CHAPTER 2 Climate Change Effect

Chapter 2

Climate Change Effect

In the second chapter, after explained the climate changes in the general knowledge, the author focusses on the climate change affects which is acceleration of rising sea level information. Through this chapter, there will be several part to explain it in more specific aspects, i.e. what are the causes of sea level rise, how and what are the effect, where it is more noticeable around the world, how much the increase has been over past 100 years or so, and why the flood hazard become one of the biggest effect in the world.

The Causes of Sea Level Rise

The issue of climate change began because of the human activities impacts has prompted different results fundamentally, including the global sea level rise. Based on the information by IPCC (2007), the global sea level rise factor shows a geographical variety due to several variables containing the conveyances of transforms in sea

circulation, salinity, warmth, and winds. The two main contributions are water mass commerce in steric impacts and continents, regulated by local to worldwide degree. Moreover, in Lombard et al. (2005), Church et al. (2008), and Luu et al. (2015) report, they mentioned that the El Nino Southern Oscillation and Pacific Decadal Oscillation are the ocean dissemination varieties example. The level of sea does not rise consistently and uniformly, and it is ascending in all sea basins (Legeais et al., 2018). The urban’s GHG substance discharges are

becoming the main causes of sea level improvement acceleration (Slangen et al., 2016). Several previous researchers report from England et al., Hamlington et al., and

McGregor et al.

in 2014, observed that in the Pacific Decadal Oscillation signal estimation, the warmth of Atlantic and Indian Oceans improved winds exchange and these improvement to the heightened ocean level ascent in the west of Pacific Oceans. More than the twentieth century, the contributions from ground water utilization, supply stockpiling, and fast ice sheet mass transformation are not assumed by coupled atmosphere models and evaluated from perceptions. Moreover, Oppenheimer et al. in 2019 argued that the aggregate taking everything into account, containing the

researcher contributions, gives a demonstrated gauge of that the level of sea changes which can be appeared differently in relation from tide-measure records and satellite altimetry documents.

In accordance with the sea temperature observations, in current decades, the thermal extension has devoted generously to the level of sea rise. The atmosphere models are reliable with the sea perceptions that temperature development had expected to keep on adding to the sea level rise throughout the following hundred years. Since profound sea temperatures change gradually, the thermal enlargement would continue for many centuries regardless of whether atmospheric concentrations of greenhouse gases emissions were balanced out. Subsequently, based on IPCC data (2014a), the global sea level has been ascending estimate all through the 21 st century. and is anticipated to increase at a quickened

The Sea Level Rise Impact

The impacts of ocean level ascent are evaluated utilizing a broad assortment of way from regional to worldwide range. The presentation of this method is implemented at all ratios to evaluate esteems presented to this ascent. It has doubtlessly detrimental results and it will associate diversely with the assortment people’s exercises and

different progression of drivers in all coastal line nations. For instance, the dwelling and development of sustainable power source requirement in the coastal areas will get this effect (Hardley, 2009), including the fundamental water transportation infrastructure such as port and maritime bases. Moreover, McGranahan et al. (2007) and Smith (2011) said that the climate intense influence on a broad vary financial enterprises which encouraging coastal societies and represent a further hazard to a considerable lot of the quickest increasing low-lying environment in the developing nations.

The significant acceleration of ascending sea level impacts are changes in coastal line and low-lying urban regions. McLeod et al. (2010) noticed that the example of that effects are coastal deterioration, flooding, and saltwater interruption into deltas and estuaries, that are aggravated by personal prompted raised. Approximately 625 million individuals living in low altitude coastal urban area is in danger which

representation to this level of sea ascent perils (Neumann et al., 2015). This hazard can drive part of the community to relocate their house from low to high areas and

influencing the dynamic of coastal

populace. Moreover, it is also affecting the worldwide population because of the degradation in endurable territory. However, the principle of its impact can happen not only in the coastal line zone but also the zones whenever near the water source and supply a sediment or deltas such as along the riverbanks. In the other hand, Nicholls et al. (2010) reported that the fundamental

biophysical effects of this are expanding deluge

devastation, dry-land misfortune because of submergence and disintegration, saltwater interruption into ground water, wetland misfortune and changes, and accelerating water tables and hindered waste.

The Most Noticeable Sea Level Rise Impact Location Around the World

The ocean level ascent previously has started to extinguish numerous low-lying urban land areas. A few areas have been permanently immersed and constrained enormous scale removal of neighbourhood communities. Penna and Rivers (2013) mentioned that in Bangladesh (i.e. Bhola Island) almost 50% has been flooded and displaced 500,000 people. Based on Hallegatte et al. report in 2013, there are total 20 coastal urban areas where normally misfortunes every year and raise most by virtue of optimistic sea level rise, if transformation keeps up just present defines guidelines or flood likelihood (see Figure 4). Additionally, Nicholls and Cazenave (2010) noticed that the most countries in the East Asia are notably powerless against ocean level ascent because of fast financial development and coastal movement of individuals to the city waterfront or coastal regions along with high paces of human subsidence in deltas where a significant number of the densely population regions are found.

Simultaneously, economic development in these nations expands the financial ability to adjust (Nicholls et al., 2010). Conversely, while numerous African nations encounter a comparative tendency in accelerated coastal cities development, degree of financial improvement is ordinarily lower (Kebede and Nicholls, 2011; Hinkel et al., 2012).

Figure 4. Coastal Cities Average Annual Losses (Hallegatte et al., 2013)

In Figure 4 above, the researcher divided into three different categories in average annual losses by per cent indicator. Alexandria in Egypt and Barranquilla in Colombia are becoming the area with the highest risk (> 100%) of coastal flood hazard because of the accelerating of sea level. One of the other reasons why they become the most risk able area because their condition geographical are on the low-lying land. Therefore, Nicholls et al (2010) also said that the government already took a mitigation to prevent submergence and persistent flooding, numerous delta metropolis currently relies upon an essential urban hard structural element for flood defence and water

treatment.

Deltas are affected by

stream and maritime tempest floods. Deltas under

changing worldwide atmosphere are caused

for the most part by unprecedented precipitation-prompted floods and ocean level ascent. McLeod et al. (2010) and Day et al. (2011) said that it will achieve about expanded coastal flooding, diminished wetland zones, increased coastal erosion, and developed salinization of developed land and ground water. The surface territory of flooding in 33 basins area over the globe is evaluated to enhance by 50% below ocean level ascent appraisal as anticipated in 2100 (Syvitski et al., 2009). Nowadays, numerous river systems convey significantly less residue to their deltas since that dregs are caught in upstream dams or is separated for material of building. With inventory of unconstrained sediments, land decline remains deficiently redressed, not to mention the bigger urban subsidence, and it begin to disappear. It is recognizable in deltas urban areas such as Bangkok, Hamburg, Jakarta, Rotterdam, and Shanghai (Deltares, 2011).

The Significant Number of Sea Level Acceleration Over 100 Year

The global average sea level additionally rises or falls when water is transferred from land to sea or vice-versa. Several human activities provide to sea level change, particularly by the ground water extraction and reservoirs construction. On previous research, this average number has improved around 0.19 metres between the year of 1900 and 2010 with a pace of about 1.7 mm per year (IPCC, 2014b). This pace is predicted to raise up again in future with further climatic temperature increment. In other words, today retreat of ice sheets and caps are making a generous contribution to the acceleration of sea level. Their contribution should diminish in resulting centuries as this store of freshwater reduces.

The Fifth Assessment information by IPCC (2014b) mentioned that this global sea level average might ascend between 0.52-0.98 metres before 21 st century is over (see Figure 5). In other hand, the National Oceanic and Atmospheric Administration (NOAA) prediction statement inform that sea level is accelerating until 2 metres in 2100. The ice sheets on the earth maintain adequate water of sea level improvement in a few metres. The ice sheets in Antarctic and Greenland are the two biggest which encompassing roughly 99% of the ice fresh water. It is assessed that if the Greenland’s ice sheet liquefies effectively, the sea level can ascend around 6 metres. Meanwhile, Antarctic’s ice sheet might cause around 60 metres. According to DeConto and Pollard future prediction (2016), Antarctic ice sheet will devote more than a metre constantly in 2100 and it will raise up above 15 metres in 2500.

Figure 5. Global Average Sea Level Rise (IPCC, 2013)

Flood Hazard (Sea Level Rise Impact)

Many significant climate impacts are correlated with outrageous occasions and it can be transient. For instance, flood or events that can reach out over months or years such as droughts. While sea level rise is responsible for significant number of the world’s most destructive floods, there have been numerous different instances of the main flooding since 2015 (WMO, 2019). Some of these floods have been generally endured reactions to exorbitant precipitation in tropical regions during the rainy season. However, others have been shorter-term floods, incorporating flash floods related with intense precipitation over a couple of hours. Overwhelming rains have likewise contributed to major avalanches in certain parts of the world. Moreover, floods are frequently connected with outbreaks of water-borne illnesses or those related to poor sanitation and it have obstructed individual’s daily exercises. As a result, post flood

debacle diseases like diarrhoea and leptospirosis can disseminate and influence on society’s health. Society are additionally experiencing misfortune from the devastation to estate due to the flooding and the expanded expenses of recovery which is an unanticipated cost overwhelm. Hadi (2017) said that the flood disaster diminishes the individual’s life quality and declined the land dwelling values. However, Otto et al. (2017) argued that climate change is relied upon to compound present society vulnerabilities and cultural disparities. In the following picture which delivered by the Columbia University’s researcher team, it tends to be seen that the flood peril frequency disseminates all over the world (see Figure 6).

Figure 6. Global Flood Hazard Frequency and Distribution (CHRR and CIESIN, 2005)

The image above contains different geospatial

representations of flood occasions. A few floods are delineated as focuses georeferenced to the nearest degree. Other floods are described by polygons and to decide frequency of flood hazard, a 2.5- minute network overlays the flood information and the quantity of flood occasions per grid cell is recorded. A flood occasion is defined as any bit of flood representation happening within a grid cell. Thus, if a grid cell is crossed by a flood polygon’s border, then the recurrence raises by one. Ifa point is within the grid cell borders, the frequency develops by one. In addition, flooding at similar zones, but at various times likewise enhance the frequency. The frequency range is characterized into deciles, 10 classes of a roughly equivalent number of grid cells. Deciles are the chosen technique of

dissemination because of contemplations of certainty with the information. Regions with white colour are not necessarily without chance from perils. However, it may rather be an ancient rarity of a veil that rejected from examination those zones with a populace density under 5 individuals for each square kilometre and without considerable agriculture (CHRR and CISEIN, 2005). In other hand, the red colour indicates areas that has the high flood occurrence frequency and the blue colour

demonstrate the low flood hazard incidence frequency.

As the most frequent sea level rise effect, flood present genuine hazard to inhabitants and the urban environment (Nicholls, 2004; Marfai et al., 2007; Hanson et al., 2010). Sivakumar (2006) noticed that from 1993 to 2002, the flood perils were reached about 40% (1,060 occasions) of total hazard risk (2,654 events) in worldwide (see Figure 7). The occurrence of flood is more frequent and contradicted with other common risks such as droughts, forest fires, high winds, and landslides. Due to their tremendous recurrence, catastrophe related with flood is regularly high. The range of developing cases is influencing the individual’s life quality and financial misfortunes. As noticed by stevens (2012), 178 million individuals were impacted by flood in 2010 with whole financial misfortunes above US$ 4 million. In addition, the risk of flood in urban’s lowland civilizations can develop in the following year in numerous global areas due to a countless driver; including climate change (i.e. expanded precipitation, extraordinary runoff, and acceleration of ocean level), land subsidence, land use management, populace development, and the expansion in resources situated in floodprone districts (IPCC, 2012; Jongman et al., 2012; Hirabayashi et al., 2013).

Figure 7. Natural Hazard Events (Sivakumar, 2006)

Recognizing these outcomes in the urban’s lowland, based on the previous research studies, the idea of flood risk mitigation has been developing and supplanting the more straightforward objective of diminishing flood hazard pinnacles or water levels (Balica et al., 2009). In fact, when seeing the ongoing city drainage ideas created throughout the most recent half century, there seems to be a constant development against more exhaustive methodology. During the year of 1970, regular end-of-pipe arrangements, with the purpose of creating sanitary outcomes in quick releasing flood pinnacles which were placed under warps since cities were experiencing flood and observing the movement of this issue from one to another areas. Fletcher et al. (2014) mentioned that city drainage encountered to recuperate capacity and infiltration limits, improve the stream paths, coordinate the quality and quantity components which make an opportunities for upgrading biodiversity and incorporate resolutions with urban landscape, and revive the city around water element as organizing components, decline socio-economic misfortunes, and reinforce a healthy environment. Recently, the idea of urban resilience has been carried into the policies consideration globally by the government and stakeholders. In other words, the general city resilience targets are pursuing continuously at low risks in future, by attempting to decrease vulnerabilities and improve the ability to react the environmental damages.

As a conclusion on this chapter, the most danger of climate change effect to the human and physical urban environment condition are tropical cyclones and sea level rise. The intensification of sea level rise happens mostly in the western topical Pacific Ocean due to the Atlantic and Indian Ocean’s surface temperature increases. This thermal extension is continually predicted to subsidize over the hundred years and provoke a danger hazard to the coastal cities and low-lying urban condition in

worldwide such as the city of Jakarta in Indonesia. Meanwhile, Indonesia is situated at the middle of Indian and west Pacific Ocean. Therefore, based on the coastal cities’ average annual losses data, Jakarta is in the number sequence position 9 and automatically included in top 10 coastal cities where average annual losses due to acceleration of sea level impact.

The impact of acceleration rising sea level is increasing the number of flood risk; building, hard structural element (e.g. dikes and roads), subsurface infrastructures (e.g. drainage and sewerage) damage; and water treatment disruption. It can be seen in the global flood hazard frequency and distribution data that Indonesia included in the

red colour zone which has the high flood occurrence. Moreover, it happens seasonally and will be exacerbated during rainy season. In other words, flood become the most frequent natural hazard and impact from the sea level rise. That impacts generally refer to effects on built and physical of urban space environment such as residential neighbourhoods, commercial, waterfront, etc. Straightforwardly, it likewise gives impact on urban environment and the community’s condition.

Accordingly, the implementation of any strategy in the policy has potential for thump on impacts. It is valid of adaptation and mitigation actions which can improve or strife with other sustainability targets in the urban environment. These can be especially intense in urban where associations and dependencies among individuals and infrastructures are particularly dense. Recognizing these potentials compromise adds in more incorporated climate change regulation and generally it is shaped inside the governance adaptation and mitigation through the strategies everywhere throughout the world (Dawson, 2007). However, these should be deliberately arranged and figured out how to boost their functionality (Gill et al., 2008). Therefore, the author identifies all the problems due to the climate change effect in Jakarta and evaluate the current Indonesia’s policies such as flood prevention and water management which still has a lack of mitigation and intervention these issues on the next chapter.

Chapter 3

Study Area Selection: Jakarta, Indonesia

According to the previous chapter, the climate change effect which is the acceleration of rising sea level have endangered and involved crucial risk to coastal civilizations globally. Therefore, the study area that author select, is the country that has a huge risk of sea level rise around the coastal line area. Currently, numerous island states are encountering that effects such as erosion, flood, and land submergence. These influences are turning into a genuine threat in coastal areas. Based on Marfai and King (2007a) report, Indonesia is one of the developing countries in South East Asia which encounters the most noteworthy number of flood risk. Indonesia known as an archipelagic and vulnerable country especially in coastal line areas (Liang and Gang, 2010). Marfai (2011) said that Indonesia endures serious issues identified such as an expansion ofwater saltiness, coastal inundation, and river flood. A lot of Indonesia’s cities low land and coastal societies have been compromised by flood, particularly city in the north of Java Island (Marfai and King, 2007b; Marfai, 2011) such as the city of Jakarta. In fact, Jakarta had encountered many flood cases in several excuses.

Jakarta was formed in the sixteenth century in Indonesia and it presently assumes a crucial role in local and national improvement. Jakarta envelops an area of around 654 km 2 and it is situated in the north of Java Island (see Figure 8). Based on UN World Urbanization Prospects latest report, Jakarta’s civil population is currently approximated at 10,770,487 in 2020 and since 2015, it has developed by 597,099 which represents a 1.15% yearly change. Thus, Jakarta is becoming the densest urban agglomerations in Indonesia. It has six regions: Jakarta Pusat (Central of Jakarta), Jakarta Barat (West of Jakarta), Jakarta Barat (West of Jakarta), Jakarta Utara (North of Jakarta), Jakarta Selatan (South of Jakarta), and Kepulauan Seribu (Seribu Island). The regions share boundaries with two different areas, the east and south with west of Java, and the west with Banten region, while the north is characterized by the sea of Java. In the geography viewpoint, Jakarta is a low-lying urban condition with flat topography. The coastal line in the northern part have inclines covering from 0° to 2°, while the south areas has a little steeper with slants (Abidin et al., 2011).

INDONESIA MAP

JAKARTA

Java Island

INDONESIA

Figure 8. Geographic Study Area Location (Jakarta, Indonesia) (Author, 2020)

The south’s upper watershed attains altitudes of 3,000 metres above sea level (see Figure 9). It is a rugged zone in the focal point of the island which incorporates Bogor region (included in the province of west Java) and the encompassing region. The Jakarta’s watershed upstream comprises of exceptionally factor with a flat contour at the downstream area and abrupt inclines upstream. Both districts are shaped by a tight and arduous valley which shapes an obstacle form (Texier, 2008). That form of the drainage basin and the current elevation particularly close the coastal line which is lower than 10 metres likewise impacts the susceptibility of Jakarta to flood risks. Every year, the land subsidence in Jakarta decline consistently and the north of Jakarta which situated in the coastal region reach 4,1 metres decrease (see Figure 10). It is happened because of the community until now still use the ground water instead of the surface or existing water resources utilization and sea level rise effect. The condition for watershed inclusion region influencing the interaction among downstream and

upstream region water arrangement

(Molle and Mamanpoush, 2012). Therefore, the adjustments in land use management impact in the capacity of ground water intrusion and raise the water movement debit. As a result, the land use transforms in the upstream region (e.g. the transformation from woodland to built-up development) have been appeared significantly to give influence on the river depleting discharge via Jakarta (Poerbandono et al., 2009).

Figure 9. Jakarta’s Three-Dimensional Satellite Panorama (Author, 2020)

Figure 10. Jakarta’s Land Subsidence in 2010 (Deltares, 2011) Jakarta’s lowland region involves a dense river circulation. There are thirteen rivers across the city and nine of them are arranged as a main river which contributes to flood disaster (see Figure 11). Among those rivers, the Ciliwung River (Kali Ciliwung) known as the greatest waterways source cause of flood hazard (Marschiavelli, 2008). Ciliwung River relatively has

an area

of 347 km 2 and 117 kilometres of main river length. This river cuts across local jurisdictional borders and crosses two different provinces which are West Java and Jakarta. Therefore, that river is becoming deliberately valuable in Indonesia and it is divided three areas of water stream such as down, middle, and upstream. Several previous investigations indicated that the reason behind Jakarta’s most flood disaster is inappropriate water drainage treatment at the upstream region. Pawitan (2004) also mentioned that the land use transformation creates

an influence on the water flow debit and water run-off volume enhancement until around 65%

at the upstream area. The flooding volume is also intensifying until 50% above average. The contribution of that water run-off at the middle and upstream are predicted increase around 42.44%, while at the downstream is more improving until 57.56% (BPDAS, 2007).

Figure 11. Jakarta’s Rivers (Author, 2020) In the other hand, tremendous precipitation magnitude is the fundamental resource of Jakarta river’s flood which had identified with outrageous rainfall. For instance, in September 14 th , 2010’s observation, the number of precipitations in Jakarta attained to 100 mm/day and it caused several Jakarta’s areas inundation (BMKG, 2010). Naylor et al. (2017) noticed that even though the effect of climate change on Jakarta’s rainfall excitement is still indistinct, it is supposed that the whole Java district encounter higher number during rainy likewise vice versa in the dry season. In addition, based on daily scheme which

produced by

the Nature

Conservancy organization in 2009, precipitation in all Java part is projected to rise up by 10% during December to February and to decline by 10% during June to August by the middle of 2050s. In fact, as a low-lying land, Jakarta is not entirely undermined by river’s flood, but also the coastal flood which provoked by high waves (Marfai et al., 2007; Ward et al., 2011). The IPCC report in 2012 noticed that the global average sea level rise will improve from 18-59 centimetres in 2100 (contrast with the year of 2000). Meanwhile in Jakarta, the acceleration number of rising sea level is around 5 mm/year and it has been distinguished over ten years (Pribadi, 2008).

Tremendous floods had been hitting the

city of Jakarta almost every five years. However, in recent decade, flooding has been at unprecedented scale particularly places around the coastal line and riverbank areas. The worst flood was in 2002 and 2007 which paralyzed some Jakarta’s urban environment areas. Flood in 2002 immersed nearly 90 areas with covering more than 16 thousand hectares, or about 1/5 total of Jakarta’s surface measure. Thus, the Governor has been censured for neglecting to actualize the fundamental flood mitigation right after the huge flood disaster in 2002. In addition, according to Meteorology, Climatology and Geophysics Agency (BMKG), Jakarta got high precipitation intensity at 377 mm/day since 2007. As a result, it caused another extensive flood and landslide in the beginning of 2020 which is New Year’s Day in January (see Figure 12).

Figure 12. Jakarta’s Flood at the beginning of 2020 in January (Coconuts Jakarta, 2020) In addition, that also can be seen on author’s GIS-flood model simulates inundated area maps (see Figure 13), the flood disaster is still spreading around Jakarta and mostly located in the northern part of Jakarta and around the riverbanks. North of Jakarta is a coastal line area which is a transitional area where the land is legitimately contiguous with the sea. This condition demonstrates that it is firmly identified with one of the sea level rise effect. It can prompt coastal hazard, especially when the inland is overwhelmed and flooded with the approaching water from the ocean or generally known as rob. Poor flood adaptation and mitigation management in coastal line could potentially injure the community’s activities in north of Jakarta. Moreover, floods in these areas are exacerbated by the subsidence of land because of the ground water extraction redundantly. However, the flood risk around the

riverbanks is commonly happen and create a vital damage to the inhabitant surrounding areas. Both flood disaster sources are still becoming the government’s concern to be mitigated.

Figure 13. Jakarta’s Flood Risk Sources in 2020 (Author, 2020)

In Figure 14 above, the Jakarta’s main water drainage such as floodgates (yellow colour) and water pumping stations (red colour) deployment are unbalanced, and their locations are improper with the flood disaster risk sources. The areas with a smaller number of these water drainage will get bigger flood area and vice versa. Therefore, the presence of this kind of water drainage is an important hard urban infrastructure element to prevent and control this kind of hazard because it can manage the water volume, supply water to and from rivers or sea, circulate the water flow, and become a water catchment in the city.

Figure 14. Jakarta’s Water Drainage Systems Location in 2020 (Author, 2020)

Since the Jakarta’s improvement was not yet followed well by the advancement of disposal treatment for conducting wastes produced, the circumstances of Jakarta’s sanitation have progressively deteriorated. Based on Acceleration of the Provision and Priority Infrastructure Committee (KPPIP) data, currently the inclusion proportion in Jakarta is only 4% of the whole region with an appropriate sewage waste treatment and the pollution pace of 84 mg/l. The remaining 96% or more than 10 million individuals live without good quality of sewerage system management. Waste from their households are disposed in open drains such as in the river (see Figure 15) and are arranged untreated. The Jakarta Environment Agency reported that 7,702 tons of the Jakarta's trash was disposed at the Bantar Gebang landfill consistently and 34% of which was plastic waste. Therefore, in the quality of sanitation aspect, Jakarta is becoming the second lowest in Southeast Asia. On the other hand, Jakarta Sewerage System (JSS) is expected to maintain the viability of the National Capital Integrated Coastal Development (NCICD), which has initiated with enhancement. Their projects are becoming a priority to the central governance. Regarding to the Jakarta’s improvement of waste

management integration, it guarantees 75% inclusion of the significance waste district service by the year of 2022.

Figure 15. Jakarta’s Garbage in Open Drains (Media K., 2017) Most of the drainage facilities are not accessible because many of them have been encroached upon by various sorts of residential, government and business districts. In the meantime, indiscriminate dumping of garbage seriously obstructs the rivers which are modified systems of natural channels and saline water from lake borders. It was expected to ease flooding and increase waterborne transportation. Nowadays, it would be difficult to revive these waterways because of the accumulated transitions that have occurred (e.g. land-fills, slum, and squatter settlements, emplacement of main streets and conspicuous buildings, water quality deterioration, etc). Therefore, the encroachment of squatters on riverbanks, the lack of water

drainage and sewerage facilities area worsen the flood risk. Directly, it has contributed to the devaluation of the quality in urban infrastructure and services at the capital city of Jakarta.

In addition, many previous studies have indicated that the developing of misfortunes which was identified to flood catastrophe are firmly connected to the high-density population (Bouwer 2011; UNISDR 2011; Jongman et al., 2012). Accordingly, the densely inhabitant’s region will improve the flood-prone peril. Jakarta has a numerous area along the coastal lines and riverbanks which frequently inhabited by low-income community because the land and property costs in non-flood-prone space tend to be higher. Moreover, the riverbanks space is correlated with slum and squatter establishment because of unrestrained urbanization. In other words, the limited space and the high demand of housing, riverbanks become the available

open space that usually utilized for illegitimate constructions

(see Figure 16). Hence, Marschiavelli (2008) said that the low-income dwellers are highly presented to the danger of flood hazard. The repetitiveness of floods is becoming a disturbance for the entirety of Jakarta's inhabitants. However, that is an extensive involvement for the Jakarta urban's 3.5 million slum citizens, who live in the flood decumbent areas (Texier, 2008; Van Voorst and Hellman, 2015). In addition, in rainy period, at least 1 metre of Jakarta’s flood would conceive financial losses and illness outbreaks (Haryanto, 2010).

Figure 16. Jakarta’s Slums and Squatters Area in 2020 (Author, 2020)