THE EFFECT OF LOCAL CLIMATE ON URBAN HEAT ISLAND TREND;
A CASE STUDY IN URBAN AREAS OF IPOH AND KUANTAN
Azhar Ishak, Zureen Norhaizatul Che Hassan, Norfarezah Hanim Edros,
Mohd Hazril Zamberi and Mohd Nashriq Abd Rahman
ABSTRACT
The effect of global warming has significantly contributed to the increases of
temperature in Malaysia and to some extent; the temperature trend over the urban areas
is relatively higher as compared to the rural. Local Urban Heat Island (UHI) could have
been contributed in small fraction towards higher temperature due to urbanization that
could cause increasing concentrations of greenhouse gases. Comparison of Urban Heat
Island Intensity (UHII) trend based on daily maximum intensity (ΔT
minimum intensity (ΔT (u-r) [min]) and daily mean intensity (ΔT
(u-r)
(u-r) [mean])
[max]), daily
in 1996 to 2005
at two urban cities, Ipoh and Kuantan has shown no significant correlation of UHII with
respect to the time. Only weak negative and positive trend is observed. Weak negative
trend could be subjected to increase of temperature at the rural assuming no changes in
temperature at the urban or the UHI phenomenon is insignificant. The positive trend
could be associated to warmer temperature over the urban areas. Further details study
using annual mean hourly temperature has indicated the existence of urban heat island
over Ipoh and Kuantan with warmer average temperature ranging from 0.5 to 1.0°C as
compared to their surrounding rural. Changes and fluctuation of UHII is affected by local
wind, the land breeze as in the case of (ΔT (u-r) [mean]) between Ipoh-Sitiawan and also
the wind strength associated to the seasonal monsoonal wind patterns, as in the case of
(ΔT (u-r) [mean]) for Kuantan-Temerloh. Analysis of (ΔT (u-r)) based on maximum, minimum
and mean daily temperature from 1996 to 2005 against population growth showed
comparatively higher trend of negative correlation between them.
Key words: temperature trend, Urban Heat Island intensity, population growth, local
climate
2
1.
INTRODUCTION
Urban Heat Island (UHI) is considered as one of the major problems in
this century posed to human beings as a result of rapid urbanization and
industrialization of human civilization. Urbanization and industrialization improve
our material life and comfort; however they also induced many problems to
human beings, such as global warming, industrial waste, and air pollution
(Rizwan, 2008). The UHI most often refers to the increase of air temperature, in
the near surface layer of the atmosphere within cities relative to their surrounding
countryside and it is so called because the pattern of isotherms forms an island
shaped pattern (James A. Voogt, 2002). The actual pattern of a given city
depends on the configuration of the urbanized area but in general a large
gradient of air temperature forms near the urban-rural followed by more gradual
rise to the city core. The huge amount of heat generated by man made or
anthropogenic heat sources (vehicles, power plants, air conditioners and heat
produced by urban structures such as using massive construction materials as
they absorb and re-radiate solar radiations) are the main causes of UHI. The
rapid increases and expansion of urban areas in terms of land used, population
growth and urban activities have intensified adverse urban environmental
impacts. The adverse effect of UHI includes the deterioration of living
environment, increase in energy consumption (Konopacki and Akbari, 2002) and
even mortality rates (Changnon et al., 1996). Indeed, these constantly
undergoing modification that were formerly occupied by agriculture and green
environment by the residential has tremendously altered the climate by changing
the physical surface of the land and producing significant amount of heat and
pollutants that could warm the city or urban areas. Urban settlements and
migrations in the needs of gaining more opportunity at the city not only create
devastating social problems but provide one of the best examples on how human
extensive economic activities and perceptions changed. As for Malaysia, the high
rate of urbanization of its population, particularly in big cities such as Kuala
Lumpur, Petaling Jaya, Penang, Ipoh, Johor Bharu and Butterworth means that
3
increasing numbers of people will be affected and exposed to impacts resulting
from heat islands in the future.
This paper highlighted the research conducted by comparing the UHII
from 6 meteorological monitoring stations (2 urban and 4 rural) to see whether
there is any trend of UHI effect. Further analysis between UHII and population
growth was also studied to show whether they have any correlation with respect
to UHI.
2.
CLIMATE OF STUDY AREA
Figure
1
represents
the
geographical
location map of the Urban Heat Island (UHI)
study areas. Three meteorological stations
in Pahang represent the east coast state
and the other three located in Perak are
representing the west coast states of
Peninsula Malaysia. In this study, the city of
Kuantan (3.78°N, 103.22°E) is treated as
the urban area. It is the state capital of
Pahang the most urbanized area situated
near the mouth of the Kuantan River and
Figure 1: Location of Study Area
faces the South China Sea. The climate is
more influences by seasonal variation of the
northeast monsoon. Kuantan's population is approximately more than 403,000 in
2005 and it is the 9th largest city in Malaysia. It is identified as one of the future
growth centres and a hub for trade, commerce, transportation and tourism.
Kuantan is also considered as the social, economic and commercial hub for East
Coast Peninsular Malaysia due to its strategic location. As an effort to catalyse
the growth of Kuantan Metropolitan Precinct, government has located a
petroleum manufacturing area in Pekan, a neighbour town of Kuantan and
4
expected to allocate some funds to enhance the growth across the region [6].
Ipoh (4.57°N, 101.1°E) the capital state of Perak is treated as the urban area.
Ipoh is the fourth largest city in Malaysia with population of 702,464 (2009) and
ranking in 2007 as sixth most populous urban centre in Malaysia [7]. Temerloh
(3.47°N, 102.38°E), Muadzam Shah (3.05°N,103.08°E), Lubuk Merbau (4.8°N,
100.9°E) and Sitiawan (4. 22°N, 100.7°E) are treated as rural areas. Sitiawan is
located near the coastal area facing the Strait of Malacca. The rest of the areas
are located inland.
Figure 2 shows the climate
Mean Monthly Rainfall for IPOH
(1951-2009)
350
264.1
Rainfall (mm)
300
250
200
216.9
197.1
of Ipoh represented by the
300.8 291.9
161.4 149.4
240.6
208.9
147.9
167.3 165.4
long term mean monthly
rainfall. It is shown that the
150
average monthly rainfall is
100
50
characterized
0
Jan
Feb
Mac
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
by
two
periods of maximum rainfall
separated by two periods
Figure 2: Mean monthly rainfall for Ipoh
of minimum rainfall. The
primary maximum occurs in October while the secondary maximum is in April.
The primary minimum occurs in February with the secondary minimum in June.
This is the typical characteristic of climate pattern over the west coast region of
Peninsular Malaysia where more rain occurs during two inter-monsoon periods
which is in the month of April and October. The northeast monsoon does have
direct impact on climate of Ipoh especially in November and December. February
and June are the driest month while October is the wettest. Similar climate
pattern is characterized for the rest of study areas as shown in APPENDIX 1
except for Muadzam Shah and Kuantan. The climate of these two stations is
characterized by the influenced of the northeast monsoon in which the wettest
month occurs in December. In general, May and June are the hottest month in
Malaysia during the establishment of southwest monsoon.
5
Figure 3 and Figure 4 show the monthly mean temperature for Kuantan
and Ipoh based on the data from 1968 to 2009 which representing typical
average temperature pattern of Malaysia.
2.1
Temperature Trend of the Study Areas
The temperatures over the
Monthly Mean Temperature °C for Kuantan (1968-2009)
study
28.0
27.5
27.1
27.4
27.2
26.8
27.0
26.8
26.4
26.5
26.0
26.6
25.0
respect to time. The El~Nino
events
24.5
24.0
in
contributed
23.5
Feb.
Mar.
Apr.
May
Jun.
Jul.
Aug.
Sep.
Oct.
Nov.
Dec.
Figure 3 : Monthly Mean Temperature for Kuantan
Monthly Mean Temp (°C) for Ipoh (1968-2009)
27.5
27.6
27.2
higher
significant trend with sharp
increased in annual mean
temperature increases from
27.1
1968
26.7
26.7
towards
has
Figure 5 for Kuantan. The
27.6
27.2
1998
temperature as indicated in
28.0
27.5 27.5
shown
annual mean temperature with
25.7
25.6
Jan.
have
significant increased of the
26.4
25.5
25.0
25.0
27.0
areas
26.5
26.3 26.3
26.5
2009
with
linear
regression of R2 value equals
to
26.0
to
0.7248
El~Nino
indicates
events
how
contributes
25.5
J an. F eb. Mar. Apr. May
J un.
J ul. Aug. S ep. Oct. Nov. Dec.
towards
increasing
temperature. From the rest of
Figure 4: Monthly Mean Temperature for Ipoh
the areas as shown in APPENDIX 2, assuming if the higher temperature trend
continue to increase linearly, it is projected that within the period of 10 years the
climate of Malaysia is expected to increase within the range of 0.10°C to 0.35°C.
6
Study of temperature trends
for the rest of meteorological
stations
in
Malaysia
has
confirmed towards similarity
of trend. It is noted that the
temperature trend over the
urban areas is higher than the
rural. The local UHI could
Figure 5: Significant TREND of Temperature in Kuantan
have
been
contributed
in
small fraction towards higher temperature due to urbanization that could cause
increasing concentrations of greenhouse gases.
3.
METHODOLOGY AND DATA
3.1
URBAN HEAT ISLAND (UHI)
An Urban Heat Island (UHI) is the name given to describe the
characteristic warmth of both the atmosphere (the air temperatures) and surfaces
in urban areas (cities) compared to their rural or non urbanized surroundings [8].
The heat island is an example of unintentional climate modification when
urbanization changes the characteristics of the Earth’s surface and atmosphere
where warmer air forms a dome or plume over the city. There are 3 types of UHI
namely the Canopy Layer Heat Island (CLHI), Boundary Layer Heat Island
(BLHI) and Surface Heat Island (SHI). CLHI and BLHI refer to a warming of the
urban atmosphere and SHI refers to the relative warmth of urban surfaces. The
SHI is observed by remote sensors operating in the thermal wavelength region
and mounted on satellite or aircraft with high spatial resolution. These sensors
detect radiation emitted and reflected by the surface rather than temperature
directly. The surface temperature is very sensitive to changes in surface
conditions and therefore shows much greater spatial variability and temporal
7
variation between day and night. The Urban Canopy Layer (UCL) is the layer of
air closest to the surface in cities, extending upwards to approximately the mean
building height. Above the urban canopy layer lies the urban boundary layer,
which may be 1 kilometer (km) or more in thickness by day, shrinking to
hundreds of meters or less at night. It is the BLHI that forms a dome of warmer
air that extends downwind of the city and wind often changes the dome to a
plume shape [9].
The environment of these study areas is considered within the UCL since the
temperature instrument installed inside the Stevenson Screen is one meter
above the ground level as follows the regulation of World Meteorology
Organization.
3.2
URBAN HEAT ISLAND INTENSITY (UHII)
The temperature difference between the urban temperature and the
background rural temperature is given by (Oke. T.R., 1987):
Urban Heat Island Intensity (UHII) = (ΔT (u-r)),
[1]
where ΔT is the temperature difference between urban (u) and rural (r) area.
This study investigates the characteristics of the daily maximum (ΔT (u-r)
[max]) , daily minimum (ΔT(u-r) [min]) and daily mean (ΔT(u-r) [mean]) Urban Heat
Island Intensity (UHII) in 2 cities and 4 towns within the period of 1996 to 2005.
Kuantan and Ipoh are treated as the urban areas while Temerloh, Muadzam
Shah, Setiawan and Lubuk Merbau (representing Kuala Kangsar) are treated as
rural areas. The temporal variation of urban and rural temperatures of these 6
meteorological stations was also studied based on annual mean hourly
temperature data over the same period of 1996 to 2005 to see in details the
effect of UHI.
8
3.3
Comparison of Urban Heat Island Intensity (UHII) with Population
Growth
The average Urban Heat Island Intensity (UHII) for Kuantan and Ipoh
based on daily maximum, daily minimum and daily mean temperature from 1996
to 2005 were plotted against the population growth difference between urban and
rural areas to see any correlation between them. The period of data in this study
is only for 10 years as such longer period could expect more representing
towards significant result. The population growth data is taken from Malaysian
Statistical Department and no population density over the cities is available.
4.
ANALYSIS AND RESULTS
4.1
Urban Heat Island Intensity (UHII) Trend
Based on daily maximum, minimum and mean temperature in the period
of 1996 to 2005, analysis to determine the UHII trend was done for Ipoh and
Kuantan as follows:
4.1.1 The UHII Trend in Ipoh
Figure 6 in APPENDIX 3 shows the daily maximum, daily minimum
and daily mean temperature for Ipoh over the period of 1996 to 2005. The
Urban Heat Island Intensity, UHII (ΔT
(u-r)),
comprises of (ΔT(u-r) [max]),
(ΔT(u-r) [min]) and (ΔT(u-r) [mean]) for Ipoh taken Sitiawan and Lubuk
Merbau as rural areas have shown that no significant correlation over the
respective period with R2 is between 0 to less than 1%. The negative and
positive trend observed is insignificant even though negative trend could
be subjected to increase of temperature (more hotter) at the rural
assuming no changes in temperature at the urban. The positive trend
9
could be associated to hotter temperature from time to time over the urban
areas.
Visual interpretation of the graphs show that the (ΔT
(u-r)
[min]) and (ΔT
(u-r)
(u-r)
[max]), (ΔT
[mean]) for Ipoh - Lubuk Merbau has indicated much
more of higher temperature for Ipoh and this could be an indication of
Urban Heat Island (UHI). However, the (ΔT
shown clear harmonic fluctuation of (ΔT
r)
[min]) and (ΔT
(u-r)
(u-r))
(u-r))
for Ipoh - Sitiawan has
both for (ΔT
(u-r) [max]),
(ΔT
(u-
[mean]). This variation could be explained due to local
climate of Sitiawan.
4.1.2 The UHII Trend in Kuantan
Figure 7 (APPENDIX 1) shows the daily maximum, daily minimum
and daily mean temperature for urban area of Kuantan over the study
period of 1996 to 2005. The Urban Heat Island Intensity, UHII (ΔT
(u-r)),
comprises of (ΔT (u-r) [max]), (ΔT (u-r) [min]) and (ΔT (u-r) [mean]) for Kuantan
taken Muadzam Shah and Temerloh as rural areas have shown quite
similar trend with Ipoh. No significant correlation over the respective
period with R2 is between 0 to less than 1%. Very small negative trend is
observed for UHII Kuatan - Temerloh.
Visual interpretation of the graphs show very clear fluctuation of
(ΔT
(u-r)
[max]), (ΔT
(u-r)
[min]) and (ΔT
(u-r)
[mean]) for Kuantan -Temerloh,
and Kuantan - Muadzam Shah. Both following the sinusoidal variation of
temperature for the areas.
Interpretation or determination of UHII using daily maximum,
minimum and mean temperature in the above analysis does not clearly
shown the trend of Urban Heat Island (UHI). This may be due to the
urbanization of Ipoh and Kuantan that does not develop as much as they
could contribute to heat island or longer period of study could have
produced something toward positive (warmer) trend of UHII.
10
4.2
The UHII Trend Based on Annual Mean Daily Temperature
As shown in Table 1, the (ΔT
(u-r)
[max]) for Ipoh shows positive value with
respect to Sitiawan and Lubuk Merbau while the maximum UHII or (ΔT
(u-r)
[max])
for Kuantan shows negative value. This indicates that the heat island occurs in
Ipoh and not in Kuantan. The analysis shows that Temerloh and Muadzam Shah
are warmer than Kuantan. Amazingly, the urbanization in Kuantan some how
does not contributed to heat island even though, Kuantan is the most urbanized
city over the east coast of Peninsula Malaysia. Furthermore, as shown in Figure
8 (APPENDIX 3), there is significant trend of maximum UHII that were plotted
against the study period towards more negative values of UHII.
4.3
Average Maximum UHII and the Population Growth of Study Area
The annual mean daily of maximum UHII or the average maximum UHII
was scatter plotted against difference of population growth between urban and
rural of the areas as in Figure 9. Data was extracted from Table 2 and Table 3
representing Kuantan and Ipoh respectively. The population growth data was
collected from Malaysian Statistical Department. The graph shows that as
population increases the average max UHII decreases with quite significant
correlation amongst them except for Ipoh. In fact, there is strong negative
correlation in the case of Kuantan - Muadzam Shah with R2 reaching 54%. This
result does not follow the actual expectation whereby increased in maximum heat
island intensities can be related to city population (James A Voogt, 2002). The
negative correlation could be due to shorter period of study, small increases of
population growth with respect to time, the urban and the rural surrounding
characteristics and the prevailing climate. Further canopy urban heat island study
should be carried out in order to really prove of the finding on why average max
UHII decreases as population increases.
11
4.4
Interpretation of UHII using Annual Mean Hourly Temperature
Based on the finding above it has shown that daily temperature gives very
broad result of the effect of Urban Heat Island (UHI) within the canopy layer
study areas. Further details study using hourly temperature was done to see the
contribution of local weather and climate to UHI. In this study the annual mean
hourly temperature was used to interpret whether there is any effect of urban
heat island. The annual mean hourly temperature is defined as the average of
hourly temperature in a day taking over a year period. Figure 10 (APPENDIX 3)
shows the annual mean hourly temperature variation over the period of 1997 to
2001 for Kuantan, Sitiawan, Lubuk Merbau, Ipoh, Temerloh and Muadzam Shah.
The mean Urban Heat Island Intensity (UHII) or (ΔT
(u-r)
[mean]) was also plotted.
It was found that temperature variation for Temerloh is higher than Muadzam
Shah and Kuantan. Negative sign of UHII for Kuantan - Temerloh as shown
occurs at 15 to 17 hour in the afternoon and the cooling rates start at 09 hour.
Comparing with the UHII of Kuantan - Muadzam Shah, no clear variation of UHII
was observed. For the case of Ipoh, it is found that Ipoh is warmer than Sitiawan
and Lubuk Merbau. The UHII for Ipoh - Sitiawan shows clear fluctuation within
the period hour and steady variation UHII for Ipoh - Lubuk Merbau.
4.4.1 Monsoonal Wind Influences Formation of Heat Island in
Kuantan
Figure 11 in APPENDIX 3 shows the details of Urban Heat Island
Intensity (UHII) for Kuantan - Temerloh, Kuantan - Muadzam Shah, Ipoh Sitiawan and Ipoh - Lubuk Merbau in the period of 1997 and 1998. The
UHII for Kuantan-Temerloh decreases with time at 10.00 am and reaches
the lowest cooling rate at 4.00 pm in the afternoon. It starts to increase at
warming rate until 10.00 pm and keeps warming during the night. The
warming night in Kuantan shows that there is an urban heat warming in
Kuantan with difference in mean temperature of 0.5°C to 1.0°C. Similar
situation happens for Muadzam Shah but with lesser warming and cooling
12
rate. It is clearly observed that Temerloh is warmer than Kuantan from
noon to 8.00 pm night. This is evidently due to the location of Kuantan.
Kuantan is situated at the coastal areas and the sea breeze cools the city.
As UHII for Ipoh - Lubuk Merbau varies from 0.3°C to 1.5°C. Figure 12
(APPENDIX 3) shows the percentage frequency and mean velocity of
wind from the various directions of 1997 to 2000 for Kuantan, Temerloh
and Muadzam Shah. The 50% of calm wind over Temerloh contributes to
warmer situation as compared to Kuantan. Kuantan receives only 25% of
calm wind. The northeasterly wind contributes another 25% of the wind.
This could be the reason why Temerloh is warmer during the day as
compared to Kuantan. Similar case happens for Muadzam Shah except
with lower warming rate as compared to Temerloh.
4.4.2 The Effect of Local Wind, the Land Breeze Towards Formation
of UHII in Ipoh
As shown in Figure 11 (APPENDIX 3) the UHII for Ipoh - Lubuk
Merbau shows warmer temperature in Ipoh over the time. The UHII for
Ipoh - Sitiawan shows Ipoh is still warmer than Sitiawan as can be seen
during the night. During the day, the UHII shows fluctuation cooling and
warming rate. This could be the result of local wind that affects Sitiawan
as it is located near the coast. As shown in Figure 12 (APPENDIX 3),
higher mean velocity from west, south and southwest (from the sea) of
sea breeze could partially trigger cool weather in the afternoon over
Sitiawan at 1.00 pm to 3.00 pm. The contribution of 40% of calm wind in
Sitiawan is still the main factor that triggers warmer temperature during
afternoon (cooling rate in Ipoh). Figure 13 (APPENDIX 3) shows the Wind
Rose Summary as comparison with Figure 12 showing the effect of sea
breeze of westerly, southerly and southwesterly that contributed partially
cool weather at Sitiawan during afternoon as compared to Ipoh. Data for
Ipoh is not available due to technical error of the database system. The
availability of this data could produce some promising result of the study.
13
5.
CONCLUSION
A number of factors contribute to the occurrence and intensity of heat
islands. These include weather, geographic location, time of day and season, city
form and city functions. In this study, the weather mainly wind, influences
formation of heat islands. Comparison of Urban Heat Island Intensity (UHII) trend
based on daily maximum intensity (ΔT
[min]) and daily mean intensity (ΔT
(u-r)
(u-r)
[max]), daily minimum intensity (ΔT
(u-r)
[mean]) in 1996 to 2000 at two urban
cities, Ipoh and Kuantan have shown no significant correlation of UHII with
respect to time with very weak negative and positive trend observed. Weak
negative trend could be subjected to warming of temperature at the rural with
respect to urban. The positive trend could be associated to warmer temperature
over the urban areas. Further details study using annual mean hourly
temperature has indicated both Ipoh and Kuantan are still warmer as compared
to their surrounding with temperature differences of 0.5 to 1.5°C. In this study,
changes and fluctuation of UHII is affected by local wind system, the land breeze
as in the case of (ΔT(u-r) [mean]) between Ipoh - Sitiawan and the wind system
associated to the seasonal monsoonal wind pattern, as in the case of (ΔT(u-r)
[mean] ) for Kuantan - Temerloh. The primary atmospheric controls on UHI
development are wind and cloud. The strongest UHII is observed during the night
when skies are clear with no cloud formation and winds are calm. In this study
the cloud cover is not taken into account when obtaining the magnitude of UHI
since average cloud cover over equatorial region is almost the same throughout
the day and the night, It has daily average of 5 to 6 octas. Analysis of UHII based
on comparing maximum, minimum and mean daily temperature from 1996 to
2005 against population growth showed comparatively higher trend of negative
correlation between them. This is due partly to small percentage of annual
population growth that economic and sosial activities do not contributed towards
temperature increases over the urban areas. This contradiction should be further
examined using current data and other parameter that might influence the UHI.
14
6.
RECOMMENDATIONS
1.
Further urban canopy layer heat island study should be carried out in
order to really prove the finding on why average max Urban Heat Island Intensity
(UHII) decreases as population increases.
2.
Boundary layer Urban Heat Island (UHI) should also be studied to see the
effect of turbulence mixing height, layer of warmer atmosphere that creates dome
and plume shapes with respect to urban heat island magnitude especially in
urbanized cities such as Kuala Lumpur, Petaling Jaya, Johor Bharu and Penang.
3.
Surface properties of the urban areas such as surface geometry, surface
thermal properties and surface conditions control most of the UHII. Study from
the viewpoint of surface properties could relate us to more understanding of
urban heat island formation. For example, increased surface area (geometry)
and trapping of solar radiation by multiple reflections leads to warming due to
greater absorption of solar radiation. Sheltering of buildings reduces convection
heat loss from the surface and near-sub surface.
4.
Heat released by urban energy use in building, vehicles and from human’s
activities contributes to the warming of cities. Study of this anthropogenic heat
should be carried out to better understanding on how warmer urban atmosphere
could intense the urban heat island.
15
REFERENCES
[1]
Rizwan Ahmed Memon, Dennis Y. C. Leung and Liu Chunho. 2008. A
review on the Generation, Determination and Mitigation of Urban Heat
Island. Journal of Environmental Science 20: 120-128
[2]
James A. Voogt. 2002.
Encyclopedia of Global Environment Change,
Causes and Consequences of Global Environmental Change Vol 3: 660666
[3]
Konopacki and Akbari. 2002. Energy Saving for Heat Island Reduction
Strategies in Chicago and Huoston. Draft Final Report, University of
California, Berkeley: LBNL- 49638.
[4]
Changnon et al. 1996. Impacts and Responses to the 1995 Heat Wave: A
call to action. Bulletin of the American Meteorological Society 77: 14971505
[5]
Oke. T.R. 1987. Boundary Layer Climates (2nd Edition), University Press,
Cambridge.
[6]
http://en.wikipedia.org/wiki/Kuantan
[7]
http://www.actionbioscience.org/environment/voogt.html
[8]
http://en.wikipedia.org/wiki/Ipoh#Economy
[9]
http://www.actionbioscience.org/environment/voogt.html
[10]
http://www.cpc.noaa.gov/data/indices/
[11]
http://idosi.org/hssj/hssj2%282%2907/8.pdf
16
APPENDIX 1
Mean Monthly Rainfall
17
APPENDIX 2
Annual Mean Temperature
18
APPENDIX 3
Figure 6: Urban Heat Island Intensity (UHII) for Ipoh
20
Figure 7: Urban Heat Island Intensity (UHII) for Kuantan
21
22
23
Figure 8: UHII towards negative trend
24
Figure 9: Average Max UHII (1996-2005) Against Population Difference for Kuantan and Ipoh
25
Figure 10: Annual Mean Hourly Temperature Variation and UHII of Kuantan and Ipoh
ΔT
mm
1997
1998
1999
2000
2001
1998
1999
2000
2001
ΔT
mm
mea
n
1997
26
Figure 11: UHII for Ipoh and Kuantan based on Annual Mean Hourly Temperature
UHII Between Ipoh-Sitiawan and Ipoh-Lubuk Merbau (1997-1998)
UHII Ipoh-Lubuk Merbau
UHII Ipoh-Sitiawan
1.5
UHII
1.0
0.5
0.0
-0.5
2
4
6
8
10
12
14
16
18
20
22
24
2
4
6
8
10
12
14
16
18
20
22
24
16
18
20
22
24
Annual Mean Hourly Temperature 1997 and 1998
UHII Between Kuantan-Temerloh and Kuantan Muadzam Shah (1997-1998)
UHII Kuantan-Muadzam Shah
UHII Kuantan - Temerloh
1.5
1.0
UHII
0.5
0.0
-0.5
2
4
6
8
10
12
14
16
18
20
22
24
2
4
6
-1.0
-1.5
-2.0
Annual Mean Hourly Temperature 1997-1998
27
8
10
12
14
Figure 12: Mean Velocity of Winds from Various Directions
28
29
30
31
Figure 13: Typical wind rose summary for Sitiawan 1987 showing mean velocity and direction of sea breeze
that partially cools Sitiawan during the day
Wind Rose Summary 1987 for April
Wind Rose Summary 1987 for June
Wind Rose Summary 1987 for October Wind Rose Summary 1987 for December
32
Table 1: The UHII for Ipoh and Kuantan based on Annual Mean Daily Maximum, Minimum and Mean Temperatures (1996-2005)
UHI INTENSITY
KUANTAN - MUADZAM
IPOH - LUBOK MERBAU
SHAH
IPOH - SITIAWAN
YEAR
KUANTAN - TEMERLOH
MAX
MIN
MEAN
MAX
MIN
MEAN
MAX
MIN
MEAN
MAX
MIN
MEAN
1996
1.179
0.466
0.359
1.054
1.014
0.724
-0.456
0.489
0.203
-1.086
0.320
0.036
1997
0.672
0.725
0.513
0.594
1.249
0.873
-0.398
0.755
0.450
-0.971
0.479
0.155
1998
0.607
0.567
0.407
0.479
1.153
0.888
-0.410
0.785
0.332
-1.030
0.471
-0.016
1999
0.473
0.724
0.313
0.327
1.163
0.844
-0.793
0.678
0.190
-0.938
0.298
0.065
2000
0.584
0.597
0.350
0.730
1.105
0.934
-0.761
0.554
0.358
-0.973
0.352
0.157
2001
0.387
0.485
0.273
0.578
1.030
0.766
-0.648
0.699
0.304
-1.248
0.392
-0.015
2002
0.877
0.790
0.492
0.561
1.147
0.774
-0.372
0.687
0.460
-1.115
0.579
0.193
2003
0.002
0.344
-0.108
-0.230
0.507
0.101
-0.775
0.558
0.140
-0.971
0.462
0.104
2004
0.418
0.485
0.247
0.230
0.914
0.471
-0.996
0.058
-0.323
-1.220
-0.187
-0.471
2005
1.020
0.090
0.127
0.476
0.525
0.451
-1.107
0.186
0.036
-1.394
0.186
-0.307
33
Table 2: Annual Mean Daily Max, Min and Mean UHII (1996-2005) and Population Growth Different for Kuantan
(KUANTAN - TEMERLOH)
YEAR
AVERAGE UHI INTENSITY
(KUANTAN - MUADZAM SHAH)
POPULATION GROWTH (x1000)
UHI INTENSITY
POPULATION GROWTH (x1000)
KUANTAN MUADZAM
KUANTAN
MUADZAM
SHAH
SHAH
316.1
97.1
219.0
MAX
MIN
MEAN
KUANTAN
TEMERLOH
KUANTAN TEMERLOH
MAX
MIN
MEAN
1996
-1.086
0.320
0.036
316.1
166.3
149.8
-0.456
0.489
0.203
1997
-0.971
0.479
0.155
327.2
161.4
165.8
-0.398
0.755
0.450
327.2
100.0
227.2
1998
-1.030
0.471
-0.016
338.7
155.9
182.8
-0.410
0.785
0.332
338.7
102.8
235.9
1999
-0.938
0.298
0.065
350.3
150.3
200.0
-0.793
0.678
0.190
350.3
105.6
244.7
2000
-0.973
0.352
0.157
361.1
143.9
217.2
-0.761
0.554
0.358
361.1
108.5
252.6
2001
-1.248
0.392
-0.015
368.9
145.0
223.9
-0.648
0.699
0.304
368.9
111.8
257.1
2002
-1.115
0.579
0.193
377.1
146.2
230.9
-0.372
0.687
0.460
377.1
115.2
261.9
2003
-0.971
0.462
0.104
385.7
147.6
238.1
-0.775
0.558
0.140
385.7
118.6
267.1
2004
-1.220
-0.187
-0.471
394.5
149.0
245.5
-0.996
0.058
-0.323
394.5
122.1
272.4
2005
-1.394
0.186
-0.307
403.3
150.4
252.9
-1.107
0.186
0.036
403.3
125.6
277.7
34
Table 3: Annual Mean Daily Max, Min and Mean UHII (1996-2005) and Population Growth Different for Ipoh
IPOH & SITIAWAN
UHI INTENSITY
YEAR
IPOH & LUBOK MERBAU
POPULATION GROWTH (x1000)
UHI INTENSITY
POPULATION GROWTH (x1000)
MAX
MIN
MEAN
IPOH
SITIAWAN
IPOH SITIAWAN
MAX
MIN
MEAN
IPOH
LUBOK
MERBAU
IPOH – LUBOK
MERBAU
1996
1.179
0.466
0.359
706.0
191.9
514.1
1.054
1.014
0.724
706.0
154.5
551.5
1997
0.672
0.725
0.513
714.6
194.5
520.1
0.594
1.249
0.873
714.6
154.0
560.6
1998
0.607
0.567
0.407
724.6
197.5
527.1
0.479
1.153
0.888
724.6
153.6
571.0
1999
0.473
0.724
0.313
735.0
200.5
534.5
0.327
1.163
0.844
735.0
153.1
581.9
2000
0.584
0.597
0.350
747.4
203.6
543.8
0.730
1.105
0.934
747.4
152.7
594.7
2001
0.387
0.485
0.273
759.6
208.2
551.4
0.578
1.030
0.766
759.6
155.1
604.5
2002
0.877
0.790
0.492
770.5
212.2
558.3
0.561
1.147
0.774
770.5
157.3
613.2
2003
0.002
0.344
-0.108
780.6
216.2
564.4
-0.230
0.507
0.101
780.6
159.4
621.2
2004
0.418
0.485
0.247
790.3
219.9
570.4
0.230
0.914
0.471
790.3
161.4
628.9
2005
1.020
0.090
0.127
800.1
223.8
576.3
0.476
0.525
0.451
800.1
163.4
636.7
35