tropical cyclones

What is a tropical cyclone?

A tropical cyclone is a storm system characterised by a lowpressure centre, which produces strong winds and flooding rain. A tropical cyclone feeds on heat released by the condensation of moist air. The latent heat gets converted into kinetic energy and feeds the strong winds emerging out of it.

Cyclonic storms have counterclockwise rotation in the Northern Hemisphere and clockwise in the Southern Hemisphere. Developed over warm water bodies — ocean and seas — they lose their strength once they move over land. They also help in the global atmospheric circulation mechanism by carrying heat and energy away from tropics towards temperate latitudes.

What are the different types of tropical cyclones?

Tropical cyclones are formed in eight basins — Northern Atlantic, Northeastern Pacific, North Central Pacific, Northwestern Pacific, Northern Indian Ocean, Southwestern Indian Ocean, South and Southwestern Pacific and Southeastern Indian Ocean.

Each basin has a different naming system. In the North Atlantic Ocean, Northwest Pacific Ocean east of the International Date Line and South Pacific Ocean, they are called hurricanes. Typhoon is the name given to a tropical cyclone formed in the Northwest Pacific Ocean west of the dateline.

In the southwest Pacific Ocean and southeast Indian Ocean, it’s called a severe tropical cyclone. Similarly, tropical cyclones in the north Indian Ocean and southwest Indian Ocean are called severe cyclonic storm and tropical cyclone respectively.

What is a storm surge?

A storm surge is an offshore rise of water caused by the low-pressure system of a tropical cyclone. During the cyclone, high-speed winds start pushing on the ocean’s surface which piles the water up higher than sea level. The low-pressure centre of the cyclone adds to the surge and the combined effect causes flooding.

Why are cyclones named?

Tropical cyclones are named to provide ease of communication between forecasters and the public. Apart from this, they can often last a week or longer and the same basin can have more than one cyclone, hence giving a name reduces confusion. Naming of cyclones started in early 20th century when an Australian forecaster named the cyclone after politicians whom he disliked. Now, cyclones are given names contributed by member nations of the World Meteorological Organisation. The new names include those of men, women, flowers and so on. In the North Atlantic and Northeastern Pacific, feminine and masculine names are alternated in alphabetic order during a given season.

What is the process of naming cyclones?

The regional body responsible for monitoring a tropical cyclone in a particular basin makes a list of cyclone names for the particular basin. There are five such bodies which keep 10 pre-designated lists of cyclone names. The names are proposed by the member countries. For instance, the names of cyclones in the northern Indian Ocean are contributed by Bangladesh, India, Maldives, Myanmar, Oman, Pakistan, Sri Lanka and Thailand.

The super cyclone of 1999

• On October 29, 1999, a super cyclone with a wind speed of 300 mph had struck Odisha, making it probably the greatest cyclonic disaster ever recorded in the last century. 
• It was first detected when it was at its low pressure stage over the gulf of Siam by the IMD cyclone surveillance system on the morning of October 24, five days before it made landfall.
• Winds of up to 260 kph raged for over 36 hours.
• Coastal districts of Balasore, Bhadrak, Kendrapara, Jagatsinghpur, Puri and Ganjam were forced to evacuate their homes.
• Landfall point:Between Ersama and Balikuda in Jagatsinghpur district (southwest of Paradip)
• Time of landfall 10.30 am, October 29, 1999
• Eye of storm: Paradip
• High wind speed : The wind speed of the super cyclone was so high that the anemometer, a device used for measuring wind speed, at the IMD office and at Paradip had failed to record it.
• Three days of torrential rain : The super cyclone centred over coastal areas of Odisha for three days was accompanied by torrential rain as a tidal surge of about 7 to 10 metre that swept more than 20 km inland. 
• Diameter of cyclone: 200 km 
• Originated from 1999 super cyclone had originated from about 550 km east of the Andaman Islands as a depression Storm Surge While the impending storm Phailin may cause a storm surge of about 1.5- 2 metre this time, the state witnessed it at 7 -10 metre in 1999. 
• Districts and towns affected : The storm in 1999 led to 45 cm to 95 cm of rainfall and affected 14 coastal districts, 28 coastal towns and two major cities of Bhubaneswar and Cuttack. 
• Death toll : While the official death toll then was 9,885 people, unofficial sources estimated the toll to be above 50,000. An estimated 1,500 children were orphaned. Of the total casualty, Jagatsinghpur district alone had accounted for 8,119 people. 
• Affected people : At least 13 million people, including 3.3 million children, 5 million women and nearly 3.5 million elderly people were affected in 1999. 
• Injured people : The storm had left 7,505 people injured  
• Livestock lost : 3,15,886 head of cattle 
• `Roof snatched : 16,50,086 houses damaged, 23,129 houses washed away, 7,46,337 houses fully destroyed and 8,80,620 houses partially damaged

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Impact Of Climatic Change On Arctic Ecosystem

Climatic change due to global warming is much severe and faster on arctic ecosystem than most other parts of the world. It is the most little resistant ecosystem. The impact of climatic change in arctic ecosystem is not local, but a global problem.

1. DISAPPEARENCE OF SUMMER SEA CAP: As the average global temperature is increasing, the glaciers, sea icecaps and snow melts. The shiny ice and snow in the arctic region has the ability to reflect the sun's energy back into the space. The permafrost –the subsurface soil that remains below freezing for two or more consecutive years – releases large quantities of methane and carbon dioxide on the exposure to the atmosphere. Also the water and rocks absorbs the heat from radiation which in turn results in the overall increase of annual global temperature (ALBEDO EFFECT). This further affects the ecosystems worldwide.
2. ARCTIC VEGETATION: The basic metabolic activities of the arctic vegetation are performed on or below 0oC. The temperature shift severely affects the character and structure of vegetation which were adapted to grow in the cold climatic condition. There will be a shift in the southern species to north suppressing the species and affecting the organisms that depends on them. The symbiotic relationship between insects and plants gets disturbed as increased temperature favors early blooming.
3. ARCTIC ANIMALLIFE: When vegetation is affected, the animal species linked to it through the food chain also gets affected. Herbivores in arctic region such as musk oxen, reindeer, lemmings and hares depend plants for their food. The wolverines, wolves and arctic foxes which prey on these herbivores also suffer due to the sudden changing climatic pattern.
4. SEA LEVEL RISE: The increased melting of glaciers, snow and icecaps due to the increase in temperature results in global sea level rise. On the disappearance of Ice forms which acts as natural breakwater against storms results in occurrence more number of severe storms and is followed by coastal inundation, erosion and sedimentation processes.
5. RANGE SHIFT: The animals such as Seals and walruses use the ice for breeding purpose and polar bears makes use of the ice for hunting fish and seals. The increased melting of ice caps reduces their natural range – location in which they can survive and reproduce – thereby decreasing their population leading to extinction.
6. AQUATIC LIFE: The fish stock in the arctic region during spring depends on algae blooms for their food. The Net Primary Productivity of the aquatic life decreases due to the increase in temperature. Absence of favorable condition for living compels them to migrate northward. It is also seen that the whales are benefited from melting of ice, as it extends their habitat. The formation of water by melting of snow increases the absorption of CO2, which decreases the pH value of water. This acidity affects the coral reefs and crustaceans.
7. MIGRATORY BIRDS: They are also affected by the climatic change, but only in a lesser way. They are the most adaptive forms. The migratory birds whose stopover sites are on the arctic system are more prone due to the imbalance in the ecosystem. Nesting will be difficult in this changing weather conditions.
8. ENERGY FLOW AND NUTRIENT CYCLING: The very existence of an ecosystem depends on the energy flow and nutrient cycling. The climate has a vital role in controlling these ecosystem processes. Any imperfection in the energy flow and nutrient cycling severely affects the ecosystem.
9. DISEASE RISK: The increased temperature favors pathogens and such microorganisms to grow and multiply rapidly. This may affect the plant and other species in the arctic ecosystem. Chances of occurrence of several diseases also has a negative impact on the ecosystem.

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Influence of Himalayas in Indian Continent

The Great Himalayas, consisting of a series of parallel ranges and having about 2500km length from west to east stands like a great wall on the northern side of Indian continent. The most significant geographical structure of India influences our nation in such a way that no other mountain system have influenced any other nation.

1. PHYSICAL BARRIER : It acts as a compound wall that separates India from central and East Asian countries. It also accounts for the difference in climatic and weather patterns between Indian sub-continent from the rest of Asia.
2. NATURAL FRONTIER : The Himalayas acts as a defense barrier and have been protecting India from foreign invasions since early times. History gives us the evidence that no invaders attacked India after crossing the Himalayas. Even though China's aggression is an exception, the significance of Himalayas cannot be ignored completely.
3. CLIMATIC INFLUENCE : The Himalayas play a very important role in influencing the climate of India. India is a monsoon land only because of the presence of Himalayas. It traps the monsoon winds from Arabian sea and Bay of Bengal and forces them to shed their moisture content within the Indian sub-continent in the form of snow and rain. It also blocks the cold winter storms of East Asia from entering India, thus protecting us from severe cold. The Himalayas splits the westerly jet streams into two branches such that the southward branch entering India plays a significant role in bringing the monsoon.
4. SOURCE REGION OF RIVERS : The Himalayas is the abundant reservoir of Great Indian rivers such as Ganga, Indus and Brahmaputra. The snow melt in summer and precipitation in winter makes them perennial rivers. i.e, having water throughout the year. The abundant waterfall, huge snowfield and large glaciers feed these drainage systems. The Himalayan rivers give life to the northern India.
5. FERTILITY OF SOIL : The entire northern plains were made by the Himalayas. The Himalayan Rivers carry slits on their way down and deposit in the northern plain. These alluvial deposits are responsible for the high fertility of this land. Therefore, it is often said that northern great plain is a gift of Himalayas.
6. HYDRO ELECTRIC POWER PROJECTS : The Himalayan valley with natural waterfalls offers the best location for construction of dams. The vast potential of Himalayan rivers offer a great range for construction of many mainstream dams.
7. BIODIVERSITY AND VEGETATION : The Himalayan ranges is famous for its rich biodiversity. There is altitudinal zonation of vegetation from the tropic to the alpine. The forests provide fuel woods, medicinal plants and various raw materials that are needed for the forest based industries. Rich pastures for grazing is also an adding feature of the Himalayas.
8. AGRICULTURE : The Himalayas does not have much flat lands, so offers slopes that are terraced for cultivation. The major crop is Rice. Crops like wheat, maize, potatoes, ginger, and tobacco are also cultivated. Tea is a unique crop which grows only on hill slopes. Many fruits such as apples, pears, peaches, mulberries, cherries along with citrus fruits are grown in the Himalayan region.
9. MINERAL RESOURCES : Himalayan region contain many valuable mineral resources. The tertiary rocks have vast potential of mineral oil. Coal is found in Kashmir. Also minerals such as Copper, Cobalt, Nickel, Zinc, Lead, Antimony, Tungsten, Limestone, Gypsum and Magnetite are also present in the Himalayan locality. The presence of Gold, Silver and other semi-precious and precious stones are also the feature of Himalayan region.
10. TOURISM : The beautiful landscapes on Himalayan mountain offer a great tourist spot. Increasing popularity of winter sports, snowfall and the cool climate, when neighboring places are under the scorching heat of summer attracts millions of tourists from different parts of the world. Hill stations such as Missouri, Shimla, Kulu, Manali, Nainital, Chamba, Ranikhat, Almora, Darjeeling, Mirik, Gangtok etc. provide huge scope of tourism due to its scenic beauty as well as healthy environment.
11. PILGRIMAGE : The Himalayas is known as the house of Gods. Apart from its tourist places, the region is studded with sanctified shrines. Kedarnath, Badrinath, Vaishnodevi, Kailash, Amarnath, Tungnath, Uttarkashi, Gangotri, Yamunotri etc. which are at high altitudes are famous pilgrim centers in the Himalayas.

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La Nina and El Nino

Sea surface temperatures play a major role in global weather and nowhere is that more evident then in El Nino and La Nina patterns. These type of patterns often lead to weather extremes, some of which can be seen in our own backyards. Sea surface temperatures indicate that we'll have a La Nina this winter, which could mean a season of weather extremes across parts of the United States.

What is La Nina and El Nino?

La Nina is described as cooler-than-normal sea surface temperatures in the central and eastern Pacific Ocean, near the equator off the west coast of South America. El Nino is like La Nina's brother, the totally opposite and attention grabbing brother. This is described as warmer-than-normal sea surface temperatures in the same area of the Pacific Ocean.

What Causes La Nina and El Nino?

Simply put, easterly trade winds over the equatorial Pacific Ocean are partly to blame for both phenomenon. For La Nina, the easterly trade winds strengthen. This blows more warm water west, and allows cold water below the ocean's surface to push towards the top near the South American coast to replace the warm water.

In an El Nino, the opposite occurs. The easterly trade winds become weaker, and can even reverse direction. The warm Pacific Ocean becomes nearly stationary or pushes eastward and gains heat. Besides affecting weather, El Nino has also been known to hurt fishing off the coast of Peru.

What Does All of This Mean for the Weather?

We're already seeing affects of the building La Nina. A typical La Nina winter will feature drier and milder conditions across the South, much like what we're seeing in the current Southeast drought and elevated fire conditions. The Pacific Northwest will become wetter than normal, while the Northeast will have cold periods, but these are usually short lived. You can read AccuWeather's 2010-2011 Winter Forecast by Chief Long Range Meteorologist Joe Bastardihere.

In an El Nino winter, we see what we had last season. The southern branch of the jet stream gets displaced across the Deep south, leading to wetter conditions from Los Angeles to the Southeast. The Northeast typically has stormy winters, which in the case of last season led to "Snowmageddon." Finally the Northwest is typically milder.

In other parts of world, La Nina and El Nino can affect Asia's Monsoon's and rainfall from Australia to Peru.

How Long Will This All Last?

Typically a La Nina lasts 9 to 12 months, while an El Nino will last roughly a year. As for this year's La Nina, forecast models are indicating slight strengthening through October and then a steady period in November and December. All of the models have the La Nina weakening throughout the spring and early summer.

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Ground Water in India

Ground Water in India

Introduction:

1. Water seeps through rocks and soil and is stored below the ground.
2. The rocks in which ground water is stored are called aquifers made up of gravel, sand, sandstone or limestone. 
3. Water moves through these rocks because they have large connected spaces that make them permeable. 
4. The area where water fills the aquifer is called the saturated zone. 
5. The depth from the surface at which ground water is found is called the water table. 
6. The water table can be a foot below the ground or a few hundred meters deep. 
7. Heavy rains can cause the water table to rise and continuous extraction of ground water can cause the level to fall. 

Figure illustrates the major definitions used in the context of groundwater. 

The underground (hydrogeological) setting of ground water defines the potential of this resource and its vulnerability to irreversible degradation. This setting in India can be divided into following categories, which are described below:

1. Hard-rock aquifers of peninsular India:

• These aquifers represent around 65% of India’s overall aquifer surface area. 
• Most of them are found in central peninsular India, where land is typically underlain by hard-rock formations. 
• These rocks give rise to a complex and extensive low-storage aquifer system, where in the water level tends to drop very rapidly once the water table falls by more than 2-6 meters. 
• Additionally, these aquifers have poor permeability which limits their recharge through rainfall. 
• This implies that water in these aquifers is non- replenishable and will eventually dry out due to continuous usage. 

2. Alluvial aquifers of the Indo-Gangetic plains:

• These aquifers are found in the Gangetic and Indus plains in Northern India.
• They have significant storage spaces, and hence are a valuable source of fresh water supply. However, due to excessive ground water extraction and low recharge rates, these aquifers are at the risk of irreversible overexploitation. 

Ground water extraction and use:

• Experts believe that India is fast moving towards a crisis of ground water overuse and contamination.
• Ground water overuse or overexploitation is defined as a situation in which, over a period of time, average extraction rate from aquifers is greater than the average recharge rate.
• In India, the availability of surface water is greater than ground water. However, owing to the decentralised availability of groundwater, it is easily accessible and forms the largest share of India’s
• agriculture and drinking water supply. 
• 89% of ground water extracted is used in the irrigation sector, making it the highest category user in the country.
• This is followed by ground water for domestic use which is 9% of the extracted groundwater. Industrial use of ground water is 2%. 
• 50% of urban water requirements and 85% of rural domestic water requirements are also fulfilled by ground water.

Irrigation through ground water:

• Wells, including dug wells, shallow tube-wells and deep tube wells provide about 61.6% of water for irrigation, followed by canals with 24.5%.
• Over the years, there has been a decrease in surface water use and a continuous increase in ground water utilisation for irrigation. 
• The dependence of irrigation on ground water increased with the onset of the Green Revolution, which depended on intensive use of inputs such as water and fertilizers to boost farm production.
• Incentives such as credit for irrigation equipment and subsidies for electricity supply have further worsened the situation.
•  Low power tariffs has led to excessive water usage, leading to a sharp fall in water tables.

Legislative and Policy Framework 

The Easement Act, 1882 

• Provides every landowner with the right to collect and dispose, within his own limits, all water under the land and on the surface. 
• Difficult to regulate extraction of ground water. 
• Gives landowners significant power over ground water. 
• Excludes landless ground water users from its purview. 

The Model Bills and National Water Policy

• Address the governance of ground water under the public trust doctrine. 
• Public trust doctrine ensures that resources meant for public use cannot be converted into private ownership.
• Government being the trustee has the responsibility to protect and preserve this natural resource for and on behalf of the beneficiaries. 
• Every person has the fundamental right to be provided water of acceptable quality. 
• Fundamental right to water has been evolved by the Supreme Court and various High Courts of the country as part of ‘Right to Life’ under Article 21 of the Constitution. Courts have delivered verdicts on concerns such as access to drinking water and on the right to safe drinking water as a fundamental right.
• Prioritises needs of rural and urban households
• Specifies other primary and secondary uses. Primary uses include water for agriculture, non-agriculture based livelihoods and municipal water supply and secondary use includes water for commercial activities. 
• Implements the principle of subsidiarity which involves giving communities the power to regulate groundwater at the aquifer level. For example, an aquifer situated entirely within a village will be under the direct control of the Gram Panchayat. 
• So far, 11 states and four union territories (UTs) have adopted and implemented ground water legislation. 
• These are: Andhra Pradesh, Assam, Bihar, Goa, Himachal Pradesh, Jammu & Kashmir, Karnataka, Kerala, West Bengal, Telangana, Maharashtra, Lakshadweep, Puducherry, Chandigarh and Dadra & Nagar Haveli.
• Further, the Central Ground Water Authority issued advisory to Chief Secretaries of all states and UTs to take necessary measures for adopting rainwater harvesting in all government buildings. So far, 30 states and UTs have made rain water harvesting mand

Plachimada Coca-Cola Case 

The Plachimada panchayat in Palakkad district of Kerala granted a license to the Coca-Cola Company in March 2000 to use groundwater for the production of its beverages. However, in 2003, the panchayat ordered the closure of the plant as it caused lowering of the water table and deterioration of the water quality. This order was challenged by the company before the High Court of Kerala. The issue is the conflict in the right of a landowner to extract groundwater and the power of the panchayat to regulate the use of groundwater by private individuals. The High Court observed that even without groundwater regulation, the existing legal position was that groundwater is a public trust and the state has a duty to protect it against excessive exploitation. Additionally, it observed that groundwater exploitation by landowners can result in negative environmental consequences. However, on appeal, the two Judge Bench of the High Court asserted the primacy of landowner’s control over groundwater in the absence of a specific law prohibiting extraction. The case is now pending in the Supreme Court. 

Institutional Framework  

1. Central Water Commission: Initiating and coordinating schemes for the conservation and utilisation of water resources in the country in collaboration with state governments; and monitoring water quality 
2. Central Ground Water Board: Developing and disseminating technology related to sustainable use of ground water; monitoring and implementing policies for the sustainable management of ground water resources; estimating ground water resources 
3. Central Ground Water Authority: Constituted under Section 3(3) of the Environment (Protection) Act, 1986 to regulate and control development and management of ground water resources; can resort to penal actions and issue necessary regulatory directives 
4. Central Pollution Control Board: Implementation of the Water (Prevention and Control of Pollution) Act, 1974 which seeks to restore water quality

Quality of ground water 

• The Comptroller and Auditor General (CAG) of India in its Performance Audit of Water Pollution in India, 2011-12 observed that despite increasing pollution of ground water sources and presence of contaminants like arsenic, nitrate, fluoride, salinity, etc., no programme at the central or state level is being implemented for control of pollution and restoration of groundwater. Additionally, the Central Pollution Control Board and the CGWB do not carry out real-time monitoring of water pollution in rivers, lakes and ground water sources. The CAG has made the following recommendations with regard to the prevention and control of pollution of groundwater: 
• The Ministry of Environment, Forests, and Climate Change needs to establish enforceable water quality standards for lakes, rivers and ground water to help protect ecosystem and human health, 
• Penalties need to be levied for violations of water quality standards, and 
• States need to take measures for source control of pollutants through sewage and agriculture runoff entering water bodies in projects for conservation and restoration of lakes 

Local management of ground water 

• The phenomena of local water users successfully managing their water resources has been observed in only a few areas. The Planning Commission recommended that local planners take the following steps while planning for ground water management:
• Determining the relationship between surface hydrological units such as watershed or river basins, and hydrological units below the ground such as aquifers,
• Identification of ground water recharge areas,
• Maintaining ground water balance at the level of the village or the watershed, and 
• Creating regulatory options at the community level such as panchayat. Examples of activities that could be regulated at the local level include drilling depth, distance between wells, cropping patterns to ensure sustainability of aquifers and participatory ground water management. 

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WESTERN DISTURBANCES

• The extended and intense cold and dry weather, not so good for agricultural point of view, has been because of feeble and fewer western disturbances (WDs) and their changed pattern this season.
• Currently, almost 40 per cent of the country (primarily Punjab, Haryana and western UP, eastern Rajasthan and Madhya Pradesh) is experiencing scanty rain this Rabi due to wayward WDs.

 WESTERN DISTURBANCES:

• Western disturbance is a weather phenomenon associated with clouds and rain
• Causes winter rain and snow; also linked to cloudy skies, higher night temperatures
• A rise in temperature is followed by rainfall or snow
• Temperatures rise is because of change in wind direction from cold north-westerly to warm south-westerly winds
• This brings down temperatures while the cloud cover in the nights does not allow the heat to escape

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Vaidyanathan committee report

Agriculture plays a very pivotal role in the Indian economy providing employment to half of the population and contributing one-fifth to the GDP. The volatility in this sector has been one of the prime concern of the policy makers. To arrest this volatility and raise the livelihood security of the nation various commissions had been set up in the past. For instance, National Commission On Farmers. Recently the government has set up an expert committee under eminent economist Prof. A Vaidyanathan to look into the issues of raising crop yield through better estimation. The recommendations of the committee are given below.

Vaidyanathan Committee Recommends Remote Sensing, National Centre for Improving Agricultural StatisticsThe expert committee set up under the chairmanship of Prof A Vaidyanathan to suggest ways to improve agricultural statistics has called for using remote sensing and restructuring the data collection machinery. In its interim report, the Expert Committee has also recommended setting up  of National Crop Statistics Centre (NCSC) to deal with all aspects of crop area and yield estimation.

Details about the Expert Committee and its recommendations are as follows:In pursuance of recommendations of Steering Committee on Agriculture & Allied Sector for formulation of 11th Five Year Plan set up by Planning Commission for thorough review of Schemes for collection of Agricultural Statistics for bringing about lasting improvements in basic system of agricultural statistics and as per decisions taken in the meeting with National Statistical Commission (NSC), the Government constituted a Committee of Experts to
(a) look into the problems relating to the methodology and procedures followed for the collection/ estimation of data on land use, cropping and yields and suggest measures for improvement and
(b) assess the potential of remote sensing techniques to collect these data and to indicate how to utilize this potential and
(c) suggest institutional framework for improvement of agricultural statistics.

The Committee submitted its interim report to the Department in July, 2010 on the deficiencies in the existing system alongwith recommendations to ensure reliable, unbiased and timely estimates of area and yield for crops at the National and State level.

The Report has brought out that the deficiencies in the current system of both area and yield estimation arises from serious lacuna in institutional arrangements to collect, supervise and validate basic data on large scale on diverse crops. The Committee recommended the need for reducing the sample size by improving the design and bringing organizational changes to ensure tighter management and maintenance of high professional standards. The Report has recommended a two-pronged strategy (a) expanding the use of remote sensing as an independent source of land use, crop area and, to the extent possible, yield estimates, (b) restructuring the scope, organization and management of existing system of collecting primary data.

The Committee has recommended the creation of (a) National Crop Statistics Centre (NCSC) as an autonomous professionally run organization fully funded by the Centre to design, organise and supervise the generation of crop area and yield estimates at the State and National level. Fieldwork would be done by the trained staff in the state bureaus appointed and dedicated exclusively to carry out the programme decided by NCSC and their cost being borne entirely out of the Central Budget.

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National policy for Farmers

The National Policy for farmers has defined the term “FARMER” as a person actively engaged in the economic and/or livelihood activity of growing crops and producing other primary agricultural commodities. It also includes all agricultural operational holders, cultivators, agricultural labourers, sharecroppers, tenants, poultry and livestock rearers, fish-growers, beekeepers, gardeners, pastoralists, non-corporate planters and planting labourers, as well as persons engaged in various farming related occupations such as sericulture, vermiculture, and agro-forestry. Apart from this, the term also includes tribal families/persons engaged in shifting cultivation and in the collection, use and sale of minor and non-timber forest produce.

The Indian government has approved the "National Policy for Farmers, 2007" based on recommendations developed by an independent commission in 2004. The independent commission was chaired by 1987 World Food Prize Laureate M.S. Swaminathan. 

The new policy aims to improve the net income of Indian farmers and includes a number of different provisions. The policy states that there is a need for an "Evergreen Revolution" in India that would use biotechnology and other new technologies to improve crop productivity without harming the environment. The policy also calls for the establishment of a National Agricultural Bio-security System and the creation of a Cabinet Committee on Food Security. India's Department of Agriculture & Cooperation is charged with developing a plan to bring the new policy into action.

Important provisions and features incorporated in the National Policy for Farmers, 2007 include: 

a) Human Dimension: Focus to be on the economic well-being of the farmers than merely on production and productivity.
b) Definition of Farmer: Expanded to include all categories of persons engaged in the sector so that they can be extended the benefits of the Policy. 
c) Asset Reforms: To ensure that every man and woman, particularly the poor in villages, either possesses or has access to a productive asset. 
d) Income per unit of Water: The concept of maximizing yield and income per unit of water would be adopted in all crop production programmes and, stress will be given on awareness and efficiency of water use. 
e) Drought Code, Flood Code and Good Weather Code: To be introduced in drought prone areas, flood prone areas and in arid areas, respectively so as to maximize the benefits of monsoon and to aid preparedness for likely contingencies. 
f) Use of Technology: New technologies which can help in enhancing productivity per unit of land and water are sought for. Biotechnology, information and communication technology (ICT), renewable energy technology, space applications and nano-technology will be used to provide opportunities for launching an "Evergreen Revolution" capable of improving productivity in perpetuity without harming the ecology. 
g) National Agricultural Bio-security System: To be set up to organize a coordinated agricultural bio-security programme. 
h) Inputs and services-Soil Health: Good quality seeds, disease free planting material including in-vitro cultured propagules and Soil health enhancement hold the key to raising productivity of small farms. Every farmer family will be issued with a Soil Health Passbook. 
i) Support Services for women: When women work in fields and forests the whole day, they need appropriate support services like crèches, child care centers and adequate nutrition. 
j) Gyan Chaupals to be established in as many villages as possible to harness the help of Information and Communication Technology. 
k) Credit & Insurance: Credit counseling centers to be established where severely indebted farmers can be provided a debt rescue package to help them out of debt trap. To cater to the needs for both credit and insurance literacy in villages, Gyan Chaupals will help in the task. 
l) Setting up of Farm Schools: These will be set up in the fields of outstanding farmers to promote farmer to farmer learning and to strengthen extension services. 
m) A comprehensive National Social Security Scheme will be launched for the farmers for ensuring livelihood security by taking care of insurance needs on account of illness, old age, etc. 
n) Minimum Support Price (MSP) mechanisms to be implemented effectively across the country so as to ensure remunerative prices for agricultural produce. 
o) Market Intervention Scheme to be strengthened to respond speedily to exigencies, specific crops to be identified. 
p) Community Food Grain Banks: To be promoted to help in the marketing of unutilized crops. 
q) Single National Market: To develop a Single National Market by relaxing internal restrictions and controls. 
r) Expanding Food Security Basket to include nutritious crops like bajra, jowar, ragi and millets mostly grown in dryland farming areas. 
s) Farmers of the future: Farmers may adopt cooperative farming, create service cooperatives, undertake group farming through self-help groups, establish small holders' estates, adopt contract farming and create farmers' companies. This is expected to increase productivity, efficiency of small farmers and would create multiple livelihood opportunities through crop-livestock integrated farming systems as well as agro processing. 

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National Mission for Sustainable Agriculture

Agriculture plays a crucial role in ensuring food security while also accounting for a significant share of India’s Gross Domestic Product (GDP). It engages almost two-thirds of the workforce in gainful employment. Several industries such as sugar, textiles, jute, food and milk processing etc. depend on agricultural production for their requirement of raw materials.

Presently, the threat of climate change poses a challenge for sustainable agricultural growth. This threat is compounded due to accumulated greenhouse gas emissions in the atmosphere, anthropogenically generated through long-term intensive industrial growth and high consumption lifestyles and preferences. While the international community is collectively engaging itself to deal with this threat, India needs to evolve a national strategy for adapting to climate change and its variabilities in order to ensure ecological sustainability in its socio-economic developmental priorities.

Thus the National Mission for Sustainable Agriculture (NMSA) was launched in 2008 with the objective of promoting Sustainable Agriculture.

The thrust areas to be addressed under this Mission are dryland agriculture, access to information, bio-technology and risk management. This National Mission would cover both adaptation and mitigation measures in the domain of crops and animal husbandry, including research.  

Sustainable agriculture is the practice of farming using principles of ecology.  Sustainable agriculture integrates three main goals- Environmental (environmental health), Social (social and economic equity) and Economic (economic profitability).

Sustainability means conserving an ecological balance by avoiding depletion of natural resources. Sustainability creates and maintains the conditions for the perfect harmony between the man and the environment as the Agriculture is being as the closest profession of man with the nature, it needs to be well tuned with the surrounding environment.

Prime Minister’s Council identified Department of Agriculture & Cooperation and DARE to play the role of Lead Agency for preparation of Mission Document on NMSA. NAPCC has identified the following focus areas (Thirst areas) for NMSA – Dry land Agriculture, Risk Management, Access to Information, Use of Bio- technology.

Priority Areas as indicated in NMSA under the NAPCC are:

Rainfed Agriculture 1. Development of drought and pest-resistant crop varieties. 2. Improving methods to conserve soil and water to ensure theirs optimal utilization. 3. Generate awareness through stakeholder consultations, training workshops and demonstration exercises for farming communities, for agro-climatic information sharing and dissemination. 4. Financial support to enable farmers to invest in and adopt relevant technologies to overcome climate related stresses.

Risk Management 1. Strengthening existing agricultural and weather insurance mechanisms. 2. Development and validation of weather derivative models by insurance providers. Ensure access to archival and current weather data for this purpose. 3. Creation of web-enabled, regional language based services for facilitation of weather based insurance. 4. Development of GIS and remote-sensing methodologies for detailed soil resource mapping and land use planning. 5. Mapping vulnerable eco-regions and identification of pest and disease hotspots. 6. Developing and implementation of region-specific contingency plans based on vulnerability and risk scenario.

Access to Information 1. Development of regional database of soil, weather, genotypes, land-use patterns and water resources. 2. Monitoring of glacier and ice-mass, impacts on water resources, soil erosion, and associated impacts on agricultural production in mountainous regions. 3. Providing information on off-season crops, aromatic and medicinal plants, greenhouse crops, pasture development, agro-forestry, livestock and agro-processing. 4. Collation and dissemination of block-level data on agro-climatic variables, land use and socio-economic features and preparation of state-level agro-climatic atlases.

Promoting Data Access 1. To improve and expand the data bases on (a) Soil profile, (b) Area under cultivation, Production and yield, and (c) Cost of Cultivation. 2. To digitize data, maintain database of global quality, and streamline the procedure governing access there to 3. To build public awareness through “National Portal” on agricultural Statistics.

Use of Bio – technology 1. Genetic engineering to convert C-3 crops to the more carbon responsive C-4 crops to achieve greater photosynthetic efficiency for obtaining increased productivity at higher levels of carbon dioxide in the atmosphere and to sustain thermal stresses. 2. Development of strategies for low input sustainable agriculture by producing crops with enhanced water and nitrogen use efficiency which may also result in reduced emissions of greenhouse gases, and crops with greater tolerance to drought, high temperature, submergence and salinity stresses. 3. Development of nutritional strategies for managing heat stress in dairy animals to prevent nutrient deficiencies leading to low milk yield and productivity. 4. Development of salt tolerant and disease resistant fresh water fish and prawn.

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NATIONAL WATER POLICY 2012

Water is a natural resource, fundamental to life, livelihood, food security and sustainable development. It is also a scarce resource. India has more than 17 percent of the world’s population, but has only 4% of world’s renewable water resources with 2.6% of world’s land area. There are further limits on utilizable quantities of water owing to uneven distribution over time and space. Precipitation is confined to only about three or four months in a year and varies from 100 mm in the western parts of Rajasthan to over 10000 mm at Cherrapunji in Meghalaya. Rivers and underground aquifers often cut across state boundaries.  Water, as a resource is one and indivisible: rainfall, river waters, surface ponds and lakes and ground water are all part of one system.

In addition, there are challenges of frequent floods and droughts in one or the other part of the country. With a growing population and rising needs of a fast developing nation as well as the given indications of the impact of climate change, availability of  utilizable  water will be under  further strains in future with the possibility of deepening water conflicts among different user groups. Low public consciousness about the overall scarcity and economic value of water results in its wastage and inefficient use. In addition, there are inequitious distribution and lack of a unified perspective in planning, management and use of water resources. 

The objective of the National Water Policy is to take cognizance of the existing situation and to propose a framework for creation of an overarching system of laws and institutions and for a plan of action with a unified national perspective.

National Water Policy was adopted in September, 1987. Since then, a number of issues and challenges have emerged in the development and management of the water resources. Therefore, the National Water Policy (1987) has been reviewed and updated in 2012.

The salient features of new National Water Policy (2012) are:

1. Constitutionally the States have the right to frame suitable policies, laws and regulations on water, the draft NWP, 2012 lays emphasis on the need for a national water framework law, comprehensive legislation for optimum development of inter-State rivers and river valleys, public trust doctrine, amendment of the Indian Easements Act, 1882, etc.
2. The draft NWP, 2012 presents a holistic picture of ecological need of the river rather than restricting it to only minimum flow requirement. It states that the ecological needs of the river should be determined recognizing that river flows are characterized by low or no flows, small floods (freshets), large floods and flow variability and should accommodate development needs. A portion of river flows should be kept aside to meet ecological needs ensuring that the proportional low and high flow releases correspond in time closely to the natural flow regime.
3. It recognizes the need to adapt to climate change scenario in planning and implementation of water resources projects. Coping strategies for designing and management of water resources structures and review of acceptability criteria has been emphasized.
4. Need and approaches towards enhancing water availability have been stipulated. Direct use of rainfall and avoidance of inadvertent evapo-transpiration have been proposed as the new additional strategies for augmenting utilizable water resources.
5. Draft proposes the mapping of the aquifers to know the quantum and quality of ground water resources in the country has been proposed with provision of periodic updation.
6. A system to evolve benchmarks for water uses for different purposes, i.e., water footprints, and water auditing should be developed to ensure efficient use of water. 
7. Water Users Associations should be given statutory powers to collect and retain a portion of water charges, manage the volumetric quantum of water allotted to them and maintain the distribution system in their jurisdiction.
8. All water resources projects, including hydro power projects, should be planned to the extent feasible as multi-purpose projects with provision of storage to derive maximum benefit from available topology and water resources.
9. The draft NWP, 2012 lays emphasis on preparedness for flood / drought with coping up mechanisms as an option. Frequency based flood inundation maps should be prepared to evolve coping strategies.
10. Appropriate institutional arrangements for each river basin should be developed to collect and collate all data on regular basis with regard to rainfall, river flows, area irrigated by crops and by source, utilizations for various uses by both surface and ground water and to publish water accounts on ten daily basis every year for each river basin with appropriate water budgets and water accounts based on the hydrologic balances.

Planning and implementation of water resources projects involve a number of socio-economic aspects and issues such as environmental sustainability, appropriate resettlement and rehabilitation of project-affected people and livestock, public health concerns of water impoundment, dam safety etc.

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Demographic transition theory

The "Demographic Transition" is a model that describes population change over time. It is based on an interpretation begun in 1929 by the American demographer Warren Thompson, of the observed changes, or transitions, in birth and death rates in industrialized societies over the past two hundred years or so.

The demographic transition model seeks to explain the transformation of countries from having high birth and death rates to low birth and death rates.

The model is based on the change in crude birth rate (CBR) and crude death rate (CDR) over time. Each is expressed per thousand populations. The CBR is determined by taking the number of births in one year in a country, dividing it by the country's population, and multiplying the number by 1000.

The crude death rate is similarly determined. The number of deaths in one year is divided by the population and that figure is multiplied by 1000.

Stage I

Prior to the Industrial Revolution, countries in Western Europe had a high CBR and CDR.

Birth Rate is high as a result of:

• Lack of family planning 
• High Infant Mortality Rate: putting babies in the 'bank' 
• Need for workers in agriculture 
• Religious beliefs
• Children as economic assets

Death Rate is high because of:

• High levels of disease 
• Famine 
• Lack of clean water and sanitation 
• Lack of health care 
• War 
• Competition for food from predators such as rats
• Lack of education

The high CBR and CDR were somewhat stable and meant slow growth of a population.

Stage II

In the mid-18th century, the death rate in Western European countries dropped due to improvement in sanitation and medicine. Out of tradition and practice, the birth rate remained high. This dropping death rate but stable birth rate in the beginning of Stage II contributed to skyrocketing population growth rates. Over time, children became an added expense and were less able to contribute to the wealth of a family. 

Death Rate decreases as a result of:

• Improved health care (e.g. Smallpox Vaccine) 
• Improved Hygiene (Water for drinking boiled) 
• Improved sanitation 
• Improved food production and storage 
• Improved transport for food 
• Decreased Infant Mortality Rates

Stage III

Along with advances in birth control, the CBR was reduced through the 20th century in developed countries. Populations still grew rapidly but this growth began to slow down. 

There are several factors contributing to this eventual decline:

• Infant Mortality Rate declined.
• Increasing urbanization changes the traditional values placed upon fertility and the value of children in rural society. Urban living also raises the cost of dependent children to a nuclear family (education acts and child labor acts increased dependency through the late 1800s). People begin to assess more rationally just how many children they desire or need. Once traditional patterns of thinking are broken the decline is likely to accelerate.
• Increasing female literacy and employment lower the uncritical acceptance of childbearing and motherhood as measures of the status of women. 
• Improvements in contraceptive technology.

Stage IV

In the late 20th century, the CBR and CDR in developed countries both leveled off at a low rate. It is characterized by stability. In this stage the population age structure has become older. In some cases the fertility rate falls well below replacement and population decline rapidly.

Drawbacks of Model

The model does not provide "guidelines" as to how long it takes a country to get from Stage I to III. Western European countries took centuries through some rapidly developing countries are transforming in mere decades. The model also does not predict that all countries will reach Stage III and have stable low birth and death rates. There are factors such as religion that keep some countries' birth rate from dropping. 

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Himalayan River System

Evolution 

Geologists believe that a mighty river called Shiwalik or Indo-Brahma traversed the entire longitudinal extent of the Himalayas from Assam to Punjab and onwards to Sind, and finally discharged into the Gulf of Sind near lower Punjab during the Miocene period. The remarkable continuity of the Shiwalik and its lacustrine origin and alluvial deposits consisting of sands, silt, clay, boulders and conglomerates support this viewpoint. It is opined that in due course of time Indo–Brahma river was dismembered into three main drainage systems: 

(i) the Indus and its five tributaries in the western part; 

(ii) the Ganga and its Himalayan tributaries in the central part; and 

(iii) the stretch of the Brahmaputra in Assam and its Himalayan tributaries in the eastern part. 

The dismemberment was probably due to the Pleistocene upheaval in the western Himalayas, including the uplift of the Potwar Plateau (Delhi Ridge), which acted as the water divide between the Indus and Ganga drainage systems. Likewise, the downthrusting of the Malda gap area between the Rajmahal hills and the Meghalaya plateau during the mid-Pleistocene period, diverted the Ganga and the Brahmaputra systems to flow towards the Bay of Bengal.

Indus River System

Indus River is one of the chief river of southern Asia. From its source in Tibet, China, the Indus flows some 1,900 miles (3,100 km) through India and Pakistan to the Arabian Sea, an arm of the Indian Ocean. All of India's section of the river is in Kashmir. The river's drainage basin occupies 332,000 square miles (860,000 km2); most of it is in Pakistan.


Its tributaries are:

Jhelum

The Jhelum River has its source in the south-eastern region of Jammu and Kashmir, in a spring lying at Verinag. The length of Jhelum river is 480 miles. The river runs partly in Pakistan and partly in India. The source of the river is situated at the base of the Pir Panjal range in the south eastern region of the Kashmir plateau. The river runs through the Wular lake and Srinagar in India, prior to moving into the Punjab province of Pakistan.

Chenab 

The Chenab River has its source at the meeting point of two rivers, the Chandra and the Bhaga. In Himachal Pradesh, the river is also called the Chandrabhaga. It flows parallely to the Pir Panjal Range. The river moves into the lands of Punjab in the vicinity of Akhnur and is subsequently connected with the Jhelum. It creates the border between the Rechna and the Jech Doabs. The Chenab also meets the Ravi and the Sutlej in Pakistan. The length of the Chenab River is 960 km.

Beas

The Beas originates from the Beas Kund near the Rohtang Pass at an elevation of 4,000 m above the mean sea level. The river flows through the Kullu valley and forms gorges at Kati and Lorji in the Dhauladhar range. It enters the Punjab plains near Pong. Then it takes southwesterly direction and meets the Satluj near Harike. The average annual flow of the Beas at Mandi is 15,800 million cubic meters. The Beas is 615 km long. 

Ravi The Ravi has its source in the Kullu hills near Rohtang Pass in Himachal Pradesh. Flowing in the northwest direction, it drains the area lying between the Pir Panjal and the Dhauladhar ranges. It enters Punjab plains near Madhopur and enters Pakistan 26km south of Amritsar. It debouches into Chenab at Sarai Sindhu near Rangpur. Its annual flow at Madhopur is 8,000 million cubic meters. 

Satlej 

The source of the river is the Rakshas Tal or Rakas Lake, which is linked to the Manasarovar Lake with a watercourse in Tibet. The river moves into Pakistan in the vicinity of Sulemanki and is subsequently met by the Chenab. The Satlej is approximately 1,500 km long.

Ganga River System
Ganga River Basin is one of the largest one and have high climatic, geographical and anthropological variations. The Ganga is the third longest river flowing through India after Indus and Brahamputra. Even then Ganga River basin is largest basin in India and occupies approximately 25 percent of the India’s land area. It is bounded in the north by the Himalayas and in the south by the Vindhya Range.

Among all river basins in India, Ganga river basin has maximum value of estimated utilizable flow of surface water i.e.50% approximately out of the average annual runoff of 501.643 cu Km. On the other hand the Brahamputra with the largest average annual runoff of 537.067 cu.Km contributes only 4% of utilizable flow of surface water. This clearly indicates the high utilitarian value of Ganga River Basin in quantitative terms.

The Ganges rises in the southern Himalayas on the Indian side of the border with the Tibet Autonomous region of China. Its five headstreams—the Bhagirathi, Alaknanda, Mandakini, Dhauliganga, and Pindar—all rise in the northern mountainous region of Uttarakhand state. Of these, the two main headstreams are the Alaknanda (the longer of the two), which rises about 30 miles (50 km) north of the Himalayan peak of Nanda Devi, and the Bhagirathi, which originates about 10,000 feet (3,000 metres) above sea level in a subglacial meltwater cave at the base of the Himalayan glacier known as Gangotri. Gangotri itself is a sacred place for Hindu pilgrimage. The true source of the Ganges, however, is considered to be at Gaumukh, about 13 miles (21 km) southeast of Gangotri.

The Alaknanda and Bhagirathi unite at Devaprayag to form the main stream known as the Ganga, which cuts through the Outer (southern) Himalayas to emerge from the mountains at Rishikesh. It then flows onto the plain at Haridwar, another place held sacred by the Hindus.

The volume of the Ganges increases markedly as it receives more tributaries and enters a region of heavier rainfall, and it shows a marked seasonal variation in flow. From April to June the melting Himalayan snows feed the river, while in the rainy season from July to September the rain-bearing monsoons cause floods. During winter the river’s flow declines.



Tributaries:
The Yamuna and the Son are its major right bank tributaries. The important left bank tributaries are the Ramganga, the Gomati, the Ghaghara, the Gandak, the Kosi and the Mahananda in the order from west to east.

• Yamuna
The Yamuna is the biggest tributary of the River Ganges in North India. The river originates from the Yamunotri Glacier on the southwestern sides of the Banderpooch crests of the Lower Himalayan Mountain Range. During its itinerary, the river passes through states like Uttar Pradesh, Uttarakhand, and Haryana. The famous river meets the Ganges at Triveni Sangam in Allahabad, a popular pilgrimage spot for the Hindus. The biggest and longest tributary of the Yamuna is the Tons River. Other tributaries of the Yamuna include the Betwa, Chambal, Sindh, Ken, Sarda, Hindon, Giri, Kunta, Hanuman Ganga, Rishiganga, and Kunta Rivers. The catchment area of Yamuna comprises the most of the Ganges Basin. The river traverses cities like Mathura, Delhi, Agra, Etawah, and Kalpi.

• Son
The Son is a large south bank tributary of the Ganga, originating in the Amarkantak plateau. After forming a series of waterfalls at the edge of the plateau, it turns northeastward. It reaches Arrah, west of Patna, to join the Ganga. The important tributaries of the Son are the Johilla, the Gopat, the Rihand, the Kanhar and the North Koel.

• Ramganga
The Ramganga is a small river rising in the Garhwal hills near Kalagarh. It changes its course to the southwest direction after crossing the Shiwalik and enters into the plains of Uttar Pradesh near Najibabad. Finally, it joins the Ganga near Kannauj. Its main tributaries are the Khoh, the Gangan, the Aril, the Kosi, and the Deoha (Gorra).

• Ghaghara
The Ghaghara originates in the glaciers of Mapchachungo near Gurla Mandhata peak south of Mansarovar. It is known as Karnali in western Nepal. After collecting the waters of its tributaries – Tila, Seti and Beri, it comes out of the mountain, cutting a deep gorge at Shishapani. The river Sarda (Kali or Kali Ganga) joins it in the plain before it finally meets the Ganga at Chhapra. Its other tributaries are the Sarju and the Rapti. Its average annual flow is 94,000 million cubic meter.

• Gantak
It rises at 7620 m in Tibet near the Nepal border and overlooks the Dhaulagiri. It is distinguished for the deep gorge across which it flows and for a large hydroelectric facility in Nepal. This river also provides water for a major Irrigation cum Hydroelectric power facility at the Indo-Nepal border at Valmikinagar. The river has a total catchment area of 46,300 sqkm out of which 7620 sqkm is located in India. The Gandaki River is mentioned in the ancient Indian epic Mahabharata.

• Kosi
It is an antecedent river with its source to the north of Mount Everest in Tibet, where its main stream Arun rises. The Kosi River is a trans-boundary river, running across important cities in Bihar and Nepal such as Biratnagar, Purnia, and Katihar. After crossing the Central Himalayas in Nepal, it is joined by the Sun Kosi from the West and the Tamur Kosi from the east. It forms Sapt Kosi after uniting with the river Arun at Triveni. Soon after debouching onto the plain the river becomes sluggish due to heavy load. The river channel is braided and it shifts its course frequently. This causes devastating floods. Thus the Kosi is known as ‘the Sorrow of Bihar’. Hanuman Nagar barrage has been constructed in 1965 to tame the river. The Kosi joins Ganga near Kursala.

Brahmaputra river system

The Brahmaputra basin covers an area of 5,80,000 Sq. Km of which 1,94,413 Sq. Km falls in India. In India, the basin lies in the states of Arunachal Pradesh, Assam, Nagaland, Meghalaya, Sikkim and West Bengal. Brahmaputra is a perennial river, feed by snow as well as by rain.

The Brahmaputra rolls down the plain of Assam east to west for a distance of 640 km up to Bangladesh border. Through its course, the river receives innumerable tributaries coming out of the northern, northeastern and the southern hill ranges. The mighty river with a well-knit network of tributaries drains an area of 56,480 Sq. Km of the state accounting for 72 per cent of its total geographical area. Most of the right bank tributaries of Brahmaputra are snow as well rain feed and are perennial. Although the left bank tributaries are mainly rain feed but perennial in nature.

It is the fourth largest river in the world in term of average water discharge at the mouth with a flow of 19,830 m3s-1. The river carries 82 per cent of its annual flow during the rainy season (May through October).

The principle tributaries of the river are:

Tista River

It rises in the Himalayas near Chunthang in Sikkim (India), flows to the south, cutting a deep gorge through the Siwalik Hills east of Darjiling (in West Bengal, India), and turns southeast to run through the Sivok Khola pass onto the plains of West Bengal. Originally, the river continued southward to empty directly into the upper Padma River (Ganges [Ganga] River). About 1787, however, the river changed its course to flow eastward, crossing the Rangpur region of Bangladesh to join the Jamuna River near Chilmari after a total course of about 200 miles (320 km).

The flow of the Tista is greatest during the summer (June to September), when the monsoon rains are heaviest and glaciers supply abundant meltwater. Its lower reaches are marked by flooding and frequent, violent course changes; navigation is impaired by shoals and quicksand near the junction with the Jamuna. The Tista Barrage is a dam that helps to provide irrigation for the plains between the upper Padma and the Jamuna.

Lohit River

The Lohit River originates in eastern Tibet, in the Zayal Chu range and surges through Arunachal Pradesh for two hundred kilometers, before emptying itself in the plains of Assam. Uncontrolled and turbulent is the features of the Lohit River. The Lohit River has derived its name because of its vigorous nature and thus it is also called the river of blood. The lateritic soil of the river forms its surrounding demography. The river flows through the Mishmi Hills, to meet the Siang at the head of the Brahmaputra valley.

Manas River

The Manas River is one of the most important tributary of the Brahmaputra. It originates in Bhutan, flows through southern Bhutan and Assam and finally joins the Brahmaputra in Jogighopa. The Manas River has a length of 376 kms and is characterized by hilly steep forests in the upper reaches and plain on the lower end of the river.

Subansiri River

It is another important tributary of the Brahmaputra which originates in the Himalayas in China and flows through Tibet and India. It has a length of 442 kms and joins the Brahmaputra in Lakhimpur district of Assam.

Dhansiri River

It originates in the Laisang peak of Nagaland and flows through Dimapur district of Nagaland and Golaghat district of Assam before joining the Brahmaputra just 5 kms away from the Kaziranga Wildlife Sanctuary. Earlier, the Dhansiri River used to flow through the Kaziranga National Park, but with time it has changed course to meet the Brahmaputra 5 kms away. This abandoned course is now called the Mora Dhansiri.

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Health and Diseases

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Environment and Bio-Diversity

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