Alluvial-transported soil, Biology

Assignment Help:

Alluvial

Materials of this catego~ya re deposited by running water in the form offroodplains, river terraces, deltas and alluvial fans. These deposits have two outstanding characteristics by, which they can usually be recognised with ease. Fit, the individual particles tend to be rounded and smootlfed by the action of running water. Second, the layers are usually distinct in that each contain particles of a particular range or size class depending upon the speed of the transporting water. Coarse materials are laid by swift water currents, whereas, fine particles are deposited by relatively calm waters.

Alluvial soils are found bo~deringri vers and slow moving bodies of water. When first formed; these deposits are sa low that they are frequently flooded at high-water stages, and at such times they receive additional increments of fine sediment, especially if they are well vegetated. At this stage of development, they are called flood plains. As the stream cuts its channel deeper, the flood plain is left above the reach of high water and is called a terrace. Large streams are frequently bordered by a series of terraces, the oldest being at considerable heights above the present water level.

Where streams enter a lake or a sea, the deposit of silt and clay that settles down at the edge of the still water may build a delta which gradually lengthens until it extends beyond the mouth of the stream. The Sunderbans in West Bengal and Bangladesh are examples of deltas, which supprt mangrove type of vegetation. Alluvial fans are formed where a stream descends from uplands, and a sudden change in gradient may sometimes occur as the stream emerges at the lower level. Deposition of sediments is thereby forced, giving rise to alluvial fans. They differ from a delta in their location and in the character of their debris. Fan material is often gravel and stony in nature
and is well drained.

Among the transported soils, the alluvial soils of the Indoagetic Plains are highly productive and have been under'cultivation for several thousands of years. The parent material of the Indo-Gangetic alluvial soils is actually in the Himalayas. Mountain and hill washes contribute huge quaiitities of sediments brought down by the rivers and deposited in the plains below. Most of the alluvial soils are under intensive crop cultivation.


Related Discussions:- Alluvial-transported soil

Fixation and movement to echinoderms, Q What is the system that permits fix...

Q What is the system that permits fixation and movement to echinoderms? The system that permits fixation and movement to substrates in echinoderms is called the ambulacral syst

Define the fact that we must eat to gain the energy, Which law of thermodyn...

Which law of thermodynamics explains the fact that we must eat to gain the energy to perform the functions of life, such as breathing? a. fourth law b. first law c. second law d

Determine the testing for albumin in urine, Determine the Testing for Album...

Determine the Testing for Albumin in Urine Acetic Acid Test About 2 - 8 mgm/dl of protein is excreted in urine which is not usually detected by routine test. The testing o

Define changes in food due to concentration process, Define Changes in Food...

Define Changes in Food due to Concentration Process? Obviously concentration that exposes food to 100°C or higher temperatures for prolonged periods can cause major changes in

Stomata can open and close in response to changes in the co2, Stomata can o...

Stomata can open and close in response to changes in the CO 2 concentration inside the leaf. Would you expect stomata to open or close if the CO 2 concentration decreased? Explai

Explain ground meristem in primary root growth, Explain Ground Meristem in ...

Explain Ground Meristem in Primary Root Growth? To review, the protoderm is the primary tissue that eventually forms the outside layer that covers the root and shoot and leaves

Meosis, briefly describe the eggs and follicles

briefly describe the eggs and follicles

Protozoa, locomotion in parameceum

locomotion in parameceum

Exercise induced ventricular arrhythmias, Ventricular arrhythmias are usual...

Ventricular arrhythmias are usually produced by excess catecholamines and vagal withdrawal and occasionally re-entry and triggered activity also plays a role. PVCs are more common

Dietary management during myocardial infarction, Dietary management during ...

Dietary management during Myocardial Infarction? Patients who suffer from an attack of myocardial infarction are hospitalized and are usually kept under strict medical supervis

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd