PREDICTING URBAN HEAT ISLANDS (UHIs) RISK AND MICRO-CLIMATE CHANGE IN DELHI METROPOLITAN REGION USING GEOINFORMATICS LUCC Environment and Millennium Development Goals Energy and CO 2 R.B. Singh and Manoj Department of Geography, Delhi School of Economics, University of Delhi, Delhi-110007, India rbsgeo@hotmail.com Water Forests and green belts Human health Linkages between LUCC, pollution and UHIs Particulate Air Pollution in selected cities, 1990-98 Mega Cities-Anthropogenic Climate Change Indian Mega Cities- growing urbanisation and industrialisation. Moving to cities in search of high income, employment, improved services and access to various amenities. The urban population in India is 285 million, which is 10 per cent of world and 21 per cent of Asia. 6 Indian cities are in top 125 cities of the world. Unprecedented pressures on environmental quality. URBAN HEAT ISLANDS (UHI) Urban heat islands refer to the elevated temperatures in built-up areas compared to more rural surroundings. City temperatures vary in accordance with its land use activities. The average temperature in city tends to rise forming Urban Heat Island. Multi dimensional Factors contributing to a heat islands Urban Heat Island (UHI) Land use is the important driving force for Urban Heat Island (UHI). After conversion of agricultural land into built-up area-convert into warmer areas because concrete material has less albedo in comparison to natural landscape and more retention capacity and thermal conductivity. Dense built-up is responsible for more absorption of heat and leads to high energy use, subsequently intensifies UHI.
CAUSES FOR URBAN HEAT ISLANDS Major causes Reduced vegetation in urban areas Properties of urban materials Urban geometry Anthropogenic heat Additional factors Weather Geographic location Delhi and UHI Atmospheric inversion, another vital phenomenon, occurs by trapping of the cold air over Delhi with gaseous pollutant. Vehicular pollution is accountable for almost 70% of the air pollution in Delhi. Degradation in air quality noticed, further threatening serious health problems. Positive relationship between existence of green cover and micro- climate. Land Use/Cover Change monitoring can bring better understanding for status of green cover and Urban Heat Island (UHI). Therefore, it is essential to monitor and predict Urban Heat Island as it has impact on the micro-climate of Delhi. VEGETATION The vegetation of Delhi is thorny scrub which is found in arid and semi arid zone. The main forest, Ridge Forest falls in the forest type in the category of Tropical thorn forest and more especially as semi arid open scrub. The vegetation of Delhi is typical Northern Tropical Thorn Forest type. Vegetation in in Delhi, 2004 Population of Delhi The population of Delhi, as on 1st March, 2001, has been worked out at 13.78 millions. Area of NCT of Delhi Rural Area: 591.91 square kilometers Urban Area: Total Area: 891.09 square Kilometers 1483 square Kilometers
Objectives To asses spatio-temporal land use changes. To find out the Spatial Distribution of Urban Heat Islands and Potential UHI and UHI Zonation Data Collection factors Economic Survey of Delhi Planning Department Delhi Census of India Methodological Framework Growth Urbanization Road Network Data Collection Land Use NRSA Toposheets by SOI GLCF Final results Comparison with Population Density Exporting Raster UHI Zonation Georeferencing Supervised classification Vectorisation Weghtage assign Overlay URBANIZATION AS DRIVER OF ENVIRONMENTAL CHANGE Highest percentage of urban population in India is in Delhi (93.01 per cent). Delhi experiences high rate of urbanisation with 1.4 million populations in year 1951 to 12.79 million in 2001. Phenomenal rise in the population of Delhi in the recent past is largely due to migration from rural India. Source: Census of India Source: Planning Department, GNCTD P e r c e n t 100 50 0 Urban Area and Population, Delhi 88.75 89.93 92.73 82.4 93.01 62 40 47 14 22 1951 1961 1981 1991 2001 Year P er cen t Delhi Rural Urban Population composition 1901-2001 100.00 88.75 89.70 92.73 89.93 93.01 82.40 75.79 80.00 70.33 62.32 52.76 57.50 60.00 47.24 42.50 37.68 40.00 29.67 24.21 17.60 20.00 11.25 10.30 7.27 10.07 6.99 0.00 1901 1911 1921 1931 1941 1951 1961 1971 1981 1991 2001 Year Urban Population Per cent to Total Urban Area Per cent to Total Area Rural Urban Source: Census of India Source: Census of India and Economic survey of Delhi Source: Census of India URBAN EXPANSION, INDUSTRIALIZAITON AND DECLINING GREEN COVER The city has already engulfed vast tract of the surrounding rural land by the dramatic sprawl and LUCC since 1961. Around late 1920s and early 1930s that the destruction of the ridge started in Delhi. The changes have been recorded in the species composition in the natural vegetation in Ridge areas. The number of industries has increased up to about 1, 26,000 at present from 8,000 in 1951. In July 1996, closure and shifting of 168 industrial units have taken place from Delhi. In September 2000, many polluting industries were shut down. In rural-urban fringe, which is facing increasing industrialization, faces the serious problems. LAND USE/ COVER CHANGE (1992-2004) LAND USE/ COVER 1992 (%) 2004 High dense residential 10.39% 22.95 % Institutional 1.16% 1.31 % Parks & Zoo 1.12 % 0.96 % Stadium & Playground 0.16 % 0.26 % River 1.17 % 0.72 % Agricultural land 44.89 % 36.94 % Scrub land 2.52 % 2.43 % Forest 1.58 % 1.43 % Ridge 6.69 % 5.52 % Riverine green 0.12 % 0.11 %
TRANSPORTATION TRENDS GROWTH OF MOTOR VEHICLES IN DELHI YEARS NUMBER OF VEHICLES INCREASE IN NUMBER OF VEHICLES ANNUAL GROWTH (%) 1996-97 28,47,695 2,18,050 8.29 2000-01 33,75,153 2,11,588 8.05 2001-02 36,17,853 2,42,700 7.19 2002-03 38,86,072 2,68,219 7.41 2003-04 41,60,760 2,74,688 7.07 2004-05 44,67,154 3,06,394 7.36 2005-06 48,30,136 3,62,982 8.13 2006-07 52,32,426 4,02,290 8.33 ENVIRONMENTAL POLLUTION Petrol driven vehicles account for more than 81 per cent of the pollution while diesel vehicles account for only 19 per cent of the total air pollution of the city. Three thermal power stations in Delhi are alone responsible for the release of about 302 tonnes of pollutants per day (10 per cent of the air pollution load). Concentration of carbon monoxide had a gradual decline but it continues to be above the danger mark of 2,000 mg/m 3. Shahzada Bagh and Shahdara (industrial areas) are characterised by very high concentration of air pollution. The core area of city exhibit warm pockets due to the thermal radiation emissions. MICRO-CLIMATIC CHANGES The city experienced increase in temperature. Risks related to industrialization and electricity generation through thermal power with large health and environmental risks by bringing change in the micro-climate The micro-climate also influences the long range monsoon system. Seasonal flooding during the heavy wet spells of the monsoon is an annual occurrence in Delhi. Temperature (in 0 o C) 27.00 26.50 26.00 25.50 25.00 24.50 24.00 23.50 23.00 22.50 MEAN ANNUAL TEMPERATURE: 1965-2004 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 Year 1987 1989 1991 1993 1995 1997 1999 2001 2003 Mean Annual Temp.(oC) of Palam Mean Annual Temp.(oC) of Safdarjung
Urban Heat Island (UHI) identification Land use is the most important indicator responsible for UHI intensification. Dense built-up leads to high energy use which is responsible for heating the urban environment. Satellite imageries classified in 5 classes taken into consideration according to their reflectance values (albedo), using tone, texture, shape, size, pattern, association and ground-truthing. Maximum weightage has been assigned to land use, 0.55 in 0 to 1 scale. 2006 11.5 1.85 28.48 19.22 38.95 Dense Built up Open Built up Bar ren/vacant land Vegetation/A gr ic ultur e land Water bodies Growth of New Central Business Districts, Nehru Place, Azadpur and Bhikaji Kama Methodological chart of UHI identification Objectives Identification of Potential Urban heat island and UHI intensity Mapping. Data Collection NRSA Census DSIDC CPCB Traffic intersections Thermal Power plants Industrial areas Land use Georeferencing Georeferencing Vectorisation Weight age Land use.55 Overlay Analysis Classification mean +/deviation Weight age Traffic intersections.15 Thermal Power plants.15 Industrial areas.15 based on standard Potential UHI
IMPACTS OF URBAN HEAT ISLANDS Increased energy consumption Climate change and Greenhouse Gases Deteriorated air quality Thermal effect on water quality and temperatures Factors in heat-related illnesses & death Wintertime benefits of UHIs: Reduction in energy needs in winter Increase in springtime length of growing season Their winter penalty is less significant than their summertime benefits PROMOTING CARBON RESILIENCE MEGA CITY Afforestation and plantation. Green buildings and Green neighborhood should be encouraged. Energy efficient appliances should be used to save energy. Light colour reflective material to be used on roofs. Land use regulations. Pyramid shape multi-storey buildings to be promoted-green roofs and cool roofs Cool pavements, and light reflective surfaces Land use and urban planning to modify concrete geometry Green Buildings through traditional cooling and heating architecture Sunrays 4 6 8 10 Model of pyramid shaped multistorey green building YEAR CHANGE IN FOREST AND TREE COVER FOREST AND TREE COVER (Sq Km) PERCENTAGE OF GEOGRAPHICAL AREA 1980-81 14.34 (Forest Cover) 0.96 1993 22 1.48 1995 26 1.75 1997 26 1.75 1999 88 5.93 2001 151 10.2 2003 263 18.07 2005 283 (177 forest cover +106 tree cover) 19.08 2007 300 20.22 2008* 326 21.98 Green Cover in Delhi-Development of Parks
SATELLITE CITIES AND COUNTER MAGNET 35 million plus cities constituted more than one-third (37.85%) of the total urban population. During the last (1991-2001) decade, the number of million plus cities increased from 23 to 35 and is likely to increase to 50 by 2011. The concept of development in Satellite Towns/Counter Magnets of Million plus Cities is an important step to develop surrounding areas. The development of satellite cities around 35 million plus cities will be helpful in achieving greater efficiency in the overall hierarchy of human settlements both at national and regional level. CONCLUSION Intensive anthropogenic activities in mega-cities are largely responsible for UHIs and micro-climate changes. It is imperative to examine spatial and temporal dynamics and dimensions of urban heat islands using geoinformatics based prediction. Forest and vegetation plantation can have an influence on carbon sequestration. Carbon resilience measures can play an effective role in mitigating climate change by adapting afforestation, nonconventional energy and promoting green buildings and neighborhoods.