Understanding Social Science

  Solar Radiation & Heat Budget of Earth Sun is the supreme source of heat and light on the surface of the Earth. Most of the energy received by earth’s surface known as insolation (incoming solar radiation) is in the form of short wavelengths. The atmosphere is largely transparent to short wave solar radiation. The insolation received is not same at all the places over the globe. Factors Causing Variability of Insolation :- ü Rotation of earth about its own axis. ü Angle of inclination of sun’s rays associated with latitude of a place. ü The length of the day. ü The transparency of the atmosphere. ü The configuration of land in terms of its aspect. ü Tilt of the Earth Spatial Distribution of Insolation:- The insolation received at the tropics is about 320 Watt/m 2 and 70 Watt/m 2 at the poles. Maximum insolation is received at the subtropical deserts due to less cloudiness (clouds absorb the radiations). Equator receives less insolation as compared to...

  Climate Change    Climatologists say that change in climate and is natural and continuous process however what has happened in recent past is unusual and rapid too. From about 1885-1940 world temperature showed an upward trend. As defined by United Nations, “Climate change refers to long-term shifts in temperatures and weather patterns.” These shifts may be natural, but since the 1800s, human activities have been the main driver of climate change, primarily due to the burning of fossil fuels which produce heat producing gases and these gases ultimately lead to global warming. Global warming is both a cause and outcome of climate change. More the earth heats up more global warming will be caused and vice versa. The World Health Organisation calls climate change the greatest threat to global health in the 21 st century. Even if efforts to minimize future warming are successful, some effects will continue for centuries. Many of these impacts are already felt at the c...

  Federalism    Today, India is an amalgamation of various small states and union territories. This is not what ‘British India’ was. In the colonial period, India was divided into princely states (controlled by prices/kings who had autonomy over their territory) such as Hyderabad, Manipur etc and British provinces (under British administration) such as Bombay, Madras etc. After independence, it was left up to leaders of princely states whether they want to merge with India, Pakistan or remain Independent. But most of the states could be merged through negotiations and dialogue and India, as we know it today was formed. Federal structure of Indian state must be appreciated for this unity along with efforts of leaders such as Sardar Patel.          What is federalism? Federalism in its simplest form is described as a system where a territory is governed by two levels of government. Although different civilizations use different notion o...

  Tip: - River courses are important and hard to learn at the same time. An effortless way to learn courses is to open a map representing the river course while you read the river course and absorb it. Note keywords related to the course. Always close your eyes and imagine the map before answering to the questions related to course of that particular river. For tributaries you can make acronyms according to your comfort.         The Peninsular Drainage System Main features:- ü The peninsular drainage system is older than that of Himalayas since the peninsular rivers have graded profiles and have almost reached their base levels. ü The Western Ghats running close to the western coast act as water divide between the large rivers draining into Bay of Bengal and the small rivulets joining the Arabian Sea. ü Most of the peninsular rivers flow from west to east; however Narmada and Tapi are exceptions. ü   The peninsular rivers lack th...

  Tip: - River courses are important and hard to learn at the same time. An effortless way to learn courses is to open a map representing the river course while you read the river course and absorb it. Note keywords related to the course. Always close your eyes and imagine the map before answering to the questions related to course of that particular river.    Himalayan drainage system:- Main features:- ü These rivers are fed by regular precipitation and melting snow from mountains/glaciers, so they are perennial in nature. ü These rivers have evolved long time back in geological history. ü They give birth to physical features such as gorges, V shaped valleys, rapids, waterfalls in their course and ox bow lakes, flood plains, braided channels and deltas at their ends. ü They shift their courses due to strong meandering tendency causing floods many a times. The Himalayan river system mainly includes – The Brahmaputra, The Indus, and The Ganga. Acronym for...