Factors affecting interception rates Interception is another important factor controlling flows and stores within the drainage basin. It is basically when plants trap water or stop it from reaching the ground during a rainfall event. Note that most ocean water evaporated is returned back the sea as ocean precipitation.
The water balance The Water balance is the balance between inputs and outputs within a drainage basin. However, there will be periods were there is more rainfall than others leading to more erosion, or drier periods where there will be deposition occurring.
All of this can be interpreted as a systems diagram. This can also be shown in a water budget, which is;. A positive balance indicates that inputs are greater than outputs and water will be stored in the system. A negative balance indicates that outputs are greater than inputs and stores will deplete and be used up. This can be shown on a soil moisture budget graph, examples for Harrogate and Malaga are shown below. This graph comprises 3 basic sections. Where potential evapotranspiration is a measure of the ability of the atmosphere to remove water from the surface through the processes of evaporation and transpiration assuming no control on water supply 2 is above precipitation soil moisture utilisation will take place, that is, soil stores will be used and not replaced.
This could continue until soil moisture depletion, where there is no water left in the soil and plants will begin to die. Once precipitation rises above evapotranspiration soil moisture recharge will occur, and soil stores will be replaced slowly.
Once the field capacity of the soil is reached the normal amount of water a soil can hold then we reach a situation of soil moisture surplus. Sources 1 - Wikipedia These are erosion, transportation and deposition. The characteristics of a river channel change along its long profile. Changes occur in the cross profile, wetted…. Figure 1. A drainage basin and its watershed.
Search for:. Coastal Landforms of Deposition. Drainage Basin Hydrological System. Landforms of Erosion. Sub-Aerial Processes. Marine Processes. Storm Desmond Case Study. Many thanks, Anthony. Drainage basin hydrological cycle Find out about the characteristics of the drainage basing hydrological cycle.
Storm Hydrograph Hydrographs can be used to illustrate discharge. The long profile of a river The long profile of a river shows changes in the height altitude of the course of a river from its source to its mouth. Sedimentary basins have been filled with layers of rock and organic material over millions of years.
Material that fills up the basin is called sediment fill. Sedimentary basins are key sources of petroleum and other fossil fuel s. Millions of years ago, tiny sea creatures called diatoms lived and died in ocean basins. Eventually, these ancient oceans dried up, leaving dry basins. The remains of the diatoms were at the bottom of these basins.
The remains were crushed under billions of tons of sediment fill, over millions of years. In the right conditions, the pressure of the sediment fill turns the diatom remains into petroleum. The Niger Delta sedimentary basin, in the countries of Nigeria, Cameroon, and Equatorial Guinea, is one of the most productive petroleum fields in Africa.
Ocean Basins Ocean basin s are the largest depressions on Earth. Edges of the continents, called continental shelves, form the sides of ocean basins. There are five major ocean basins, coordinating with the major oceans of the world: the Pacific basin, the Atlantic basin, the Indian basin, the Arctic basin, and the Southern basin. Many smaller basins are often considered oceanic basins, such as the North Aleutian Basin, between the Pacific and Arctic Oceans.
Tectonic activity constantly changes ocean basins. Seafloor spreading and subduction are the most important types of tectonic activity that shape ocean basins. Seafloor spreading happens along the boundaries of tectonic plates that are moving apart from each other.
These areas are called mid-ocean ridge s. New seafloor is created at the bottom, or rift , of a mid-ocean ridge. Ocean basins that have mid-ocean ridges are expanding. The Atlantic basin, for instance, is expanding because of seafloor spreading. Subduction happens along the boundaries of tectonic plates that are crashing into each other.
In these subduction zones, the heavier plate moves underneath, or subduct s, the lighter one. Ocean basins that experience subduction, such as the Pacific basin, are shrinking. Even though ocean basins make up more than 70 percent of the total land on Earth, scientists know relatively little about them. Some oceanographer s and some astronomer s! It is very difficult to get information about landforms of the ocean basin, such as trench es and mid-ocean ridges.
These landforms are thousands of feet below the surface of the water. Few instruments can endure the intense pressure, cold, and dark at the bottom of ocean basins. Occasionally, researchers themselves explore ocean basins in special submarine s called submersible s. Photograph by Elad Cohanim , MyShot. It is more than million square kilometers 59 million square miles all of the continents could fit into it. It is also the oldest basin; researchers say its rocks are million years old.
In addition to the benefits to fisheries, agriculture and hydroelectricity, the waters of the Pacific drainage provide a valuable resource to the lumber, pulp and paper, and mineral processing industries as well as municipalities.
This region of 2. A 27, km 2 zone of southern Saskatchewan and southeastern Alberta drains into the Mississippi Basin and then to the Gulf of Mexico. The most important section of the drainage basin is the 1 million km 2 drained by the Saskatchewan—Nelson river system.
The Bow , Oldman and North and South Saskatchewan rivers rise on the eastern slopes of the Rockies and flow east for 1, km through the central plains. Extensive tracts in the plains region drain into interior depressions sloughs. Many of these sloughs have no outlet, and many others have outlets only in the wetter years to the principal streams which enter a chain of lakes in south-central Manitoba. Here the flow is joined with that of the Red River flowing in from the south and the Winnipeg River from the east.
The latter carries drainage from southeastern Manitoba, the Lake of the Woods region of Ontario and Minnesota. The principal source areas of streamflow for the Nelson are the eastern slopes of the Rockies and the lake area of Manitoba, northwestern Ontario and the adjacent states. The Nelson and Churchill rivers are sites of large hydroelectric-power generating facilities. The North and South Saskatchewan river system is important to agriculture since it flows through a region of fertile soils limited in their productivity by uncertain rainfall.
The water supply from the Bow, Oldman, North and South Saskatchewan rivers and their tributaries is vital to cities, towns and industries of Alberta and Saskatchewan. The high variability of local tributary flow has necessitated construction of many dams to provide carry-over storage from years of abundant flow to years of low discharge.
There are at least 15 individual watersheds of 30, km 2 or more in area. The region, part of the Canadian Shield , consists of massive ancient crystalline rocks. As a result of glaciation there are large areas of lakes, ponds and swamps. In some parts as much as 15 per cent of the drainage area is covered by fresh water.
The many lakes result in fairly uniform rates of river flow throughout the year. The waters are generally of good quality and minimally influenced by human activities.
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