Session A8- Instream flow needs mapped over natural flows: What are the stochastic characteristics of failure?
Location
UMass Amherst
Start Date
29-6-2011 2:35 PM
End Date
29-6-2011 2:55 PM
Description
Instream flows were developed for two New Hampshire rivers. This talk focuses on the frequency of times when the instream flow and duration are not met (failure), the severity of the water deficit, the characteristics of the failure probability distributions, regionalization of the results, and potential management approaches to attain instream flows. The two rivers in this study are the Lamprey and Souhegan Rivers. Instream flows were developed for various bioperiods through the year. The instream flows are both flow and duration specific for each bioperiod. Natural long term hydrology was developed from today’s gaged flows by removing human disturbances from the records. By comparing the instream flows to the long period flow records, the probability distributions of flows were fitted to the failure characteristics (frequency of occurrence, duration, deficit volume). These probability distributions can then be used to predict extreme events much as is done for flood predictions. In addition, the characteristics of these distributions can be put into a fashion that allows them to be applied regionally. That is, with estimates of watershed size and average streamflow, the effects (failure characteristics) of applying similar instream flows to other streams can be estimated.
Session A8- Instream flow needs mapped over natural flows: What are the stochastic characteristics of failure?
UMass Amherst
Instream flows were developed for two New Hampshire rivers. This talk focuses on the frequency of times when the instream flow and duration are not met (failure), the severity of the water deficit, the characteristics of the failure probability distributions, regionalization of the results, and potential management approaches to attain instream flows. The two rivers in this study are the Lamprey and Souhegan Rivers. Instream flows were developed for various bioperiods through the year. The instream flows are both flow and duration specific for each bioperiod. Natural long term hydrology was developed from today’s gaged flows by removing human disturbances from the records. By comparing the instream flows to the long period flow records, the probability distributions of flows were fitted to the failure characteristics (frequency of occurrence, duration, deficit volume). These probability distributions can then be used to predict extreme events much as is done for flood predictions. In addition, the characteristics of these distributions can be put into a fashion that allows them to be applied regionally. That is, with estimates of watershed size and average streamflow, the effects (failure characteristics) of applying similar instream flows to other streams can be estimated.
Comments
Dr. Ballestero is a hydrologist and water resources engineer. He is an associate professor of civil engineering at the University of New Hampshire, plus for the past five years he has had an Intergovernmental Personnel Agreement with the US Fish & Wildlife Service to perform all aspects of stream restoration in Pennsylvania. Dr. Ballestero has recently been involved with instream flow development in New Hampshire, assisting with creating the New Hampshire stream crossing guidelines, and various stream restoration projects including: sediment studies, dam removal, storm water management, fish passage design; and stream restorations.