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
Explain Sinus Venosus Defect with Partial Anomalous Venous Connection ? In this defect the atrial septal defect is situated just below the orifice of superior vena cava above

floral formula of family rosaece

Nutrition, Feeding, Digestion All organisms require a fairly steady supply of nutrient materials from the environment to obtain energy in order to stay alive. The animals are

How is the responsible slromal swelling pressure for corneal hydration? Slromal Swelling Pressure Stromal Swelling Pressure (SSP) is the pressure exerted by GAG (Glycosa

S T ARC H - Polymer of a-D-glucose. Starch is glucosan homopolysaccharide which is the major reserve food of plants. Starch is formed as an end product of photosynt

What differences would you expect to see among pea seedlings grown for 10 days in total darkness and pea seedlings grown in the light for the similar period of time?   The s

Why is holophytic nutrition a mode of autotrophic nutrition

Explain the Lectins or Haemagglutinins? These are sugar binding proteins, having the ability to bind and agglutinate red blood cells (RBCs). You will find that they occur in mo

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Conduct of Perfusion :  At the beginning of the bypass, the pump output is usually kept at 2.4 litres per meter per minute. On coming off bypass, the flow is gradually reduced til