Title: Surface-Groundwater interactions on the Eastern Snake River, ID
1Surface-Groundwater interactions on the Eastern
Snake River, ID
2Outline
- Objective Estimate of seepage loss along a
segment of the Eastern Snake river -
- River Channel Generation (RCMM)
- Unsteady flow simulation(10 non-raining days)
- Compare the outflow hydrograph with the actual
hydrograph - Calculate volume of water lost to the aquifer
3 Misc. Facts about Idaho
- 3,100 miles of river, more than any other state
- 85 of all commercial trouts
- Number one producer of potatoes
- Paris and Montpellier 30 miles apart
4Study area
Unconfined aquifer Highly fractured basalt Water
Supply from snowmelt Precipitation 8 in/yr
5Human impact on the Eastern Snake system
(source IDWR)
Less surface water irrigation More efficient
irrigation Increased pumping
6Water Budget
7Increased stress on the aquifer
(source IDWR)
8Eastern Snake aquifer Model
9Eastern Snake aquifer
10River Channel generation
113D Representation of river reaches
- Bathymetric data
- (Expensive, unavailable)
- 2D 3D representation
- 2D plan view (DOP)
- Calculate location of the thalweg
- Approximate cross-sections with analytical
functions
122D representation of the river segment
- Calculate Depth/Width for a 2 yr flow
- Offset the NHD flow line by W/2 to obtain the
channel boundary
Depth
Width
2D Plan view
13River Channel generation (RCMM)
- REQUIRES 2D representation of the river segment
- GENERATES 3D representation
- Thalweg Calculates the radius of curvature
- Locates the thalweg using the
radius of curvature/thalweg - relationship
- Cross-sections Analytical (Beta functions) from
the thalweg location
14Generated cross-sections
15Exporting river channel into HEC-RAS
16Unsteady simulation
- 10 day simulation
- Upstream boundary condition USGS flow hydrograph
(_at_Minidoka) - Downstream boundary condition stage hydrograph
(_at_Kimberley) - Compare the calculated/observed
- hydrograph
17Acknowledgments
- Dr Merwade (CRWR)
- Allan Willie (Hydrologist, IDWR)
18