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I I I . M E T H O D O L O G Y A N D M A T E R I A L S
3.1 Study Site
The research was conducted in Surabaya, East Java, Indonesia, which is geographically located at 112°36’-112°21’ East and 7°12’-7°21’ South. The extent of
Surabaya city area is 34,465 ha, consisting of 31 sub-districts with 163 villages. Surabaya represents the city of Indonesia that has relatively high temperature,
ranging from 20° to 34.7°C, with the humidity ranging from 35 to 98 and air pressure at about 1014.8 Mbs. The precipitation rate is about 183.2 mmyear, with
highest precipitation occurred in December to May. Wind speed average is 7.0 knot, with the maximum speed at about 26.2 knot. Historically, the lowland of Surabaya
city came from the sediment formation of the sea area. Known by the soil type predominantly found, i.e.: clay-sand alluvial and limestone hill in part of western
Surabaya.
Figure 3.1: Location of Study Site
20 Surabaya municipal mostly belongs to lowland area with average altitude
ranging from 3 to 9 meter above sea level. Meanwhile the hilly area is located in southwestern namely Bukit Lidah and Bukit Gayungan having altitude ranging from
25 to 50 meter. The coastal areas span from the west municipal border to Tanjung Perak
harbor and Eastern area of Sidoarjo regency border. The coastal area includes 9 sub- districts and 17 districts. Generally the coastline is located in the Eastern and
Northern as well as western part of the Surabaya city Figure 3.2. In the Eastern part of Surabaya city, the predominant landuses are fish and salt ponds, wetland, fields,
and swamp while in the Northern part is fish ponds, warehouse building, harbor with some settlement area.
3.2 Data
The main and supporting data used in this study include: a
IPCC data model for global sea level projection used from MRI – CGCM model with SRES A1B scenario. Data global sea level was derived from
WCRP World Climate Reseach Program that can be accessed from https:esg.llnl.gov:8443data.
b Tidal gauge data from University of Hawaii Sea level center and
Indonesian Navy annual report 2010. The tidal data were derived from UHSLC University of Hawaii Sea Level Center which can be accessed
in http:ilikai.soest.hawaii.eduuhslcdatai.html. Data were provided from 1991 to 2004.
c SRTM Shuttle Radar Topography Mission acquired in 2006, with 30 m
spatial resolution collected by National Mapping and Coordination Survey Agency Bakosurtanal. SRTMDEM data used for establish
contour line and elevation model. d
Sea wave level surface data from AVISO Archiving, Validation and Interpretation of Satellite Oceanographic data 1993-2008. AVISO is
Satellite altimeter data which is a combination merge from multiple satellite altimeters including TOPEX Poseidon T P, GFO, Envisat,
ERS-1 and 2, and Jason-1, available from October 1992 to October 2008.
21 This data was used by author as a parameter to define maximum value of
sea level in transition month of El-nino La-nina. e
RBI Rupa Bumi Indonesia Map 2001 at scale of 1:50.000 created by the National Mapping and Coordination Survey Agency Bakosurtanal. The
RBI map is topographic map in the form of digital vector data. The other data are landuse landcover map coupled with attribute data such as
administration, river, road, etc. The RBI was used for mapping and tidal flood analysis.
f Surabaya subsidence level data for 2003 ~ 2004 which were derived from
Indonesian Geology Bureau. The subsidence data was used as a parameter to calculate relative sea level.
g The Indonesian Navy tidal gauge annual report data were used as a
reference and prediction of tidal floods occurrence can be done in Surabaya city.
h Interview data by the local resident and observation at the potential
inundation areas.
3.3 Required Tools
