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I . I N T R O D U C T I O N
1.1. Background
The global warming as a consequence of rapid growth of population and industrialization anthropogenic forcing, has impact to the global climate and the
environment. One of the impacts of global warming is sea level rise. Sea level rise related to the changes in global temperature which become warmer. There are some
main processes influencing for sea level rise, namely: thermal expansion, ocean current variations, submarine topography, the melting of glaciers and ice caps, and
the loss of ice from the Greenland and West Antarctic ice sheets Douglas et al., 2000; IPCC, 2007; Kinver, 2008.
Since 1990 sea level has been rising at a rate of 3.4 millimetres per year, twice as fast as its average over the 20th century. Those conditions were linked the
rate of sea level by global temperature rise. The temperature is getting warmer causing faster sea level rises. There is a correlation between global sea level and
global temperatures. According to recent report by the Intergovernmental Panel on Climate Change IPCC estimates that in response to rising temperatures 1.0°-
3.5°C higher than 1990 levels in 2100, sea level will have risen by around 15-95 cm by the year 2100. Having correlated temperature history with sea-level history,
Rahmstorf 2007 estimated future sea level position based on projections of future temperature.
The researchers predicted the global sea levels will rise exceed to 200 cm in the 21
st
century Vermeer, 2009; Grinsted et al., 2009; and Jevrejeva et al., 2010. Rising of sea level has an impact including: decimating the national territory,
decreasing coral reef populations, sinking islands, economic loss, etc. Indonesia has approximately 81,000 kilometers of coastline and 17,000
islands Dahuri et al. 2001. When the sea level has risen about one meter, this can decimate the national territory. Indonesia has predicted to have sea level increase by
the end of this century that potentially submerges some coastline up to 50 meters inland. It was estimated that more than 405,000 hectares of Indonesian land will be
submerged, thousands of small islands will disappear, hundreds of thousands of hectares of fishponds and paddy fields in tidal areas will be lost, and coastal abrasion
and seawater intrusion will threaten even the terrestrial population Rolasisasi, 2008.
2 One form of the sea level rise impact is tidal flood. Tidal flood may occur due
to high tide wave overflowing coastal land. Today about 50 of the worlds population lives in this critical interface between land and water, where 13 of the
worlds 20 largest cities are located at the coastal regions. Cohen et al 1997 estimated that in 1994 about 2.1 billion people 37 of the worlds population lived
within 100 km of a coast. However increasing populations and development of the largest cities are placing significant stresses on the losses and other resources
destruction, when the disaster caused by the rise of sea level appeared. In Indonesia, tidal flood occurred almost on all of Northern region of the Java
Islands Pantura, such as Jakarta, Subang, Cirebon, Semarang, and Surabaya. Sofian 2008 reported that rapid sea level rise in Jakarta, Semarang, and Surabaya,
predicted causing the inundation flood in area having elevation between 0 and 4 meter above sea level. Moreover the dynamic climate anomaly of the climate
hazards could also raise the amount of the tidal flood. Surabaya as the second largest Indonesian city has more valuable to the
study; it is driven by the economic rationalities with PDRB Domestic Bruto Regional Product in million about 154 billion rupiahs and population about 3
million BPS, 2009. Tidal flood may cause diseases, economical loss and also damage to the infrastructure corrosive. Wuryanti 2002 said there is an indication
of the sea level rise in Surabaya; the tidal flood for 12 ~ 48 hours in 2002 had caused inundation level in range between 5 to 100 cm. In last January and 19th February
2010 there was tidal flood in some area of Surabaya with inundation level ranging from 20 to 160 cm within 30 minutes to 6 hours Iwa, 2010.
This research is study about the prediction of the sea level rise in common and extreme conditions on the basis of MRI-CGCM data model, and examining
vulnerable area which affected by tidal flood in coastal region of Surabaya city.
1.2. Objective of Research
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