climatic changes edited&final

8/6/2019 Climatic Changes Edited&Final

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Figure 1: Average ice extent from 1979-2003

Figure 3: Madden-

Julian Oscillation

Figure 2:

Hadley cell

THE CLIMATE CHANGE AND THE TERAI

Neeraj Chatterji1 and Ranajit Gupta2

1Student and Researcher, Interdesign, 220/2 Panditia Road Extn., Kolkata 700 029,India.

2Architect, Engineer and Chief Consultant, Interdesign, 220/2 Panditia Road Extn., Kolkata 700 029,India.

1. INTRODUCTION

Climate change is a recurring phenomenon inthe long evolutionary cycle of planet Earth andours has been fortunately a “benign” periodbetween the “glacials”. The last glaciationsoccurred in the Pleistocene epoch period beganabout 70,000 and ended between 10,000 and15,000 before present and since then, we areheading for an inter-glacial period, now eggedon unfortunately by global warming.

It is however clear, these periods of mild/benign

climate are more of an exception rather than therule. In the coming eons, humans would have toadjust themselves to more rigorous times,recasting, new objectives and framing newpolicies of survival.

2. CLIMATE CHANGE AND GLOBAL WARMING-INTERGLACIAL

The geological interval of warmer global averagetemperature brings about major changes thatalter ecosystems and biospheres and can affect

all human activities very considerably.The changes in this interglacial would mean agreater frequency of extreme events likecyclones etc. with unprecedented precipitationand heat cycle. The unlocking of the ice cover in the poles and in the mountains leads tohigher ocean levels and an obvious invasion of the sea and back waters. Moreover, theimbalance in temperatures affects sea water temperatures and the ‘El Nino’ phenomenon of weak monsoon may become a rule rather than aseven-eight years singular phenomenon. Theterai region of North India has a peculiar

connection to both snow cover and the sea,the monsoon being regulated by the Himalayansnow line and temperatures in the Indian/PacificOcean. Obviously the disturbance in the Hadleycell – a key parameter in the monsoon’sregularity would mean unpredictable weather patterns and unreliable rainfall.

To make the situation worse, the Madden –Julian oscillation (MJO) is proving to beanother spoiler, extracting moisture of themonsoon in its dry anticyclone phase andcontributing to torrential rains in its wet cyclonic

phase. Unfortunately it does not obey theregulations of the advancing and retreatingmonsoonal system. Here again the problem is



Figure 6: Inter-

relationship chart

Figure 4: El Nino

Figure 5: The climatic

system

not of the quantity of the rainfall but itsunregulated pattern.

The monsoon is the one source of reliable water supply in the region and its vagaries would pushthe terai and the sub continent into dire straits.

The South-West monsoon will be uncertainand a need for harnessing the maximumpossible benefits during adversity would becomeour prime concern.

3. THE TERAI REGION AND CLIMATE CHANGE

The Terai region of South Asia has a closesymbiotic relation with the S-W monsoon systemand, vagaries in the precipitation would mean asubstantial change in ecosystems andbiospheres. The receding Himalayan snow linewould push the coniferous forests upwards andstrain the survival of the deciduous forestsbelow. A shift of biosphere upwards (altitude)can therefore be expected along with large scaleerosion and loss of forest cover.

The Himalayan foothills are a microcosm of thesub-continents problem, in tune with the risingpopulation, critical climate changes and issuesin food production.

The monsoon clouds that hit this region are

seeded historically by the riverine forests.(Mangrove of the Sunderban regions and nowthe defunct middle Indian forests along with thedeciduous and coniferous jungles of the terai)The human settlements and agriculturalinvasion has taken a heavy toll on theseseeding forests, thus also the capability of thewater retention during monsoonal rains. Theweakened monsoon is now expected to becomeeven weaker.

The snow fed North Indian Rivers like Ganges,Bramhaputra, that are the life line of the

subcontinent are perennial but they might soonbecome a seasonal phenomenon like the Taptior the Godavari. This would be the death knellfor agricultural enterprise in the Indo-Gangeticfood basket. We are now faced with a situationwhere the change of climate would affect rainfallquantum, intensity and cycle, while themitigating aspects of the forest - terrain, albedo,and erosion are simply not working for us.

The loss of coastal land is a kind of retreat of human settlements inland, and resource



Figure 7 and 8: The riverine system

• Uncertain rainfall

• Increase in the extreme events

• Absence of mitigating factors

• Shift of biosphere

• Loss of land – gains of sea

• Increase in disasters/landslides

• Measures of land and resources

pressure in the Terai region will soon be felt.The declining natural resources would mean achange in agro economic practices as also a re-thinking of urban sprawl and settlement density

The retreat of the Himalayan snowline would

uncover vulnerable slopes, and unless quickremedies are taken large scale land slides,erosion and silt deposition might disrupt theentire mountain draining/riverine system.

The invasion of the sea and the lack of steadyperiodic rainfall affect freshwater supplies andthis looming water management problemwould have a direct bearing on agriculture andhuman settlements.

4. THE TERAI REGION: GEOLOGY AND WATER CYCLE

The Himalayan system is mostly late tertiary andthe Terai region consists of foothills withvulnerable shale formations, still recent and thusopen to erosion and landslides.

Heavy undergrowth and forests do help inholding back these folded mountain systems buteven then they are unstable. The tea gardens of the Terai are happily a source of defenseagainst natural erosion, but there excellentdrainage is not being mobilized for water management.

The riverine system collecting the rainfall andsnow melt are more or less channeled in theupper reaches washing down boulders and silt.The same tributaries join up near the foothills toform the vast alluvial riverine plains thatmeander, floods and change course quiteregularly.

The greatest danger of climate change isfactoring torrential rainfall, long dry spells anddisappearing snow with stream management.Even today, typhoons and low pressure systemsregularly cause landslide and sediment

accumulation, leading to uncertainties in thewater flow. This problem would be crucial both inthe upper reaches as well as the plains.

The Terai although well forested is in dire needof greater foliage cover and upper streammanagement. Only then could the difficulties of sporadic rainfall etc. can be overcome throughwise storage and water release.

The cascading system of drainage/erosioncould completely restructure land use patternsand water management in the Terai. The loss of forest cover and landslides etc. could cause

further dry spells, increasing snow melt –creating more floods, sedimentation



I) Present Climate system heading for a change,similar to the archaic (prehistoric) climatic systems –250,000 to 300,000 years ago.

II) Interglacial causing:

Pressure systems disturbances

Rise in water levels

Change in climate and heat cycles

Reduction in settlement areas

Reduction in agricultural land

Increase in wetlands

downstream, causing more disaster in the plainsand endangering agricultural pursuits.Preservation of the tea garden is a viablealternative and any encroachment of largehuman settlements a danger.

5. MITIGATION FAILURES

The large tracts of forests in Sunderbans, theterai region and middle India which once playeda role in moderating extreme climatic eventshave all but disappeared. This has led to moreunpredictable monsoons and extreme water related problems in these inland regions.

The human land use pattern (both agro and

urban) has significantly changed the feature of the top soil and its Albedo. Low protection levelshave helped in peeling of top soil (erosion) andhastening soil fatigue.

6. ISSUES CONFRONTING THE FUTURE OF THE TERAI

The gradual ingress of the sea will reduce landto sea ratio altering the future land use pattern.The reduction in the arable land will have animpact on the agricultural output but a growingpopulation will demand an increase in theproduction, which becomes impossible under amalignant climate.

An alternative to present agro activities andoutput is the shifting from land to the sea namelyutilizing water based resources: pisciculture,aquaculture.

The issues that plague the region:

1. Major land use problems.

2. Social / political problems leading toconflicts.

3.

Unfulfilled objectives –

• Forests have to be protected.

• Present agricultural practicemay cause long term problems

• Urban and semi-urban sprawl

will have to end



Figure 9: A gradual retreat of coastal and mountain frontier ecosystems

Figure 11: Water management system.

Figure 10: Water collection system through Hydrological cycle.

• Compact land use/newendeavors

• More innovative lifestyles andeconomic activities.

In many cases the settlements whose land useand economic efficiency is low or negative alongwith wasteful practices, need to be banned. Aresettlement plan in the upper reaches woulddemand forest based economics – exploitingorchards, apiaries, herbariums and timber.Economic forestry is not a panacea per se butwith inbuilt safeguards (Bio diversity) canrelease a large, land dominated agriculturalpopulation.

7. WATER MANAGEMENT AND STREAM CONTROL

With the snow line moving up, the forestrysystem in the Terai (deciduous and coniferous)will undergo transformation along with the entireexisting biosphere. The glacier fed rivers willenter dry spells and may run completely dryoccasionally, leading to seasonal nature of theserivers.

Water storage and recharge – not onlyprovides a solution for curtailing soil erosion butalso presents potential water solutions. Therecovery of forestation, wise water managementand adaptive agricultural practices, could give anew lease of life to the region as well as asubstantial part of the subcontinent.

One of the main features of water managementand storage here is the use of ‘mini hydel’power generation. This would provide much

needed energy to the region while encouragingcottage and small industries in the hills. Theexisting Tea industry reeling under power shortage would benefit. A large shift fromagriculture to secondary and tertiary activitiescan be expected and encouraged. In this regard,it is of utmost importance that Tea Gardens shiftto organic mode and its well drained plantationsprovide a source of water storage in theimmediate vicinity. Use of pesticide etc. can onlycontaminate a ready source of water.

Introspection into the problems of the Terai in

face of climatic change reveals a microcosm of alarger global issue of adopting ourselves to



Figure 12: Tonle Sap flood plain.

more difficult environments and times. Theproblems facing the people of Jalpaiguri, Indiaare not very different and a search for solutionshere may revolutionize developments elsewherein the region.

8. THE TONLE SAP ECOSYSTEM - AN EXAMPLE

The Tonle Sap is the largest freshwater lake inSoutheast Asia. A unique hydrologicalphenomenon resulting from the link with theMekong causes seasonal inundation of a vastfloodplain around the lake.

Using natural flooding as a method of rejuvenating the soil by the deposition of silt, itprovides agricultural as well as aquaticproductivity.

Adopting the lessons of overflow water management

• The Tonle Sap is an ecosystemand biosphere created successfully inthe lower Mekong plain.

• The terai system in the foothills

would be a little more complex with itscascading system, optimizing land andwater use across a spectrum of biospheres each interdependent andsymbiotically related.

• Forest Management is acorollary of good hydrology andalthough climate change might jeopardize the coniferous cover in thehigher reaches, it is possible to sustainforest cover and in fact encourageeconomic forestry if proper hydrologicalpractices are to be followed.

• The lower reaches are alwayspressurised to grow more food andwould have to yield greater harvests.Thus any loss of upper hill forests mayunwittingly increase floods, undesiredsiltation along with meager water supply.

• Forestry and hydrology isinvariably linked in the process of land

recovery and adaptive land use.



Figure 13: Map of Tonle Sap

Figure 14 &15: Tiered system and mapping.

Forests – Initial collector zone.

Eco tourism and hydel catchment

More forest

cover

Terracing

Plantation

• The Siem Reap river basinintegrating advanced hydrologicalpractices has created a legendarysystem at Angkor Wat in the 12th

century. The hydrological excellence of the system has rarely been surpassed.

Likewise it may be helpful to orientdevelopment towards a hydrologicalsolution in the Terai with modestresources.

The Jalpaiguri area running up to the foothillshas certain similarities and could absorb thelessons of Tonle Sap.

9. WATER MANAGEMENT AND LAND USE – A TIERED SYSTEM

The introduction of a tiered system for mountains, foothills and flat plains is an attemptat water and land management in NorthernIndia. The Terai at the Himalayan foothills isideally suited for such a systematic analysis.With the advent of GIS (GeographicalInformation Systems) and the variousinterpretive satellite imagery services, it is easier today to generate geomorphic maps thatincludes altitude,slope,soil,climate andvegetation etc.

Our proposal of a Three Tiered system aims at ahierarchic order of intervention, manipulationand land use pattern. The densely populatedTerai region has to reserve some of its areas for natural biospheres or else its survival in thelower plains will be doubtful.

1. The upper tier is an area where somebiosphere change will take place due to thedisappearing snow line. In terms of water management, this is an initial collector zone asalso the first check on erosion. Forestry here isof utmost importance both as a means of

moisture retention as well as erosion control.Moreover, evapo-transpiration will helpprecipitation and the monsoon.

Human intervention and the landusage should be limited in absoluteterms, although some hydel catchmentscan be created. Eco-tourism, trek routeswould be a positive development.

2. The middle tier is the crucial belt wherelarge populations of the plains meet the sparselydwelled upper slopes. The climate change willaffect this area substantially as it is today, the

zone of large deciduous forests, although



Terraced agricultural

zone

Forest cover

Interim storage and

recharge zone

Large lakes and

underground

recharge

• Mountain stream-check dam

• Infiltration /recharge in upper reaches

• Collection in small lakes

• A forestation for seeding monsoons as well aswater retention.

•

Contour settings in foothills.(macro landscapingcontrols)

• Green corridors in lower regions

• Better use of smaller land resources

Figure 16: Three tier system.

Figure 17: The middle tier.

Figure 18: The lower foothills and the plains.

systematically destroyed by human activitiesincluding terraced agriculture.

The seeding of the monsoon clouds willrequire forest cover, but then thepressure of population wouldnecessarily mean economic activity.

This area is most prone to erosion andlandslides and would have to be strictlyprotected against random humansettlements. Agricultural activities wouldhave to be in proper terraced fields witha statutorily controlled forest cover for acres of cultivated land.

The water management here is evenmore important as much as the maininterim storage and recharge zone.Check dams, small lakes along with minihydel projects would be the order of the

day. To enhance economic activity, asubstantial change in the agriculturalactivities is needed. Economic forestryhas to couple itself with large scaleherbariums, orchards, and floralhorticulture. Activities such as bee-keeping, forest product exploitation andbio medical ventures could beencouraged. In short, larger populationdensities are possible provided agro-economic activities are organizedaround a resurgent forestry.

3. The lower foothills and the plains are thestarting point of the meandering alluvial streams.Here, large lakes and underground recharge isessential to provide water downstream. Thepressure on land would raise substantialconflicts of usage. Here again, the age oldagricultural practices and occupations wouldhave to go through metamorphosis. Activitieswould now be water related namely pisciculture,algae harvesting and large scale water-tourism.The shift of economic activity from agriculture(fields) requires investment in ‘downstreamforest industry’ – namely high end timber (building and home industry), food processingand animal husbandry.

10. THE TERAI AND THE PLAINS

It is important that corridors of greennamely forest land should streak outtowards the deltas, assuring morebenign climatic conditions while makingmaximum use of the monsoon clouds.Forest cover is one of the few mitigatingaspects in the future climate changescenario of typhoons, dry spells, andinundations. The loss of agricultural landhas to be made up with greater productivity on the remaining landbetween the strands of forest/foliage



Objectives and Development Agenda

• Integrating forests and itsresources.

• Discipline of re-use and recycle.

• Strict upstream regulation –possible banning of settlements inorder to protect the ecosystemsfrom long term damage induced bythe land and resource usage bythese settlements.

• Storages - barrages of lakes for continuous water usage throughout the year.

New Economic Opportunities

• The retreat of economicopportunities (output andproductivity) from land based towater and forest based.

• Fishing

• Water recreational activities

• Aqua culture

• Forest based products

• Special cultivation

• Timber production

• Paper industry – which isquestionable on the return type.

Figure 19: Plan showing Jalpaiguri, India.

Figure 20: Plan showing Government Engineering College,

Jalpaiguri, India.

(green corridors) that will also act aswater reservoirs. Here again teagardens and other plantations(orchards) will certainly help. Thisintegrated agro activity is now a bywordin Thailand and in South East Asian

areas. Here indeed lies a future.It is along the strands of forest that smallrainwater collection systems can beeffectively established.

10. IMPLEMENTING POLICIES OF CHANGE

The inevitable dire scenario of climate changeshould force us to quickly harness the means for an Action Plan, Implement and monitor the

proposed drastic changes in land use and water management as also the control of humanhabitation.

Apart from legal hurdles and financial limitations,the policy of confronting the coming hard daysduring climate change requires proper planningand manpower. Logistics and new infrastructurewill be at the core of a success story. For this totake place, the local bodies and moreparticularly, the relevant institutes have to gear themselves up to provide the basic inputs of engineering, agronomy, forestry, hydrology,seismology and pisciculture. They would have to

act as facilitator to the population, providingspecialized inputs connecting to sophisticatedinstitutional data (Satellite imagery etc.) andtraining prospective entrepreneurs to newer activities.

11. LOGISTICS AND INFRASTRUCTURE

The role of institutes and centre of higher learning as a harbinger of change creates an

unavailable knowledge base and data centre. Italso adds to the extension activities for thecreative enterprises – preparing a future ineconomic and social development throughengineering

a) Hydraulics

b) Seismology

c) Soil mechanics and geo-engineering

d) Timber and forest management

e) Forestry and forest products(economic)



• Spices

• Herbs and medicinal plants

• Orchards / apiary

f) Timber as an industrial material

• Wood based products

• Paper based products

g) Timber as a building material

• Seasoning and treatment

• Introduction to woodconstruction

• Standardized woodconstruction in developed countries(cheaper)

• Large scale substitution

h) Fisheries (tract farms)

It is strange that the Terai has hardly bothered toemulate the excellent ventures of the other hillyregions namely Himachal Pradesh andUttaranchal, India.

The objectives and development agenda for the

Terai has been laid out in some detail in thispresentation. It is a perspective on how to createopportunities during distress and plan ahead for mitigation rather than abject surrender.

The plethora of problems should not hold us tostart a consorted effort in organizing astructure/development plan of the Terai with‘proscriptive’ and ‘prescriptive’ policiesclearly stated.

REFERENCE:

1. Mondol, S. and Gupta, R. An approach to a climatic model. (2002)

2. Morton, R.A., 1977, Historical shoreline changes and their causes: Transactions Gulf

Coast, Association of Geological Societies.

3. Stroeve, J. and Meier, W. (1999 updated 2005).Sea Ice Trends and Climatologies from

SMMR and SSM/I, Boulder, Colorado USA.

4. Rui, H., and B. Wang, 1990: Development characteristics and dynamic structure of tropical intraseasonal convection anomalies. J. Atmos. Sci., 47, 357-379.

5. J. G. Lockwood. Causes of climate. John Wiley and Sons, 1979.



6. http://ottomanski.com

7. M.S. Krishnan, Geology of India and Burma, 1982, 6th Edition, CBS Publishers and Distributors.

8. Maps from Google earth.

9. http://www.noaa.gov

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