The Hydrological Cycle is a closed system, where water is continuously cycled between the oceans, the land, and the atmosphere in a series of processes known as the global hydrological cycle.
Water moves through the hydrological cycle via a series of flows or transfers. Water is also stored within the system, for example, in a lake.
Below is a diagram to show the hydrological cycle:
**Student Quiz Round**
Can you match the components to their meanings?
1) _______: water soaking into the soil from the surface.
2) _______: water moving within rocks below the ground.
3) _______: water moving downhill through the soil layers. It will generally move slowly, but flow may concentrate along the lines of roots or soil weaknesses and form natural pipes; the flow in these will be much faster.
4) _______: water deposited on the ground as a liquid or as a solid, for example rain, hail, snow, or even fog.
5) _______: water moving downhill with rivers.
6) _______: water moving across the surface of the ground. This my happen when the rain cannot soak quickly enough into the ground, for example whre there are tarmac surfaces or hard-baked soil, or even during heavy rainfall. Saturated overland flow is more common and occurs when the soil is saturated and infilration cannot take place.
7) _______: the combined processes of evaporaton and transpiration that result in the loss of water from the leaf. Transpiration is the loss of water through tiny holes called stomata in the leaf surface. In practice it is very difficult to calculate the two amounts seperately, so they are often grouped together.
8) _______: plants trap some of the precipitation so it may not immediately pass to the ground. Some may drip to the ground as throughfall; some may flow down the stem as stemflow. Alternatively, the precipitation may evaporate directly off the leaf and never reach the ground.
9) _______: water moving from the surface layers of soil into deeper layers of soil and rock.
10) ______: water changing from its liquid form to a gas (water vapour) and returning to the atmosphere.
**Channel Flow, Evaporation, Evapotranspiration, Groundwater Flow, Infiltration, Interception, Overland/Surface Flow, Percolation, Precipitation, Throughflow**
The drainage basin as part of the hydrological system
A drainage basin is an area of the land's surface from which a river receives its supply of water. The edge of a drainage system can be marked by an imaginary line called the watershed. The watershed is usually marked by areas of higher land.
Drainage Basin System
Unlike the hydrological system, the drainage basin works as an open system requiring inputs from outside in order to function. Below is a diagram of the drainage basin system:
Drainage basins have many different characteristics that influence how quickly or slowly the main river within them responds to a period of intense rainfall. More information is explained in the following section about storm hydrographs.
Storm Hydrographs
The dischatrge of a river at any point can be plotted on a hydrograph. A storm, or flood, hydrograph shows the river's response to a single rainfall event. An annual hydrograph indicates the yearly pattern of flow. Both types of hydrograph are useful tools as they allow us to study drainage basin processes and river channel response.
The main features of a storm hydrograph can be viewed in the figure below:
http://www.s-cool.co.uk/alevel/geography/river-profiles/storm-hydrographs-and-river-discharge.html#reading-the-hydrograph
You've found some great diagrams here which wuold be great to use in lessons. These are all central elements of courses at Key Stage 3, GCSE and A-level, just at different levels of complexity. How can we ensure that we don't just repeat work at each stage? i.e. how can we develop a progressive deepening of leanring at each level without stduents just feeling they are repeating work?
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