eChapters

The change of state of water from solid and liquid to the vapour and its diffusion into the atmosphere is referred as Evaporation. In the meteorology, evaporation is defined as the maximum possible loss of moisture from a wet, horizontal, flat surface exposed to weather which exist in the vicinity of plants.

FACTORS AFFECTING EVAPORATION

1. Those affecting water supply at the evaporating surface. i.e., soil and plants including soil storage capacity, rainfall and irrigation and

2. Those affecting energy supply to the evaporating surface like solar radiation.

Cloud usually consists of very small droplets of water which cannot fall appreciably below the cloud base without evaporation. In this condition clouds are stable. Rain drops are about a million times heavier than cloud drops and rain develops only if the cloud droplets grow by some mechanism. Cloud Seeding mechanism depends on the difference in vapour pressure over ice and super cooled cloud, water evaporates of the droplets and migrate to the ice crystal, which grows and begins to fall increasing their growth rate by coalescence with other droplets and eventually melting and falling as rain drops. Presence of ice nuclei determines whether ice crystals form in a supercoold cloud or not. Ice crystals form on naturally occurring nuclei at temperatures of – 10⁰ to 30⁰ C. At warmer temperatures, either the efficient ice-forming nuclei are often deficient in the atmosphere or the cloud may occur with tops supercooled but not to an extent which activates the ice nuclei available. It should be possible to initiate precipitation by introducing ice crystals or by supplying artificial nuclei.

Variation in field crops between years is associated with many factors. This is mainly due to weather, soil and management factors. There is complex reaction of weather variables among themselves as well as with other factors. Therefore, many attempts were made to study the effect of weather variable on crop yield through simulation modeling.

To many Bio Fertilizer is still an unclear term. Often they are identified as urban and rural organic wastes, plant extracts, organic components etc. However, Bio Fertilizer is mostly commonly referred to the use of soil micro organisms to increase the uptake and availability of plant nutrients.

Bio Fertilizer have gained a good deal of momentum and the industry after a slow start is now gaining more and more importance globally. The major reasons for this are that they:

"Where is your Dhoti, Dr. Mehta ?” Dr. Varghese Kurien surprised me as I entered his office at IRMA (Institute of Rural Management Anand). That was April 2000, soon after I had taken over as the Vice Chancellor of the erstwhile Gujarat Agricultural University (GAU) and had decided to call on him during my visit to the Anand Campus. (At that time GAU was the largest University in the Asia with four main campuses – Dantiwada, Anand, Junagadh and Navsari and about 65 experimental farms / stations spreaded all over).

The march of weather factors during crop period is never smooth and regular. Agriculture, because of its dependance on climate is inevitably subjected to unpredictable long and short term fluctuation characteristic of atmosphere conditions. Climate introduces an element of risk in farming which makes it particularly hazardous occupation.

A Weather hazard in this context can be defined as any type of extreme weather condition that can damage the crops and animals leading to abnormal decrease in production and income. The extent to which these hazards create risk depends on the time of occurrence, intensity and duration of the hazard besides the age, stage of development and inherent resistance of the crop or livestock involved. Major abnormalities affecting the crop production are:

El Nino means ‘The Little One’ or ‘Christ Child’ in Spanish. It was originally recognized by fisherman of the coast of South America as the appearance of usually warm water in the Pacific Ocean, occurring near the beginning of the year i.e. around Christmas. That is why the name is used. El Nino, the periodic warming of Pacific Ocean waters that affects the weather worldwide. C. Fred and T. Andrus of the University of Georgia studied the ancient fish bones from refuse left about 6000 years ago by ancient peoples in Peru and found that ocean catfish lived in water that averaged 60 to 70 warmer than now and that there was little variation in temperature. He concluded that if El Nino was occurring at the modern rate, once every two to seven years, then the bones from the fish would have reflected the temperature variation.

Environment in which crops are grown dictates their final yield. Of these environmental factors, climate and weather the uncontrolable factors, have maximum influence on crop productivity. Vagaries of weather subject a crop to different ecological situations from year to year leading to differential responses of crops to input resources. This situation limits the use of costly inputs for realizing optimum yield. While weather itself cannot modify, the hazardous weather can often be mitigated by agronomic management. Therefore, the primary requirement for initiating agronomic measures against weather hazards is foreknowledge of weather situation that is likely to develop in an area.

Crop yield is influenced by genetical (heredity), external (environmental) and management factors that occur during the crop growing period. The external environment is the climate which regulates and determines the growth and development and final output of crop plants. But, man has no control over weather, hence it is dominance over the success or failure of agricultural enterprises. According to the World Meteorological Organization, the weather induced variability in crop yield is as high as 50 per cent. Therefore, weather should be taken as one of the inputs in agricultural planning.

The earth has two motions. (1) Rotation and (2) Revolution. The earth rotates about its axis (west to eastward) with a speed of 464 m/s or 1669 km/hr. Its angular speed of rotation is about 7.29 x 10^-5 radians/sec or 0.26244 radians per hour. This rotation causes day and night and diurnal variations of weather.

The rotating earth revolves round the sun in an elliptical orbit (with the sun at one of its Foci) with a speed (orbital speed) of about 1.073 x 10⁵ km/hr or 29770 m/s or 29.8 km/s. This revolution causes seasons. It has been stated earlier that the apparent path of the sun with respect to the celestial sphere is called ecliptic.

Naturally Greenhouse gases are cover as blanket on the Earth and kept it about 33⁰C warmer than it would be without these gases in the atmosphere. This is called as the “Greenhouse Effect”.

Over the past century, the Earth has increased in temperature by about 0.5⁰C and many scientists believe that this is because of an increase in concentration of the main greenhouse gases viz., carbon dioxide, methane, nitrous oxide and fluorocarbons. People are now calling this climate change over the past century the beginning of “Global Warming”.

The term soil refers to the outer, loose material of the earth’s surface, a layer distinctly different from the underlying parent rock. A number of features characterize this region of the earth’s crust. It is the natural medium, which supports plant growth. It provides the physical support needed for the root system and also supplies nutrients needed for plant growth. It is a perennial source of organic matter. It supports a vast population of microorganisms.

Ever since industrial revolution altered the whole gamut of economic activity at least two hundred years ago, the path of economic growth including its modified form economic development had appeared unending and limitless. The whole focus of economic activity is to produce mere goods and services for use by the mankind so that life could be more comfortable and satisfying. Increasing population and increased needs of more goods and service was also seen as a hindrance or limitation in the march towards economic growth and development.

AIR

Air is a non-homogenous mixture of gases, solid particles, and liquids; It consists of gases and particles with small settling velocity that exhibit stability in a gravitational field. Atmosphere has four major layers Troposphere from 0-17km., Stratosphere from 17-50km., Mesosphere from 50-90 km. and Ionosphere is from 90-100 km. (95% of the air by weight is contained in the Troposphere i.e. from 0-17 km).

The communication system provides the forecaster with a large mass of figures; the next step is to put them into a suitable form for study. This is done by plotting the observations on a large outline map which in popular term is called a “Weather map” technically a “Synoptic chart” simplified synoptic charts appear in some newspaper.

A chart or map on which meteorological data presented and analysed is called a synoptic chart. Synoptic means having the same view point. The representation of the meteorological data in synoptic chart are atmospheric wind, temperature, pressure, cloud, precipitation, dew point etc., over a long area at a given local standard times.

Food, clothing and housing are the three basic needs of a man. After that the additional requirement of a man are personal health and happiness. These can be considered as human factors. The material factors are agriculture, industry, trade, water resources management, insurance.

The continuous increase in population made the planners, researchers and cultivators to increase the food production to feed all the people. So, the second green revolution has to follow. Due to increase in air temperature and climate change, the cultivation practices to change based on the changing climatic condition. The study of climate is not only necessary for food production, but also needed for transportation, storage, value addition and consumption.

The need of the cloth for man is not only for style. The basic need is to protecting the human body from the climatic factors like heat and cold. Clothing must provide to maintain the body heat at about 37^oC. Clothing must be made based on the local climatic condition. So, the traditional fiber for making the cloth is better for health.

Housing provides the internal controlled climate to the human being. It provides comfort to the inhabitants. Like clothing traditional styles, sites and methods of housing have to be followed based on the climatic condition. Though people are living in the multi-storied building, they have to concentrate on comfort in the case of sufficient aeration and ventilation. In India, the Vastu Sastrum is nothing, but it provides the needs of the human livings for their comfort with sufficient light and air.

The climatic factors for a particular day are not similar to previous day. Similarly, definitely the climate of one season is not similar to other season. Man needs some recreation in the comfort climatic areas. So, he/she needs cool climate for stay that necessitate to air conditioner particularly during summer.

Abstract

Continental erosion and fluvial transport play an important role enhancing mobilization of organic carbon from soils and transferring this pool to the ocean through downstream rivers and streams. The Ganges-Brahmaputra river system represents one of the largest transporters of terrestrial carbon to ocean. Intensive agriculture in the Ganges basin coupled with atmospheric deposition (AD) of nitrogen may render the soil more prone to erosion loss of carbon and nutrients. The aims of this study were to quantify atmospheric deposition of nitrogen (AD-N) in the watershed and to assess the influence of land use and AD-N on carbon and nitrogen transport in Ganga River. We collected samples in summer low flow along a 1595 km long transect of the river to assess the status of DOC under variable land use and AD-N input and, at monthly intervals along a 35 km long transect to understand seasonal patterns and the influence of local control. Our study shows average deposition of reactive-N (NO₃^- + NH₄⁺) range from 19.7 kg ha^-1yr-1 in upper stretch to 38.6 kg ha-1yr-1 in the middle stretch. The AD-N in lower stretch was almost similar to the values recorded in the middle stretch of the watershed. The average concentrations of dissolved organic carbon (DOC) and dissolved inorganic nitrogen (DIN) in the river range from 0.62 to 5.3 mg L-1 and 52.0 to 385.6 µg L-1 respectively. The land-derived carbon and nitrogen emerging in surface runoff showed positive correlation with AD-N and the river DOC showed synchrony with land use, AD-N and autochthonous carbon pool. Our data indicate that DOC in Ganga River is rising and the land use together with AD-N is an important driver of rising DOC. We suggest that future climate model should consider large scale regional time series data on changing state of atmosphere-land-water coupling and associated shifts in carbon and nutrient transport of major rivers. This has relevance predicting region specific climate change drivers and preparing action plan for integrated river basin management (IRBM).

AIR POLLUTION FROM AUTO EXHAUST

Motor vehicles are the major source of a number of pollutants, in particular carbon monoxide (CO),nitrogen oxides (NOx), unburnt hydrocarbons (HC),ozone (O3) and other photo chemical oxidants and lead (Pb) and, in smaller proportions Total Suspended Particulate Matter (TSPM), sulphur dioxide (SO2) and volatile organic compounds.

Particulate Matter

Anthropogenic emissions of particulate matter include fossil fuel (diesel and petrol) combustion from mobile and stationary sources (Rogge et. al., 1993a-c), biomass burning (Forest fires, landfills, agricultural activities and incinerators) (Oros and Simoneit, 1999) natural gas (Rogee et. al., 1993c), wood (McDonald et. al., 2000) and coal combustion (Mastral and Callen, 2000).

Metals

Metals are ubiquitous in the modern industrialized environment. Heavy metals like cadmium, iron, molybdenum, lead, nickel, tin and zinc are present in the environment in trace concentrations. These metals are universally present in soil, water, air and biota (Freedman, 1995). Global anthropogenic heavy metal inputs to ecosystem through air, water and soil have increased substantially world wide over last century (Nriagu, 1996).