated various water quality requirements that affect city managers. As trees affect the environment, the ability to quantify these effects could lead to the incorporation of urban vegetation management strategies (and potential funding) to help meet these environmental regulations. Urban trees can potentially be used to meet clean water regulations associated with Total Maximum Daily Loads (TMDLs) (http://www.epa.gov/owow/tmdl/intro.html) and storm water programs ( http://www.epa.gov/region6/water/npdes/sw/ms4/).

How can Hydro help urban forest managers & urban planners?

The Hydro model could be used to determine how various best management practices (including urban forestry) affect water quality. In addition, by altering the precipitation inputs to simulate storms of various intensities, the model can be used to determine how management practices can affect local flooding. Model results can be used to improve urban forest management and urban planning and design to help improve water quality and reduce the risk of flooding.

Who developed Hydro?

Hydro was developed by a team of scientists and technicians from SUNY College of Environmental Science and Forestry, USDA Forest Service, Northern Research Station, and the Davey Institute. The principal model developer was Dr. Jun Wang.