rivers

estuary

when the river meets the sea it will slow down and sill flood over its banks at the mouth creating a wide body of water

delta

river mouth with lots of deposition

oxbow lake

when a meander develops and its neck becomes narrower due to erosion and deposition until it connects creating a straight course leaving a C shaped lake

interlocking spurs

the river moves around hard rock when it’s moving downwards leaving zig zag spurs

drainage basin

area if land where rainwater runs down a slope and collects in one place

watershed

edge if the drainage basin

hydrological cycle transfers

condensation, evaporation, collection, precipitation, inflitration, transpiratiom, evapotranspiration, surface runoff, throughflow, ground water flow

transpiration

plants take up liquid water from the soil and ‘breathe’ it into the atmosphere as water vapour

distributaries

when the delta is split into small channels

infiltration & percolation

the transfer of water downwards through the soil & rock into the aquifer/groundwater store

throughflow

thid takes place between the ground surface & the top of the ground water store as a result of gravity, water moves slowly horizontally through the soil until it reaches a stream/river

hydrograph

graph that shows the changes of discharge in a river over time

discharge

volume of water in a river at a given place & time

storm hydrographs

shows changes afetr rainfall

river regime graphs

shows the discharge of a river over the course of a year

confluence

where a tributary joins the mian channel

what physical factors affect discharge?

rainfall, vegetation, soil type, depth/width of river, number of tributaries, channel gradient, geology, velocitiy/river speed

baseflow

the ‘normal’ discharge of the river

stormflow

additional discharge of the river as a result of the rainstorm

lag time

the delay between peak rainflow and peak discharge

rising/falling limb

when river discharge starts to rise/fall

bankfull discharge

the point the river is full

peak precipitation

rainfall is highest

peak flow/discharge

highest point of discharge

factors that influence the shape of the storm hydrographs

precipitation, temperature, vegetation, cemented ground, water abstraction, dams, impermeable rocks, steep slopes, drainage density

erosion

wearing away of the earth’s surface by river, wind/ice

hydraulic action

process where the force of moving water impacts cracks and holes in the riverbank or bed

attrition

rought rocks hitting each other eventually turning into smooth rocks

abrasion

rocks and material that scrapes the riverbed and riverbank

traction

large boulders rolled on the bed

saltation

small boulders bounce along the bed

suspension

lighter material carried along by the river flow

physical weathering

when rocks are physically cracked into smaller pieces e.g. freeze & thaw, wind abrasion

chemical weathering

when the weak acids in the rain dissolves some rocks

biological weathering

when seeds are dropped in the cracks of a rock & roots grow inside them breaking them over time

mass movement

movement of material down slopes under the force of gravity

slumping

when the bottom of the cliff is cut by a river and the cliff quickly collapses

soil creep

when individual pieces of soil slowly move down the cliff under the force of gravity

factors affecting erosion, weathering & mass movement

climate, slope, geology, altitude, aspect

long profile

name of the line starting from the source (in the uplands) to the mouth ( in the lowlands)

rivers long profile contains?

discharge, channel width, channel depth, average velocity, load quantity, load particle size, channel bed roughness, slope angle (gradient)

river velocity

how fast the water in the river is moving

hydrological cycle stores

lake, sea/ocean, river, soil, groundwater, aquifer, surface water, clouds, ice