2. River Hydrology short - Sunshine Coast Elder College · 2018-04-03 · Charlton 2008,...
Transcript of 2. River Hydrology short - Sunshine Coast Elder College · 2018-04-03 · Charlton 2008,...
2. River HydrologyRivers are part of the global hydrologic cycle
Contributions to streamflow
Charlton 2008, Fundamentals of Fluvial Geomorphology
Hortonian overland flow (surface runoff)
Saturation overland flow (surface runoff)
Through flow (sub-surface runoff)
Groundwater flow
Measuring Streamflowdischarge: volume of water [cubic metres] passing through a cross-section of a river per unit time [seconds]:
discharge [m3/s or cms] = mean flow velocity [m/s] times cross-sectional area [m2]
Charlton 2008, Fundamentals of Fluvial Geomorphology
modern measurements of discharge use acoustic Doppler current profilers (aDcp)
https://youtu.be/3SPwz3VYnbM
Hydrographs
hydrograph: a plot of discharge over time
Dis
char
ge (
cms)
• quick flow: water that enters the channel quickly by overland flow and through flow
• base flow: water that enters the channel slowly by groundwater flow
Charlton 2008, Fundamentals of Fluvial Geomorphology
Floods
causes: rain storms and/or snowmelt, ice-jams, dam failures
importance: control sediment movement and channel morphology, damage infrastructure, cause fatalities
Nadi
Tom River
Ob
Rive
r
Tomsk
10 km
Global Discharge
river ranking by average daily discharge