Weather and climate
Atmospheric conditions at a specific time at a particular place are referred to as weather. Atmospheric conditions depend upon a variety of factors. (Figure 9.1) We frequently express our opinion about the weather by making statements like, ‘Today, it is too cold’ or ‘It is very hot today.’
Weather depends upon the prevailing conditions of the air. The climate of a particular region is the average of daily readings of various weather-related parameters recorded for several years. Hence, climate is a long term predominant condition of the atmosphere
Changes in weather
Climate does not change continuously. Climate is that which remains constant in a region for a long duration. Thus we see that weather is related to a specific location and specific time whereas climate is related to a longer duration and larger area. Changes in the weather may occur for short periods of time whereas changes in the climate take place slowly over a much long duration.
Climate plays a very important role in our day to day life. It influences our basic needs like food, clothing and shelter as well as our occupations. Climate is especially important for an agrarian country like India. Various climatic factors like direction and speed of wind, temperature, atmospheric pressure, etc. are considered during construction of runways, seaports, huge bridges and skyscrapers, etc.
While ascertaining the climate of a particular region, a review of earlier studies of various aspects of climate is very important. Most countries in the world have established meteorology departments for making and recording such observations. These departments have ‘observatories’ which are equipped with modern instruments and technology.
If present climatic conditions are analysed with reference to the past climatic conditions, we can predict climatic changes of the future. However, as climate is the net result of a complex mixture of various atmospheric factors, forecasting it is very complicated and difficult. Forecasting is easy for places where climatic changes are slow and of a limited nature. However, where climatic changes are complex, interdependent and rapid, making forecasts is very difficult.
The science that studies the inter-relationships between the various components of air, natural cycles, geological movements of the earth and climate is called meteorology. Meteorology includes the study of storms, clouds, rainfall, thunder, lightning, etc. Depending upon the study of such factors, weather forecasts are made. They are useful to common people, farmers, fisheries, aviation services, water transport and various other organizations
India Meteorological Department
The India Meteorological Department was founded by the British in 1875 at Shimla. Its head office is at Pune and its Regional Offices are at Mumbai, Kolkata, Chennai, Nagpur and Delhi. Maps are prepared every day which indicate the daily predictions about the weather. Such maps are prepared and published twice in every 24 hours. In this institute, research goes on continuously on various aspects like instruments for climatic readings, predictions about climate made using radar, predictions about climate related to siesmology, predictions regarding rainfall by satellites, air pollution, etc.
The India Meteorological Department provides important information regarding weather and climatic conditions to other departments like aviation, shipping, agriculture, irrigation, marine oil exploration and production, etc. Predictions regarding calamities like dust storms, sand storms, heavy rainfall, hot and cold waves, tsunami, etc. are communicated to various departments, all types of mass communication media and all citizens. For this purpose, India has launched several satellites equipped with highclass technology. Observatories at several locations are doing excellent work in the analysis of the information received from these satellites.
Monsoon model and climate prediction
The tradition of forecasting the monsoon season in India is older than 100 years. After the famine of 1877, H. F. Blanford, the founder of IMD had made such a prediction for the first time taking the snowfall in the Himalayas as a parameter for this prediction. In the decade of the 1930’s the then director of IMD, Sir Gilbert Walker had underlined the relationship between various worldwide climatic factors and the Indian monsoon, and, based on available observations and previous recordings related to this relationship he put forth a hypothesis regarding the nature of the monsoon. With the initiative of Dr Vasantrao Govarikar in the decade of the 1990’s a monsoon model based upon 16 worldwide climatic parameters was developed. This model was in use from 1990 to 2002.
Solid waste management : need of the hour
Observe the garbage collected in the dustbin of your classroom and make a list of the various materials in it. Discuss with your teacher, how these materials can be properly disposed of. Can we do the same with the garbage generated in our house? Think about it.
- What is main difference between what we see in the two pictures alongside (9.2 A and B)?
- What should we do to permanently maintain the condition seen in picture B?
Many waste materials are generated through the various daily human activities. This is called solid waste. If these waste materials are properly disposed of, they can be a valuable source of energy. Currently, solid waste is a serious world wide problem as it causes both water and soil pollution. Solid waste is also serious problem from the point of view of economic growth, environmental degradation and health. It has posed a serious threat to nature and human habitat because of the air, water and soil pollution it causes.
Biodegradable waste : This type of waste is easily degraded by microbes. It mainly includes kitchen waste (spoiled food, fruits, vegetables) ash, soil, dung, parts of the plants, etc. This waste is mainly of organic type and is also called ‘wet solid waste’ or ‘wet garbage’. If it is carefully decomposed, we can get compost and fuel of good quality from it. Such bio-fuel projects have been started in many cities. Non-biodegradable waste : This type of waste is not easily degraded because it requires a very long period of time and the use of various techniques. It includes plastic, metal and other similar materials. This type of waste is also called ‘dry solid waste’ or ‘dry garbage’
Necessity of solid waste management :
- For preventing environmental pollution and to keep the surroundings clean.
- For energy as well as fertilizer production and through that to generate work and employment opportunities.
- To reduce the strain on natural resources through treatment of solid waste.
- To improve the health and quality of life and to maintain environmental balance.
It is the need of the hour to implement solid waste management practices to avoid the possible problems due to solid waste generated from urban and industrial areas and to maintain a clean environment. For this purpose, we should implement measures like increasing the efficiency of production processes so that minimum waste will be generated, reducing garbage production by recycling and reuse of waste materials.
If the time required for degradation of the solid waste generated around us is long, it seriously affects other environmental factors. What care will you take to avoid this ?
Figure 9.5 A, below shows a method of storing waste and 9.5 B, shows the use of specific dustbins as per the type of waste. Think about how such eco-friendly waste management can be achieved by following these methods in our homes, too.
Various natural disasters like thunderbolts (lightning), floods, fire and man-made disasters like accidents, bomb explosions, chemical accidents in industries, stampedes in mass gatherings, riots, etc. occur around us from time to time. They cause large scale damage to life and property.
First aid to disaster victims : The main objective of first aid is prevention of death, preventing deterioration of health and starting the process of rehabilitation. Hence, it is important to know about the emergency measures or first aid practices to be followed
Basic principles of first aid :
Life and Resuscitation – ABC
- Airway : If the victim has difficulty breathing, the head should be held in a backward sloping position or the chin should be raised so that the respiratory passage remains open.
- Breathing : If breathing has stopped, the victim should be given artificial ventilation by mouth to mouth resuscitation.
- Circulation : If the victim is unconscious, then after giving mouth to mouth respiration twice, the heart should by pressed down hard by pressing the chest with both the palms. These two actions should be repeated alternately about 15 times. This is called cardio-pulmonary resuscitation (CPR). It helps to bring the circulation back to normal.
Other emergency measures: Boats are used by the civil administration to rescue people trapped in a flooded area. As an emergency measure, wooden boards, bamboo floats, air-filled rubber tube from a tyre can be used to advantage. ²²² A fire-extinguisher is a portable appliance that can be easily carried anywhere. Various appliances are used to put out a fire. Visit the fire department in your city and collect detailed information. (For more information, refer to lesson 13.)