Hydrology
Drainage Basin and Hydrological System
Page 1:
Drainage Basin:
Area where a river gets its water from
Raindrop falling on the basin surface eventually enters the main river
Watershed:
Highland area separating two drainage basins
Gauging Station:
Place at the end of the basin for collecting river flow data
Page 2:
Hydrological System:
Receives water from precipitation as input
Water takes various routes and is stored in the basin
Leaves through evapotranspiration or flowing into larger rivers/sea
Page 3:
Input - Precipitation:
Rainfall, snowfall, sleet-fall, hailfall
Interception Storage:
Water retained by vegetation
Factors Influencing Interception:
Type of vegetation, wind velocity, duration of storm
Page 4:
Interception Storage:
Retention of water by vegetation
Throughfall and Stemflow:
Water passing through foliage or along stems
Factors Influencing Interception:
Type of vegetation, wind velocity, duration of storm
Page 5:
Interception Factors:
Filled up in rainstorm start
Influenced by storm intensity, season, climate
Climate Influence:
Arid regions have higher interception loss
Page 6:
River Runoff:
Total water leaving the basin
Components of Runoff:
Overland flow, throughflow, baseflow, direct precipitation
Overland Flow:
Thin sheet of water causing river floods
Formation of Overland Flow:
Hortonian model based on rainfall intensity and soil infiltration capacity
Page 7:
Hortonian Overland Flow Model:
Rainfall intensity vs. infiltration capacity
Formation of Overland Flow:
Excess rainfall leads to surface accumulation and flow
Application of HOF Model:
Active in arid regions, limited in humid regions due to vegetation