Land and Watershed Management - Practices of Irrigation and On-farm Water Management - page 193

Chapter 6
Land and Watershed Management

Contents

6.1 Concepts and Scale Consideration ....................... 194
6.2 Background and Issues Related to Watershed Management ............ 195
6.2.1 Water Scarcity ............................ 196
6.2.2 Floods, Landslides, and Torrents .................... 196
6.2.3 Water Pollution ............................ 196
6.2.4 Population Pressure and Land Shrinkage ................ 196
6.3 Fundamental Aspects of Watershed Management ................ 197
6.3.1 Elements of Watershed ........................ 197
6.3.2 How the Watershed Functions ..................... 198
6.3.3 Factors Affecting Watershed Functions ................. 198
6.3.4 Importance of Watershed Management ................. 198
6.3.5 Addressing/Naming a Watershed .................... 198
6.4 Land Grading in Watershed .......................... 199
6.4.1 Concept, Purpose, and Applicability .................. 199
6.4.2 Precision Grading .......................... 200
6.4.3 Factors Affecting Land Grading
and Development ........................... 201
6.4.4 Activities and Design Considerations in Land Grading .......... 203
6.4.5 Methods of Land Grading and Estimating Earthwork Volume ....... 205
6.5 Runoff and Sediment Yield from Watershed .................. 212
6.5.1 Runoff and Erosion Processes ..................... 212
6.5.2 Factors Affecting Runoff ....................... 213
6.5.3 Runoff Volume Estimation ...................... 214
6.5.4 Factors Affecting Soil Erosion ..................... 219
6.5.5 Sediment Yield and Its Estimation ................... 221
6.5.6 Sample Workout Problems on Sediment Yield Estimation ......... 223
6.5.7 Erosion and Sedimentation Control ................... 225
6.5.8 Modeling Runoff and Sediment Yield .................. 226
6.6 Watershed Management ........................... 227
6.6.1 Problem Identification ........................ 227

Components of Watershed Management ................ 228 6.6.2