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1. Determine the water level rise in an unconfined aquifer produced by a seasonal precipitation of 3.5 cm. The aquifer's porosity is 32% and the part of the water volume the rock retains is 8%. 2. The specific storage of a 41-m thick confined aquifer is 5*105 m³. How much water would the aquifer produce if the piezometric surface is lowered by 11 m over an area of 1.5 km²? 3. Water flows through three confined aquifers in series as shown in the Figure below. For piezometric heads in the observation wells of 63.1 m and 60.2 m, determine the flow rate per unit width of the aquifer and the head losses in each component of the aquifers between the observation wells. 63.1 m 60.2 m K₂= 50 m K₁-30 m/day K₂ = 10 m/day 50 m/day 500 m 1100 m 400 m 4. A field sample of an unconfined aquifer is packed into a test cylinder. The length and diameter of the cylinder are 75 cm and 35 cm respectively. The field sample is tested for a period of 2.5 minutes under a constant head difference of 10 cm. As a result, 48 cm³ of water is collected at the outlet. a) Determine the hydraulic conductivity of the aquifer b) During those 2.5 minutes, how far would water have travelled in the test cylinder if effective porosity was measured as 30 %?
5. In the pond below, Material 1: K-2x10-7m/s; Material 2: K-8x10-8m/s. Below material 2, the ground is unsaturated. a) What is the flux from the bottom of the pond? 1 10m b) What is the head at the interface between the two materials? 3m material 1 Im material 2 Om 6. Below are two triangular unit hydrographs for 2 neighbouring catchments. UH B 20 m³/s UH A 25 m²/s 2 hr 3 hr 8 hr (a) What is the area of catchment B? (b) What can you say about the runoff response of each catchment? (c) Net rainfall of 10 mm in the first hour, 20 mm in the second hour and 15 mm in the third hour falls on catchment A. Calculate the resulting run-off as a function of time. (d) Net rainfall of 5 mm in the first hour, 10 mm in the second hour and 8 mm in the third hour falls on catchment B. Calculate the resulting runoff as a function of time. (e) The rivers flowing out from catchments A and B meet shortly after they leave the catchments. A storm with the net rainfall given above moves across the two catchments, with the rainfall starting an hour later on catchment B than catchment A. Calculate the resulting combined run-off as a function of time. (f) The simple triangular 1-hr unit Hydrograph 'UH A' from above was actually generated using the data below. Use the data to generate a 2hr hydrograph. Plot your hydrograph and fit a simple triangular UH to it. What's the peak flow of your 2-hr UH? And the time to peak flow? Check that that volume implied by your UH is appropriate. 3 4 5 6 Time (hr) Flow (m3/s) 0 0 1 2 10.5 19.75 16.25 5 0 6 hr 11
7. When just full, a reservoir has a surface area of 0.8 km², and this area is approximately constant as the water depth above this level, h, increases (where his in metres). The outflow from the reservoir is given (in m³/s) by the formula 0-90h¹ Consider a scenario in which this reservoir is subjected to a flood with flow rates given in the table below. Time (hours) Inflow (m/s) 0 0 1 2 3 4 5 18 22 12 0 6 a) What is the total volume of water represented by this flood? b) Carry out a flood storage routing calculation. Find the maximum water depth in the reservoir and its maximum outflow rate, and the time when this occurs.
8. The highest annual discharges of a river were statistically analysed for a periods of 45 years. The fourth largest flood was 1,300 m/s. Determine: a) the period in which the flood of 1,300 m/s may reoccur once; b) the percentage chance that this flood may occur in any one year; c) the percentage chance that this flood may not occur in the next 25 years, d) the percentage chance that this flood may occur once or more in the next 25 years; e) the percentage chance that a 40-yr flood may occur once in 40 years, f) the percentage chance that a 40-yr flood may occur one or more times in 40 years. Determine the percentage probability that a 30-yr storm a) may occur in the next 15 years; b) may occur in the next year, c) may not occur in another 20 years.
10. Using simple reservoir simulation, estimate storage over time; maximum reservoir capacity is 11 volume units, and the initial volume at time zero is 9 volume units. Please a) estimate the largest spill over the simulated period b) and the simulated storage at the beginning of 7th time step. Time Inflow Demand step (LAB) (LAB) 4 4 6 5 6 11. A hydropower storage station (i.e. reservoir) has a storage capacity of 7x10 m², which can be released for generating electricity over a 6.5 hour period. If the effective head is 450m, and the generator efficiency is 87%, a) Calculate the average power output and the total electrical energy produced in 6.5 hours. b) The reservoir above is part of a pumped storage scheme. It takes 9 hours to refill the reservoir. Because of frictional drag, the effective head when pumping is 520m. For pumps having an energy efficiency of 80%, calculate the input power to the pumps. 0 1235 ∞0 10 m 4 37 567 8 6 3 6 76 5965 8
12. Coursework exercises pertaining to Topic 6 Subsection - Water resource system modelling Modelling coursework exercise 1: This exercise is based on the model network named "Allocation". To access the model network used in this exercise, log in to the modelling system and click on the project "Training material," which is available by default upon creating an account. Under this project, you will find the model network with the name "Allocation." Make the following changes to the model and answer the coursework questions afterward, . Create a new scenario and name it "Prioritize_industrial_supply" by cloning the "baseline scenario. In this new scenario, assign a higher water allocation priority to the "Industrial water abstraction" node than the "Municipal water abstraction" and the "irrigation water abstraction" nodes. To achieve that, change the allocation penalty of the "Industrial water abstraction" node to -30. . Create a new scenario and name it "Low_storage" by cloning the "baseline" scenario. In this new scenario, reduce the maximum storage capacity of the "Storage reservoir" to 1000 m². To achieve that, double click on the reservoir node and change "max_volume" from 3500 Mm' to 1000 Mm¹. . Run all model scenarios to update the model outputs before answering coursework questions, which are on page 4 of this document. Modelling coursework exercise 2: This exercise is based on the model network named "Eastern Nile Model". To access the model network used in this exercise, log in to the modelling system and click on the project "Training material," which is available by default upon creating an account. Under this project, you will find the model network with the name "Eastern Nile Model." Make the following changes to the model and answer the coursework questions afterward. . Create a new scenario and name it "Higher GERD_releases" by cloning the "baseline" scenario. In this new scenario, increase the release values of the "GERD" based on the data below. To achieve that, double click on the "GERD_control" node, then edit the "release_values" by changing the values under the "value" column according to the table below. volume value 1 230 2 0.66 200 3 0.310088. 150 4 0.011 230 50 5 0.01 . Create a new scenario and name it "Higher_Sudan_abstraction" by cloning the "baseline" scenario. In this new scenario, increase the water abstraction targets of the "Gezira and Managil" to the values in the table below. To achieve that, double click on the "Gezira and Managil" node, then edit "max_flow," and change the values under all months to the data below. 1
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 050 50 40 31 33 45 50 45 55 55 45 50 . Run all model scenarios to update the model outputs before answering coursework questions, which are on page 4 of this document. Coursework questions: a) Based on Exercise 1, what is the "simulated_volume" of the storage reservoir in June 2021 in the "Low_storage" scenario? b) Based on Exercise 1, what is the "simulated_flow" of the "Industrial water abstraction" node in September 2021 in the "Prioritize industrial_supply" scenario? c) Based on Exercise 2, what is the "simulated_volume" of the "GERD" node in Ethiopia at the end of the simulation period in the "Higher GERD_releases" scenario? d) Based on Exercise 2, what is the "simulated_volume" of the "HAD" node in Egypt in January 1980 in the "Higher_Sudan_abstraction" scenario?