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IV. RESULT AND DISCUSSION
4.1 Characteristic of Study Area
The characteristics of a catchment area will influence the transformation of rainfall into discharge in hydrologic system. It explains the importance of research
on characteristic of upper Cimanuk catchment area.
4.1.1 Physiographic and Geology setting
Physiographic of the catchment area is within the Bandung zone that has volcanic quarter Bemmelen, 1949. The catchment is surrounded by mountains, in
the west is bounded by Papandayan Mountain +2,573 asl and GunungKareta Mountain +2608 asl, while its eastern boundary is Cikuray Mountain +2,820 asl.
The flow pattern is mostly radial in mountain region. The pattern of the middle part of the catchment, where most part of the main river flows, is rectangular which is
characterized by tectonic activity. Figure 4.1 shows distribution of elevation and 3 dimensional visualization of the catchment area. Elevation of catchment area is
derived from SRTM The Shuttle Radar Topography Mission image with 30 x 30 m
resolution. Slope and length of slope are two factors that determine the topography of
catchment area. Those factors are important for surface runoff because they determine velocity and volume of runoff Asdak, 2002. Figure 4.2 shows slope
distribution in UCCA. The Slope of the bounding mountains is generally very steep on the top and getting slighter on lower flank of mountain. Smoother slopes can be
found in the middle of study area, where main river of Cimanuk flows. Type of drainage pattern of study area is dominated by dendrithic type.
Geological condition of upper Cimanuk catchment area is mostly formed by volcanic material resulted from volcanic eruption of Mt Papandayan and Mt
Cikuray. There are three separated geological age in this area; the younger volcanic rock late Holocene in western part; mio-pleistocene rock in eastern part; and
Pleistocene age in the middle of Upper Cimanuk Catchment area Van Bemmelen, 1949 and Azwar, 1992. The geology map of study area is shown in figure 4.3.
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Figure 4.1 Elevatio
on Map and
3D VIS
3D visualiza
Ciku
SUALIZATION
ation of Upp
uray Mt.
per Cimanuk
Papand
Kareta Mt
k Catchment
dayan Mt.
t.
Area.
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Figure 4.2 Slope Map of Upper Cimanuk Catchment Area
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Figure 4.3 Geology map in Upper Cimanuk Catchment Area
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4.1.2 Soil Characteristics
Kategori