Food scarcity

  According to FAO Food Security  is “a situation in which all people at all times have access to adequate quantities of safe and nutritious food to lead a healthy and active life”. This definition requires three basic conditions to be met: 1) adequacy, i.e. supplies from domestic production, stocks and imports are sufficient to meet the … Read more

Green Revolution and its impact on major crops of India

  The Green Revolution was initiated in the 1960’s to address the issue of malnutrition in the developing world. The technology of the Green Revolution involved bio-engineered seeds that worked in conjunction with chemical fertilizers and heavy irrigation to increase crop yields. Green Revolution was largely confined in wheat crop and in northern India such … Read more

Indian monsoon, mechanism, onset and retreat

  The word “monsoon” comes from the Arabic word mausim, meaning season.Monsoons refer to a system of winds in the tropical regions under which the direction of winds is reversed completely between the summer and the winter seasons. Under this system, the winds blow from land to sea in winter and from sea to land … Read more

Drainage Systems Himalayan and the Peninsular

  Drainage: Flow of water through well-defined channels. Network of such channels is called a drainage system . Drainage basin: An area drained by a river and its tributaries. Watershed: Boundary line separating one drainage basin from other. River basins are larger watersheds. Drainage pattern of an area depends on the geological time period, nature … Read more

 Climatic changes

    It is the long term change in the statistical distribution of weather patterns over periods of time Though it has been happening naturally for millions of years, in recent years it has accelerated due to anthropogenic causes and has been causing global warming. UNFCCC defines climate change as – “a change of climate … Read more

Greenhouse effect

  The greenhouse effect is a natural process that warms the Earth’s surface. When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. It is the process by which radiation from a planet’s atmosphere warms the planet’s surface to a … Read more

Classification of climates, (Koppen and Thornthwaite)

  Climatic Regions of India : Koeppen’s Classification Climate Type Climatic Region Annual Rainfall in the Region Amw (Monsoon type with shorter dry winter season) Western coastal region, south of Mumbai over 300 cm As (Monsoon type with dry season in high sun period) Coromandel coast = Coastal Tamil Nadu and adjoining areas of Andhra Pradesh … Read more

 Air masses and fronts

  Airmasses   An airmass is a large body of air with relatively uniform thermal and moisture characteristics. Airmasses cover large regions of the earth, typically several hundred thousand square kilometers. Airmasses can be as deep as the depth of the troposphere or as shallow as 1 to 2 km. Airmasses form when air remains … Read more