Land use and land cover changes in a tropical river basin: a case from Bharathapuzha River Basin, Southern India.

Land use and land cover changes in a tropical river basin: a case from Bharathapuzha River Basin, Southern India. 1. Introduction Landscape changes, transformations and conversions, are results ofvarious pressures on ecosystems and have been progressing largely inconcert with human settlements. All the natural areas including forests,grasslands, wetlands, and shores around the globe often undergo diversekinds of transformation and conversion in varying degrees. Thetriggering factors for landscape changes may be biophysical,technological, institutional or economical [1-3]. Analyzing the spatialand temporal changes in land use and land cover (LULC) is one of theeffective ways to understand the current environmental status of an areaand ongoing changes. Urbanization, a major cause of land use changes andland conversions [4], has made natural habitats open to unpredictableand long lasting changes that may later challenge the very existence ofthe ecosystems that offer several known and unknown precious ecosystemgoods and services. It is obvious that the world is undergoing a shift frompredominantly rural based society to urban. At present in North America,Europe and Latin America more than 70% of population has become urbanand in Asia and Africa the figure will be around 40%. According to thePopulation Reference Bureau (2007), by 2030 more than 60% of the wholeworld's population will be urban. During the last three centuriesin the world nearly 1.2 million [km.sup.2] of forests and woodlands, 5.6million [km.sup.2] of grasslands and pastures have been converted intoother types of land use, and the cropland has increased sharply totwelve million [km.sup.2] during the same time span [5]. However, theblame for such changes and urbanization could not be totally placed onpopulation increase since large proportion of the humankind stillremains homeless and with deplorable purchase power to meet theirday-today survival requirements. Development and welfare have remainedalien to the major section of human population of world over largely dueto disparities in distribution and access to resources. As far as a river basin is concerned, the spatio-temporal changesin land use in the basin have a direct influence on its hydrologicalrealm [6]. Currently fresh water resources in several parts of the globeis facing severe crisis in availability due to unsustainable water useaggravated by the unpredictable and unforeseen changes in the global andlocal climate. The climate change coupled with urbanization and rampantalterations in land use in the basins made most of the world'sfresh water flow regimes under severe pressure and change. Deforestationand conversion of water logged wetlands in to built-up areas directlyaffects the ground water recharging capacity and natural water flowregimes. Remote Sensing (RS) and GIS have been widely applied to understandthe LULC changes and is considered to be a powerful tool to document thespatio-temporal changes of an area for the purpose of conservation andmanagement of natural habitats [7,8]. The multispectral satellite imagesprovide satisfactory spectral resolution which in turn offers a reliablemeans to diagnose LULC changes. Change detection generally employs oneof the two basic methods: pixel-to-pixel comparison andpost-classification comparison [9]. The post classification methodcompares two or more separately classified images of different dates[10,11]. In India, large-scale landscape alterations happened just after theindependence (www.iipsenvis.nic.in). In this phase'development' was conceived to be the process of bringing allpossible types of lands under plough. Ecological goods and services ofthe various types of ecosystems and lands were perhaps of little concernor unknown to the then policy makers and advocates of development.Conservation of ecosystems and species was practically unheard of inpractice and its natural areas particularly the forests and wetlandsexperienced wide spread conversions and modification. Changes havehappened both in the plains as well as at higher elevations. TheHimalayas [1] and North east India, [12] and Western Ghats are the twomajor regions in the country that experienced extensive landscapechanges [13-16]), while these are the two major biodiversity hotspots inthe country [17] and vital for the environmental, social and culturalsetup of the country. The state of Kerala, flanked by the Western Ghats on its east, iswell known for its unique pattern of development characterized by highlevel of socio-economic growth. Human resource have been the major assetin the state and non-resident Keralites have been channelizing in largeamount of money to the state primarily to support their families back athome [18]. The flow of foreign currency, in recent years to the tune ofIndian Rupees 3040000 crores per annum, has promoted extensivesocioeconomic changes and building construction in the state. Profuselandscape changes in Kerala have happened during the last few decades.Towards the later half of the last century the land use changes werehighly associated with the socioeconomic changes that happened in thestate such as Land Reform Act (1971) which assured release of hugelandholding to the public at large from the hold of feudal landowners[19-20], although the land reforms is blamed to have deprived theindigenous tribes and other such underprivileged and marginal section oftheir land holdings. The break down of joint families to the growingculture of nuclear family and high population density coupled with highforeign remittance to the state increased the demand for housingresulting in the process of land conversion becoming more precipitous.In this context the present study was undertaken to evaluate the LULCchange happened in Bharathapuzha River basin during 1973-2005. 2. Study Area Bharathapuzha River basin (BRB) is the second longest (209 km) butlargest river basin among the west flowing 41 river basins in the Keralastate of India. The river is considered to be one of the east-flowing'medium' rivers of the country. Lying between 10[degrees]25' to 11[degrees]15' north and 75[degrees] 50' to76[degrees] 55' east the western most extremity of theBharathapuzha watershed is located in the Palakkad Gap, the 30 kmdiscontinuity in the other wise continuous Western Ghats. The river originates from different parts of the Western Ghats, assmall brooks and rivulets which later joins and form four majortributaries namely Kalpathipuzha, Gayathripuzha, Thootha, andChitturpuzha. The main river finally discharges to the Arabian Sea atPonnani on the west coast (Figure 1). The river has a total basin areaof 6,186 [km.sup.2] of which 4,400 [km.sup.2] falls in the state ofKerala and the rest in Tamil Nadu state of India. The river basin covers1/9 of the total geographical area of the state. The flow regime of theriver covers highlands (> 76 m), midlands (76-8 m) and low lands(< 8 m). The surface water potential of the basin is 7478 million m3and the total utilizable yield is 4,146 million m3 [21]. The river isthe life line water resource for a population (approximately fourmillion) residing in four administrative divisions, namely Malappuram,Trissur and Palakkad districts of Kerala and partly Coimbatore, andThiruppur districts of Tamil Nadu. Eleven irrigation projects andseveral surface dams in the river basin cater 493064 ha agriculture[22,23]. The general land use in the basin varies according to the localphysiography. Rice and coconut are the dominant crops in the costalregions of the basin. In the mid lands the major crops are rice, banana,tapioca, seasonal vegetables and coconut while in the high land regionand some of the mid land region rubber plantations and coconut groovesdominates. The river basin experiences more or less a unique climaterealm from the rest of the state of Kerala perhaps for its location,beginning in the eastern aspect of the Palakkad plains, in the PalakkadGap, flanked by mountain ranges of the Western Ghats [24]. Anomalies inthe general rainfall [25] and in surface temperature of the region havebeen observed in the last couple of decades. In recent years the riverbasin is also reported to be facing severe dearth of water and droughtconditions. 3. Methodology The LANDSAT TM data, with a pixel resolution of 30 meter, were collected for 1973, 1990 and 2005 for the whole basinfrom Global Land Cover Facility (www.glcf.umd.edu). Data before, afterand in between these years were found not available. The basin area wasdelineated using the Survey of India (SOI) topographic map series (58A/4, A/8, A/12, A/16, E/4, B/1, B/5,B/9,B/13, B/2, B/6,B/10, B/14,F/2,B/11, B/15, F/3; 49 N/13, N/14) of 1:50,000 scale. Geometric correctionand ground truthing were carried out by field surveys using GlobalPositioning System (GPS), and ancillary data from topographic maps andGoogle Earth images. Supervised classification requires training sets asthe reference signature. On the basis of these training sets the whole populations of pixels wereclassified. We used Arc GIS 9.3 and ERDAS IMAGINE 8.5 for the entirestudy. The village-wise population data of the basin were also collectedfrom various government offices. [FIGURE 1 OMITTED] [FIGURE 2 OMITTED] 4. Results and Discussion The RS data has been classified in to six major classes(agriculture, natural vegetation, plantation, roads, urban centers andwater bodies) and accordingly the land use changes in the Bharathapuzhariver basin during the time span of 1973-2005 were examined (Figure 2).In the basin, during the early period (1973-1990) of the study, landunder natural vegetation cover (44%) dominated followed by the areaunder agriculture. During the second half of the study period land underurban centers became important (32%) followed by the area underplantation. The area under agriculture remained almost same (26%), whilethe area under natural vegetation cover declined to considerably lowerproportion in the total area of the basin. In 2005, the area under urbancenters remains as the major land use type in the basin, followed byagriculture at the second position. In over all, the area under thenatural vegetation cover consistently showed a trend of decline. On theother hand a positive trend of growth in urban centers in the basin wasobserved during the whole period (Table 1). The natural vegetation cover in the basin showed a drastic declineduring the first half of the study period; however, it remained almostunvarying during the next half (Figure 3). While the agricultural areain the basin was found remaining to be unchanged during the first halfof the study period, it showed a notable fall during the next half(Figure 4). On the other hand, area under plantation and under waterresources showed a steep increase during the period 1973-1990. Duringthe next half (1990-2005) a steep decrease was seen in these land usetypes (Figure 5 and Figure 6). The urban area in the basin showed aconsistent increase thorough out the study period (Figure 7). The areaunder road that remained more or less invariable during the early periodrose during the later stage of the study (Figure 8). [FIGURE 3 OMITTED] [FIGURE 4 OMITTED] [FIGURE 5 OMITTED] [FIGURE 6 OMITTED] [FIGURE 7 OMITTED] The decrement in the area under natural vegetation during 1973-1990in Bharathapuzha River basin can be attributed to the forest lossreported in the state (~ 5000 hectares per annum). The study conductedby Jha et al., [15] reported comparatively higher deforestation rate inPalakkad district from rest of the areas in the state. A major factorthat promoted natural vegetation loss in the Bharathapuzha River basinis the spread of area under plantation. It is reported that during1951-2000 the area under rubber plantation has increased by 627% andthat of coconut by 106% in the state [26]. In a span of mere one year(1970-71), rubber and coffee plantation increased to 117% [27].Presently, rubber plantations cover about 18% of the total agriculturalland and 11% of the total geographical area of the state [28]. Suchexpansions happened mainly in the highland areas, since these areas wereless occupied than the mid and lowland areas of the state and largechunks of lands were under feudal landowners. The conversion of wetlandagriculture to more gainful (at that time) plantation crops particularlycoconut and arecanut was also happening during the same period due tothe social and economic shifts that happened in the country as well asin the state [29,30]. [FIGURE 8 OMITTED] According to George and Chattopadhyay [31] the deforestation in thestate is mainly due to infrastructure development, such as roads,hydroelectric and irrigation projects, and other institutionalamenities. The reduction in the natural vegetation in the Western Ghatsis notably associated with the implementation of Hydroelectric Projects[32-34]. Hydroelectric projects apart from their direct impact onnatural habitats cause much higher collateral damages by opening upaccess to remote wilderness [35]. The Kanjirapuzha irrigation project inthe Thootha puzha sub basin has happened during the period. The initialgrowth and later decline in area under plantation can be correlated withthe social, political and economical shifts in the state as well as inthe country. During the early nineties with the liberalization of thecountry's economy the planters and agriculturists in Kerala facedhuge financial crunch with the crash in the market price of theirproducts [36]. For example, import of coconut oil for industrial usesand its culinary cheaper substitute the palm oil from East Asiancountries was a blow to coconut farmers, while freely available andlow-cost spices and allies and rubber was a blow to other farmers. The sharp out growth in urban centers in the basin in the initialyears is related with the declining natural vegetation area and in thelater years to the decline in area under agricultural wetlands.According to 1981 census the basin had a population of 2 million people,which has increased to 4.6 millions in 2001 [37-40]. Deforestationprocesses in other parts of the state also are found correlated withpopulation growth and infrastructure development [41]. During the late90s wetland agriculture and even plantations crops were loosing theirattractiveness in the basin, as was the case in several other partsKerala [19,30,42]. According to Eapen [29] urban agglomerations or outgrowths were rare in Kerala till 1981 while later on their number havebeen almost doubling every decade. The recent census shows that 25% ofthe total population of the state comes under urban category, muchcloser to the national statistics (27.8%). Meanwhile people were alsoabandoning their agriculture/plantations due to ina- dequate returns.However, the sudden rise in the real est- ate market attracted lots ofpeople to invest money in bu- ilding construction as well in tourismventures [18]. For the high demand for building construction, largelyresid- ences, many low lying lands and wetlands at several locationsnearby the main river as well as its tributaries are getting filled upand converted. A rapid Growth in real estate business was observed in the statesince late nineties [18]. The declaration of the 8th five year planduring 1998 by the central government that assured private support for'national housing and habitat development policy' gave it afurther drive. Significant changes in the laws and regulations,including the urban land (Ceiling and Regulation) act by the centralgovernment and amendment to the National Housing Bank (NHB) act providedattractive climate for foreign investments further pushing up the realestate growth [43]. The rapid development in retail, entertainmentsectors, financial institutions, information technology centers and theboom in the tourism sector all enhanced the growth. More over the KeralaLand Reform Act (1971) acted towards abolishing the system of jointfamily (especially matrilineal) and development of nuclear families[44]. This resulted in the growth of nuclear families, of husband andwife and unmarried children, and housing units outpacing the populationgrowth in the state. Statistics shows the state is still having a highdemand for houses; demand almost doubling as the year passes (Figure 9).Since the real estate sector is believed to provide much higher annualreturn on investment, ranging 10-12%, compared to other investments[45], it attracts the resident and non resident Keralites more or lessequally. The growing demand for real estate investment is reflected inthe bench mark price for land fixed by the state government in March2010, that reaches up to Rs. 50/-lakhs per cent (~ Rs. 10000/sq feet,reaching up to the rate in some of the well developed cities in thecountry) in certain areas, an incredible level of land cost. Real estate is also believed to be a safe long term investmentamong all sections of the society who has additional surplus income tosave. Moreover, it is highly lucrative for the middlemen and thepromoters of real estate ventures who orchestrate and boost up themarket value of land. Conversion of wetlands to households is a usualpractice in Kerala. Most of the agriculture belts of Palakkad have gotlegally converted as housing plots prior to the Land acquisition(amendment) bill (2007). The new 'Regulatory Framework forConservation of Wetlands (2008) by the central government also does notaffirm the future of rice paddies, an ecosystem on its own supporting arange of species and offering a range of ecological services, althoughit deter filling up wetlands for other uses. No notable increase could be seen in the area under road during thefirst half of the study period; however, towards 2005 the area hasalmost got doubled. This may be very well attributed to the conversionof agriculture lands to built-up parcels. Urbanization always involvegrowth of infrastructure; buildings, roads, communication facilitiesetc. At present the road density in Bharathapuzha River basin is only16.24 km/100 [km.sup.2] and is apparent to grow rapidly in the comingyears. In the state of Kerala the road network is growing up in rapidpace connecting in fact all the individual houses/residences, althoughthe roads are not much improved in terms of their quality. The roaddensity of the over all state is 374.9 km/100 [km.sup.2], much higherthan the density in the Bharathapuzha River basin and far ahead of thenational average (74.9 km/100 [km.sup.2]). Road development is thesingle most critical factor that opens up any ecosystem or traditionalrural setup for rapid changes. Infrastructure development demandsconsiderable lands to be divested from its former/original use andrelegation from ecologically important area to an ecologicallyinsignificant one. [FIGURE 9 OMITTED] Recent analysis of the river basin shows changes in climateparticularly rainfall [24,25]. Similarly our analysis on the historicaldischarge at various stations along the river course shows astatistically significant decrement in the total amount of water flow inthe river Bharathapuzha. The present study in this context isdocumenting the significant physiographic changes happening inBharathapuzha River basin during the last four decades. The study alongwith all other related works on the river basin emphasize the need for ascientific management plan for sustainable development of theBharathapuzha River basin, keeping guard of its ecological setup,environmental resources and ecological services. 5. Summary The present study attempts evaluating the LULC changes in a highlyvulnerable medium sized river basin located in a high population densityarea India, the Bharathapuzha river basin with the aid of LANDSATthematic layers from 1973-2005 time periods. The study could findextensive changes in the LULC in the basin; in terms of fall in thenatural vegetation cover, increase in the urban area, decrease in areaunder wetland agriculture, and increase in the road density. The presentstudy brings out that the pattern of change in the basin more or lessconforms to such changes happening all over the state of Kerala. doi: 10.4236/jgis.2010.24026 6. Acknowledgements We would like to thank Dr. Rajendran (Annamalai university,Chidambaram), Mr Balasubramani and Mr Prasad (Madurai KamarajUniversity, Madurai) for various help during the analysis. Received May 8, 2010; revise June 20, 2010; accepted June 25, 2010 7. References [1] P. K. Joshi and S. Gairola, "Land Cover Dynamics inGarhwal Himalayas--A Case Study of Balkhila Sub-Watershed," Journalof the Indian Society of Remote Sensing, Vol. 32, No. 2, 2004, pp.199-208. [2] S. O. Jingan, N. Jiupai, W. Chaofu and X. Deti, "Land UseChange and its Corresponding Ecological Responses: A Review,"Journal of Geographical Science, Vol. 15, No. 3, pp. 305-328. [3] S. Zhao, C. Peng, H. Jiang, D. Tian, X. Lei and X. Zhou,"Land Use Change in Asia and the Ecological Consequences,"Ecological Research, Vol. 21, No. 6, 2006, pp. 890-896. [4] M. G. Turner, W. H. Romme, R. H. Gardner, R. V O'Neill andT. K. Kratz, "A Revised Concept of Landscape Equilibrium:Disturbance and Stability on Scaled Landscapes," Land Ecology, Vol.8, No. 3, 1993, pp. 213227. [5] N. Ramankutty and J. A. Foley, "Estimating HistoricalChanges in Global Land Cover: Croplands from 1700 to 1992," GlobalBiogeochemical Cycles, Vol. 13, No. 4, 1999, pp. 997-1028. [6] J. Wilk and D. A. Hughes, "Simulating the Impacts ofLand-Use and Climate Change on Water Resource Availability for a LargeSouth Indian Catchment," Hydrology Sciences, Vol. 47, No. 1, pp.19-30. [7] H. Long, G. K. Heiligb, X. Lic and M. Zhang,"Socioeconomic Development and Land-Use Change: Analysis of RuralHousing Land Transition in the Transect of the Yangtze River,China," Land Use Policy, Vol. 24, No. 1, 2007, pp. 141-153. [8] M. Guler, T. Yomraloglu and S. Reis, "Using Landsat Datato Determine Land Use/Land Cover Changes in Samsun, Tu- rkey,"Environmental Monitoring and Assessment, Vol. 127, No. 1-3, 2007, pp.155-167. [9] R. K. Jaisawal, R. Saxena and S. Mukherjee, "Applicationsof Remote Sensing Technology for Landuse/Landcover ChangeAnalysis," Journal of the Indian Society of Remote Sensing, Vol.27, No. 2, pp. 123-128. [10] P. G. Pilon, P. J. Howarth and R. A. Q. Bullock, "AnEnhanced Classification Approach to Change Detection in SemiaridEnvironments," Photogrammetric Engineering & Remote Sensing,Vol. 54, No. 10, 1988, pp. 17091716. [11] T. Fung and Q. Zhang, "Land Use Change Detection andIdentification with Landsat Digital Data in the KitchenerWaterlooArea," In: Remote Sensing and Methodologies of Land Use ChangeAnalysis, C. R. Bryant and E. F. LeDrew, Eds., Department of Geography,University of Waterloo, 1989, pp. 135-153. [12] N. Lele and P. K. Joshi, "Analyzing Deforestation Rates,Spatial Forest Cover Changes and Identifying Critical Areas of ForestCover Changes in North-East India during 1972-1999," EnvironmentalMonitoring and Assessment, Vol. 156, No. 1-4, 2008, pp. 159-170. [13] U. M. Chandrashekara, "Anthropogenic Pressure onStructure and Composition of a Shola Forest in Kerala," IndianJournal of Mountain Science, Vol. 3, No. 1, 2005, pp. 58-70. [14] D. Venugopal, "Development-Conservation Dilemma in theNilgiri Mountains of South India," Journal of Mountain Science,Vol. 1, No. 1, 2004, pp. 74-80. [15] C. S. Jha, C. B. S. Dutt and K. S. Bawa, "Deforestationand Land Use Changes in Western Ghats, India," Current Science,Vol. 79, No. 2, 2000, pp. 231-238. [16] A. K. Negi, B. P. Bhatt and N. P Todaria, "LocalPopulation Impacts on the Forests of Garhwal Himalaya, India,"Environmentalist, Vol. 19, No. 4, 1999, pp. 293-303. [17] N. R. Gunawardene, A. E. D. Daniels, I. A. U. N. Gunatilleke,C. V. S. Gunatilleke, P. V. Karunakaran, K. G. Nayak, S. Prasad, P.Puyravaud, B. R. Ramesh, K. A. Subramanian and G. Vasanthy, "ABrief Overview of the Western Ghats-Sri Lanka BiodiversityHotspot," Current Science, Vol. 93, 2007, pp. 1567-1572. [18] P. P. N. Raj and P. A. Azeez, "Real Estate andAgricultural Wetlands in Kerala," Economic and Political Weekly,Vol. 44, No. 5, 2009(a), pp. 63-66. [19] R. Mahesh, "Farm Size-Productivity Relation Ship: SomeEvidence from Kerala," KIED Working Paper, Kerala Institute forEnvironment and Development, Thiruvananthapuram, 2000. [20] G. Gopikuttan and K. N. P. Kurup, "Paddy Land Conversionin Kerala an Inquiry into Ecological and Economic Aspects in a MidlandWatershed Region," Centre for Development Studies,Thiruvananthapuram, 2004. [21] CWRDM, "Water Resources Development of BharathapuzhaBasin, a Status Report," 1991. [22] CWRDM, "Master Plan for Drought Mitigation in Palak kadDistrict," 2004. [23] S. P. Ravi, C. G Madhusoodhanan, A. Latha, S.Unnik rishnan and K. H. A Bachan, "Tragedy of Commons: The KeralaExperience in River Linking," River Research Centre, Thrissur,2004. [24] P. P. N. Raj and P. A. Azeez, "Changing Rainfall in thePalakkad Plains of South India," Atmosfera, Vol. 23, No. 1, 2010,pp. 81-88. [25] N. Raj and P. A. Azeez, "Historical Analysis of the FirstRain Event and the Number of Rain Days in the Western Part of PalakkadGap, South India," Climate Change: Global Risks, Challenges andDecisions IOP Conference Series: Earth and Environmental Science,2009(b). [26] B. M. Kumar, "Land Use in Kerala: Changing Scenarios andShifting Paradigms," Journal of Tropical Agricultural, Vol. 42, No.1-2, 2005, pp. 1-12. [27] T. J. Nossiter, "Communism in Kerala: A Study in Political Adaptation," Royal Institute of International Affairs,Hurst & Co. Publishers, New York, 1982. [28] S. Chattopadhyay and M. Chattopadhyay, "Sustainable LandManagement in Kerala, India-A Bio-Physical Approach," Proceedingsof Geo-Information for Sustainable Land Management (SLM), K. J. Beek, K.D. Bie and P. Driessen, Eds., Enschede ITC Journal, Vol. 3, No. 4, 1997,pp. 165-174. [29] M. Eapen, "Economic Diversification in Kerala: A SpatialAnalysis," Centre for Development Studies, Thiruvananthapuram,1999. [30] N. Raj and P. A. Azeez, "The Shrinking Rice Paddies ofKerala," Indian Economic Review, Vol. 6, 2009(c), pp. 176-183. [31] P. S. George and S. Chattopadhyay, "Population and LandUse in Kerala, Growing Populations, Changing Landscapes: Studies fromIndia, China, and the United States," The National Academy ofSciences, The National Academies Press, 2001. [32] V. M. Meher-Homji, "Probable Impact of Deforestation onHydrological Processes," Climatic Change, Vol. 19, No. 2, 1991, pp.163-173. [33] A. G. Pandurangan and V. J. Nair, "Changing Pattern ofFloristic Composition in the Idukki Hydro-Electric Project Area,Kerala," Journal of economic and taxonomic botany, Vol. 21, 1996,pp. 15-26. [34] M. K. Soman, K. K. Kumar and N. Singh, "Decreasing Trendin the Rainfall of Kerala," Current Science, Vol. 57, No. 1, 1998,pp. 7-12. [35] P. A. Azeez, S. Bhupathy, A. Rajasekharan, P. R. Arun, D.Stephan and D. Kannan, "Comprehensive EIA (Botanical and ZoologicalAspects) of the Proposed Puyankutty Hydroelectric Project, Kerala,"Salim Ali Centre for Ornithology and Natural History (SACON),Coimbatore, Tamil Nadu, 1999. [36] P. T. Sunil, "Dimensions of Agrarian Distress: The Caseof Wayanad District, Kerala," Financing Agriculture--NatationalJournal of Agriculture & Rural Development, 2007, pp. 7-12. [37] Census of India, "District Census Hand BookPalakkad," 2001(a). [38] Census of India, "District Census Hand BookThrissur," 2001(b). [39] Census of India, "District Census Hand BookMalappuram," 2001(c). [40] Census of India, "District Census Hand BookCoimbatore," 2001(d). [41] S. Chattopadhyay, "Deforestation in Parts of WesternGhats Region (Kerala), India," Journal of Environmental Management,Vol. 20, 1985, pp. 219-230. [42] R. M. Raj, "Patterns of Social Change among the MigrantFarmers of Kannur District--A Case Study," Project Report Submittedto Kerala Research Programme on Local Development, Centre forDevelopmental Studies, Thiruvananthapuram, 2003. [43] H. Joshi, "Identifying Asset Price Bubbles in the HousingMarket in India-Preliminary Evidence," Reserve Bank of IndiaOccasional Papers, Vol. 27, No. 1-2, 2006, pp. 7388. [44] P. N. Sushama, "Transition from High to Replacement LevelFertility in a Kerala Village," Health Transition Review, Office ofPopulation Health and Nutrition, New Delhi, Vol. 6, 1996, pp. 115-136. [45] P. G. Mahurkar and Senthil, "Final Paper on Real EstateFund Management Indian Perspective," Asian Real Estate Society,AsRES Conference, New Delhi, 2004. P. P. Nikhil Raj, P. A. Azeez Environmental Impact Assessment Division, Sdlim Ali Centre forOrnithology and Natural History Anaikatty, India E-mail: {ppnraj, azeezpa}@gmail.comTable 1. Total land cover (in %) as a proportion to the total area,and the net change during the study period. 1973 1990 2005 Change (%) during 1973-1990Agriculture 27.84 27.54 19.15 -0.30Natural vegetation 43.43 12.07 12.28 -31.36Plantation 7.46 14.20 8.64 6.74Roads 7.61 8.40 16.24 0.79Urban centers 9.83 32.63 41.76 22.80Water resources 3.82 5.16 1.93 1.34 Change (%) during Change (%) during 1990-2005 1973-2005Agriculture -8.39 -8.69Natural vegetation 0.21 -31.15Plantation -5.56 1.18Roads 7.83 8.62Urban centers 9.13 31.93Water resources -3.23 -1.89