Run the model in scenario A but this time assume with the width of the river is 5 m and the elevation of the bottom of the sediments is 995 m. Compare the results with those in scenario A. What is the effect of reducing the width of the river?   

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Project Description": A town is planning to expand its water supply by constructing a pumping well in an unconfined sand and gravel aquifer as shown in Figure 1. The well is designed to pump constantly at a rate of 18,000 m'iday. Well construction was stopped by the Environment Public Authority (EPA) who claimed that pumping would significantly reduce groundwater discharge to the weland and impact harmfally the ecosystem. In addition, the high pumping rate would lower discharge to the river and influence downstream water availability. The town claimed the fully penetrating river boundary to the north and groundwater divide located near the center of the valley would prevent any change in flow to the wetland. SLATE MOUNTAN METERS RIVER RIVER LEY10 2250 WELL 11 SLATE MOUNTAN AREAL RECHARGE 100 0-20.00 1 Wetland SLATE BEDROOK Figure 1: Map and cross-section of the aquifer and location of the a proposed fully penetrating pumping well 1500 m from the river PEAT AND WATER Phase (1): Model Construction The length of the aquifer valley is represented through 40 rows of cells, each with a cellsize Ay =250m. The width of the valley is represented by 18 columns with size Ax=250m. The model uses a single unconfined aquifer with a bottom and top elevations 980 and 1020, respectively. Areal recharge occurs at along average uniform rate of 0.001 m/day. An unconfined aquifer horizontal bydraulic conductivity of 50 miday is used, and the anisotropy ratio is 18. The specific yield of the aquifer is 0.1. The wellfield is located in coll (4)(69.1). The conductivity of the river bottom is K- 50 miday, and the thickness of the riverbed is - 1 m. The hydraulic beads along rows I and 40 represents the levels of water in the river and wetland 1000 m, where the no flow cells should be assigned along the columns 1 and 18 Phase (243): Analysis & Results Using your program, provide results for the following three assessment scenarios 1. Scenario A: Pre-development conditions SteadyState Construct a three dimensional steady-state model of the aquifer between the river and wetland for conditions prior to pumping using the information in Figure 1. River and wetland represent boundaries as constant head boundaries with head set at 1000 m. The side boundaries are no-flow boundaries. Draw the water-table profile in a north-south cross section and label the simulated groundwater divide between the river and weland Discuss the natural flow regime. Discuss the model mass balance. Compute the discharge to the river and wetland Scenario A_R: Run the model in scenario A but this time assume with the width of the river is 5 m and the elevation of the bottom of the sediments is 995m. Compare the results with those in scenario A. What is the effect of reducing the width of the river? Project Description": A town is planning to expand its water supply by constructing a pumping well in an unconfined sand and gravel aquifer as shown in Figure 1. The well is designed to pump constantly at a rate of 18,000 m'iday. Well construction was stopped by the Environment Public Authority (EPA) who claimed that pumping would significantly reduce groundwater discharge to the weland and impact harmfally the ecosystem. In addition, the high pumping rate would lower discharge to the river and influence downstream water availability. The town claimed the fully penetrating river boundary to the north and groundwater divide located near the center of the valley would prevent any change in flow to the wetland. SLATE MOUNTAN METERS RIVER RIVER LEY10 2250 WELL 11 SLATE MOUNTAN AREAL RECHARGE 100 0-20.00 1 Wetland SLATE BEDROOK Figure 1: Map and cross-section of the aquifer and location of the a proposed fully penetrating pumping well 1500 m from the river PEAT AND WATER Phase (1): Model Construction The length of the aquifer valley is represented through 40 rows of cells, each with a cellsize Ay =250m. The width of the valley is represented by 18 columns with size Ax=250m. The model uses a single unconfined aquifer with a bottom and top elevations 980 and 1020, respectively. Areal recharge occurs at along average uniform rate of 0.001 m/day. An unconfined aquifer horizontal bydraulic conductivity of 50 miday is used, and the anisotropy ratio is 18. The specific yield of the aquifer is 0.1. The wellfield is located in coll (4)(69.1). The conductivity of the river bottom is K- 50 miday, and the thickness of the riverbed is - 1 m. The hydraulic beads along rows I and 40 represents the levels of water in the river and wetland 1000 m, where the no flow cells should be assigned along the columns 1 and 18 Phase (243): Analysis & Results Using your program, provide results for the following three assessment scenarios 1. Scenario A: Pre-development conditions SteadyState Construct a three dimensional steady-state model of the aquifer between the river and wetland for conditions prior to pumping using the information in Figure 1. River and wetland represent boundaries as constant head boundaries with head set at 1000 m. The side boundaries are no-flow boundaries. Draw the water-table profile in a north-south cross section and label the simulated groundwater divide between the river and weland Discuss the natural flow regime. Discuss the model mass balance. Compute the discharge to the river and wetland Scenario A_R: Run the model in scenario A but this time assume with the width of the river is 5 m and the elevation of the bottom of the sediments is 995m. Compare the results with those in scenario A. What is the effect of reducing the width of the river?

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The effect of reducing the width of the river is that the fl... View the full answer