Distributed Hydrologic Modeling Using GIS Distributed Hydrologic Modeling Data Sources and Structure Surface Generation Spatial Variability Infiltration Modeling Hydraulic Roughness Digital Terrain Precipitation Measurement Finite Element Modeling Distributed Model Calibration Distributed Hydrologic Modeling Hydrologic Analysis and Prediction. 1. 5 REFERENCES 127 7 DIGITAL TERRAIN 129 1. 1 INTRODUCTION 129 1. 2 DRAINAGE NETWORK 130 1. 3 DEFINITION OF CHANNEL NETWORKS 135 1. 4 RESOLUTION DEPENDENT EFFECTS 138 1. 5 CONSTRAINING DRAINAGE DIRECTION 141 1. 6 SUMMARY 145 1. 7 REFERENCES 146 8 PRECIPITATION MEASUREMENT 149 1. 1 INTRODUCTION 149 1. 2 RAIN GAUGE ESTIMATION OF RAINFALL 151 ADAR STIMATION OF RECIPITATION 1. 3 R E P 155 1. 4 WSR 88D RADAR CHARACTERISTICS 167 1. 5 INPUT FOR HYDROLOGIC MODELING 172 1. 6 SUMMARY 174 1. 7 REFERENCES 175 9 FINITE ELEMENT MODELING 177 1. 1 INTRODUCTION 177 1. 2 MATHEMATICAL FORMULATION 182 1. 3 SUMMARY 194 1. 4 REFERENCES 195 10 DISTRIBUTED MODEL CALIBRATION 197 1. 1 INTRODUCTION 197 1. 2 CALIBRATION APPROACH 199 1. 3 DISTRIBUTED MODEL CALIBRATION 201 1. 4 AUTOMATIC CALIBRATION 208 1. 5 SUMMARY 214 1. 6 REFERENCES 214 11 DISTRIBUTED HYDROLOGIC MODELING 217 1. 1 INTRODUCTION 218 1. 2 CASE STUDIES 218 1. 3 SUMMARY 236 1. 4 REFERENCES 237 12 HYDROLOGIC ANALYSIS AND PREDICTION 239 1. 1 INTRODUCTION 239 x Distributed Hydrologic Modeling Using GIS 1. 2 VFLO™ EDITIONS 241 1. 3 VFLO™ FEATURES AND MODULES 242 1. 4 MODEL FEATURE SUMMARY 245 1. 5 VFLO™ REAL TIME 256 1. 6 DATA REQUIREMENTS 258 1. 7 RELATIONSHIP TO OTHER MODELS 259 1. 8 SUMMARY 260 1.