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CHAPTER III
STUDY AREA
3.1
Study area
Damansara is situated between Bangsar and Petaling Jaya in the state of Selangor.
It is set in a premium location adjacent to the established residential and commercial
areas. Damansara that was developed on solid soil is part of the klang river system with
3 water quality stations. The region is a mix of agricultural, forest, settlement/ urban/
industrial, and water bodies. It has a total area of about 4,300 sq.kms and a total
population of about 0.34 million people.
The Damansara basin has a total catchment area of 149Sq.km and its main river
Sg. Damansara stsrts from the northen hill reserve forest of Sg. Buloh to flw towards
south and southeast. It is about 21 km long and its journey to downstream it joins with 6
major tributaries before eventually joining Sg. Klang. These tributaries are Sg. Kayu Ara
, Sg. Pelumut, Sg. Rumput, Sg.Pelampas, Sg. Air Kuning and Sg. Payong.
S. Kayu Ara is the largest from these tributaries that is has length of 13 km,
corresponding sub-catchment areas about 29.50 km sq and average flow is865. It is a
river system draining a fast developing urbanizing catchment with about 50% of the
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areas already developed for commercial, housing and industrial. Figure 3.1 is shown the
Damansara basin
Figure 3.1
Damansara Basin
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There is 16 rainfall stations in Damansara basin but only one stations been
analysis in this project that is stations rainfall no. 12. The location of rainfall stations at
Sg. Kayu Ara, Damansara catchment been shown at Figure 3.2.
Figure 3.2
catchment
The location of rainfall stations at Sg. Kayu Ara, Damansara
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3.2
Landuse and Population
In the Klang Valley, Sg. Damansara Catchment is includes some of the most
rapidly developing urban areas. The total population is about 340 000 and will projected
to double with the completion and occupation of housing projects currently under
construction. The population is spread across the lowlying parts of the catchment, within
residential areas surrounding sattelite urban centers such as Taman Tun Dr. Ismail,
Damansara Town, Shah Alam, Subang Town and Petaling Town.
Table 1.0 : Landuse Category and its Corresponding Area in 1998
______________________________________________________________
Landuse Type
Area (km )
% Cover
______________________________________________________________
Housing
47
30.1
Industrial Area
20
12.8
Sports and recreational facilities
16
10.3
Agricultural and vacant land
16
10.3
Forest reserves
15
9.6
Institutional and public facilities
16
8.4
Commercial area
12
7.7
Palm oil plantation
8
5.1
Park and cemetery
8
5.1
Lakes and ponds
1
0.6
______________________________________________________________
Total
156
100.0
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3.1.1 Selection of Sites
The study areas or sites will be selected such that they are built-up and have well
defined catchment, and runoff from other areas do not enter into the drainage system of
the selected area. The different landuse categories to be used for this study will include,
mainly the following:
-
single story bungalow house;
-
single storey terrace house;
-
residential flats;
-
shop house;
-
school buildings; and
-
commercial buildings, etc.
Once the sites are selected, their hydrological parameters such as area, slope,
roughness, time of concentration, imperviousness, directly connected impervious area
(DCIA) to the drainage system, etc. will be determined. Few representative sites of
similar landuses will be selected to study develop a correlation. Number of sites will
depend on the technical, logistic and other available resources.
For this study, the sites will be selected from the urban areas, mainly from Kuala
Lumpur and Selangor, which will be based on different landuse categories. Further more
some sites will be selected from the area going through development procedures so that
the pre and post development scenarios can easily be determined thorough the study.