The Study on Integrated Water Resources Management for Poverty Alleviation and Economic Development in the Pampanga River Basin in the Republic of the Philippines
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NATIONAL WATER RESOURCES BOARD THE REPUBLIC OF THE PHILIPPINES THE STUDY ON INTEGRATED WATER RESOURCES MANAGEMENT FOR POVERTY ALLEVIATION AND ECONOMIC DEVELOPMENT IN THE PAMPANGA RIVER BASIN IN THE REPUBLIC OF THE PHILIPPINES FINAL REPORT VOLUME III: SUPPORTING REPORTS JANUARY 2011 JAPAN INTERNATIONAL COOPERATION AGENCY CTI ENGINEERING INTERNATIONAL CO., LTD. in association with NIPPON KOEI CO., LTD. Composition of Final Report Volume I: Summary Volume II: Main Report Volume III: Supporting Reports Sector A: Topography and Meteo-Hydrology Sector B: Socio-Economy Sector C: Agricultural and Fishery Water Management Sector D: Municipal Water Supply, Sanitation and Sewerage System Management Sector E: Flood and Sediment Disaster Management Sector F: Water-related Environmental Management Sector G: Watershed Management Sector H: Water Resources Development and Management Volume IV: Supporting Reports Sector I: Socio-Environmental Consideration Sector J: Guideline for Formulation of IWRM Plan Sector K: Formulation of IWRM Plan Sector L: Plans for Legal and Institutional Framework Sector M: Water-related Data Management Appendix: Minutes and Discussion Records on SC, TWG and Stakeholder Meetings Exchange Rate used in the Report is: PHP 1.00 = US$ 0.0217 = JP¥ 1.934 US$ 1.00 = PhP 46.15 = JP¥ 89.25 (as of 31st December 2009) Sector A Topography and Meteo-Hydrology Sector A. Topography and Meteo-Hydrology Table of Contents Pages A.1 Introduction ............................................................................................................................ A-1 A.2 Topographic Conditions ......................................................................................................... A-2 A.2.1 General .................................................................................................................. A-2 A.2.2 Topographic Classification ................................................................................... A-2 A.2.2.1 Preparation of Digital Elevation Model (DEM) ........................................ A-2 A.2.2.2 Classification by Elevation ........................................................................ A-2 A.2.2.3 Classification by Slope .............................................................................. A-3 A.2.2.4 Summary of Regional Topography ............................................................ A-3 A.2.3 Change in Topography by Pinatubo Eruption in 1991 .......................................... A-4 A.3 River Systems and Sub-Basins .............................................................................................. A-5 A.3.1 Delineation of Sub-Basins in the Study Area ........................................................ A-5 A.3.2 Characteristics of Main Rivers and Sub-Basins .................................................... A-6 A.3.2.1 Pampanga Main River System .................................................................. A-6 A.3.2.2 Angat River System ................................................................................... A-7 A.3.2.3 Pasac River System ................................................................................... A-8 A.4 Meteorology and Hydrology ................................................................................................ A-10 A.4.1 Monitoring Data for Meteorology and Hydrology.............................................. A-10 A.4.1.1 Meteorological Data ................................................................................ A-10 A.4.1.2 Hydrological Data ................................................................................... A-11 A.4.2 Meteorology ........................................................................................................ A-12 A.4.2.1 General .................................................................................................... A-12 A.4.2.2 Gap Filling of Precipitation Data ............................................................. A-12 A.4.2.3 Estimation of Potential Evapotranspiration (PET) .................................. A-13 A.4.2.4 Temporal Variation in Meteorological Conditions .................................. A-13 A.4.2.5 Spatial Distribution of Meteorological Conditions .................................. A-14 A.4.2.6 Extreme Event ......................................................................................... A-16 A.4.2.7 Expected Regional Climate Change by IPCC 4th Report ........................ A-17 A.4.3 Hydrology ........................................................................................................... A-18 A.4.3.1 Overview in Runoff Condition ................................................................ A-18 A.4.3.2 Temporal Variation of Water Quantity ..................................................... A-18 A.4.3.3 Extreme Event ......................................................................................... A-19 A.4.3.4 Issues in Hydrological Data ..................................................................... A-19 A.5 Geology and Hydrogeology .................................................................................................. A-21 A.5.1 Geology ............................................................................................................... A-21 A.5.1.1 General .................................................................................................... A-21 A.5.1.2 Quaternary- Recent (R) ........................................................................... A-21 A.5.1.3 Sedimentary Rocks .................................................................................. A-21 A.5.1.4 Igneous Rocks ......................................................................................... A-22 A.5.2 Hydrogeology ..................................................................................................... A-22 A.6 Land Subsidence ................................................................................................................... A-24 i A.7 Long-term Rainfall-Runoff Simulation .............................................................................. A-26 A.7.1 General ................................................................................................................ A-26 A.7.2 Rainfall-Runoff Simulation Model ..................................................................... A-26 A.7.3 Input Data ........................................................................................................... A-28 A.7.3.1 Monthly Total Precipitation ..................................................................... A-29 A.7.3.2 Monthly Total PET .................................................................................. A-29 A.7.4 Model Calibration ............................................................................................... A-29 A.7.5 Generated Long-term Runoff Discharge ............................................................. A-31 List of Tables List of Tables in Report Table A. 2.2.1 Elevation Classification in the Study Area .......................................................... A-3 Table A. 2.2.2 Slope Classification in the Study Area ................................................................. A-3 Table A. 2.2.3 Category of Topographic Condition in the Study Area ........................................ A-4 Table A. 3.1.1 Main Features of Sub-Basins ............................................................................... A-6 Table A. 3.2.1 Topographic Features of Sub-basins of Pampanga Main River System .............. A-7 Table A. 3.2.2 Topographic Features of Sub-basins of Angat River System .............................. A-8 Table A. 4.2.1 Climate Classification in the Philippines ........................................................... A-12 Table A. 4.2.2 Monthly Variation of Precipitation at Key Stations ........................................... A-14 Table A. 4.2.3 Monthly Variation of Climatic Parameters at CLSU Munoz ............................. A-14 Table A. 4.2.4 Monthly Variation of Precipitation and PET for the Entire Study Area ............. A-15 Table A. 4.2.5 Probable Annual Total Precipitation .................................................................. A-16 Table A. 4.2.6 Probable Total Dry Season Precipitation ........................................................... A-16 Table A. 4.2.7 Probable Maximum 1day Precipitation ............................................................. A-17 Table A. 4.2.8 Regional Averages of Temperature and Precipitation Projections for SEA region ................................................................................................................. A-17 Table A. 4.3.1 Annual Average Runoff Discharge in the Study Area ........................................ A-18 Table A. 4.3.2 Probable Annual Average Discharge and Minimum Monthly Discharge at HMS343 ............................................................................................................. A-20 Table A. 5.2.1 Ratio of Categorized Hydrogeological Area in the Sub-Basins ......................... A-23 Table A. 7.5.1 Estimated Mean Annual Average Discharge at Representative Control Points ................................................................................................................. A-32 List of Annex Tables Annex-T A.3.1.1 Elevation and Slope Classification for Each Sub-Basin .............................AT-1 Annex-T A.4.1.1 List of Meteorological Stations ...................................................................AT-2