Kerala
Kerala ( ; ) is a state on the Malabar Coast of India. It was formed on 1 November 1956, following the passage of the States Reorganisation Act, by combining Malayalam-speaking regions of the erstwhile regions of Cochin, Malabar, South ...
(38,863 km2; 1.18% of
India
India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...
's land) is situated between the Lakshadweep Sea to the west and the Western Ghats to the east. Kerala's coast runs some 580 km in length, while the state itself varies between 35–120 km in width. Geologically, pre-Cambrian and
Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
formations comprise the bulk of Kerala's terrain. The topography consists of a hot and wet
coastal plain
A coastal plain is flat, low-lying land adjacent to a sea coast. A fall line commonly marks the border between a coastal plain and a piedmont area. Some of the largest coastal plains are in Alaska and the southeastern United States. The Gulf Co ...
gradually rising in elevation to the high hills and mountains of the Western Ghats. Kerala lies between northern latitude of 8°.17'.30" N and 12°. 47'.40" N and east longitudes 74°.27'.47" E and 77°.37'.12" E. Kerala's climate is mainly wet and maritime tropical,Chacko T & Renuka G, 2002, Temperature mapping, thermal diffusivity and subsoil heat flux at Kariavattom of Kerala, Proc Indian Acad Sci (Earth Planet Sci Retrieved on 12 January 2006. heavily influenced by the seasonal heavy rains brought up by the monsoon.
''Climate''
Kerala, which lies in the tropic region, is mostly subject to the type of humid tropical wet
climate
Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologi ...
experienced by most of
Earth
Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...
Köppen climate classification
The Köppen climate classification is one of the most widely used climate classification systems. It was first published by German-Russian climatologist Wladimir Köppen (1846–1940) in 1884, with several later modifications by Köppen, notabl ...
, it belongs to the category of
Tropical monsoon climate
An area of tropical monsoon climate (occasionally known as a sub-equatorial, tropical wet climate or a tropical monsoon and trade-wind littoral climate) is a tropical climate sub-type that corresponds to the Köppen climate classification category ...
Meanwhile, its extreme eastern fringes experience a drier tropical wet and dry climate. Kerala receives an average annual rainfall of 3107 mm – some 7,030 crore m3 of water. This compares to the all-India average is 1,197 mm. Parts of Kerala's lowlands may average only 1250 mm annually while the cool mountainous eastern highlands of Idukki district – comprising Kerala's wettest region – receive in excess of 5,000 mm of
orographic precipitation
Orography is the study of the topographic relief of mountains, and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as ''oreography'', ''orology'' or ''oreology'') falls within the broader discip ...
(4,200 crore of which are available for human use) annually. Kerala's rains are mostly the result of seasonal monsoons. As a result, Kerala averages some 120–140 rainy days per year. In summer, most of Kerala is prone to
gale
A gale is a strong wind; the word is typically used as a descriptor in nautical contexts. The U.S. National Weather Service defines a gale as sustained surface winds moving at a speed of between 34 and 47 knots (, or ).storm surges, and torrential downpours accompanying dangerous cyclones coming in off the Indian Ocean. Kerala's average maximum daily temperature is around 37 °C; the minimum is 19.8 °C.
The moisture-laden winds of the Southwest
Monsoon
A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal osci ...
, on reaching the southernmost point of the
Indian Peninsula
The Indian subcontinent is a physiographical region in Southern Asia. It is situated on the Indian Plate, projecting southwards into the Indian Ocean from the Himalayas. Geopolitically, it includes the countries of Bangladesh, Bhutan, India ...
, because of its topography, divides into two branches; the "Arabian Sea Branch" and the "Bay of Bengal Branch". The "Arabian Sea Branch" of the Southwest monsoon first hits the Western Ghats, making Kerala the first state in India to receive rain from the Southwest monsoon.
Geography
A substantial portion of Malabar Coast including the western coastal lowlands and the plains of the midland may have been under the sea in ancient times. Marine fossils have been found in an area near Changanassery, thus supporting the hypothesis. Pre-historical archaeological findings include dolmens of the
Neolithic
The Neolithic period, or New Stone Age, is an Old World archaeological period and the final division of the Stone Age. It saw the Neolithic Revolution, a wide-ranging set of developments that appear to have arisen independently in several p ...
era in the
Marayur
Marayur or Marayoor is a town in Devikulam taluk of Idukki district in Kerala, India. It is located 42 kilometers north of Munnar on SH 17 connecting Munnar with Udumalpet, Tamil Nadu. Marayur is situated at around 1,600 metres (5,200 ft) abo ...
Wayanad
Wayanad () is a district in the north-east of Indian state Kerala with administrative headquarters at the municipality of Kalpetta. It is the only plateau in Kerala. The Wayanad Plateau forms a continuation of the Mysore Plateau, the southern ...
, date back to the Neolithic era around 6000 BCE.
Eastern Kerala consists of land encroached upon by the Western Ghats; the region thus includes high mountains, gorges, and deep-cut valleys. The wildest lands are covered with dense forests, while other regions lie under tea and coffee plantations (established mainly in the 19th and 20th centuries) or other forms of cultivation. Forty-one of Kerala's forty-four rivers originate in this region, and the Cauvery River descends from there and drains eastwards into neighboring states. Here, the Western Ghats form a wall of mountains penetrated near Palakkad; here, a natural mountain pass known as the
Palakkad Gap
Palakkad Gap or Palghat Gap is a low mountain pass in the Western Ghats between Coimbatore in Tamil Nadu and Palakkad in Kerala. It has an average elevation of with a width of . The pass is located between the Nilgiri Hills to the north and ...
breaks through to access inner India. The Western Ghats rises on average to 1500 m elevation above sea level. Certain peaks may reach to 2500 m. Just west of the mountains lie the midland plains, comprising a swathe of land running along central Kerala. Here, rolling hills and shallow valleys fill a gentler landscape than the highlands. In the lowest lands, the midlands region hosts paddy fields; meanwhile, elevated lands slopes play host to groves of rubber and fruit trees in addition to other crops such as
black pepper
Black pepper (''Piper nigrum'') is a flowering vine in the family Piperaceae, cultivated for its fruit, known as a peppercorn, which is usually dried and used as a spice and seasoning. The fruit is a drupe (stonefruit) which is about in dia ...
,
tapioca
Tapioca (; ) is a starch extracted from the storage roots of the cassava plant (''Manihot esculenta,'' also known as manioc), a species native to the North and Northeast regions of Brazil, but whose use is now spread throughout South America ...
, and others.
Wayanad
Wayanad () is a district in the north-east of Indian state Kerala with administrative headquarters at the municipality of Kalpetta. It is the only plateau in Kerala. The Wayanad Plateau forms a continuation of the Mysore Plateau, the southern ...
is the sole
Plateau
In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ...
in Kerala. The eastern regions in the districts of
Wayanad
Wayanad () is a district in the north-east of Indian state Kerala with administrative headquarters at the municipality of Kalpetta. It is the only plateau in Kerala. The Wayanad Plateau forms a continuation of the Mysore Plateau, the southern ...
,
Malappuram
Malappuram (also Malapuram) () is a city in the Indian state of Kerala, spread over an area of including the surrounding suburban areas. The first municipality in the district formed in 1970, Malappuram serves as the administrative headquarter ...
(
Chaliyar
Chaliyar River is the fourth longest river in Kerala at 169 km in length. The Chaliyar is also known as Chulika River, Nilambur River or Beypore River as it nears the sea. Pothukal, Chungathara, Nilambur, Mampad, Edavanna, Kavanoor, Pera ...
valley at
Nilambur
Nilambur is a major town, a municipality and a Taluk in the Malappuram district of the Indian state of Kerala. It is located close to the Nilgiris range of the Western Ghats on the banks of the Chaliyar River. This place is also known as 'Teak ...
), and
Palakkad
Palakkad (), formerly known as Palghat, historically known as Palakkattussery is a city and municipality in the Indian state of Kerala. It is the administrative headquarters of the Palakkad District. Palakkad is most densely populated municipal ...
(
Attappadi
Attappady (HQ:Agali) is a tribal taluk in Kerala state covering an area of . It is carved out from Mannarkkad taluk in Palakkad district on February 2021. Attappady Reserve Forest is a protected area comprising 249 km2 of land area in ...
Valley), which together form parts of the
Nilgiri Biosphere Reserve
The Nilgiri Biosphere Reserve is a biosphere reserve in the Nilgiri mountains of the Western Ghats in South India. It is the largest protected forest area in India, spreading across Tamil Nadu, Karnataka and Kerala. It includes the protected ar ...
and a continuation of the Mysore Plateau, are known for natural
Gold
Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...
fields, along with the adjoining districts of
Karnataka
Karnataka (; ISO: , , also known as Karunāḍu) is a state in the southwestern region of India. It was formed on 1 November 1956, with the passage of the States Reorganisation Act. Originally known as Mysore State , it was renamed ''Karnat ...
.
Finally, Kerala's coastal belt is relatively flat, teeming with paddy fields, groves of
coconut trees
The coconut tree (''Cocos nucifera'') is a member of the palm tree family ( Arecaceae) and the only living species of the genus ''Cocos''. The term "coconut" (or the archaic "cocoanut") can refer to the whole coconut palm, the seed, or the ...
, and heavily crisscrossed by a network of interconnected canals and rivers. The comparative water-richness of the coastal belt can be partly gauged by the fact that
Kuttanad
Kuttanad ( ml, കുട്ടനാട്) is a region covering the Alappuzha, Kottayam and Pathanamthitta Districts, in the state of Kerala, India, well known for its vast paddy fields and geographical peculiarities. The region has the lo ...
, with its backwaters canals and rivers, itself comprises more than 20% of India's waterways by length.
Kuttanad
Kuttanad ( ml, കുട്ടനാട്) is a region covering the Alappuzha, Kottayam and Pathanamthitta Districts, in the state of Kerala, India, well known for its vast paddy fields and geographical peculiarities. The region has the lo ...
, also known as ''The Rice Bowl of Kerala'', has the lowest altitude in India, and is also one of the few places in world where cultivation takes place below sea level. Minerals including
Ilmenite
Ilmenite is a titanium-iron oxide mineral with the idealized formula . It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing ...
,
Monazite
Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the cerium- ...
,
Thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high me ...
, and
Titanium
Titanium is a chemical element with the symbol Ti and atomic number 22. Found in nature only as an oxide, it can be reduced to produce a lustrous transition metal with a silver color, low density, and high strength, resistant to corrosion in ...
, are found in the coastal belt of Kerala. Kerala's coastal belt of
Karunagappally
Karunagappally is a municipality in the Kollam district of Kerala, India. It is 24 km north of Kollam and south of Alappuzha. Karunagappally taluk consists of Alappad, Ochira, Adinad, Karunagappally, Thazhava, Pavumba, Thodiyoor, Kallalibh ...
is known for high background radiation from
thorium
Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately soft and malleable and has a high me ...
-containing
monazite
Monazite is a primarily reddish-brown phosphate mineral that contains rare-earth elements. Due to variability in composition, monazite is considered a group of minerals. The most common species of the group is monazite-(Ce), that is, the cerium- ...
sand. In some coastal panchayats, median outdoor radiation levels are more than 4 mGy/yr and, in certain locations on the coast, it is as high as 70 mGy/yr. The most important of Kerala's forty-four rivers include the
Periyar
Erode Venkatappa Ramasamy (17 September 1879 – 24 December 1973), revered as Periyar or Thanthai Periyar, was an Indian social activist and politician who started the Self-Respect Movement and Dravidar Kazhagam. He is known as the 'F ...
(244 km in length), the
Bharathapuzha
Bharathappuzha ("River of Bhārata"), also known as the Nila or Ponnani River, is a river in India in the state of Kerala. With a length of 209 km, it is the second longest river that flows through Kerala after the Periyar. It flows throu ...
(209 km), the
Pamba River
The Pamba River (also called Pampa River) is the longest river in the Indian state of Kerala after Periyar and Bharathappuzha, and the longest river in the erstwhile former princely state of Travancore. Sabarimala temple dedicated to Lord Ayyapp ...
(176 km),the
Chaliyar
Chaliyar River is the fourth longest river in Kerala at 169 km in length. The Chaliyar is also known as Chulika River, Nilambur River or Beypore River as it nears the sea. Pothukal, Chungathara, Nilambur, Mampad, Edavanna, Kavanoor, Pera ...
river(169) the Chalakudy Puzha(144 km), the Kadalundipuzha (130 km), and the Achancoil (128 km). Most of the remainder are small and entirely fed by the
Monsoon
A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal osci ...
s.
There are 44 rivers in Kerala, all but three originating in the Western Ghats. 41 of them flow westward and 3 eastward. The rivers of Kerala are small, in terms of length, breadth and water discharge. The rivers flow faster, owing to the hilly terrain and as the short distance between the Western Ghats and the sea. All the rivers are entirely monsoon-fed and many of them shrink into rivulets or dry up completely during summer.
The
Kerala Backwaters
The Kerala backwaters are a network of brackish lagoons and canals lying parallel to the Arabian Sea of the Malabar coast of Kerala state in south-western India. It also includes interconnected lakes, rivers, and inlets, a labyrinthine system ...
region is a particularly well-recognized feature of Kerala; it is an interconnected system of
brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuari ...
water lakes and river
estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...
that lies inland from the coast and runs virtually the length of the state. These facilitate inland travel throughout a region roughly bounded by Thiruvananthapuram in the south and
Vatakara
Vatakara, also spelled Vadakara (formerly Badagara), , french: Bargaret, is a Municipality in the state of Kerala, India. Vatakara is located between Kannur and Kozhikode. The municipality of Vatakara covers an area of and is bordered by Ma ...
(which lies some 450 km to the north). There are 34 backwaters in Kerala Lake Vembanad—India's largest body of water —dominates the backwaters; it lies between Alappuzha and Kochi and is over 200 km2 in area. Major lakes of Kerala include:
Mountains
The Western Ghats is a continuous mountain range of 450 km along the eastern side of Kerala. It forms almost an unbroken wall guarding the eastern frontier and helps the people of Kerala to lead a sheltered life of their own through the centuries. The Western Ghats is also responsible for the high and steady rainfall in Kerala. It converts 50% of Kerala into highlands and is studded with more than 50 peaks above 5000 feet above
Mean Sea Level
There are several kinds of mean in mathematics
Mathematics is an area of knowledge that includes the topics of numbers, formulas and related structures, shapes and the spaces in which they are contained, and quantities and their changes. ...
. With a height of 8841 feet (2,695 metres),
Anamudi
Anamudi is a mountain located in Ernakulam district and Idukki district of the Indian state of Kerala. It is the highest peak in the Western Ghats and in South India, at an elevation of and a topographic prominence of . The name Anamudi lite ...
is the highest peak in India outside
Himalayas
The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...
. Anamudi is located in Idukki district in Kerala. The
Athirappilly Falls
Athirappilly Falls, is situated in Athirappilly Panchayat in Chalakudy Taluk of Thrissur District in Kerala, India on the Chalakudy River, which originates from the upper reaches of the Western Ghats at the entrance to the Sholayar ranges. ...
, which is situated on the background of Western Ghat mountain ranges, is also known as ''The
Niagara
Niagara may refer to:
Geography Niagara Falls and nearby places In both the United States and Canada
*Niagara Falls, the famous waterfalls in the Niagara River
*Niagara River, part of the U.S.–Canada border
*Niagara Escarpment, the cliff ov ...
of India''. It originates from the peak of
Anamudi
Anamudi is a mountain located in Ernakulam district and Idukki district of the Indian state of Kerala. It is the highest peak in the Western Ghats and in South India, at an elevation of and a topographic prominence of . The name Anamudi lite ...
and is also the largest waterfall in the state.
Natural Hazards in Kerala
Kerala is prone to several natural hazards, the most common of them being
landslides
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, ...
,
flooding
A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrolog ...
,
lightning
Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ...
,
drought
A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...
,
coastal erosion
Coastal erosion is the loss or displacement of land, or the long-term removal of sediment and rocks along the coastline due to the action of waves, currents, tides, wind-driven water, waterborne ice, or other impacts of storms. The landward ...
, earthquakes,
Tsunami
A tsunami ( ; from ja, 津波, lit=harbour wave, ) is a series of waves in a water body caused by the displacement of a large volume of water, generally in an ocean or a large lake. Earthquakes, volcanic eruptions and other underwater explo ...
, wind fall and epidemics.Yesodharan EP, Kokkal K & Harinarayanan P (eds), 2007, State of Environment Report of Kerala 2007 – Volume II: Natural Hazards, Kerala State Council for Science, Technology and Environment, Government of Kerala, Thiruvananthapuram, India , Retrieved on 1 July 2008.
Landslides
The highlands of Kerala experience several types of landslides, of which
debris flow
Debris flows are geological phenomena in which water-laden masses of soil and fragmented rock rush down mountainsides, funnel into stream channels, entrain objects in their paths, and form thick, muddy deposits on valley floors. They generally ...
s are the most common. They are called 'Urul Pottal' in the local vernacular. The characteristic pattern of this phenomenon is the swift and sudden downslope movement of highly water saturated overburden containing a varied assemblage of debris material ranging in size from soil particles to boulders, destroying and carrying with it every thing that is lying in its path. The west facing Western Ghats scarps that runs the entire extent of the mountain system is the most prone physiographic unit for landslides. These scarp faces are characterised by thin soil (regolith) cover modified heavily by anthropogenic activity. The highlands of the region experience an annual average rainfall as high as 500 cm from the South-West, North-East and Pre-Monsoon showers. A review of ancient documents, investigation reports and news paper reports indicates a lesser rate of slope instability in the past; 29 major landslide events that occurred in the recent past was identified through the review.Kuriakose SL, Sankar G & Muraleedharan C, 2009a, History of landslide susceptibility and a chorology of landslide prone areas in the Western Ghats of Kerala, India, Environmental Geology, 57(7), 1153–156 Retrieved on 1 July 2008. The processes leading to landslides were accelerated by anthropogenic disturbances such as deforestation since the early 18th century, terracing and obstruction of ephemeral streams and cultivation of crops lacking capability to add root cohesion in steep slopes. The events have become more destructive given the increasing vulnerability of population and property. Majority of mass movements have occurred in hill slopes >20° along the Western Ghats scarps, the only exception being the coastal cliffs. Studies conducted in the state indicates that prolonged and intense rainfall or more particularly a combination of the two and the resultant persistence and variations of pore pressure are the most important trigger of landslides.Kuriakose SL, Jetten VG, van Westen CJ, Sankar G & van Beek LPH, 2008, Pore Water Pressure as a Trigger of Shallow Landslides in the Western Ghats of Kerala, India: Some Preliminary Observations from an Experimental Catchment, Physical Geography 29(4) 374–386 , Retrieved on 12 January 2009. The initiation of most of the landslides were in typical hollows generally having degraded natural vegetation. All except 1 of the 14 districts in the state are prone to landslides. Wayanad and Kozhikode districts are prone to deep-seated landslides while Idukki and Kottayam are prone to shallow landslides. A very recent study indicates that the additional cohesion provided by vegetation roots in soil is an important contributor to slope stability in the scarp faces of the Western Ghats of Kerala.Kuriakose SL, van Beek LPH & van Westen CJ, 2009b, Parameterizing a physically based shallow landslide model in a data poor region, ''
Earth Surface Processes and Landforms
''Earth Surface Processes and Landforms'' is a peer-reviewed scientific journal published by John Wiley & Sons on behalf of the British Society for Geomorphology. It covers geomorphology and more in general all aspects of Earth sciences dealing wi ...
'' 34(6), 867–88 Retrieved on 5 April 2009.
Flooding
Although the Kerala state does not experience floods as severe as in the
Indo-Gangetic plain
The Indo-Gangetic Plain, also known as the North Indian River Plain, is a fertile plain encompassing northern regions of the Indian subcontinent, including most of northern and eastern India, around half of Pakistan, virtually all of Bangla ...
s, incidence of floods in the State is becoming more frequent and severe. The latest among them was the
2020 Kerala floods
During the heavy rainfall over the monsoon period from 1 June to 18 August 2020, all 14 districts in Kerala were affected with 104 dead and 40 injured. Five districts in Kerala were flooded on 7 August 2020 (Idukki, Wayanad, Malappuram, T ...
. The continuous occurrence of high intensity rainfall for a few days is the primary factor contributing to the extreme floods in the State. Other factors include wrong land use practices and mismanagement of the
water resources
Water resources are natural resources of water that are potentially useful for humans, for example as a source of drinking water supply or irrigation water. 97% of the water on the Earth is salt water and only three percent is fresh water; slight ...
and forests. The human interventions contributing to flood problems are predominantly in the form of reclamation of wetlands and water bodies, change in land use pattern, construction of dense networks of roads, establishment of more and more settlements, deforestation in the upper catchments etc. Increasing floodplain occupancy results in increasing flood damages. A number of extreme flood events occurred during the last century causing considerable damage to life and property highlight the necessity for proper flood management measures in the State. The flood problems are likely to worsen with the continued floodplain occupancy and reclamation of water bodies and wetlands. It is estimated that about 26% of the total geographical area accommodating about 18% of the total population of the State is prone to floods.
Lightning
Kerala is a place of high lightning incidence compared to most of the other parts in India because of its weather patterns and the location of the Western Ghats. Higher population density and vegetation density result in more casualties. Lack of awareness also aggravates the situation. Accidents caused by ground conduction from trees, which is a special feature of Kerala, add to the casualties and loss of property. The records show that the months April, May, October and November have the highest lightning rates. The most active time of the day is from 15:00 to 19:00. Of the fourteen districts, five have much higher rates than others. The severe impact of the hazard on the state and its people is seen from the very high average casualty rates of 71 deaths, 112 injuries and 188 accidents per annum. Losses to telephone communications, networked systems and
electrical equipment
Electric(al) devices are devices that functionally rely on electric energy ( AC or DC) to drive their core parts (electric motors, transformers, lighting, rechargeable batteries, control electronics). They can be contrasted with traditional mech ...
are also very high.
Drought
Kerala has been experiencing increasing incidents of drought in the recent past due to the weather anomalies and developmental pressures resulting from the changes in
land use
Land use involves the management and modification of natural environment or wilderness into built environment such as settlements and semi-natural habitats such as arable fields, pastures, and managed woods. Land use by humans has a long h ...
, traditional practices, and life style of the people. The increase in population and subsequent expansion in irrigated agriculture, and industrial growth necessitated the exploitation of more water resources. The changes in the land and
water management
Water resources are natural resources of water that are potentially useful for humans, for example as a source of drinking water supply or irrigation water. 97% of the water on the Earth is salt water and only three percent is fresh water; slightl ...
practices affected the fresh water availability during summer months. Although the deviation in the annual rainfall received in Kerala, in any year from the long term average is very small, there is considerable variation in the rainfall availability during the different seasons. About 95 percent of annual rainfall is confined to a six-month monsoon period between June and November, leaving the remaining six months as practically dry. Soman (1988) reported that over major part of the Kerala State, extreme as well as these where the rainfall is more compared to other areas. The changes in rainfall pattern may have association with the environmental modifications due to human interventions on the natural ecosystems. The State of Kerala experiences seasonal drought conditions every year during the summer months. Even in the years of normal rainfall, summer
water scarcity
Water scarcity (closely related to water stress or water crisis) is the lack of fresh water Water resources, resources to meet the standard water demand. There are two types of water scarcity: physical or economic water scarcity. Physical water ...
problems are severe in the midland and highland regions. Severe drought conditions often result from the anomalies in monsoon rainfall combined with the various anthropogenic pressures. A study on the incidence of droughts based on the aridity index shows that during the period 1871– 2000, the State of Kerala experienced 66 drought years, out of which, twelve each were moderate and severe droughts. The droughts have a large dimension of economic, environmental and social impacts. With the implementation of a number of irrigation projects, the idea of drought in Kerala slowly shifted to unirrigated paddy, and upland crops. The water scarcity in summer is mainly reflected in dry rivers and lowering of
water table
The water table is the upper surface of the zone of saturation. The zone of saturation is where the pores and fractures of the ground are saturated with water. It can also be simply explained as the depth below which the ground is saturated.
T ...
. This adversely affects the rural and urban drinking water supply. As seen in the majority of drought incidents, even a 20% fall in the northeast monsoon, can make the water scarcity situation worse during the summer. Since the State has more of perennial plantation crops compared to other places of India, the effect of a drought year in Kerala continues to be felt for several more years after it has occurred. Thus, for better planning of the drought management measures, the term drought with reference to plantation crops should be redefined based on rainfall received or available
soil moisture
Soil moisture is the water content of the soil. It can be expressed in terms of volume or weight. Soil moisture measurement can be based on ''in situ'' probes (e.g., capacitance probes, neutron probes) or remote sensing methods.
Water that enters ...
during summer months instead of total monsoon rainfall.
Tsunami
The Kerala coast was significantly affected by the
2004 Indian Ocean tsunami
An earthquake and a tsunami, known as the Boxing Day Tsunami and, by the scientific community, the Sumatra–Andaman earthquake, occurred at 07:58:53 local time (UTC+7) on 26 December 2004, with an epicentre off the west coast of northern Suma ...
. The coast located in the shadow zone with respect to the direction of propagation of the tsunami encountered unexpected devastation. Although the tsunami affected parts of Kerala coast, maximum devastation was reported in the low coastal land of Kollam, Alappuzha and Ernakulam districts, particularly a strip of 10 km in Azhikkal,
Kollam district
Kollam district (), (formerly Quilon district) is one of 14 districts of the state of Kerala, India. The district has a cross-section of Kerala's natural attributes; it is endowed with a long coastline, a major Laccadive Sea seaport and an in ...
. This varying effect along the coast could be attributed to local amplification of tsunami waves in certain regions. About 176 people were killed and 1600 injured in the coastal belt. Further, the tsunami pounded 187 villages affecting nearly 250,000 persons in Kerala. As many as 6,280 dwelling units were completely destroyed, 11,175 were damaged and nearly 84,773 persons were evacuated from the coastal areas and accommodated in 142 relief camps after tsunami. As this tsunami is believed to be first of its kind to have significantly affected the Kerala coast, the post-tsunami field investigations and measurements would give valuable information on various changes brought by the tsunami. Immediately after the tsunami, several organizations have carried out field surveys in many affected areas along the coast.
Geography education in Kerala
Undergraduate and Masters level education is offered in the Universities of Kerala. Research in Geography is carried out in a variety of organizations like Department of Geography, University College, National Centre for Earth Sciences Studies, Kannur University etc.
References
*
See also
*
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date L ...