Environmental Protection Program Cooperative Agreement No. 517-A-00-09-00106-00 Report SWAT HYDROLOGICAL MODELING AND THE IMPACT OF CLIMATE AND LAND USE CHANGE ON THE YAQUE DEL NORTE, OZAMA, HAINA, AND NIZAO WATERSHEDS. Riverside Technology, inc. July 2013 “This publication was made possible by the generous support of the American people through the United States Agency for International Development (USAID) under the terms of its Cooperative Agreement Number 517-A-00-09-00106-00 (Environmental Protection Program) implemented by prime recipient The Nature Conservancy and partners. The contents and opinions expressed herein are the responsibility of the ENVIRONMENTAL PROTECTION PROGRAM and do not necessarily reflect the views of USAID.” FINAL REPORT: SWAT HYDROLOGICAL MODELING AND THE IMPACT OF CLIMATE AND LAND USE CHANGE ON THE YAQUE DEL NORTE, OZAMA, HAINA, AND NIZAO WATERSHEDS. Riverside Technology, inc. 2950 East Harmony Road, Suite 390 Fort Collins, Colorado 80528 USA T: (970) 484-7573 | F: (970) 484-7593 www.riverside.com TABLE OF CONTENTS TABLE OF CONTENTS 1.0 Executive Summary ..................................................................................................... 1 1.1 Background .........................................................................................................................1 1.2 Objective ............................................................................................................................1 1.3 Approach ............................................................................................................................1 1.4 Findings ..............................................................................................................................2 2.0 Introduction ................................................................................................................ 4 2.1 Study Area ..........................................................................................................................5 3.0 Data Collection and Analysis ........................................................................................ 6 3.1 Spatial Data Sets .................................................................................................................6 3.2 Climate Data ..................................................................................................................... 14 3.2.1 Precipitation Data ............................................................................................................... 14 3.2.2 Temperature Data ............................................................................................................... 19 3.2.3 Other Climate Data: Wind Speed, Relative Humidity and Solar Radiation ......................... 19 3.3 Streamflow Data ............................................................................................................... 21 3.4 Regulation Data ................................................................................................................ 21 3.5 Climate Change Data ......................................................................................................... 22 4.0 Land Use Land Cover Modeling .................................................................................. 23 4.1 Meeting Keynotes Speakers ............................................................................................... 23 4.2 Meeting Methodology and Findings ................................................................................... 24 4.3 Methodology to Develop the Scenarios:............................................................................. 27 4.3.1 GEOMOD Land Change Model ............................................................................................ 27 4.3.2 Data Requirements ............................................................................................................. 30 4.3.3 Driver Maps ......................................................................................................................... 31 4.3.4 Superposition of Rules ......................................................................................................... 33 4.3.5 Deliverables ......................................................................................................................... 34 4.3.6 Results ................................................................................................................................. 36 5.0 Selection of Climate Change Projections .................................................................... 46 5.1 Climate Change Projections in the Hot-Dry Climate Zone .................................................... 47 5.2 Climate Change Projections in the Wet-Warm and Median Climate Zones .......................... 52 5.3 Seasonality of the Climate Change Projections ................................................................... 53 6.0 SWAT Model ............................................................................................................. 57 6.1 SWAT Model Setup ........................................................................................................... 57 6.1.1 Watershed Delineation ....................................................................................................... 57 6.1.2 HRU Definition ..................................................................................................................... 60 6.1.3 Climate Input ....................................................................................................................... 63 6.2 Model Calibration ............................................................................................................. 63 6.3 Calibration Approach......................................................................................................... 64 6.3.1 Nizao Basin .......................................................................................................................... 64 i TABLE OF CONTENTS 6.3.2 Haina Basin ......................................................................................................................... 66 6.3.3 Ozama Basin ....................................................................................................................... 68 6.3.4 Yaque del Norte Basin ......................................................................................................... 71 6.4 Calibration Summary ......................................................................................................... 74 7.0 Modeling the Effect of LULC and Climate Changes in the Hydrologic Response of the Basins 75 7.1 Results .............................................................................................................................. 79 7.2 Haina Basin ....................................................................................................................... 79 7.2.1 Water Yield .......................................................................................................................... 79 7.2.2 Peak Flow ............................................................................................................................ 80 7.2.3 Sediment ............................................................................................................................. 80 7.2.4 Baseflow .............................................................................................................................. 80 7.3 Nizao Basin ....................................................................................................................... 86 7.3.1 Water Yield .......................................................................................................................... 86 7.3.2 Peak Flow ............................................................................................................................ 86 7.3.3 Sediment ............................................................................................................................. 86 7.3.4 Baseflow .............................................................................................................................. 87 7.4 Ozama Basin ................................................................................................................... 100 7.4.1 Water Yield ........................................................................................................................ 100 7.4.2 Peak Flow .......................................................................................................................... 100 7.4.3 Sediment ........................................................................................................................... 100 7.4.4 Baseflow ............................................................................................................................ 101 7.5 Yaque del Norte Basin ..................................................................................................... 118 7.5.1 Water Yield ........................................................................................................................ 118 7.5.2 Sediment ........................................................................................................................... 118 7.5.3 Peak Flow .........................................................................................................................