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CLIMATE CHANGE IMPACTS IN KERALA-AN OVERVIEW. Dr.Roy Kunjappy Convenor, FANSA-Kerala Chapter/ Director CCHR Centre for Community Health Research (CCHR), Sadanathil bungalow, Vettikavala, Kottarakara ,
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CLIMATE CHANGE IMPACTS IN KERALA-AN OVERVIEW Dr.Roy KunjappyConvenor, FANSA-Kerala Chapter/ Director CCHR Centre for Community Health Research (CCHR), Sadanathil bungalow, Vettikavala, Kottarakara , Kollam ,Kerala; India. Tel: 91 474 2403358; Mob: 09847282833; E-mail:roycchr@sify.com ; http://www.cchrindia.org
Kerala Geography • Location: Kerala is a small strip of land lying at the south-west corner of India. It lies to the north of the equator between 8° 18' and 12° 48' north latitude and 74° 52' and 77° 24' east longitude. • Extend: Kerala extends over an area of 38,863 sq.km which is only 1.03 percent of the total area of India. It has a total coastline of 580 km. Its width varies greatly from west to east. It is about 120 kilometres at its maximum and just 30 kilometres at its minimum.
Physiography • Kerala is divided into three geographical regions- • Highlands • Midlands • Lowlands
Highlands • The Highlands slope down from the Western Ghats (also known as the Sahyadri) which rise to an average height of 900m, with a number of peaks well over 1800 m in height. It is 18650 sq.km in area and accounts for 48 percent of the total land area of Kerala. • This is the area of major plantations like tea, coffee, rubber and various spices. This area is often known as the Cardamom Hills. This region is one of the largest producers of many spices especially cardamom from which it earns its name • Most of the rivers of Kerala originate from the Western Ghats.
Midlands • The Midlands, lying between the mountains and the lowlands, is made up of undulating hills and valleys. It is 16200 sq.km in area ie, about 40 percent of the total land area. • This is an area of intensive cultivation. Cashew, coconut, arecanut, tapioca, banana and vegetables of different varieties are grown in this area.
Lowlands • Lowlands are also known as the Coastal Area. It covers an area of almost 4000 sq.km. It is made up of numerous shallow lagoons known locally as kayels, river deltas, backwaters and shores of the Arabian sea and is essentially a land of coconuts and rice. • This area is very fertile and most of the paddy cultivation is along this area. Kuttanad region of Kerala is one of the very few places in India where cultivation is done below sea level.
Climate • Although Kerala lies close to the equator, its proximity with the sea and the presence of the fort like Western Ghats, provides it with an equable climate which varies little from season to season. • The temperature varies from 28° to 32° C.Southwest Monsoon and Retreating Monsoon ( Northeast Monsoon ) are the main rainy seasons.
Climatic seasons • The temperature in Kerala normally ranges from 28° to 32° C (82° to 90° F) on the plains but drops to about 20° C (68° F) in the highlands. • Owing to its diversity in geographical features, the climatic condition in Kerala is diverse. It can be divided into 4 seasons - Winter, Summer, South-West Monsoon and North-East Monsoon.
Climate in Kerala • Kerala receives an average rainfall of 118 inches (3,000 millimeters) annually. • The rainfall amount in the State decreases towards the south with decrease of height of Western Ghats. The southern most district of Thiruvananthapuram where Western Ghats are nearest to the sea coast and its average height is also least in the State receives minimum amount of rainfall. • Kerala would have been a dry land because of the dry winds blowing from the north, but for the Western Ghats which prevent this wind from entering the land.
Temperature rise • Temperature data for seven IMD stations of kerala were collected from National Data Centre of IMD, Pune from 1956 to 2004.(49years) • There was an increase in maximum temperature over Kerala by 0.64° C during the period of 49 years, • Increase in minimum temperature was 0.23° C. • Overall increase in annual average temperature was 0.44° C. • It indicated a clear upward trend in surface air temperature of Kerala
Temperature rise • Between 1961 and 2003 ( India Meteorological Department ) the mean annual maximum temperature over Kerala has risen by 0.8 degree centigrade, • The mean annual minimum temperature has risen by 0.2 degree Celsius and • The average increase by 0.5 degree centigrade
Temperature rise:Indian Institute of Tropical Meteorology,Pune) • Place of study :Kozhikode (North Kerala)&Trivandrum(South Kerala) • Period of study: 1901—2007 • Annual max. temp. of North kerala increased by 1.2.degree celsius per 100 years • Annual max.temp. of South kerala increased by 1.0.degree celsius per 100 years • The increase in temp. was 0.4 degree celsius per decadeduring the past three and half decades
INCCAReport 2010 • Indian Network of Climate Change Assessment Report-November 2010 • Climate Change and India: A 4X4 Assessment -A sectoral and regional analysis for 2030s”
Temperature-(IMD)Indian Meteorological Department,Pune All-India annual mean, maximum and minimum temperature variations during 1901-2007
Increase in temperature projected • Projections for the 2030s indicate an all-round warming over the Indian subcontinent associated with increasing GHG concentrations. • The annual mean surface air temperature is projected to rise by 1.7°C and 2.0°C in 2030s
Western coastal region • In the western coastal region, mean annual temperatures are likely to increase from a minimum of 26.8±0.4oC to 27.5±0.4oC in the 2030s. • The rise in temperature with respect to the 1970s will be between 1.7oC and 1.8oC
Precipitation • Kerala showed decreasing trend inmonsoon rainfall for the period 1901-2007 • After 1999,rainfall was below long term average rainfall (except in 2006) • Another study showed that Kerala experienced decline in annual monsoon rainfall during the recent past decades(1961 and 2003 )
Projected increase in precipitation (INCCA Report,2010) • All the regions namely the Himalayan region, the Western Ghats, the Coastal Area and the North-East Region in India show a small increase in annual precipitation in the 2030s with respect to the baseline, that is 1970s.
Coastal region • Projections for the western coast indicate a variation in rainfall from 935±185.33mm to 1794±247mm, which is an increase of 6%–8% with respect to the1970s an increase that is ranging from 69 to 109 mm. • Though June, July and August (monsoon)show an average increase of 8mm rainfall in 2030’s with respect to 1970’s, • The winter rainfall is projected to decrease on an average by 19 mm during the period January and February in 2030’s with reference to 1970’s. • The period March, April and May also show a decrease in rainfall with respect to1970s
Shift in rainfall pattern • Rainfall data for the IMD stations of the State of Kerala for the period from 1871 to 2008(140 years) revealed a declining trend in annual and southwest monsoon rainfall during the past 60 years • and an increasing trend in post monsoon rainfall, indicating likely shifts in rainfall patterns.
Trends in seasonal precipitation extremes-an indicator of CC • A study on seasonal precipitation pattern in Kerala during five decades(1954-2003) showed that the seasonal extremes in rainfall cause floods and water scarcity which are indicators of climate change (Indrani Pal and Abir Al Tabbaa,2008)
Kerala state faces problems • Kerala state was facing serious crisis in major areas of food security, agriculture, health and marine resources due to climate change. • The agriculture sector in Kerala was badly affected due to continuous rain. • Similarly continuous rain has affected maintenance and construction of roads (Achuthanandan,2010)
Crop Damage Due to Untimely Rain in Kerala • The untimely rain in Kerala, which hit the entire region since March 14, 2008 has caused crop damage and flooding. • It is estimated that farmers could not harvest paddy worth about Rs. 128 crores (1280 million rupees) due to unexpected flooding in the Kuttanad fields.extending to 2000 hectares which is quite unusual with the normal summer rain. • Experts suggest that this untimely rain • is a clear evidence of climate change.
Thermo-sensitive crops • The thermo-sensitive crops like black pepper, cardamom, tea, coffee and cocoa will be badly affected as temperature range (the difference between maximum and minimum temperatures) is likely to increase and rainfall is likely to decline
Pepper output likely to fall in 2009 • Heavy pre-monsoon showers (and a lethal attack by wasps) may hit pepper production in Kerala, the main producer of the commodity in India. • The industry estimates that production in fiscal 2009 would be 40,000-45,000 tonnes compared with the 50,000 tonnes produced last year(2008).
Production declines Increase in maximum temperature of 1-3° C during summer 2004 adversely affected thermo-sensitive crops like black pepper and cocoa in Kerala (Rao et al.,2008).
Crops affected • The prolonged wet spell in kharif 2007(summer crop) and unusual rains in 2008 devastated the paddy production to a large extent in kerala. • Records show that almost all the plantation crops suffered to a great extent in 1983 and 2004 due to disastrous summer droughts
Shift from foodgrain crops • A clear shift was noticed from foodgrain crops (Paddy) to non-foodgrain crops in Kerala over a period of time(1952-2008). • Increase in area under coconut, arecanut, banana, black pepper and rubber was noticed at the cost of phenomenal decline in rice area. • One major reason was frequent floods in monsoon season and droughts during • summer season, apart from various other reasons
Cashew production declines • Though Kerala stood first in cashew production a decade ago, at present it occupies only fourth position and likely to go down further. • It was due to steady decline in cashew area and also occurrence of weather aberrations during the reproductive phase of cashew (Rao et al.,2008).
Climate change hits mango production • Nearly 2,500 farmers in Muthalamada grama panchayat in Palakkad district are engaged in mango farming on an acreage of 4,000 hectares. The annual production is 35,000 tonnes of high quality mangoes such as Alphonso, Malgova, Sindhooram, Kalapadi, Banganapilly, etc.
MANGO • Climate change and unseasonal rain in November and January • over the last two years(2009 and 2010) have dampened the • prospects of mango farmers in Muthalamada, known for its • early mango harvest and large-scale export of the fruit. • Late flowering of the fruit and the resultant delay in harvest • has hit the annual export market. • Muthalamada mangoes fetch a high price in the international • fruit market mainly on account of early availability,from January.
Climate change is affecting the growth of fruits in Kerala. • Kanthalloor in Idukky district, the only winter fruit-growing centre of Kerala, bordering Tamil Nadu, is experiencing unprecedented weather changes. • Apple, strawberry, orange, cherimoya, plum, guava, gooseberry, peach and passion fruit… The fruit bowl of the hill station is rich and diverse. • The variations in weather-the rain patterns have changed and there is unprecedented heat( temperature rise) • The flowering season of apple and many other fruit trees has changed. Apple trees used to bloom in February, indicating the beginning of spring. Now it is advanced. • All have badly impacted on the quantity of fruit production.
Coastal:Coconut • As per INCCA report(2010), yields of coconut are projected to increase in the west coast of India (includes kerala) by up to 30% due to temperature increase. • Increase in coconut yield IN THE WEST COAST may be mainly attributed to projected increase in rainfall (~10%) and relatively less increase in temperatures, apart from CO2 fertilization benefits
Effect on small pelagic fishes • The oil sardine Sardinella longiceps and the Indian mackerel Rastrelliger kanagurta are tropical coastal and small pelagic fish, forming massive fisheries (21% of marine fish catch of India).
Distribution in Malabar coast • The oil sardines, were known for their restricted distribution in Malabar coast (kerala)14degreeN along the southwest coast of India where the annual average sea surface temperature ranges from 27 to 29oC.
Distribution to North Until 1985, almost the entire catch of oil sardine was from the Malabar coast. In the last two decades, however, the catches from north beyond kerala are consistently increasing, contributing about 15% to the all-India oil sardine catch in the year 2006 (Vivekanandan et al., 2009). The surface waters of the Indian seas are warming by 0.04oC per decade, and the warmer waters (27-28.5oC) is expanding to latitudes north of 14oN, enabling the oil sardine to extend their distributional range to northern latitudes (Maharashtra and Gujarat)
Distribution to southeast • Another notable feature is the extension of oil sardine distribution to the east coast of India as well. • Until the mid-1980s, the oil sardine did not form fisheries along the southeast coast. In the 1990s, oil sardine emerged as a major fishery along the southeast coast
Warming is beneficial • It is also found that the catches from the Malabar upwelling zone have not decreased, indicating distributional extension and not a distributional shift. • These observations indicate that the abundance of oil sardine has increased over the decades, ie. the current warming is beneficial to herbivorous small pelagics
Indian mackerel • Compared to the oil sardine, the Indian mackerel Rastrelliger kanagurta had wider distribution along the Indian coast, but the catches and abundance were predominantly along the southwest coast. • Statistics showed that the mackerel catch in the south east coast increased from10.6% of all India mackerel catch(1961-76) to 23.2%(1997-06) • It is indicative of extension of mackerel to northern boundaries
Mackerels opt north and vertical extension • Fish catch statistics show that the Indian mackerel, in addition to extension of northern boundaries, are found to descend to deeper waters in the last two decades • The mackerels are expanding the boundary of distribution to depths as they are able to advantageously make use of increasing temperature in the sub-surface waters. It is a vertical extension of distribution, and not a distributional shift.
Global sea level rise • Globally, sea level is expected to continue to rise over the next several decades. During 2000 to 2020 the rate of thermal expansion is projected to be 1.3 ± 0.7mm/year • In the absence of the availability of regional projections, for the 2030s, global projections can be used as a first approximation of sea-level rise along the Indian coasts in the next few decades.
Sea-level rise • Global sea-level change results mainly from two processes, mostly related to recent climate change, that alter the volume of water in the global ocean through • a) thermal expansion and • b) the exchange of water between oceans and other reservoirs (glaciers and ice caps, ice sheets, other land water reservoirs, including through anthropogenic change in land hydrology and the atmosphere).
Sea level rise by 1.3 mm\year • Observations based on tide gauge measurements along the Indian coast, for a period of 20 years and more for which significantly consistent data is available indicate that • the sea level along the Indian coast has been rising at the rate of about1.3mm/year on an average.
Sea level rise in Kochi (Kerala) • The mean sea level rise trends in Kochi (kerala), based on 54 years of available data, is 1.75mm per year
Inundation of coastal areas • Estimation of inundation of coastal areas due to sea level rise was made for one location (Kochi) along the west coast of India. • The estimate shows that the inundation area will be about 169 km2 of the coastal region surrounding Kochi for a 1.0 m rise in sea level • .Since Kochi region covers the backwaters, a lot of inland areas far from the coast, but adjacent to the tidal creeks, backwaters and lakes will be inundated. This causes considerable increase in the total area of inundation
Projected coastal inundationdue to sea- level rise Coastal inundation (red in colour) map of Kochi region for a 1.0 m sea-level rise
Salinity intrusion • The potential impacts of global climate change in coastal Kerala are salinity intrusion into aquifers and rise in salinity of wetlands (Thrivikramaji,2008) • Studies indicate that fall in rainfall and sea level rise, along with other factors have resulted in salinity intrusion affecting ground water resources in the coastal districts of the state.
Salinity in coastal aquifers • It has also been observed that over exploitation of ground water in certain stretches of kerala coast has contributed to the entry of salinity into the coastal aquifers from the sea. • Though this tendency is mainly observed during the summer months, when recharge is partially zero, there is a possibility for aggravation of the problem due to increase in withdrawal rate to cater to the requirements of dense coastal population. • Further aggravation is possible due to low rainfall, sea level rise and other climate change impacts
Sunstroke\Heat stroke (?)Reported • Sunstroke\Heat stroke has been reported from places like Palakkad in kerala in March2010 and during previous years: • In the first week of March2010, temperatures across all districts in Kerala have risen to an unprecedented high. (Palakkad it reached41degree celsius ) • Due to the heat, 10 people from the northern districts of Palakkad, Kannur and Thrissur suffered severe burn injuries and were hospitalised for emergency first aid care.