State Water Resources Research Institute Program
Project ID: 2012AK107B
Title: Monitoring runoff in glaciated watersheds to assess groundwater recharge and flooding risks
Project Type: Research
Start Date: 3/01/2012
End Date: 2/28/2013
Congressional District: Alaska
Focus Categories: Hydrology, Floods, Groundwater
Keywords: Runoff, glacier, groundwater recharge, climate change
Principal Investigators: Liljedahl, Anna; Arendt, Anthony
Federal Funds: $ 21,026
Non-Federal Matching Funds: $ 3,230
Abstract: Alaska has one of the most dynamic hydrological cycles on Earth, with many regions experiencing large amplitude mass variations driven by exchanges of water between atmospheric and terrestrial systems. Understanding and predicting the spatial and temporal patterns in Alaska hydrology is vitally important to a wide range of local community, industry and state and federal agency stakeholders. For example, communities located near rivers rely on flood forecasts to minimize potential harm to life and property; hydroelectric companies require information on the present and future patterns in water availability at generation sites to plan for facility operations; farming communities need detailed information on groundwater stores to plan for maximizing crop yields; and state and federal agencies rely on accurate monitoring to assess the effects of changes in discharge on ecosystems. Hazards associated with extreme hydrological events, such as the breach of moraine-dammed lakes, affect all stakeholders due to the potential damages to communities, infrastructure and downstream ecosystems.
Glaciers occupy the headwaters of many Alaska watersheds and play a key role in modulating the characteristics of watershed discharge. Glaciers provide a base level of streamflow in dry summer months and can dramatically alter the discharge of rivers in the absence of precipitation inputs. Glaciers are also extremely sensitive to climate variations. In a warming climate, glacier runoff will likely increase and lead to increased occurrences of hazards associated with flooding, but may over time decrease as glaciers lose volume. The relationship between glacier mass balance, climate and discharge is complex and poorly understood in Alaska due to a lack of monitoring. Both glacier mass balance and discharge must be monitored simultaneously in order to develop improved decision making tools such as models and hazard maps, so as to inform community and ecosystem management strategies.
The goal of this study is to expand discharge monitoring efforts at two glaciated watersheds located in continental and maritime ecosystems in Alaska. These discharge measurements will be made at rivers draining glaciers on which mass balance monitoring efforts are or will be implemented simultaneously. At one site, Jarvis Creek, Delta Junction, which is located in the semi-arid interior Alaska, our discharge measurements will be used to assess how changes in river dynamics will affect military training locations and groundwater recharge rates that are important to nearby farming activities. At another site, in maritime Valdez, our discharge measurements will be used to assess the likelihood of a moraine-dammed lake to breach under a range of future climate scenarios. We are requesting funds to acquire a StreamPro ADCP system that will allow take measurements without entering the water. This is necessary because the measurement of glacier streams is extremely difficult using conventional point-by-point methods. Our efforts at the two study sites will leverage studies and field efforts ongoing at the University of Alaska Fairbanks and the Alaska State Division of Geological and Geophysical Surveys. Our discharge measurements will allow us to parameterize and calibrate physically-based watershed models so that we can establish a relationship between climate inputs and river outputs. We can then us the calibrated model to predict watershed response to extreme events and future changes in climate, providing a tool for mapping of potential flood hazards, predict changes in groundwater recharge, and assess discharge magnitudes for hydroelectric projects.
Graduate student education will be a primary goal of this effort. We request salary support for a currently-enrolled student who will assist with implementation of studies at both field sites. We will also partner with community, industry and government stakeholders to distribute our findings and provide modeling tools and hazard maps.