Drought-water stress and adaptations, Biology

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.

Posted Date: 12/11/2012 12:32:46 AM | Location : United States







Related Discussions:- Drought-water stress and adaptations, Assignment Help, Ask Question on Drought-water stress and adaptations, Get Answer, Expert's Help, Drought-water stress and adaptations Discussions

Write discussion on Drought-water stress and adaptations
Your posts are moderated
Related Questions
This innovative, pacemaker-based approach to the treatment of patients with heart failure who have a wide QRS complex (>140 ms) on 12-lead ECG aims at providing electromechanical c

How do I use a pedigree charts

Q. What is the function of the plant cell wall? The plant cell wall has protective and structural functions. It plays an significant role in the constraint of the cell size, pr

P HYSICA L PROPERTIES OF PROTOPLASM - 1 .       Phase reversal - Due to difference in temperature outer part is gel and inner part of sol 2.       Tyndall effect - Be

what is the mode of nutrition in pisces

Prosthodontic considerations In order to achieve good results, understated features should always be examinated. 1. Smile Line: A high smile line increases the esthetic

It is defined as the total amount of heat produced, when unit mass/volume of the fuel has been burnt completely and the products have been cooled to room temperature (~ 15 0 C).

What characteristics of fatty acids are false? (Dissolves in water, used for energy storage, used to build lipids, found in triglycerides, found in steroids)?

Titration of inverted honey solution It involves the titration of the inverted honey solution. Carry out the titration in the following manner. 1) In a conical flask take 5

What is the plant hormone remarkable for stimulating flowering and fruit ripening? What are the uses and practical inconveniences of that hormone? The plant hormone notable for