Part 6 Groundwater Simulation of Master Plan
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PART 6 GROUNDWATER SIMULATION OF MASTER PLAN Study on Sustainable Water Supply for Bogotá City and Surrounding Area Based on the Integrated Water Resources Management, Colombia Final Report (Supporting Report) PART 6 GROUNDWATER SIMULATION OF MASTER PLAN Table of Contents Page Table of Contents .........................................................................................................................i List of Tables and Figures .......................................................................................................... ii Page PART - 6. GROUNDWATER SIMULATION....................................................................... 6-1 CHAPTER 1. OUTLINE OF THE MODEL........................................................................ 6-1 1.1. BOUNDARY CONDITIONS............................................................................. 6-1 1.2. NEWLY PLANNED PUMPING WELLS .......................................................... 6-3 1.3. CALIBRATED MODEL..................................................................................... 6-4 CHAPTER 2. DRADOWN FORECAST............................................................................. 6-5 2.1. HEAD OBSERVATION WELLS........................................................................ 6-5 2.2. HEAD OBSERVATION RESULTS.................................................................... 6-5 2.3. DISCHARGE - DRAWDOWN RELATION...................................................... 6-8 2.4. HEAD RECOVERY WITH TIME......................................................................6-8 2.5. DRAWDOWN IN QUATERNARY SEDIMENT LAYERS .............................6-11 Final Report-Supporting Report i Study on Sustainable Water Supply for Bogotá City and Surrounding Area Based on the Integrated Water Resources Management, Colombia List of Tables and Figures Page Table-6. 1 Details of Boundary Conditions............................................................................... 6-1 Table-6. 2 Details of Planned Wells in the Model..................................................................... 6-3 Table-6. 3 Detailed Location of Observation Wells .................................................................. 6-5 Table-6. 4 Head Observation Data for the Cretaceous Aquifer................................................. 6-6 Table-6. 5 Discharge (Q) - Drawdown (s) Relation .................................................................. 6-8 Table-6. 6 Head Recovery with Time after Termination of Pumping for Scenario 1 ............... 6-8 Table-6. 7 Head Recovery with Time after Termination of Pumping for Scenario 6 ............... 6-9 Table-6. 8 Drawdown in Quaternary Sediment Layers for Scenario 6 ................................... 6-11 Figure-6. 1 Cross-sectional Views of Grid/layer and Boundary Conditions of the Model....... 6-2 Figure-6. 2 Head Distribution of the Calibrated Steady State Model ....................................... 6-4 Figure-6. 3 Drawdown in the Cretaceous Aquifer at Different Pumping Rates........................ 6-7 Figure-6. 4 Time-Drawdown relations for Scenario 1 to 6 ..................................................... 6-10 Final Report-Supporting Report ii Study on Sustainable Water Supply for Bogotá City and Surrounding Area Based on the Integrated Water Resources Management, Colombia PART - 6. GROUNDWATER SIMULATION CHAPTER 1. OUTLINE OF THE MODEL 1.1. Boundary Conditions The basic information (model structure, parameters, boundary conditions) of the model is given in Table 1 of the main report. The following table presents the details of the boundary conditions employed in this model. Table-6. 1 Details of Boundary Conditions Structure Boundary condition (BC) Layer BC Type Detail 1st layer: Constant Head Boundary In basin: Fixed heads for rivers and dams, Quaternary General Head Boundary GHB for mountain ridges (see Figure 1 in main report) External Head = cell top – 50 m, Conductance = 1200m2/day Recharge boundary Groundwater recharge (see Figure 2 in main report) Drain boundary Outside Bogota basin: Drain for major rivers Conductance = 2~10 m2/day 3rd & 4th layer: Constant Flux Boundary 4897 existing wells, fully penetrated (see Figure 3 in main report) Guadalupe (Pumping well) Pumping rate range 0.89~6684 m3/day 59 newly planned wells (hypothetical) 8th layer General Head Boundary for outermost perimeter cells Paleozoic External Head = cell top + 15 m, Conductance = 400m2/day 10th layer: General Head Boundary for outermost perimeter cells Paleozoic External Head = cell top + 100~500 m, Conductance = 400m2/day 12th layer No Flow Boundary No groundwater is considered to move across the bottom of the Paleozoic model. The vertical cross-section of the model showing grid/layer and major boundary conditions is shown in Figure-6.1. Vertical cross-section along column 52 (vertical exaggeration = x 20) Final Report - Supporting Report (6-1) Study on Sustainable Water Supply for Bogotá City and Surrounding Area Based on the Integrated Water Resources Management, Colombia Vertical cross-section along row 60 (vertical exaggeration = x 20) Figure-6. 1 Cross-sectional Views of Grid/layer and Boundary Conditions of the Model Note: ・ The columns are vertical strips in the model plan view (Figure 1 in main report) and serially numbered 1 to 105 from the left. ・ The rows are horizontal strips in the model plan view (Figure 1 in main report) and serially numbered 1 to 120 from the top. ・ Red cells: well boundary, blue cells: constant head boundary, pink cells: drain boundary, green cells: general head boundaries. Final Report - Supporting Report (6-2) Study on Sustainable Water Supply for Bogotá City and Surrounding Area Based on the Integrated Water Resources Management, Colombia 1.2. Newly Planned Pumping Wells The following table shows the list of the 59 pumping wells newly planned in this study. Some wells are located close together and thus integrated in one cell in the model. Such integrated result is shown in the right most two columns titled “Output Cell” and “No of wells per cell”. Table-6. 2 Details of Planned Wells in the Model Pump rate Output cell No. of wells SN Name (New) Code Row Column (m3/d) (m3/d) per cell 17 S-1 8743 84 28 5857.6 18 S-2 8743 84 28 5857.6 -11715.2 2 19 S-3 8744 84 29 5857.6 -5857.6 1 14 S-4 8849 85 29 5857.6 15 S-5 8849 85 29 5857.6 16 EX-1 8849 85 29 5857.6 -17572.8 3 13 S-6 8954 86 29 5857.6 -5857.6 1 9 B-1 9061 87 31 5857.6 10 B-2 9061 87 31 5857.6 11 EX-2 9061 87 31 5857.6 -17572.8 3 8 B-3 9166 88 31 5857.6 -5857.6 1 12 U-103 9070 87 40 0 0 1 6 U-3 9385 90 40 5857.6 7 U-4 9385 90 40 5857.6 -11715.2 2 4 U-2 9490 91 40 5857.6 -5857.6 1 2 EX-3 9595 92 40 5857.6 3 U-1 9595 92 40 5857.6 -11715.2 1 1 U-101 9805 94 40 0 0 1 5 U-102 9491 91 41 0 0 1 23 - 8127 78 42 0 0 1 21 E-2 8337 80 42 5857.6 -5857.6 1 20 E-1 8757 84 42 5857.6 -5857.6 1 27 E-4 7918 76 43 5857.6 -5857.6 1 26 E-3 8023 77 43 5857.6 -5857.6 1 24 E-102 8128 78 43 0 25 - 8128 78 43 0 0 2 22 E-101 8338 80 43 0 0 1 28 E-103 7814 75 44 0 0 1 58 Y-20 5296 51 46 5857.6 -5857.6 1 56 Y-18 5401 52 46 5857.6 -5857.6 1 54 Y-16 5506 53 46 5857.6 55 Y-17 5506 53 46 5857.6 -11715.2 2 <Note> 52 Y-14 5611 54 46 5857.6 The numbers under “code” 53 Y-15 5611 54 46 5857.6 -11715.2 2 51 Y-13 5716 55 46 5857.6 -5857.6 1 correspond to a cell in the 49 Y-11 5821 56 46 5857.6 model. Thus the wells that have 50 Y-12 5821 56 46 5857.6 -11715.2 2 the same code are located in the 47 Y-9 5926 57 46 5857.6 same model grid cell to produce 48 Y-10 5926 57 46 5857.6 -11715.2 2 46 Y-8 6031 58 46 5857.6 -5857.6 1 a combined pumping rate under 44 Y-6 6136 59 46 5857.6 “Output cell”. 45 Y-7 6136 59 46 5857.6 -11715.2 2 42 Y-4 6241 60 46 5857.6 The pumping rate of wells are 43 Y-5 6241 60 46 5857.6 -11715.2 2 39 Y-1 6346 61 46 5857.6 that for Scenario 4 in the 40 Y-2 6346 61 46 5857.6 drawdown forecast. 41 Y-3 6346 61 46 5857.6 -17572.8 3 38 E-14 6451 62 46 5857.6 -5857.6 1 34 E-10 6766 65 46 5857.6 The pumping rate of a pumping 35 E-11 6766 65 46 5857.6 -11715.2 2 well (wells taking water out of 33 E-9 6871 66 46 5857.6 -5857.6 1 the model) is defined to have 32 E-8 6976 67 46 5857.6 -5857.6 1 negative value in the model. 31 E-7 7081 68 46 5857.6 -5857.6 1 29 E-5 7291 70 46 5857.6 30 E-6 7291 70 46 5857.6 -11715.2 2 The shaded wells are 59 Y-21 5192 50 47 5857.6 -5857.6 1 temporality or permanently not 57 Y-19 5402 52 47 5857.6 -5857.6 1 in operation for some reasons. 37 E-13 6662 64 47 5857.6 -5857.6 1 36 E-12 6767 65 47 5857.6 -5857.6 1 64 Y-26 4878 47 48 5857.6 -5857.6 1 62 Y-24 4983 48 48 5857.6 63 Y-25 4983 48 48 5857.6 -11715.2 2 60 Y-22 5088 49 48 5857.6 61 Y-23 5088 49 48 5857.6 -11715.2 2 67 Y-29 4564 44 49 5857.6 -5857.6 1 65 Y-27 4669 45 49 5857.6 66 Y-28 4669 45 49 5857.6 -11715.2 2 Total -345,598 Final Report - Supporting Report (6-3) Study on Sustainable Water Supply for Bogotá City and Surrounding Area Based on the Integrated Water Resources Management, Colombia 1.3. Calibrated Model The final outcome of the calibration under steady state condition as head distribution maps in plan view.