Hydrological Processes, Hazards and Management 1
T H E H Y D R O L O G I C A L C Y C L E
 Describe the global hydrological cycle
 Describe the basin hydrological cycle in terms of inputs, flows, storages, outputs and feedback
Inputs:
 What are the various types of precipitation? How can precipitation intensity vary?
Flows:
 How does infiltration take place?
 What are the factors affecting infiltration rate and capacity? o Rainfall characteristics o Soil texture o Vegetation o Soil compaction o Antecedent soil moisture o Urbanization
 How does infiltration rate vary over the short term?
 How is saturation overland flow generated?
 How is Hortonian overland flow generated?
 What are the sources of channel flow?
 What are the types of river channels? o Perennial o Intermittent o Ephemeral
Storages:
 What are the types of interception?
 What are the factors affecting interception? o Rainfall intensity and duration o Vegetation
 What are the different types of soil moisture conditions?
 How does soil moisture storage vary seasonally?
 How does soil texture affect available water capacity?
 Differentiate between porosity, primary and secondary permeability
 What factors affect the form of a water table?
 What can cause the water table to fluctuate? o Seasonal o Long-term
 How do springs and artesian wells form?
 How does groundwater affect channel flow?
 What are the problems associated with groundwater utilization and pollution? o Subsidence o Pollution o Saltwater intrusion
Outputs:
 Differentiate between actual and potential evapotranspiration
 What are the factors affecting the rate of evapotranspiration? o Temperature o Relative humidity o Wind speed o Vegetation cover
F L O O D S
 What are the causes of floods? o Rainfall/snow/icemelt o Volcanic action o Landslides o Dam failure
 What are the flood intensifying conditions o Basin conditions o Channel conditions
 What are the effects of floods?
 How are floods managed? o P[P]MR
C A T C H M E N T M A N A G E M E N T
 How are catchments managed with regards the alteration of channel characteristics?
 What conflicts of interest arise in the process of catchment management? o Upstream/downstream o Political/economics/environments/etc.
C H A N N E L M O R P H O L O G Y
 What factors affect river discharge/energy? o Volume of water o Mean velocity
 Hydraulic radius
 Channel slope
 Roughness
 What factors may affect stream velocity? o Upstream/downstream o Urbanization
 What are the river erosion processes? o Corrasion o Attrition o Solution o Hydraulic action
 What are the components of river erosion? o Vertical downcutting o Lateral erosion o Headward retreat
 What are the river transport processes? o Traction o Saltation o Suspension o Solution
 Differentiate between river capacity and competence and note how river velocity affects these
 What are the changes in sediment load downstream?
 What features are associated with deposition? o Alluvial fans o Point bars o Flood plains
 Interpret the Hjulstrom curve
 How do meandering rivers form?
 What features are associated with meandering rivers?
 How may meandering rivers change in form?
 How do braided channels form?
 What features associated with braided channels?
 How is Strahler’s method used in stream ordering?
 What are the limitations of Strahler’s method?
 How is drainage density calculated?
 Interpret a storm hydrograph
 What are the factors influencing the form of a storm hydrograph? o Location of rainstorm o Nature of precipitation o Basin characteristics o Vegetation