Loss Measurement of Houses on Physical and Socio-Economical Aspects

2.3. SURABAYA

2.3.1. General condition

1. Urban Scope

a. Geography

Surabaya as the capital city of East Javais locates located on coastal area which, administratively were enclosed by :

  • North : MaduraStrait and Bangkalan Regencies
  • West: Gresik Regencies
  • East: MaduraStrait
  • South: Sidoarjo Regencies

Astronomically[k1] it are located in 712’ up to 721’ South latitude and 11236’ up to 12754’ East longitude. Most of the area locates on low land between 3 up toand 6 m above sea level and the height[k2] is 25 up to 50 m above sea level. Municipality Surabayais also places located around hill called Bukit Lindah and Gayungan on southwest direction. Total area under authority of The Municipality Surabaya is 32,638 Ha and it consists of 5 Assistant Majors, 28 Regencies and 163 Villages or Sub-Districts, as shown Fig.2.3.1.

Surabayais known as metropolitan city covers an area of 32,639 Ha (326 km2) most of which low land with which almost 50% located in coastal areas. Although the whole land use in Surabaya was categorized as urban land, there are still founded rural areas such as rice field, dry rice field, fishpond or forest used. This type mostly could be founded in the border of Surabayapartly on west, southwest, and east region of the center.

From total area, thereThe total areaareis 12,474.42 Ha or and 38,89% is used for housing, 20.02% is used for rice field, 19.98% is used for dry rice field and the remaining rest is used for others functions such as industrial land, warehouses, etc.

Land use in east part of Surabayamajority was mainly founded for rice field, fishpond or coastal area (about 52.07% in totally), while approximately 50% of total area in west region was dominated for fishpond, salt-making pond[k3].

As the capital city,Surabaya carries the governmental center with typical activities such as industrial and commercial sectors[k4]. In such condition then has stimulated[k5] the people to move in. According to data demography year 2000 indicated that, population is about 2.4 million people with and the density is approximately 75 people/Ha. The growth population was estimated 0.32% in central city –0.32% while,7.34% in coastal district 7.34%. Fast development growth in central city has consequence those inhabitants to move out to outskirts of city were usually unoccupied lands in coastal areas[k6].

Those people mostly are fishermen, fishpond worker, salt-maker, or traditional boat renter. By their limited skill has prevented the inhabitants to work in other sector beside marine-based activities[k7]. Even though the people also complained about narrower land recently[k8]. Looking to their daily condition, the inhabitant was classified as low-income people.

Focusing into coastal areas where those areas locate nearest distance from coastline[k9]. It may be consist of wet and dry land that still have been affected by sea behavior. In Surabaya those area covers between Tanjung Perak harbor in west direction to and district of Sidoarjo in east direction as shown in Fig.2.3.2 and table below.

District / Sub-District
Benowo / Romo Kalisari and Tambak Oso Wilangun
Asemrowo / Tambak Langen, Greges and Kalianget
Krembangan / Morokrembangan and Peak Barat
Semampir / Ujung
Pabean Cantikan / Perak Utara and Perak Timur
Kenjeran / Tambak Wedi, Bulak Banteng
Bulak / Kedung Cowek,Kenjeran, Komplek Kenjeran, Sukolilo, Bulak
Tambaksari / Kalijudan
Sukolilo / Keputih
Mulyorejo / Dukuh Sutorejo, Kalisari and Kejawan Putih Tambak
Rungkut / Medokan Ayu and Wonorejo
Gunung Anyar / Gunung Anyar Tambak

b. Climate

Alike a tropical city,Surabaya has two seasons, dry and wet seasons. Months In from November up to April are months for dry season, months from July up to October for are wet season, while the remainingsfor are transition season. Temperature in Surabayawas is between 22.7 up toand 33.7C in daily average[k10], maximum air moisture is 97% and air pressure is 101.84Mbs.

Wind flow direction in last 10 years recorded trend to west direction between December up to and February and to east direction between May up toand October, while the remaining was is changeable direction.

According to rainfall record from 10 stations that organized by Meteorology and Geophysical central, The Brantas Irrigation Agency, Public Works Surabaya showed the maximum rainfall[k11] for 1980 to 1990 period indicated bellow.

c. Morphology

Looking into morphology Surabaya, there are large area will be directly affected to impact of sea level rise. From 32,639 Ha total area about 25,919 Ha or 80.72% is located in low land with –which is between 0.5 up toand 5 m SHVP or between 3m up toand 8 m height. By this condition the area susceptible to inundate if one-meter increasing of sea level[k12]. While theThe remaining area or 20% of total area was categorized low wave hilly. This area was found particularly in east, north and part of south region. The height of this land was lower than 10 m of from sea level and the slope of area was less than 3%. Spreading hilly areas cover District Lokarsanti and Karangpilang. Height of this area is up to less than 30 m of from sea level surface and slope of land is 5 – 15%.

By such areas, City Government reported that the areas can be categorized in 3 zone based on quality of inundation an area. In coastal areas can be indicated in Fig.2.3.4.

Non-inundated zone covers 9155.09 Ha

Periodical inundated zone covers 606.53 Ha

Always inundated zone covers 6337.05 Ha

Overlaying one-meter height contour to the inundated zone show that the Sub District which have pre-requirement as defined in surveyed area which consists of Benowo, Asemrowo, Krembangan, Pabean Cantikan, Semampir, kenjeran and Mulyorejo.

d. Geology

Type The soil in this land is composed by alluvial deposit, which develop fromdevelopped by river and coastal features. Mostly BrantasRiver and RowoRiver affected the characteristic for river feature and some part area in east and north of Surabayawhich continue to along MaduraStraitwhich has coastal characteristic.

The granular size of this soil was between 0.075 mm up toand 2 mm. It encompasses clay, silt and clay siltysilty clay. A thin sheelfish shellfish layer was founded in some places. Geologic of Municipality Surabaya consists of clay and sandy layer. Alluvial soil that is susceptible for of cropland[k13]is dominated condition of soil. The soil was founded in west of Surabaya contain a highly lime soil that less open for plantation[k14].

Based on Geologic studied[k15] by Geology Directorate of Bandung the soil capacity in carrying a building construction is indicated that:

(1)Soil in Surabaya varies types and uneven spreading areas that differ capacity in place to place[k16]

(2)In old city part such as in the following districts of[k17] Wonokromo, Sawahan, Genteng, Tegalsari, Gubeng, tambaksari, Simikerto, Semampir, Paben Cantikan, Krembangan and Bubutan were classified a clay soil with 10 –18 m depthwhich depth is 10 –18 m. The building foundation that would be constructed in this type soil has to be grounded on 25-30 m depth.

(3)The hilly area in west city mostly contains clay soil so the building foundation has to be grounded on 4 up to 10 m depth.

Determining of soil capacity in carrying the building as described above has to consider main parameters such as:

Texture soil based on the size granular soilgranular size of soil. For Surabaya mostly has fine granular size soil granular.

The depth of fertile soil that available for plantation in 98% of total area has. E effective soil has 90 cm depth and the remaining or 13% has between 60 up toand 90 cm depth.

The slope of land.The slope of 80% of total area shown is 0 – 2 % result so the flow speed of surface water was is slow.

Except in hilly area there were is not erosion caused by eroded eroding of water surface.

Assessment of drainage condition was estimated by duration of inundation in a certain time[k18]. There were classified three condition, unaffected inundation, inundate in periodic and high frequency of inundation.

Concerning to the chemical and physical parameter of the groundwater as water source in coastal areas Surabaya mostly cannot be , it mostly is not drinkable. According to the study by Mining Agency of Surabaya that, the groundwater condition can beis distinguished to some zones.

(i)Zone of Ground Freshwater. This zoning has high potential for drinkable water by controlled exploration[k19]. In this zone are it is not suggested to develop settlement of other function, which those activities have to high groundwater needed for[k20].

(ii)Zone Low Potential of Ground Freshwater. This zone is suitable for any activity such as settlement or other function, which need less groundwater needed.

(iii)Zone Moderate Potential of Ground Saltwater. To exploration[k21] the groundwater in this zoning has to be fully controlled to prevent the salinity concentration.

(iv)Zone Low Potential of Ground Saltwater. In this zoning people can use the water for any daily activity but undrinkable. Although to exploreexploring the groundwater was not specifically requirement.

(v)Zone of ground Saltwater.

Mostly the freshwater condition in Surabaya has been polluted due to sea intrusion and sedimentation result. The salinity concentration was not only in the coastal area but also spread in farout upland area. Based on 83 sample points in randomlyrandomly in areas, result of the research of Local Mining Agency Surabaya in 1996 shown showed that the intruded area was larger than fresh area, especially in northwest, north, east and southwest areas of Surabaya. Beside that partly of the central and south city also has intruded area with which high salinity concentration happen. This condition, however, was caused by connate water due to sedimentation or sea intrusion.

The areas where have over standard of drinkable source was 22,814 Ha or 78.54% of total area, while the freshwater areas locate only in 6235 Ha or 21.46%. This report, however need to be considered by decision-maker to readjust the urban planning in protecting the health environment.

e. Housing

The area of housingin Surabaya is about 38,89% of the total area of SurabayaCity. Based on monograph of sub district of Surabaya 1999 total houses in Surabaya are 109.575 houses, consisting of 46.032 unit permanent houses and 63.543 unit temporary houses. In line with trend of the population which is moved from city center to fringe area which is signed by that the growth of population in fringe area is much more higher than city center, the trend of location of housing areas are also moved to fringe area. The condition is signed that many new housing area now are located in the fringe area. The fringe area here is located in the western and northern area of SurabayaCity and some of them are located in coastal area. The kinds of housing consist of formal housing and informal housing. Formal housing is the housing built by developer and informal housing is the housing built by every household itself.

2. Inundated Area

The inundated zone in costal area can be seen in Fig. 2.3.4 and Fig. 2.3.6. From the figure and also based on interview withwhich is the official from Agency of Flood Anticipation (Dinas Penanggulangan Banjir), the condition is caused by overflow of river and also impact of tide rise (pasang surut). If those conditions happen in the same time, the intensity of flood become higher. The condition indicated indicates that sea level rise will has a big impact in Rungkut District. One of the reason is the area of Rungkut District is dominated by low land area and most of them bellow are below the highest tide.

For more detail, according to District Rungkut reported, the location that has been categorized inundated zone consists of

No / Sub District / Location / Height inundation (cm) / Duration (days)
1 / Kali Rungkut / Rungkut Lor (RW VI) / 50 up to[k22] 100 / 4
Mejoyo (RW VII) / 30 up to 70 / 4
Kaliwaru (RW VIII) / 50 up to 100 / 5
Rungkut Harapan (RW II) / 30 up to 50 / 4
2 / Rungkut Kidul / Jl. Kalimir (RW II) / 20 / 2 up to 3
Jl. Kalimir (RW III) / 20 / 2 up to 3
3 / Kedung Baruk / Kedung Baruk (RW I) / 5 / 1
Kedung Asem / 20 / 2
Kedung Baruk (RW I dan IV) / 20 / 2
Gorong-gorong sebelah gg IX / 20 / 3
Sekitar sungai aftur (RV IV) / 20 / 3
4 / Penjaringansari / Jl. Pandugo (RW I) / 10 up to 20 / 1
Jl. Pandugo II (RW I) / 10 up to 20 / 2
Jl. Pandugo III (RW I) / 10 up to 20 / 2
Jl. Raya Penjaringan (RW II) / 10 / 1
Jl. Kendalsari Gg. I / 15 up to 25 / 2
Jl. Raya Pandugo (RW IV) / 15 up to 25 / 2
Kompleks Pandugo Baru (RW IV) / 10 up to 20 / 2
Pandugo Timur (RW V) / 10 up to 20 / 1
Pandugo Praja II (RW VI) / 10 / 1
Penjaringan Asri (RW VII) / 5 up to 10 / 1
YKP Pandugo I (RW VIII) / 5 up to 10 / 1
YKP Pandugo II (RW IX) / 10 up to 20 / 1
Penjaringan Timur (RW X) / 10 / 1
5 / Medokan Ayu / Jl. Raya Medokan Ayu (RW II) / 10 up to 20 / 1
Jl. Raya Jembatan (RW II) / 10 up to 20 / 1
Jl. Tambak Mendokan Ayu (RW II) / 10 up to 20 / 2
Jl. Wonoayu (RW III) / 20 up to 30 / 2
Jl. Medayu Utara (RW IX) / 10 up to 20 / 1
Jl. Raya Pandugo (RW III) / 10 up to 20 / 2
6 / Wonorejo / Jl. Wonorejo Timur (RW VII) / 20 / 1
Jl. Wonorungkut (RW II) / 10 up to 20 / 1
Source: Report of District Rungkut 2001

3. Study Area

a. Administrative Boundary

According to gGuide method in selection of survey area, is decided by the surveyor decided based on steps as below.

(1)Assessment that border of costal area that has large settlement in the land use

(2)Plotting one meter height contour in selected area

(3)Based on Inundated zone, select an District as vulnerable area

(4)Based on land use map, select the Sub-district which has large settlement area

However four steps above can be observedtaken thoughby collectioncollecting secondary data from intuitional report or the report of previous research.Therefore the surveyors decided to analysis analyze District RungkutRungkut District as study area.

District of Rungkut is located in Eastern part of SurabayaCity and consists of 6 sub district as Table below.

No. / District[k23] / Area[k24] / Population / Density[k25]
Rungkut Kidul / 137 / 16940 / 124
Medokan Ayu / 653 / 7350 / 12
Wonorejo / 370 / 5293 / 15
Penjaringan Sari / 181 / 10408 / 58
Kedung Baruk / 146 / 15880 / 109
Kalirungkut / 258 / 24743 / 96
Source : Sub Districts on Figure 2000

The primary investigation on physical aspect (building) was done in Medokan Ayu and Kalirungkut sub district, while the primary investigation on aspect of socio-economy was done in Medokan Ayu, Kalirungkut, Penjaringan Sari, and Rungkut Kidul sub district.

District Rungkut covers 2108 Ha area with total population 75,823 people and density 36 peoplepersons/Ha.

b. Socio Economic Profile

Population of Rungkut District year 2001 is about 79556 persons, consists of male 38715 persons and female 40841 peoplepersons. The occupations of the people are labor, farmer, fisherman, trader, and government official.

No. / Occupation / Number / %
1 / Labor / 28956 / 68.84
2 / Farmer / 4414 / 10.49
3 / Fisherman / 426 / 1.01
4 / Trader / 4382 / 10.42
5 / Government Official / 2577 / 6.13
6 / Other / 1309 / 3.11
Source : Monograph of Rungkut District 2001

Land use of Rungkut District has is the following figure.

No. / Land Use / %
1 / Housing, IndustriIndustry, and their facilities / 30.74
2 / Paddy Field / 51.92
3 / Fishpond (tambak[k26]) / 8.58
4 / Swamp/Wet field (rawa[k27]) / 8.58
5 / Dry Field / 0.18
Source : Monograph of Rungkut District 2001

Based on existing land use in Rungkut District is dominated by undeveloped area about 69,24% of total area such as paddy field, fishpond, wet field and dry field. Domination of un-build areas indicated that there are a lot of areas possibly to be converted to housing, industry, trade and services area, etc.

No. / Industry class / Number / Number of Workers
1 / Middle and Big Industry / 225 / 3263
2 / Small Industry / 66 / 729
3 / Home Industry / 72 / 255
Source : Monograph of Rungkut District 2001

Based on table above industry class in Rungkut District is dominated by big and middle industry instead of small and household industry. Number of big and middle industry is caused by existence of industrial estate located in Rungkut District. The existence of industrial estate make Rungkut District is be a strategic area in the constellation of SurabayaCity.

c. Infrastrcuture

Type and number of facilities in Rungkut District has figure asis figured in table below. The education facilities consist of kindergarten, elementary school, junior high school, senior high school, college, and university. Religion facilities consist of mosques and churchs. Health facilities consist of small hospital, and dispensary. Markets consist of market with permanent building and without permanent building.

No. / Facilities / Jumlah[k28]
1 / Education (School) / 79
2 / Religion / 108
3 / Health / 20
4 / Market / 7
5 / Hotel and Restaurant / 6
Source : Monograph of Rungkut District 2001

In Rungkut District number of houses are 15.662 units, consist of 15.578 units permanent houses and 84 units temporary houses, with and the total area of Rungkut District is 875 hectare Ha or 50,1 % of the area of Rungkut District. Some the houses are rental houses. The existences of rental houses are because there is industrial estate in Rungkut District. T, therefore there are a lot of workers come and stay in the Rungkut District.

Regarding inundated areas, some of the housing areas are located in the these areas, which are very sensitive to be inundated. Most of them are informal housing areas. The inundated housing areas increase almost every year because of new development such as formal housing, industrial estate, university, etc. That is because catchments area has been reduced because the development has converted undeveloped area such as rice field and other wetlands areas.

d. Housing

High density of landed houses dominatesd building type in surveyed area. In general the constructions of surveyed houses are building permanent used reinforced concrete frame and masonry. When housing is classified by structure, some of wooden houses are found in surveyed area. According to District Monographic year 2001, a number of structure house construction divided according to structure is as following belows.

Building type / number
Permanent houses / 8568
Semi permanent houses / 3599
Wooden houses / 1608

The spreading housing area in Rungkut District also can be seen in Land Use Planning as Fig. 2.3.7 below. This figure shows that housing area dominated in this Sub-District

Based on Detailed Spatial Planning of Surabaya City, land use plan of Rungkut District is dominated by housing and industry. Land use plan for housing is intended to accommodate the spillover of population of SurabayaCity. This is because the city center of SurabayaCity is only intended for trade and service and non longer accommodates new housing activities and which will be located in fringe area like Rungkut District. Therefore Rungkut District has to accommodate those activities. Besides new housing, Rungkut District also has to accommodate industrial and commercial areas.