Distribution Pattern and Geological Factor Review in the Construction of Office Buildings in the City of Bandung During Dutch East Indies Colonial Era

: Geologically, the city of Bandung is built on a former large lake known as the Ancient Bandung Lake and when the water recedes it forms a topography in the form of a basin known as the Bandung Basin. The interesting thing is that when the Dutch East Indies Colonial government built Jalan Raya Pos and office buildings they tended to choose the northern part of the basin over the southern part. This study aims to determine the pattern of distribution of office buildings along Jalan Raya Pos during the Dutch East Indies Colonial era and review geological factors that influenced it. This research was conducted by studying the distribution pattern of the building through the nearest neighbor analysis method and its location from Jalan Raya Pos and the geological map of the Bandung Basin. The results of this study show that office buildings built during the Dutch East Indies Colonial were dominantly concentrated in the northern part of Jalan Raya Pos which were randomly distributed, located in the northern part of the Bandung Basin with an altitude between 704 – 725 m sea level, dry plains, and stable soil conditions with topography relatively flat. Meanwhile, in the southern part, the topography continues to decline until the bottom of the Basin which has an average elevation of 600 m sea level. The main rocks in the northern part of the Bandung Basin are volcanic products, while the southern part is lake deposits so the soil surface in the southern part has a wetter and unstable condition because the constituent rocks are the clay. This also has implications for the available groundwater potential, in the northern part relatively having a character with much better quantity and quality than the southern part. This condition made the Dutch East Indies Colonial government prefer the north side of Jalan Raya Pos and the northern part of Bandung Basin in constructing office buildings which are randomly distributed more in the north of Jalan Raya Pos, which is 87%, while in the south 13% in the period from 1810 – 1940.


Introduction
In the past, the Bandung area used to be just a village called Kampung Bandong [12]. In the middle of Bandung today, initially there was only one road in the form of a footpath which was a connecting road between Bandong Office Buildings in the City of Bandung During Dutch East Indies Colonial Era which was located at the confluence of the Tjikapoendoeng river and the Tjitaroem river with Tjipaganti which was located upstream of the Tjipagantie river [13]. In the sixteenth century this village was part of the Islamic Mataram Kingdom. During the colonial period, the name Bandong could be seen, among others, on a Portuguese map in 1755, an English map in 1817, and a Dutch map in 1818, 1840, and 1920 [9]. Meanwhile, during the Portuguese period, Jalan Raya Pos was not yet visible on a Java map [25]. Jalan Raya Pos which was built in 1810 by the Dutch East Indies Colonial government began to be seen on British maps in 1817 and Dutch maps in 1818, 1840, and 1920. Since 1840 the city of Bandung has continued to grow rapidly following other cities in Java that have developed such as Batavia, Semarang, and Surabaya [15]. Even the Dutch East Indies Colonial government at that time planned to move the capital from Batavia to Bandung. Along with this, many office buildings were built along Jalan Raya Pos which stretches between Cimahi -Ujung Berung [10]. From a number of office buildings and city parks, there is a tendency for the Dutch Colonial government to prioritize development in the northern part of Bandung City, especially in the northern part of Jalan Raya Pos [18]. Considering that there were no geologists at that time, it is interesting to know the possible reason why the Dutch East Indies colonial government tended to build the northern part compared to the southern part in relation to the condition of the Bandung basin at that time, which geologically was a basin formed from the former ancient Bandung Lake which drained around 16000 years ago [5]. As an approach to know the distribution pattern of office buildings in Dutch East Indies colonial era in Bandung City, the closest neighbor method and geological conditions were used.

Office Buildings Around Jalan Raya Pos
In general, office buildings in the city of Bandung were built between 1812 and 1940 and are centered around the zero-kilometer point of Bandung. Of the 31 office buildings built during the Dutch East Indies colonial era, most of them are located in the northern part of Jalan Raya Pos, which was built by General Daendels, as many as 27 buildings (87%), and a small portion are in the southern part of 4 buildings (13%). This is not without reason, considering that the northern part is intended as the official of the Dutch East Indies colonial government, while the southern part is intended as the center of government and the residence of the indigenous population. Meanwhile, based on the year of construction (Figure 1), the number of office buildings built during the colonial period can be divided into the following periods.
1) In the 1810 -1850 period (the initial period after Jalan Raya Pos was built) only 1 office building was built, namely the Bandung Regent's government building in the southern part. 2) In the period 1850 -1900, 3 office buildings were built, i.e. two in the northern part and one in the southern part.  From Figure 1 it can be seen that in general the construction of office buildings in the Bandung city during the Dutch East Indies colonial period was slow, especially at the beginning of the construction period until 1910, but increased sharply in the period 1910 -1920 in line with the plan to move the center of government and the military from Batavia to Bandung [24]. After that, from 1930 the construction of offices in Bandung City experienced a decline in line with the monetary depression that hit the world and the entry of Japanese colonial in Indonesia, especially to Bandung city [11]. As a result, the plan to move the capital from Batavia to Bandung finally failed.
During the Dutch East Indies colonial period, the distribution of office building developments was centered around the zero-kilometer point in Bandung city or around Jalan Asia Afrika. The zero kilometer point itself is the beginning of development and development in the Bandung city, since the Governor General of the Dutch East Indies named William Daendels (1808 -1811) stuck a wooden stick at that point at the beginning of the construction of Jalan Raya Pos Anyer -Panarukan (Grote Postweg) which crossed the city of Bandung. At that time, September 25, 1810 Daendels accompanied by the Regent of Bandung Regency, Wiranatakusumah II (1794 -1826) stuck a wooden stick and said: "zorg, dat als ik terug kom hier een staad is gebouwd" which means: try if I come back here, in this area a city has been built [20]. Currently the zero-kilometer point is right in front of the West Java Province Highways Office.
Furthermore, Table 1 below shows the distribution of office building locations and their descriptions [7]. Until 1940, the development and distribution of office buildings starting from the zero-kilometer point were mostly dominant in the north direction from Jalan Raya Pos, while in the southern part there were only 4 office buildings as can be seen in Figure 2. the land in the southern part, at that time there were still many swamps and most of the soil was traces of mud from the remnants of the Bandung Ancient sediments so that it did not provide bearing capacity for foundations and building construction.

Office Buildings Distribution Pattern
The distribution pattern of office buildings in the city of Bandung during the Dutch East Indies Colonial was calculated using the nearest neighbor analysis method. In applying this method, first, the closest distance between one building and another is calculated. The nearest neighboring buildings and their distance can be seen in Table 2 for the northern part and Table 3 for the southern part. By taking into account the area and number of buildings, an index number will be obtained that describes the spatial distribution pattern [21]. The T value of the nearest neighbor distribution index itself is obtained through the following formula. The pattern of distribution of office buildings in the Bandung city during the Dutch East Indies Colonial period can be determined through the following criteria for the T index value [17].

Northern Part Distribution
The

Southern Part Distribution
The area of Bandung during the Dutch East Indies Colonial (1906 -1949)

Geological Factor Review
Office buildings built during the Dutch East Indies Colonial era, geologically, are above the Bandung Basin. The Bandung Basin itself is a land formed from a former large lake known as the Ancient Bandung Lake which receded about 16000 years ago or during the last ice age, then formed a topography in the form of a basin [3]. The Bandung city, which is located in the basin, generally has an elevation of more than 700 meters above sea level (masl). The location with the highest elevation is located in Ledeng Village, Cidadap District with an elevation of 892 masl and the lowest elevation is located in Rancanumpang Village, Gedebage District with an elevation of 666 masl [4].
In the era of the Dutch East Indies Colonial government, the southern part of Bandung city of Jalan Raya Pos was still mostly mud soil (some of which was used as rice fields), many swamps and lakes, even when the capital city of Bandung Regency was moved from Dayeuh Kolot to the outskirts of the Cikapundung River which is in the southern part of Jalan Raya Pos, the natural conditions were still the same. The swamps that are located south of the Regent's Office, then made a large pond (Sundanese: pond = balong) so that the term Balonggede emerged and is now the name of a village in Bandung City. Meanwhile, from Tegallega to the south, west and east, the area is still in the form of swamps. The abundance of swamps, lakes and mudflats in the southern part of Bandung cannot be separated from the archaeological traces left behind from the former Ancient Bandung Lake in the past [1,16]. It is not surprising that in the southern area of Bandung city there are many place names that are preceded or accompanied by the words "situ" (small lake) and "ranca" (Sundanese: ranca = swamp). According to Bachtiar and Syafriani, 2010, in their book, Danau Bandung Purba, there are 18 place names that use the word situ and 96 place names that use the word ranca. Places that used to be there or planned have more unstable soil conditions so that they are less suitable to be used as residential or office areas. The condition of the soil in the southern part of Jalan Raya Pos, which has lots of lakes and swamps, is likely to be a consideration for Herman Wilem Daendels who prefers the northern part to open the road.
Daendels probably got the information from his main assistant, namely Andries de Wilde, the first landowner in the Priangan region who controlled and knew the conditions in the area [6]. Andries de Wilde himself was not a geologist, but a surgeon in the Dutch East Indies army artillery troops. The real geologist, namely Van Bemmelen who was born in Jakarta in 1904, just appeared and wrote a book on the Geology of Indonesia after independence, namely in 1949 with his book entitled The Geology of Indonesia. However, if it looks at the geological map of the Bandung Basin ( Figure  4), it turns out that the rock layers in the southern part of Jalan Raya Pos and the office buildings are former deposits of Ancient Bandung Lake [19], meanwhile, the soil layer in the northern part is relatively more stable, because the conditions are drier than the muddy in southern part. Thus, the selection of Jalan Raya Pos in the northern part of the Bandung Basin along with its buildings that Daendels and Andries de Wilde had made was in accordance with the geological conditions which were only discovered at a later date after the independence of Indonesia. Based on the geological map, it can be seen that the Bandung plain is broadly composed of two rock formations, namely the Kosambi Formation and the Cibeureum Formation. The Kosambi Formation or known as the Lake deposits are composed of tuffaceous claystone, tuffaceous siltstone, and tuffaceous sandstone with a thickness ranging from 10 -125 m [22,14]. The Cibeureum Formation is composed of volcanic product rocks in the form of volcanic breccia to tuff which can reach a thickness of about 80 m [22]. This geological condition is not only related to the rocks that make up the Cibeureum Formation which is in the north more stable than the rocks that make up the Kosambi Formation, which is in the south, but also has implications for its hydrogeological conditions or groundwater. The rocks that make up the Cibeureum Formation are generally good groundwater carriers or act as aquifers, so that the potential for groundwater, both quality and quantity, is relatively better. The Kosambi Formation which contains a lot of layers of clay and mud will certainly have implications for the relatively low groundwater potential, both in quantity and quality. This is explained in the results of research conducted by Soekiban (1983) and Iwaco-Waseco (1990) which explain that the northern part which is composed of rocks of the Cibeureum Formation is an area with high productive groundwater, while in the southern part which is composed of the Kosambi Formation is an area with moderate productive groundwater [8,23]. This of course makes a separate consideration for the pattern of settlement development considering that groundwater as a source of water for daily needs is a basic need that must be met.
Another thing that Daendels might consider in determining road routes in the Bandung area is the topography. The northern part of the Bandung basin and the northern part of Jalan Raya Pos are on a higher slope than the southern part as can be seen in Figure 5. In the north-central part of the basin has a relatively flat topography. But after that, further south to the Citarum River, the slope of the land surface decreases with a maximum slope of 12.8% or about 7.3 degrees as can be seen in Figure 6. If the road route is chosen too south, there will be a high risk of possible flooding. and unstable soil conditions.

Conclusions
Based on the discussion above, the following conclusions can be drawn.
Since Jalan Raya Pos was built in 1810 by the Governor General of the Dutch East Indies Colonial named William Daendels, the city of Bandung has continued to grow with the growth of government and private buildings along Jalan Raya Pos. Along with the construction of Jalan Raya Pos, office buildings were also built along the highway. The development of office buildings in the city of Bandung, since the construction of Jalan Raya Pos (1810) until 1910 has been slow. During that time, there were only 5 office buildings. However, after 1910 to 1920 it increased sharply with the plan to move the center of government (capital) and military from Batavia to Bandung. After that, from 1930 the construction of office buildings in Bandung City experienced a decline in line with the monetary depression that hit the world and the entry of Japanese colonialism in Indonesia, resulting in the failure of Bandung City to become the capital of government. The distribution pattern of 31 office buildings in Bandung during the Dutch East Indies Colonial period was random and most of them were located in the north of Jalan Raya Pos, which was 27 buildings (87%), while the others were in the southern part of 4 buildings (13%).
Geologically, the location along Jalan Raya Pos as well as the buildings built during the reign of the Indies are on the north side of the Bandung Basin which is the former ancient Bandung Lake which dried up about 16000 years ago. The rock layers on the north side of Jalan Raya Pos which are volcanic products are more stable than those on the south which are clayey. While the remnants of ancient Bandung Lake deposits in the form of mud, swamps and lakes in the southern region, during the Dutch East Indies Colonial administration, it was likely that the construction of office buildings in the south was less than in the north of Jalan Raya Pos. These geological conditions also affect the hydrogeological conditions or groundwater of the Bandung Basin, namely the northern part is composed of waterbearing rocks (aquifers) which are highly productive, while the southern part is moderately productive. This of course also influenced the pattern of development during the reign of the Dutch East Indies Colonial.