III. METHODOLOGY
3.1 Time and Location
This research was conducted from March to July 2008 including process of developing method and implementation of method. Developing the method was
accomplished at Bogor Agricultural University, while implementation of method was conducted for study area in Sidoarjo Regency, East Java Province.
3.1.1 General Overview of Study Area
The study area is working area of The National Sidoarjo Mudflow Mitigation Team Badan Penanggulangan Lumpur Lapindo or BPLS, which is
located in Sidoarjo Regency, Province of East Java covering three districts i.e. Porong, Jabon and Tanggulangin. The location is shown in Figure 3.1.
Figure 3.1 The study areas in Sidoarjo, East Java
Sidoarjo is located about 20 km South of Surabaya the capital of East Java Province. The boundary of the study area lies between the latitude of
7
o
30
’
35
”
- 7
o
32
’
47
”
S and longitude 112
o
41
’
59
”
- 112
o
44
’
00
”
E President Regulation No. 142007. Porong River flows through the Southern part of the
study area where mud is emptied into the Java Sea.
3.1.2 Geological Condition
Based on Geology Technique Map Malang Sheet, the sand of the area surrounding mud flood centre point belongs to alluvium Pusat Lingkungan
Geologi, 2007. This alluvium is in the form of river sediment that consists of sandy silt which is dominantly spreading on top layer followed by sand and sandy
clay. Generally, the strength level of soil and rock for this formation is very low Pusat Lingkungan Geologi, 2007.
The geologic map of Porong – Banjarpanji shows a well-defined surface structure called Watukosek fault zone IAGI, 2007. Watukosek fault is parallel
and very close to the hot mudflow centre point near the Banjarpanji-1 well. Similar patterns and directions from the fracture and mudflow centre can be
interpreted as the mudflow is related to the fracture zone IAGI, 2007.
3.1.3 Climatology
Information on climate condition is obtained from Juanda Geofisic and Meteorology Agency, Surabaya during 5 years from 2000 to 2004. The
temperature of the area is approximately 27.4
o
C to 27.7
o
C. The lowest temperature ever achieved during last 5 years is 19.1
o
C and the highest
30
temperture is 37
o
C. The lowest temperature occurs on July-August, while the highest temperature occurs on October-November.
The average rainfall of the area is 170 mm with 82.8 rainy days. Wet season occurs between November to April, while dry season between May to
October. In the wet and dry seasons the relative humidity is around 76.4 – 78.4 and 73.6 – 78.8 respectively.
3.1.4 Demography
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