Polavaram Indirasagar Dam Project

Polavaram Project is a multi-purpose irrigation project which has been accorded national project status by the central government.

• This dam across the Godavari River is under construction located in West Godavari District and East Godavari District in Andhra Pradesh state and its reservoir spreads in parts of Chhattisgarh and Odisha States also.

Indirasagar Polavaram an interstate project on river Godavari has been conceived as a part of recommendations of Godavari Water Disputes Tribunal (GWDT).

• GWDT finalized its award in 1980 .The award identifies individual projects that can be taken up by the co-basin states of Maharashtra, Madhya Pradesh (including Chhattisgarh), Orissa, Karnataka and Andhra Pradesh (AP) on the main Godavari river as well as its tributaries.
• As a part of the award, the states of Andhra Pradesh, Madhya Pradesh and Orissa executed an agreement dated 02-04-1980 to enable clearance of Polavaram Project to be undertaken by AP. 
• The agreement provides for construction of the project with a Full Reservoir Level of 150 Feet and with a spillway discharging capacity of 36 Lakh Cusecs at pond level of 140 feet and not less than 20 Lakh Cusecs at a pond level of 130 feet.
• In order to protect the lands and properties above level of 150 feet, in Orissa and Chhattisgarh, protective embankments with adequate drainage sluices have been provided at the cost of the project. 

Seshachalam Hills

The Seshachalam Hills are hilly ranges part of the Eastern Ghats in southern Andhra Pradesh state, in southeastern India.

• The ranges were formed during the Precambrian era (3.8 billion to 540 million years ago). 
• Minerals contained in these hills include sandstone and shale inter bedded with limestone.
• The ranges are bounded by the Rayalaseema uplands to the west and northwest, and the Nandyal Valley to the north.

• Tirupati, a major pilgrimage town is located in the hills. 
• The hills contain seven peaks namely, Anjanadri, Garudadri, Narayanadri, Neeladri, Seshadri, Venkatadri and Vrishabhadri, the highest at about 600 m (2,000 ft) above sea level.
• The seven peaks are said to represent the seven hoods of Lord Adisesha, the king of serpents in Hindu mythology.
  • The Srivenkateshwara National Park is also located in these ranges.
• The famous Natural Arch, Tirumala Hills is also a part of Seshachalam Hills, which dates back to the period in between Middle and Upper Proterozoic Eon. 
• In 2010 it was designated as a Biosphere Reserve. It has large reserves of Red Sandal wood which is used in medicines, soaps ,spiritual rituals.

Rajmahal Hills

Rajmahal Hills are hills formed from rocks dating from the Jurassic Period and named after the town of Rajmahal which lies to the east in the state of Jharkhand in India. 

• The hills are oriented in a north-south axis with an average elevation of 200–300 m (600-1,000 ft). 
• The River Ganga meanders around the hills changing direction of flow from eastwards to southwards. Volcanic activity in the Jurassic caused the formation of these hills. 
• The upper regions of the Rajmahal Hills are inhabited by the Sauria Paharia tribe while the valleys are dominated by the Santhal tribe who cultivate the land. 
• The ancient plant fossil formations of Rajmahal and Mandro in Sahebganj district have been given the 'geological heritage site' status by the Geological Survey of India (GSI). This is to preserve the area from rampant excavation.
  
  
  
• The Rajmahal hill range is believed to be one of the oldest mountain range and finest Jurassic-era fossil beds in the world. 

Westerlies

Westerlies:-

Winds blow all the year round from the Atlantic Ocean towards Europe. Since they blow from the west, these winds are called "westerlies".

(Actually these winds blow from the Southwest towards the Northeast)

These winds are warmer than the land temperature and are also moist. The climate of the Western Europe is affected by these warm and moist winds all the year.

Western Europe: Showers all the year round-

The westerlies which blow throughout the year also bring ample moisture to northern and western Europe. Since these winds blow from the sea, they carry lots of moisture and regularly cause rainfall. This is why it rains throughout the year in northern and western Europe. 

Western Europe also benefits from the gulf stream. The warm currents are very good for fish breeding as they contain ample food materials for the fishes. As a result, the fishery industry is very well developed in the North Sea near Britain. This part of the North Sea is called "Dogger Bank". 

Peninsulas:-

Landmasses that are surrounded by the sea on three sides and connected to the mainland on the fourth side are called Peninsulas.

ex: Italy is a peninsula. Norway and Sweden are also a part of the peninsula, known as Scandinavian Peninsula.

Bays & Gulfs:-

Bays and gulfs are parts of the sea enclosed by land on three sides. In a  bay, the land curves inwards and the mouth of the bay is usually wide as in the case of Bay of Bengal.

A gulf is a narrow inlet of the sea and has a narrow mouth. The entire Baltic Sea is a large gulf. 



Importance of Bays and Gulfs:

Since the bays and gulfs are protected from the storms of the high seas, they are very useful for building harbors where ships can be safely anchored and cargo can be loaded or unloaded. 

Indira Gandhi Canal

Indira Gandhi Canal

The Indira Gandhi Canal is the longest canal in India and the largest irrigation project in the world.

Indira Gandhi Canal is 649 km long and consists of Rajasthan feeder canal and Rajasthan main canal and runs through 167 km in Punjab and Haryana and remaining 492 km in Rajasthan.

 The canal is one of the project of Green revolution in India and also runs through The Great Thar Desert.

Duars

Duars, also spelled Dwars or Dooars, region of northeastern India, at the foot of the east-central Himalayas. The name Duars (“Doors”) is derived from the several passes that lead from the region into the Lesser Himalayas. Area 3,400 square miles (8,800 square km).

It is divided by the Sankosh River into the Western and Eastern Duars. Both were ceded by Bhutan to the British at the end of the Bhutan War (1864–65). 

• The Eastern Duars, in western Assam state, comprises a level plain intersected by numerous rivers and only slightly populated. 
• The Western Duars lies in northern West Bengal state and is a portion of the Tarai, a lowland belt linking the Himalayas and the plains region. The Western Duars is an important centre of the tea industry. 

The Western Dooars is known as the Bengal Dooars and the Eastern Dooars as the Assam Dooars. 

• Dooars is synonymous with the term Terai used in Nepal and northern India.

The Dooars belonged to the Kamata Kingdom under the Koch dynasty; and taking advantage of the weakness of the Koch kingdom in subsequent times, Bhutan took possession of the Dooars. 

This region was controlled by the kingdom of Bhutan when the British annexed it in 1865 after the Bhutan War under the command of Captain Hedayat Ali. 

The area was divided into two parts: the eastern part was merged with Goalpara district in Assam and the western part was turned into a new district named Western Dooars. 

• Again in the year 1869, the name was changed to Jalpaiguri District. 

After the end of the British rule in India in 1947, the Dooars acceded into the dominion of India and it merged with the Union of India shortly afterwards in 1949.

The Dooars region politically constitutes the plains of Darjeeling District, the whole of Jalpaiguri district and Alipurduar district and the upper region of Cooch Behar district in West Bengal and the districts of Dhubri, Kokrajhar, Barpeta, Goalpara and Bongaigaon in the state of Assam.

The beauty of the region lies not only in its tea gardens but also in the dense jungles that make up the countryside. 

• Many wildlife sanctuaries and national park like Manas National Park in Assam, 
• Jaldapara National Park, Buxa National Park, Gorumara National Park, Chapramari Wildlife Reserve and the Mahananda Wildlife Sanctuary in West Bengal are located in this region.

A number of rare endangered species of animals like tiger, rhinoceros and elephant make their habitat in the forests of the Dooars. 

• Other animals includes different types of deer, bison, birds and reptiles. 

source: wikipedia and encyclopedia

Monsoon

A monsoon is a seasonal change in the direction of the prevailing, or strongest, winds of a region. 

• Monsoons cause wet and dry seasons throughout much of the tropics. 
• Monsoons are most often associated with the Indian Ocean.

Monsoons always blow from cold to warm regions. The summer monsoon and the winter monsoon determine the climate for most of India and Southeast Asia.

Summer Monsoon

The summer monsoon is associated with heavy rainfall. It usually happens between April and September. 

• As winter ends, warm, moist air from the southwest Indian Ocean blows toward countries like India, Sri Lanka, Bangladesh, and Myanmar. 
• The summer monsoon brings a humid climate and torrential rainfall to these areas.

Winter Monsoon

The Indian Oceans winter monsoon, which lasts from October to April, is less well-known than its rainy summer equivalent. 

• The dry winter monsoon blows from the northeast. These winds start in the air above Mongolia and northwestern China. 

Winter monsoons are less powerful than summer monsoons in Southeast Asia, in part because the Himalaya Mountains prevent much of the wind and moisture of the monsoons from reaching the coast. 

• The Himalayas also prevent much of the cool air from reaching places like southern India and Sri Lanka, keeping them warm all year. Winter monsoons are sometimes associated with droughts.

Not all winter monsoons are dry, however. Unlike the western part of Southeast Asia, the eastern, Pacific coast of Southeast Asia experiences its rainy season in the winter. The winter monsoon brings moist air from the South China Sea to areas like Indonesia and Malaysia.

Other Monsoons

The Asian-Australian monsoon, which includes the Indian Ocean, stretches from northern Australia to Russias Pacific coast. This huge monsoon wind system then stretches into the Indian Ocean. Finally, it reaches its end on the Indian coast of Africa.

Monsoon winds exist in other parts of the world, too. The North American monsoon happens once a year, usually in the middle of summer. 

• Warm, moist air from the Gulf of California blows northeast, while warm, moist air from the Gulf of Mexico blows northwest. 

These two winds meet over the Sierra Madre Occidental mountains in central Mexico. The monsoon brings moisture to the mountain ecosystem before continuing north to the U.S. states of Arizona, New Mexico, and Texas.

• The North American monsoon can be a natural aid to fire fighters. Summer temperatures in Arizona regularly reach more than 100 degrees Fahrenheit, making wildfires difficult to contain. 
• The North American monsoon is also the primary water source for most desert ecosystems in the region. 
• However, it can also confuse and interrupt daily life for people and businesses not used to dealing with heavy rain.

credit:-

• NGC

Trade Winds, ITCZ and Equatorial Currents

The tropical ocean encompasses broad areas of the Atlantic, Pacific, and Indian Ocean basins and is closely linked to the tropical atmosphere. 

Trade Winds:-

The prevailing surface winds over the tropical ocean are the trade winds that blow persistently from the northeast (toward the southwest) in the Northern Hemisphere and from the southeast (toward the northwest) in the Southern Hemisphere. 

The name for these winds was coined by sea captains who sailed for trading companies and took advantage of their persistent speed and direction when crossing the ocean. 

Trade winds drive both North and South Equatorial Currents westward, thus transporting warm ocean-surface waters in that direction. 

• Equatorial Counter Currents and Equatorial Under Currents return some warm waters eastward. 
• Counter Currents flow along the surface whereas Under Currents flow at greater depths below the surface.

Intertropical Convergence Zone (ITCZ):- 

The trade winds of the two hemispheres converge in a narrow east-west zone located near the equator known as the Intertropical Convergence Zone (ITCZ). 

The ITCZ is an important component of the planetary-scale atmospheric circulation that is particularly well defined over the tropical ocean. Warm and humid air ascending in the ITCZ gives rise to clusters of showers and thunderstorms that produce locally heavy rainfall. 

For mariners the region of the tropical ocean near the equator is known as the doldrums, feared by the captains of sailing ships because of light and variable winds. 

Seasonally, the ITCZ moves with the sun, shifting northward during the Northern Hemisphere spring and southward during the Northern Hemisphere autumn but generally remaining north of the equator, especially over the Atlantic Ocean. 

• Consequently, the eastward-flowing Equatorial Counter Current, separating the surface current systems of the two hemispheres, also lies mostly just north of the equator.

The South Equatorial Current crosses the equator in the Atlantic and to a lesser extent in the Pacific. In this way, it transports surface waters and heat into the Northern Hemisphere. The return flow is through subsurface currents. 

The cape at the easternmost point of South America diverts part of the flow of the South Equatorial Current into the southward flowing Brazil Current. The remainder continues northwestward along South America's northeast coast into the Caribbean Sea.

The islands of Indonesia mark the boundary between the Indian and Pacific Oceans but do not completely block the flow of seawater between the two ocean basins. 

Warm, low salinity waters from the Pacific are transported into the Indian Ocean's South Equatorial Current. 

• These waters flow through the many passages between the thousands of Indonesian islands and replenish the large amounts of water removed by evaporation from the northern Indian Ocean. 

The summer Asian monsoon circulation transports this water vapor over India and Southeast Asia where it falls as torrential rains. After flowing westward across the Indian Ocean, these waters enter the South Atlantic via the Agulhas Current flowing around southern Africa. 

• The summer monsoon is associated with heavy rainfall. It usually happens between April and September. 
• As winter ends, warm, moist air from the southwest Indian Ocean blows toward countries like India, Sri Lanka, Bangladesh, and Myanmar. The summer monsoon brings a humid climate and torrential rainfall to these areas.

The Indonesian islands partially block the inter-ocean flow, which leads to an accumulation of warm surface waters in the western equatorial Pacific Ocean that is linked to El Niño/La Niña.

Hills in North East

A portion in the lower Himalayan mountains range is known as Assam Himalaya between the border of Bhutan and the Great Bend of the Tsangpo River. 

• Yarlung Tsangpo River originates from Lake Manasarovar in Mount Kailash and known as "Dihang river" in Arunachal Pradesh. Yarlung Tsangpo is the upper stream of Brahmaputra River that flows through its origin, Tibet, known by its Tibetan name. It originates at Angsi Glacier in western Tibet southeast of Mount Kailash and Lake Manasarovar. It later forms the South Tibet Valley and Yarlung Tsangpo Grand Canyon before passing through the state of Arunachal Pradesh, India, where it is known as Siang. Downstream from Arunachal Pradesh the river becomes wider and at this point is called the Siang. After reaching Assam, the river is known as Brahmaputra. From Assam, the river enters Bangladesh at Ramnabazar. 
• Siang and its Tribhutaries: Lohit, Kameg, Dikrong, Tirap, Dibang, Subansiri, Dihing, Kamlang flow through Brahmaputra River.
• Namcha Barwa is the highest mountain peak of Assam Himalaya range.

Most the part of Arunachal Pradesh is covered by the great Himalayas and rest of the part with by the Patkai hills. 

• Gorichen peak is the highest Himalayan peak in the region, located between Tawang and West Kameng district of Arunachal Pradesh. 
• Namdapha National Park, Mouling National Park are two national parks in Arunachal Pradesh.

The patkai mountain range also known as Purvanchal Range, one of the eight mountain range in India and the major of India’s North Eastern states. 

• Patkai Range consists of the three major hills, the Patkai-Bum,the Garo-Khasi-Jaintia and Lushai Hills. 
• Pangsau mountain Pass is the best place to see its conical peaks, steep slopes and deep valleys.

The Lushai Hills also known as Mizo Hills is one of the three part of Patkai mountain range, located partially in Mizoram and Tripura. 

• Mizo Hills is highly covered with dense bamboo jungle and open grass covered slopes.
• Blue mountain is the highest peak of Lushai Hills.

The hills of Khasi is the part of major Garo-Khasi range in Meghalaya and also the part of the Patkai mountain ranges. Khasi Hills got its name by Khasi tribes of the region. 

• Cherrapunji-the wettest place in the world is situated in the East Khasi Hills and Lum Shyllong is the highest peak near to Shillong.

The Garo Hills is located in Meghalaya state and part of Garo-Khasi range,The region is known as one of the wettest places on earth. 

• Garo Hills highest peak is known as Nokrek Peak and home to many places of interest such as cloud covered Tura peak, Imilchang Dar waterfall,Balpakram Wildlife Park,Naphak Lake and most famous limestone caves of Siju,one of the longest in Asia.

The Naga Hills are actually part of Indian Territory mountain ranges of Arakan Mountains between the western Burma and the Naga Hills district. Naga Hills is one of the major tribal region of Nagaland state and inhabited by Naga people.

The Jampui hill range is one of the most famous place in northeast state of Tripura and habitants are mainly Mizo or Lushai. 

• Jampui Hills is famous for its unique Orange Festival,view of rising and setting sun and excellent panoramic views of the deep valley and villages around.

The Chin Hills is a range of mountains extends northward from Manipur to Chin State of Myanmar. 

• Chin Hills are the part of Arakan Mountain Range with an highest peak of Nat Ma Taung with 3,053 m(10,500 feet). 
• Chin Hills are very close to Lushai Hills of Patkai Range and offers a wide range of flora and fauna.

Mekong Ganga Cooperation (MGC)

The Mekong-Ganga Cooperation (MGC), established in the year 2000, focusses on expanding cooperation between India and five countries of the Mekong region, viz. 

• Cambodia, Laos, Myanmar, Vietnam and Thailand

The key areas of cooperation under MGC are tourism, culture, education, and transport & communications, which aim to strengthen the ties between the peoples of the two regions. 

History:-

• The Mekong-Ganga Cooperation (MGC) is an initiative by six countries – India and five ASEAN countries, namely, Cambodia, Lao PDR, Myanmar, Thailand and Vietnam launched in 2000 at Vientiane, Lao PDR, for cooperation in tourism, culture, education, as well as transport and communications. 
• Both the Ganga and the Mekong are civilizational rivers, and the MGC initiative aims to facilitate closer contacts among the people inhabiting these two major river basins. 
• The MGC is also indicative of the civilizational, cultural and commercial linkages among the member countries of the MGC down the centuries. 

Efforts are also underway to widen collaboration between MGC countries in SMEs, conservation of rice germplasm, health and pandemic management, establishment of a Common Archival Resource Centre at Nalanda University and through Quick Impact Projects. 

• The most visible manifestation of MGC is the MGC Museum of Traditional Asian Textiles at Siem Reap, Cambodia, established with Indian assistance in April 2014. 

The Ministry of External Affairs has, through the ASEAN-India Cooperation Fund, granted six scholarships to students from Cambodia, Laos, Myanmar and Vietnam to pursue a Masters degree at Nalanda University. 

• Selected students are eligible for waiver of full fees, including tuition fees, boarding, lodging and travel fare, for the period of study. 
• A total of 4 students (2 from Laos, 2 from Myanmar and none from Cambodia) are currently studying at Nalanda University under this scholarship.

Mekong River:-

The Mekong is a trans-boundary river in Southeast Asia. It is the world's 12th-longest river. 

• From the Tibetan Plateau the river runs through China's Yunnan province,Myanmar, Laos, Thailand, Cambodia and Vietnam. 
• In 1995, Laos, Thailand, Cambodia and Vietnam established the Mekong River Commission to assist in the management and coordinated use of the Mekong's resources. 
• In 1996 China and Myanmar became "dialogue partners" of the MRC and the six countries now work together within a cooperative framework.

The extreme seasonal variations in flow and the presence of rapids and waterfalls in the Mekong make navigation difficult. 

Even so, the river is a major trade route between western China and Southeast Asia.

Courtesy:-

• PIB
• and other websites

Drought

Approximately 16 per cent of India’s geographic area, mostly arid, semi-arid and sub-humid is drought-prone. 

Due to high temporal and spatial variability in rainfall and wide variations in physio-graphic and climatic conditions in the country, droughts are experienced in varying intensities (moderate or severe) almost every year irrespective of a good monsoon.

The National Commission on Agriculture classifies three types of drought:

1. Meteorological: When there is significant decrease from normal precipitation in India (>10%)
2. Agricultural     : When soil moisture & rainfall are inadequate to support crop
3. Hydro-logical  : When prolonged meteorological drought leads to depletion of water resources

Drought on the basis of time of onset can be of three types:

1. Early Season: Delayed Rainfall
2. Mid Season  : Inadequate soil moisture between two rain events
3. Late Season : Early cessation of Rains or insufficient rains

Cyclone Management in India

Cyclone Management in India:-

Tropical Cyclone (TC), also known as ‘Cyclone’ is the term used globally to cover tropical weather systems in which winds equal or exceed ‘gale force’ (minimum of 34 knot, i.e., 62 kmph).

The frequency of cyclones in the NIO (North Indian Ocean) Basin is bi-modal, which is specific to this region.

•        Cyclones occur in the months of May–June and October–November, with their primary peak in November and secondary peak in May.

Thirteen coastal states and Union Territories (UTs) in the country, encompassing 84 coastal districts, are affected by tropical cyclones.

•        Four states (Tamil Nadu, Andhra Pradesh, Orissa and West Bengal) and one UT (Puducherry) on the east coast and

•        One state (Gujarat) on the west coast are more vulnerable to hazards associated with cyclones.

About 8% of the area in the country is prone to cyclone-related disasters. Tropical cyclones are characterised by destructive winds, storm surges and very heavy rainfall, each one having its own impact on human and livestock, and their activities.

Of these, storm surge is responsible for 90% of the loss of lives associated with cyclone disaster. Storm surge, which is a coastal phenomenon, is the inherent catastrophic feature of cyclones the world over.

•        The degree of disaster potential depends on the storm surge amplitude associated with the cyclone at the time of landfall, characteristics of the coast, phases of the tides and vulnerability of the area and community.

Cyclone Impact Mitigation:-

Although it is not possible to completely avoid natural disasters, their effects can be minimised by taking some known long- and short term structural and non-structural mitigation measures such as-

• •        Developing proper early warning systems,
• •        Creating awareness at all levels in the concerned communities,
• •        Coastal afforestation,
• •        Construction of shelters, embankments, dykes,
• •        Coastal roads, bridges, canals, etc., through better preparedness, mitigation measures and improved response mechanisms.

National Cyclone Risk Mitigation Project:-

The National Cyclone Risk Mitigation Project (NCRMP), to be implemented with financial assistance from the World Bank, is envisaged to have four major components:

• •        Component A: Improvement of early warning dissemination system by strengthening the Last Mile Connectivity (LMC) of cyclone warnings and advisories.
• •        Component B: Cyclone risk mitigation investments.
• •        Component C: Technical assistance for hazard risk management and capacity building.
• •        Component D: Project management and institutional support.

Institutional Structure:-

• •        The Cabinet Committee on Management of Natural Calamities (CCMNC):
• CCMNC has been constituted to oversee all aspects relating to the management of natural calamities, including assessment of the situation and identification of measures and programmes considered necessary to reduce its impact, monitor and suggest long-term measures for the prevention of such calamities formulate and recommend programmes for public awareness for building up society’s resilience to them.
• •        At the district level, the District Disaster Management Authorities (DDMAs), which constitute the very bedrock of the entire DM apparatus, will be in charge of DM and will control and coordinate all line departments, i.e., police, fire services and any other form of support system as part of their response. In the planning stage, the Collector/District Magistrate/Deputy Commissioner will head all planning and preparedness exercises pertaining to DM.

Steps to be taken:-  

                

•        Establishing a state-of-the-art cyclone EWS involving observations, predictions, warnings and customised local-scale advice for decision-makers (national/state/district level) for managing the impact of cyclones

•        Expanding the warning dissemination outreach by using the services of Direct-To Home (DTH) transmission in remote and rural areas (Panchayats) which cannot be otherwise covered, to introduce weather channel and broadcast cyclone warnings from high-power coastal radio stations including the use of satellite radio service like World Space, Ham radios, community radio and VHF network

•        Establishing a comprehensive Cyclone Disaster Management Information System (CDMIS) covering all phases of DM to provide on-line services to the departments of Disaster Management in the states

•        Structural safety of lifeline infrastructure in coastal areas

•        Establishing a robust system of locating multi-purpose cyclone shelters and cattle mounds

•        Ensuring cyclone resistant design standards are incorporated in the rural/ urban housing schemes in coastal areas

•        Regulating infrastructure and development activities in coastal zones

•        Mapping and delineation of coastal wetlands, patches of mangroves and shelterbelts

•        Developing Integrated Coastal Zone Management (ICZM) frameworks for addressing the sustainability and optimal utilisation of coastal resources as also cyclone impact minimisation plans

•        Implementing coastal flood zoning, flood plain development and flood inundation management

•        Evolving eco-system restoration plans for degraded ecological zones

•        Developing integrated hazard mitigation framework taking into account cyclone and associated storm surge, wind hazard, rainfall-runoff, river flood