Drought-water stress and adaptations, Biology

Assignment Help:

Drought

Drought refers to a condition of water shortage and it can result from many reasons. Frequently less than the normal rainfall is a common cause of drought. Less than 75% of normal rainfall may be defined as drought. We may, however, bear in mind that not only the total rainfall but its distribution in time is vitally important for crops. Small deficit (or surplus) in rain is not necessarily directly related to agricultural productivity. A severe drought reduces stream flow and recharging of aquifer. This results in lowering of water. table, loss of agricultural crops, wild life and aquatic life. Water level in lakes, streams and reservoirs drops due to failure of rains. As a result crop yield and fodder production suffer adversely resulting in food scarcity and human discomfort, and stress to livestock. The incidence of forest fue increases and overall conditions become difficult.

Due to the pressure of growing population over-exploitation of water resources has become a universal feature. Consumption of bsh water is due to rapidly growing urbanisation, industrialisation and mechanised agriculture which leads to over-exploitation of water resources. over-expioitation of fresh water resources can create severe limitation to growth and development. Excessive withdrawal of ground water in coastal areas  has resulted in salt water intrusion into the aquifers . Consequently, the ground water has become unfit for human consumption and agriculture on account of high salinity. Ponds, bogs and streams are sites where ground water appears at the land surface. Excessive withdrawal of ground water and overdrawing of ground water lower the water-table as well as the level of water in lakes and streams and may completely dry them up.


Related Discussions:- Drought-water stress and adaptations

How is this neural organization important for the diversity, Is the nervous...

Is the nervous system in platyhelminthes more or less sophisticated than in cnidarians? What are the main neural structures found in flatworms? How is this neural organization impo

Explain deformaties of the cliest wall should be noted, Explain Deformaties...

Explain Deformaties of the Cliest wall should be Noted a) Pectus carinatum (pigeon chest): may be associated with Marfan syndrome. b) Pectus excavatum: commonly seen in Marfan

Types of leaves, Types of leaves Collect leaves from such plants as lil...

Types of leaves Collect leaves from such plants as lilies, bamboo, corn, willow and geraniums. View that the monocots (lily, bamboo, corn, sugar cane) have the veins running pa

Define lipoprotein metabolism, Q. Define Lipoprotein Metabolism? Lipopr...

Q. Define Lipoprotein Metabolism? Lipoproteins serve to transport absorbed dietary fat and endogenously synthesized cholesterol and triglyceride. Nevertheless, it is possible t

Human respiratory system - bronchioles, BRONCHUS - In thorax trachea is...

BRONCHUS - In thorax trachea is devided in to 2 bronchi that enter into lungs of its own side. Rings present in it. BRONCHIOLES - These are branches of bronchus.

What is genotypical proportion of these gametes, Which is the kind of gamet...

Which is the kind of gamete (for a given trait) produced by a dominant homozygous individual? What is genotypical proportion of these gametes? And what about the recessive homozygo

How to increase the levels of physical activity, How to increase the levels...

How to increase the levels of physical activity? The benefits of physical fitness should be spread among the public through mass media. 1. Physical activity should be encour

Maintenance of gut lining, Maintenance of Gut Lining After studying th...

Maintenance of Gut Lining After studying the digestive enzymes you would wonder why the gut linings are not digested themselves. This is because animals have several mechanism

Explain ventricular septal defects vsd chsude technique, Explain Ventricula...

Explain Ventricular septal defects VSD Chsude Technique ? Ventricular septal defects are closed on cardiopulmonary bypass. Approach is through median stemotomy. Ascending aort

What is meant by bioassay, What is meant by bioassay? Name the two bio...

What is meant by bioassay? Name the two bioassays that are used to determine auxin activity in plants.

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