MALIR EXPRESSWAY PROJECT FROM JAM SADIQ BRIDGE SUPER HIGHWAY M9. HYDROLOGY & HYDRAULIC REPORT Table of Contents LIST OF FIGURES ....................................................................................................... i LIST OF TABLES ........................................................................................................ ii EXECUTIVE SUMMARY ......................................................................................... iii CHAPTER 1 .................................................................................................................. 5 OBJECTIVE AND SCOPE OF STUDY .................................................................... 5 1.1 BACKGROUND ................................................................................................ 5 1.2 INTRODUCTION .............................................................................................. 7 1.3 OBJECTIVE ..................................................................................................... 10 1.4 APPROACH ..................................................................................................... 10 CHAPTER- 2 .............................................................................................................. 12 2 HYDROLOGY FEATURES ......................................................................... 12 2.1 GENERAL ........................................................................................................ 12 2.2 TOPOGRAPHY AND TERRAIN ................................................................... 12 2.3 WATERWAYS ................................................................................................ 13 2.4 CLIMATE......................................................................................................... 14 2.5 RELATIVE HUMIDITY.................................................................................. 14 2.6 WIND MOVEMENT ....................................................................................... 15 2.7 TEMPERATURES ........................................................................................... 16 2.8 SOILS ............................................................................................................... 17 2.9 TECHNICAL DATA........................................................................................ 18 2.9.1 MAPS ............................................................................................................... 18 2.9.2 RAINFALL DATA .......................................................................................... 18 2.9.3 DISCHARGE DATA ....................................................................................... 18 2.10 CATCHMENT AREA ..................................................................................... 18 2.11 HYDROLOGY AND DRAINAGE ................................................................. 19 CHAPTER-3 ............................................................................................................... 20 3 FIELD INVESTIGATION ............................................................................ 20 3.1 CONDITIONAL SURVEY .............................................................................. 20 3.2 KARACHI FLOOD CONTROL PLAN .......................................................... 22 3.3 CITY STROM WATER DRAINAGE ............................................................. 23 3.3.1 MANZOOR COLLONY NALA ...................................................................... 23 3.3.2 MANZOOR COLLONY NALA ...................................................................... 23 3.3.3 MANZOOR COLLONY NALA ...................................................................... 23 3.3.4 MANZOOR COLLONY NALA ...................................................................... 23 MALIR EXPRESSWAY PROJECT FROM JAM SADIQ BRIDGE SUPER HIGHWAY M9. HYDROLOGY & HYDRAULIC REPORT 3.4 PICTORIAL OBSERVATIONS ...................................................................... 24 CHAPTER-4 ............................................................................................................... 26 4 HYDROLOGY AND HYDRAULIC ANALYSIS ....................................... 26 4.1 METHODOLOGY AND ASSUMPTIONS ..................................................... 26 4.2 HYDROLOGICAL ANALYSIS: ..................................................................... 26 4.2.1 WATERSHED DELINEATION ...................................................................... 26 4.2.2 MALIR WATERSHED .................................................................................... 27 4.2.3 DESIGN APPROACH: .................................................................................... 29 4.2.4 FREQUENCY ANALYSIS: ............................................................................ 29 4.2.5 COMPUTATION OF RAINFALL INTENSITY ............................................ 34 4.3 RAINFALL-RUNOFF ANALYSIS ................................................................. 34 4.3.1 UNIT HYDROGRAPH (TRIANGULAR) METHOD .................................... 34 4.4 RESULTS OF RAINFALL RUNOFF ANALYSIS ........................................ 36 4.5 HYDRAULIC STUDY USING HEC-RAS ..................................................... 36 4.5.1 GENERAL:....................................................................................................... 36 4.5.2 INTRODUCTION TO HEC-RAS .................................................................... 36 4.5.2 hec-ras model Development ............................................................................. 38 4.5.3 MODEL GEOMETRY ..................................................................................... 38 4.5.4 RIVER REACHES AND CROSS-SECTIONS ............................................... 39 4.5.5 MANNING’S ROUGHNESS CO-EFFICIENT .............................................. 40 4.5.6 DETAILED HYDRAULIC ANALYSIS ......................................................... 40 4.7 CONCLUSION ................................................................................................ 44 CHAPTER-5 ............................................................................................................... 45 EMBANKMENT AND SLOPE PROTECTION ..................................................... 45 ANNEXURE-A ........................................................................................................... 49 ANNEXURE-B ............................................................................................................ 74 ANNEXURE-B ............................................................................................................ 99 MALIR EXPRESSWAY PROJECT FROM JAM SADIQ BRIDGE SUPER HIGHWAY M9. HYDROLOGY & HYDRAULIC REPORT LIST OF FIGURES Figure 1: Location plan of the proposed alignment ............................................................. 6 Figure 2: GIS map for Karachi city ..................................................................................... 9 Figure 3: Satellite image shows the tidal areas and Malir River ......................................... 9 Figure 4: Map of Karachi city showing the River Malir and its watershed ...................... 10 Figure 5: Topography and Contour of Karachi city courtesy: floodmap.net .................. 13 Figure 6: Cropping at the prism of Malir River ................................................................. 20 Figure 7: the water gauge painted at the Motorway Bridge .............................................. 21 Figure 8: Industrial Waste water out falling in to Malir River .......................................... 22 Figure 9: Catchment area of Malir Basin .......................................................................... 28 Figure 10: Delineated watershed using GIS tools of Malir River ..................................... 28 Figure 11: Plotted rainfall intensities for Karachi ............................................................. 33 Figure 12: The Open project window of HEC-RAS ......................................................... 37 Figure 13: geometric and cross section entering window ................................................. 38 Figure 14: the flow data window ....................................................................................... 38 Figure 15: the output windows of HEC-RAS .................................................................... 38 Figure 16: HEC-RAS geometric window shows reaches cross section ............................ 39 Figure 17: Surveyed cross section at chainage 38+400 of Malir River ............................. 40 Figure 18: Q50, Q100 water levels at Chainage 39+345 .................................................. 41 Figure 19: Q50, Q100 water levels at Chainage 1+175 .................................................... 42 Figure 20: Malir River L-section showing water levels of 1977, 78 50 Year & 100 Year Return Period .............................................................................................................. 42 Figure 20: typical drawing of stone pitching ..................................................................... 45 Figure 21: Typical drawing of granular material ............................................................... 46 Figure 22: typical drawing of side filter ............................................................................ 46 Figure 23: typical drawing of toe protection ....................................................................