Land Suitability for Settlement Development in Semarang Coastal Area

Population growth has an impact on increasing the need for land use. The availability of land for settlement development in urban areas is very limited, so that there are people who occupy land that is unsuitable. The coastal area of Semarang City is located on the northern outskirts of the city, indicating an increase in settlement areas. The characteristics of coastal areas that have flat morphology and border the sea are flood-prone areas. This study aims to analyze land suitability for settlement development in the coastal area of Semarang. Suitability based on land capability, and completeness of settlement facilities. To provide information about settlement development locations that are safe and have complete facilities. Settlement development locations in accordance with spatial planning documents and land availability. Using quantitative descriptive methods and spatial analysis with geographic information systems and remote sensing imagery as spatial data. The stages of analysis include analysis of physical aspects, analysis of land capability, analysis of settlement service levels and analysis of land suitability for settlement development. The results showed that currently there are 1696.80 ha of suitable land for the development of settlements in the Semarang Coastal area. Most of them are in Genuk District (60.88%) and Tugu District (26.89%). The research findings can be used as government considerations in compiling spatial policy recommendations related to Sustainable Settlement Development in the Coastal Areas of the Semarang City.


Introduction
Semarang is the Capital City of Central Java Province which has a population of 1,656,564 people with a population growth of 0.25 [1].The rapid population growth in urban areas is due to the urbanization process and the concentration of population in urban areas [2].The impact of population growth is increasing the need for settlements areas.Factors of the physical characteristics of the settlement environment and the factor of the availability of settlement service facilities can influence settlement development [3].
Population, human activities, and pollution are problems in coastal areas of developing countries.Some of the problems in coastal areas are caused by very fast population growth [4].Coastal Areas which are transitional areas between land and sea Ecosystems are affected by changes in land and sea 1264 (2023) 012032 IOP Publishing doi:10.1088/1755-1315/1264/1/012032 2 conditions [5].Because the coastal area is bordered by the sea, the occurrence of seawater flooding (rob) caused by high tides inundating the land cannot be avoided.Some of Semarang's coastal problems are slum areas and tidal floods.The slum areas in Semarang Utara District shows poor environmental conditions because it is located in an area affected by tidal floods [6].The function of Semarang coastal area is as a center for trade and services, a center for industrial activities and as the main transportation node for Java Island [7].The increasing rate of population growth and the concentration of industrial activities in the coastal area of Semarang has led to the development of settlements.Inappropriate selection of residential areas will result in environmental degradation and natural disasters.In Brazil, the increasing of settlements density have resulted in environmental damage [8].One indication of environmental degradation is the quality of environmental settlements which tend to decrease [9].
In the suburbs of Semarang, a settlement was built on unsuitable land because it was located in a disaster-prone area [10].Increased demand for housing/settlements which is not fulfilled by the availability of land causing disaster-prone areas to be used as residential areas.Land quality is a physical constraint that becomes a major obstacle and limits development activities.Disaster-prone areas have low land capacity to support settlement development.Disaster-prone land as settlements was found in the Coastal Area of Semarang City, namely in Tambak Lorok Village, Tanjung Emas Village, Bandarharjo Village, Tanah Mas Village, Genuk Village and Kaligawe Village [11].
The decline in the quality of the settlement environment can be identified by the inadequate settlement/environment facilities and infrastructure.Frequent tidal flooding in Genuk Village, Semarang Coastal Area causes physical damage to settlements and infrastructure [12].Completeness of settlement facilities is the most influential factor on settlement development [10].There are various settlement characters in the coastal area of Semarang City.Settlements in Genuk District, which are dominated by industrial activities, are often affected by tidal disasters and show a decrease in the quality of the residential environment [13].
Land suitability is essentially a description of the suitability level of a plot of land for a particular use [14].Classification of land suitability for settlements is a process of assessing and classifying land in the sense of relative/absolute suitability of land for a use for the benefit of living for local residents equipped with adequate facilities and infrastructure.The classification of land groups and systems is adjusted to the potential of the land.Land with high capacity is expected for activities that have high potential so that it can be used intensively.
Based on the problems that have been described, the Land Suitability for Settlement Development in Semarang Coastal Area research aims to analyze land suitability to find settlement development locations in the Semarang Coastal Area.The suitability of residential land is analyzed based on land capability and service level of residential environmental facilities, as the basic needs of settlements.Using Geographic Information Systems in its analysis of remote sensing images as a source of spatial data.Remote sensing data can be obtained easily without having direct contact with the object [15], [16].The research findings can be utilized by the Government as a consideration in formulating policies on Sustainable Settlement Development of the Semarang Coastal Area.Settlement development that can create access to basic services and a healthy residential environment and can anticipate a decline in the quality of settlements.

Data & Methods
The study area is the Semarang Coastal Area, covering four districts namely Genuk District, Semarang Barat District, Semarang Utara District, and Tugu District with an area of 87.10 km 2 and bordering the Java Sea.The total population of the Semarang City Coastal Area is 434884 people distributed in 45 villages.The population density is low in Genuk District 4680 per km 2 and Tugu District 915 per km 2 [1]. Figure 1 shows the Map of the Study Area.Research on Land Suitability for Settlement Development in Semarang Coastal Area used quantitative descriptive method.All data and information were analysed quantitatively with spatial approach by using overlay analysis technique with utilizing remote sensing imagery and Geographic Information System.Stages of analysis performed are as follows: • Analysis of the physical characteristics of the environment, aims to determine the physical characteristics of the Semarang Coastal environment, namely: slope, morphology, altitude, soil type, geology, rainfall, hydrogeology, land use, disaster hazard and hydrogeology.This data comes from https;//smartcity.semarangkota.go.id 2020 [17].Land classification and scores used for the analysis of the capabilities of the Semarang Coastal Area can be seen in Table 1 to Table 11.Land capability for development is determined based on the score and weighted value of 9 (nine) Land Capability Units (LCU).Each LCU is given a weight value.This weight value is based on the influence of land capability units for urban development.The weight values used for land capability analysis can be seen in Table 10.Natural disasters LCU 5 Source : Departemen Pekerjaan Umum Direktorat Jenderal Penataan Ruang, 2007 [18] The score of each LCU is multiplied by its weight value and then totaled.Furthermore, several classes are made based on the minimum and maximum total value.Each class has different abilities as shown in Table 11.

Physical Characteristics of the Semarang Coastal Area
Land Use of the Semarang Coastal Area consists of Residential, Industry, Trade and Services, Agriculture, vacant land and water bodies.Settlements are the most extensive 3771.19 ha (43.25%).Land in the planning area is a natural resource that has limitations.The physical quality of the soil determines its function.To build a safe settlement must consider the physical aspects of the environment.
In general, the coastal characteristics of Semarang City have geological conditions consisting of alluvial surface deposits and marine layers (92.02%) and bottom sedimentary breccia rocks with soil types Inceptisol (52.97%) and Entisol (39.20%).Geological conditions are the conditions of the area based on the rocks found in the inner part of the earth.The coastal area of Semarang City is at an absolute altitude between 0-500 meters above sea level.Slopes (0-2%) occupy most of the area (8054.84ha).Areas with a slope (0-2%) are flat or almost flat morphology, no denudation, no difficulty in processing [27].Rainfall in the Semarang Coastal Area is 2500-3000 mm/year, evenly distributed in all areas.Hydrogeological conditions can be interpreted as the condition of an area based on the characteristics of groundwater and its relationship/interaction with rock layers in the soil.This condition shows the distribution and movement of water in the soil and rocks in the earth's crust (aquifers).The productivity level of the Semarang Coastal groundwater is moderate.

Land Capability
Land capability is the capacity of a land to support land development activities without the risk of damage.Capability is a land characteristic that includes soil properties, topography, drainage, and environmental conditions to support life or activities [28].Land capability is defined as an assessment of land capability for certain uses as assessed from each of the inhibiting factors [29].Analysis of land capability, analyzing the level of land capability for certain land uses in an area based on basic physical aspects [30].
The level of land capability in each Land Capability Unit (LCU) is determined based on the value/score of the physical environment variables.The results of the analysis of the Nine Semarang Coastal Land Capability Units show that the Easy to work LCU, Slope stability LCU, Foundation stability LCU and Drainage LCU.Most are classified as very high.The land is very easy to cultivate for the development process.The level of stability of the slopes in the development area in accepting loads, stable, not prone to landslides, safe to be developed for buildings/settlements.The level of foundation stability is high, the land is able to support heavy buildings in urban development.While high drainage capacity indicates the ability of the land to drain rainwater naturally easily so as to avoid puddles.Figure 3 shows the high level Land Capability Unit for the Semarang Coastal Area.Moderate level of land capability is the result of LCU analysis of water availability and disasterprone LCU.Moderate water availability means that there is little shallow groundwater, but plenty of deep groundwater.The ability of the Semarang Coastal Area's land to accept natural disasters is also at a moderate level, especially the geological disasters of floods, earthquakes and land movement.Figure 4 shows the Medium Level Land Capability Unit for the Semarang Coastal Area.Analysis of Morphology LCU aims to identify the shape of the landscape/morphology of the planning area that is capable of being developed according to its function.The Semarang Coastal Area shows low level morphology LCU meaning it has uncomplicated morphological conditions, the land is flat and easy to develop as a place for settlement and cultivation.Low level Erosion LCU means that the possibility of land to experience erosion is very small, a few layers of soil are carried away by wind and water.While the land capability unit for waste disposal is low, it shows that the area is not suitable as a waste disposal site.Figure 5 shows a very low level of Land Capability Unit for the Semarang Coastal Area.12 shows Land Capability for the Development of the Semarang Coastal Area.Most of the Semarang coastal area has a very high level of development (50.90%) and high level (45.58%).This happened because the area was quite safe, far from the sea and not affected by tidal flooding.

Settlement Facilities
One of the problems that occur in urban areas is population growth which has an impact on the expansion of settlement development.An increase in the concentration of residential population is often not followed by an increase in settlement facilities.As a consequence of the increase in population, there is an increase in the need for settlement facilities.The availability of housing facilities is a function of service to the community.An analysis of the service level of settlement facilities was carried out to determine the completeness of settlement facilities in the Semarang Coastal Area.Using indicators of the number and completeness of the types of settlement facilities, which consists of government facilities, educational facilities, health facilities, religious facilities, trade facilities, cultural and recreational facilities and open space facilities.The types of facilities used in this study follow the Indonesian National Standards.(SNI).Table 13 shows the number and types of settlement facilities in the Semarang Coastal District.Semarang Barat District has the highest number of facilities, namely 1715.Source: Semarang Central Bureau of Statistics, 2022 [1], [19]- [22] The service level of settlement facilities in the Semarang Coastal Area is determined based on scoring the number and completeness of its types using village analysis units.Figure 6

Land Suitability for Semarang Coastal Settlement Development
Land Suitability for Settlement Development in the Semarang Coastal Area aims to find areas for settlement development, based on the level of land suitability for activities and the level of settlement facility services.Determination of land suitability ranking, using the land capability variable as the main determinant.Land capability has a more important influence than settlement facilities.Development of settlements on unsuitable land capabilities will lead to disaster.A low level of land capability indicates that the physical aspect of support for settlement development activities is also low while settlement facilities that are incomplete can be accessed from the nearest residential area.Figure 7 shows the distribution area of the land suitability level for settlements in the Semarang Coastal Area.The research findings show that most of the Semarang Coastal Area has a high level settlement suitability (83.62%).There are two areas that have a low level of suitability with different conditions.The first area has Land capability is high and service level of settlement facilities is low, then The Second areas have Low Land Capabilities, and High Service Levels of settlement.The first area is 1119.00ha (12.53%) occupying the Village of Terboyo Kulon, and Terboyo Wetan located in Genuk District and Tambakharjo Village, located in Semarang Barat District.The second area is 309.02 ha (3.54%) occupying Kembangarum Village, Manyaran Village, Ngemplaksimongan Village, Bongsari Village, Bojongsalam Village located in Semarang Barat and Tugurejo Village, Karanganyar Village located in Tugu District.
Based on the availability of non-built-up land areas in the Semarang Coastal Area in 2023 and Spatial Planning Document [7], [31], it can be seen the area that has high suitability for settlement development in the Semarang Coastal Area is 1696.80ha.Table 14 shows available and suitable areas for settlement development in the Semarang Coastal Area.Research on Land Suitability for Settlement Development in the Semarang Coastal Area supports the concept of sustainable settlement development [32]- [34] An effort to meet current housing needs with paying attention to the potential of the land and not harming future generations.

Conclusion
Most of the land use for the Semarang Coastal Area is settlements with an area of 43.25%.This residential area is located Semarang Barat District.Semarang Barat District and Semarang Utara District are BWK III whose main function is sea transportation.air transportation and provincial government service offices [7].The Semarang Coastal Area has a flat morphology (slope 0% -2%) with an area of 8054.83 (92.37%).This condition causes flood-prone areas in the Semarang Coastal Area to be quite extensive.
Based on the analysis of land capability units.it is known that the land capability of the Semarang Coastal Area has a very high (50.90%)and high (45.58%)level to be developed as an urban area.Some are distributed in the central part of the Semarang Coastal Area.This area is quite safe.far from the sea and not affected by tidal flooding.The level of land capability. is an accumulation of various physical aspects which are limiting factors and supporting land potential.High level land capability indicates land suitable for settlement.This is in accordance with previous research which states that there is still potential residential land for residents of Semarang City that can still meet their needs for the next 20 years [35] Settlement facilities are the basic needs of settlement development planning.Availability and completeness of settlement facilities is a function of service to residents.Settlement areas that have a low level of service for settlement facilities occupy the Semarang Barat District area.namely the Cabean and Tambakharjo Villages.Meanwhile.for the Genuk District.there are in the Villages of Muktiharjo Lor.Terboyo Wetan and Terboyo Kulon.The level of facilities is low because the number of settlement facilities is few and incomplete.
The research findings show that most of the Semarang Coastal Area has a high settlement suitability rate (83.62%).Areas with a low level of suitability occupy two areas namely; the first area has high land capability and low service level of settlement facilities.This is in accordance with previous research which stated that slum organizations in several Villages of the Coastal Area in Semarang City are included in the level of severe slums and poor environmental quality [6].The second area has low land capability.and the service level of settlement facilities is high.It is known that the settlement development area in the Semarang Coastal Area is 1696.80ha.This area is in accordance with the availability of non-built-up land areas on the Semarang City Coast in 2023 and the Semarang Planning Spatial Document for 2011-2031.
Land Suitability Research for Settlement Development in the Semarang Coastal Area supports the concept of sustainable settlement development.which is an effort to meet the current housing needs of the population without compromising the needs of future generations.This is in line with one of the Sustainable Development Goals (SDGs) point 11.namely Sustainable Cities and Communities.In this goal there is a housing target and the Sustainable Development Goals which states that housing is an important component of the 2030 Agenda for Sustainable Development and an essential driver for achieving many of the Sustainable Development Goals. or SDGs.Adequate and affordable housing leads to benefits in health.education and economic opportunities [36]

Acknowledgments
Thanks to the Diponegoro University Institute for giving us the opportunity to conduct research.This research was funded by the 2023 Engineering Faculty RKAT Fund.Diponegoro University with a Strategic Research scheme.

Figure 1 .
Figure 1.Map of the Semarang Coastal Area[17] Analysis of land capability aims to analyze the level of land capability for certain land uses based on basic physical aspects.Based on the analysis of land capability, it can be seen that the level of land capability to be developed as an urban area.Land capability analysis is carried out by analyzing the Nine types of Land Capability Units (LCU), namely; Morphology LCU, Easy to work LCU, Slope Stability LCU, Foundation Stability LCU, Water Availability LCU, Erosion LCU, Drainage LCU, Waste Disposal LCU, and Natural Disasters LCU [18].• Analysis of the service level of settlement facilities is an analysis to determine the basic service level of settlements.Data on the number of facilities was obtained from the Central Statistics Agency; Genuk District in numbers, North Semarang District in numbers.West Semarang District in numbers, and Tugu District in numbers 2022 [27]-[30].Using indicators of the availability of settlement facilities namely; Government facilities, Education facilities, Health facilities, Religious facilities, Trading facilities, Culture and recreation facilities, Open space facilities.The analysis was carried out based on the Indonesian National Standards Concerning Procedures for Planning Housing Environments in Urban Areas 2004 [23].• Analysis of land suitability for the Semarang Coastal area for settlement development is determined based on land capability, service level of settlement facilities, availability of residential land and suitability to the Spatial Planning Document.Figure 2 shown Analysis Framework.

Figure 4 .
Figure 4. Medium Level Land Capability Unit for The Semarang Coastal Area (5) Water Availability LCU (6) Disaster Prone LCU

Figure 6 .
Figure 6.Service level of settlement facilities in the Semarang Coastal Area

Figure 7 .
Figure 7. Land Suitability Level for Settlement Land in the Semarang Coastal Area

Table 10 .
Land Capability Weighting

Table 12 .
Land Capability for The Development of Semarang Coastal Area

Table 13 .
Number and Types of Settlement Facilities in Semarang Coastal Districts shows the service level of settlement facilities in the Semarang Coastal Area.Residential areas that have lowlevel service facilities occupy parts of the Semarang Barat District, namely Cabean Village and Tambakharjo Village.Meanwhile, other low-level housing facilities are available in Muktiharjo Lor Village, Terboyo Wetan Village and Terboyo Kulon Village in Genuk District.1264 (2023) 012032

Table 14 .
Recommendations for Settlement Development in the Semarang Coastal Area