Developing The Public Spaces Alternative in Palu City

Abstract

A public space is an area that accommodates all the activities of city residents, both individually and in groups, and should be utilised optimally as a responsive, democratic, and meaningful space. Limited public space can pose a problem; thus, it is necessary to develop new public spaces to accommodate all community activities and needs. This research aims to analyse the forms of public space development for medium cities in Indonesia, with Palu City as the case study. The study employed the Analytic Hierarchy Process (AHP) and Complex Proportional Assessment (COPRAS) methods to determine urban public spaces’ form and development using existing criteria and alternative potential spaces. The AHP method in this research is designed to calculate the criteria weights. Meanwhile, after the criteria weights were obtained, the COPRAS method was utilised to determine the best alternative from several existing alternatives. The study results indicated that the post-liquefaction area (memorial park) in the Balaroa sub-district can serve as a potential alternative for developing the public space. The development of public space in Palu city in selected locations based on AHP-COPRAS analysis was directed by a green design approach and local wisdom (genius loci). The expected impact of this design approach is to produce a better living environment that can support ecological and socio-cultural and provide economic benefits (welfare) for the surrounding community.

Introduction

People universally need public space to do various activities, such as interacting with their environment and as an area where people can carry out their activities. The existence of a reciprocal relationship between human behaviour and the environment (public space settings) is very important to be studied for the development and optimisation of urban public space function (Diver et al., 2019). The setting in a public space is related to environmental cognition influenced by organismal, environmental, and local cultural factors (Aguila et al., 2019). This study aims to analyse alternatives and forms of public space development in the city of Palu, Indonesia, by considering public space planning with optimal public space functions that are able to accommodate existing space functions.

Community activities in public spaces require a setting to interpret the activities in the form of space. There are twelve attributes that emerge from human and environmental interactions such as comfort, sociality, visibility, accessibility, sensory stimulation, control, activity, crowding, adaptability, meaning, and legibility (Schreuder et al., 2016; Weissman, 1981). An approach that involves understanding privacy factors, a sense of space, and spatial behaviour that influence perceptions of environmental comfort and the quality of public space use is the measurement offered in anticipating the possibility of less success in a public space design. Cities should aim to provide a consistently satisfying aesthetic and sensory experience for the community, as the visual aesthetic encounter in urban spaces plays a vital role in creating excellent and healthy urban landscapes (Santosa et al., 2023).

The increasingly intense development pressure on the development of public spaces in urban areas has encouraged efforts to increase and develop urban public spaces, especially in areas with rapid economic growth and services, such as Palu City. Hence, it becomes crucial for further research to regard the way to develop urban public space that can accommodate all the functions of public space, comprising democratic space, responsive space, and meaningful space that has deep meaning and longing as an effort to express desires and needs in public spaces.

Research on the development of urban public space can be carried out by combining the AHP (Analytical Hierarchy Process) method and the COPRAS (Complex PRoportional Assessment) method. In compiling the model, AHP was used to compare variables that become determinants in the decision-making process. AHP can be applied to many location selection issues. Its application is not limited to location selection only; it can also be utilised to address any multi-criteria decision issue (Alwedyan, 2024). However, some scholars argued that the AHP method is ineffective in cases with many criteria and alternatives (Chamid & Murti, 2017; Pebrianti et al., 2022). Therefore, another method was needed to complement the AHP weakness (Febryanto, Berlianto, & Prihono, 2023). This research utilised another decision-making method called the COmplex PRoportional Assessment (COPRAS) method. The COPRAS method was first introduced by Zavadskas et al. in 1994 (Lu et al., 2021; Mahdiraji et al., 2014). This method is beneficial for evaluating maximum and minimum criteria. Some scholars have acknowledged its reliability and accuracy in solving multi-attribute problems with direct and proportional dependence on the utility and significance degree of investigated alternatives on the system criteria (Ecer, 2014; Mahdiraji et al., 2018; Rasiulis et al., 2016; Tamošaitiene & Gaudutis, 2013).

Podvezko (2011) compares the COPRAS and SAW methods and concludes that the SAW method only uses maximum evaluation criteria, while for minimum evaluation criteria, the value must be changed first to maximum values . The COPRAS method can eliminate the limitations of the SAW method. Thus, this research exploits and elaborates the AHP-COPRAS method to determine Palu City’s form and development of public space. Based on the AHP method, the criteria for urban public space are specifically differentiated, namely system of setting and system of activity, and refer to the requirements for the function of public space such as responsive space, democratic space, and meaningful space (Carr et al., 1992; Piyaputri & Gamal, 2021). The public space criteria are then described into several more specific sub-criteria to obtain the best alternative for public space development, including a sense of belonging to space, a harmonious environment, accessibility, and spatial adequacy.

These forms and developments will be ranked from best to worst alternative. Alternative development using the AHP method produces alternatives that are only based on the basic criteria for public space function as explained by Carr (1992); more specific development is carried out using the COPRAS method by adding other sub-criteria, including,

1. 1)   Feelings of security, comfort, and freedom to activity, to have a point of view, to communicate (criteria; sense of belonging to a space).
2. 2)   Solving the accessibility and flexibility problem of the city, increasing the quality of life of the community, increasing the diversity of activities, enriching the quality of the environmental setting, and forming the site environment (criteria; harmonious environment)
3. 3)   Ease in fulfilling the needs, ease of public access, strategic location, and available facilities, Attractive (criteria; accessibility), and
4. 4)   The potential for spatial adequacy for the development of urban public spaces

This research demonstrated the utilisation of the AHP-COPRAS method in finding the best alternative for public space new development location in a medium-sized city, under the scenario where the public space becoming limited and not optimally functioning, with Palu City as the case study. The finding of this study contributes by providing suggestions for city development direction that benefit the local government, especially the construction of public spaces development that offer new alternative locations for its optimal function.

The planning recommendations from this study determine the location for new development areas of city public space that proposed the rejuvenation of inactive areas impacted by disaster. Furthermore, this study is expected to contribute by giving insight into determining the future development direction of urban public space employing the AHP-COPRAS method, which can be implemented in other cities in Indonesia or around the globe with similar settings and situations with the case study location.

Material and Methods

Research Design

This research uses the AHP (Analytic Hierarchy Process) and COPRAS (Complex PRoportional Assessment) methods. AHP is one MCDM method that assists decision-makers in finding the best alternative from many optional elements. AHP uses the relative importance of existing criteria alternatives and has many advantages in explaining the decision-making process. Several principles are used to solve problems with AHP: compiling, hierarchy, and assessing criteria and alternatives. Criteria and alternatives were analysed using pairwise comparisons with a scale of 1 to 9 to express opinions on various issues (Midyanti, 2018; Saaty & Vargas, 2012).

Several principles are implemented in resolving problems by AHP: creating hierarchies, evaluating criteria and alternatives, determining priorities, consistency, measuring consistency, calculating the consistency index (CI) with a formula, calculating consistency ratios, and checking hierarchical consistency. From the AHP method, several initial alternatives will derived. In this case, eight alternative locations were determined. Furthermore, to get the best solution to determine the direction of development of public open space for the ideal ratio, the COPRAS (Complex PRoportional Assessment) method is used to make decisions that assume a direct and proportional dependence on the level of significance of alternative location used. Complex PRoportional Assessment has a good level of selectivity because it can determine objectives from conflicting criteria where the criteria can be beneficial (benefit) or unprofitable (cost). The COPRAS method will produce fewer alternatives (5 alternative locations), which will then be analysed using several criteria and indicators to produce the best alternative location (Figure 1).

Figure 1. Research Design

Figure 2. AHP Process Hierarchy

Figure 3. COPRAS Process Criteria Hierarchy

Figure 4. COPRAS Process Hierarchy

The AHP (Analytic Hierarchy Process) method in this research is employed to calculate the criteria weights (Figure 2). After the criteria weights are obtained, the COPRAS (Complex PRoportional Assessment) method determines the best alternative from several existing alternatives (Figure 3 and Figure 4). Public space development will be obtained according to the performance index (PI) value using the AHP-COPRAS method. An alternative performance index value above the average will become the priority recommendation for developing public space.

In determining the priority for each criterion and alternative using the pairwise comparison, the level of decision consistency was measured based on low consistency considerations using the following formula:

$CI=\frac{\left({𝛌}_{max}-𝐧\right)}{n}$ (1)

Where: CI stands for consistency index, λ refers to the number of elements present, and n indicates the relative priority element in question

Meanwhile, to calculate the consistency ratio (CR), the following formula was employed:

$CR=\frac{\mathrm{\text{CI}}}{\mathrm{\text{IR}}}$ (2)

Where: IR refers to the Random Consistency Index

The hierarchical consistency was checked carefully and corrected when the value exceeded 10%. However, when the consistency ratio (CI/IR) ≤ 0.1, then the calculation results were accurate (Midyanti, 2018).

The COPRAS method has good selectivity because it can determine the objectives from conflicting criteria where the criteria can be beneficial or unprofitable. The process sequence in determining COPRAS is in a few steps, such as 1) preparing the attributes to be identified; 2) normalising the matrix; 3) normalising the weighted matrix; 4) calculating the maximum and minimum index values; 5) calculating alternative weights; 6) calculating the quantitative utility of each alternative. This method solves the problem with the following steps (Arisantoso et al., 2022; Patil et al., 2022):

Normalising the decision matrix D with the following expression:

$x^{*}{i}_j=\frac{x{i}_j}{{\sum }_i^m=1x{i}_j}$ (3)

for j = 1, 2, ..., n

where:

x* i_j : normalised performance rating of alternatives i and j criteria

j : number of alternatives

m : criterion weight

Determining the normalisation weights of the decision matrix 𝐷′ by the following equation:

$D^{\prime }={[d{i}_j]}_{\mathrm{\text{mxn}}}=x^{*}{i}_j\mathrm{\text{.}}{w}_j$ (4)

where: d refers to Decision matrix normalisation, n is number of criteria

Calculating the sum of the normalised weights for the benefit and non-benefit criteria is done using Equations (5) and (6). A higher value is better for achieving goals for the benefit criteria, while a lower value is better for non-benefit criteria.

${S_i}_{+={\sum }_{j=1}^{k}d{i}_j}$ (5)

${S_i}_{-={\sum }_{j=k+1}^{n}d{i}_j}$ (6)

Where S stand for normalised weight criteria, k represent benefit criteria

Determining the relative importance or priority of Qi alternatives using the expression:

$Q_i=S_i+\frac{{{\sum }_i^m=}_1{S}_i\_}{S_i\_{\sum }_i^m=1\frac{1}{S_i\_}}$ (7)

Calculate the performance index (Pi) of each alternative with equation:

$P_i=\frac{Q_i}{Q_{max}}x100\%$ (8)

Where: Qi is relative importance or priority of alternatives

𝑄Max is the maximum relative value. The performance index value (Pi) obtains all alternative candidate rankings.

Case study area

The research location is in the central area of Palu, Central Sulawesi province, Indonesia. Palu City is decided as the research locus was based on the city’s public spaces as a basic community need and gradually becoming smaller and with number of limitations. Public space existence is also the mandate of Law Number 11 of 2020 concerning work creation (Indonesian Legislative Council, 2020). The development of Palu City, which has a fairly high population density, is affecting living environment conditions and making horizontal spaces gradualy limited, impacted to the city impression of being slump, dirty and chaotic.

Figure 5. Map of research areas

Palu City is the capital as well as the largest city of Central Sulawesi. Palu is located on the northwestern coast of Sulawesi and borders Donggala Regency to the north and west, Parigi Moutong Regency to the east, and Sigi Regency to the south. The city boundaries encompass a land area of 395.06 km2 (152.53 sq mi) (Figure 5). Palu is the centre of finance, government, and education in Central Sulawesi and one of several major cities on the island. The city hosts the province’s main port, biggest airport, and public universities.

Palu is located in Palu Bay; it was initially a small agricultural town until it was selected to become the capital of the newly created province of Central Sulawesi in 1953. Palu is located on the Palu-Koro Fault and is frequently struck by earthquakes, such as the 2018 Sulawesi earthquake.

Types of green open space based on Palu City Regional Regulation No. 4 of 2015 concerning Green Open Space in Urban Areas are divided into city parks, nature tourism parks, recreational parks, residential and residential neighbourhood parks, office and commercial building environmental parks, grand forest park; city Forest; protected forest; landforms such as mountains; hills, slopes and valleys; nature preserve; Botanical Garden; zoo; public cemetery; sports field; field ceremony; open parking; urban agricultural land; lines under high voltage (SUTT and SUTET); river borders, beaches, buildings, lakes and swamps; security lanes for roads, road medians, railway tracks, gas pipes and pedestrians; Green areas and belts, airfield buffer zones; and a roof garden.

Result

Public Space

According to Hakim (Hakim, 1987) and Pattacini (Pattacini, 2021), public space is outside a building, so the definition of open space is a space outside a building. This definition emphasises that the open space pattern depends on the shape and arrangement of the surrounding building mass. Planning and designing public space in one area is successful if users can utilise the open space and when the existing setting becomes part of their lives. According to Carr (Carr et al., 1992)A good use of public space if it has three criteria:

1. 1)   Responsive space is designed to meet the community’s needs, such as physical comfort, relaxation, and active and passive communication.
2. 2)   Democratic space can protect users’ rights in public space, like of physical and visual (freedom of view), symbolic freedom, freedom of activity, and a sense of belonging and occupancy.
3. 3)   Meaningful space provides users with a physical and social connection with the space, whether related to history, supporting various user activities, feeling safe and comfortable, or connecting to other events.

The environmental form criteria of open space in urban areas are designed must be able to (Carr et al., 1992; He et al., 2022):

1. 1)   Improving the relationship between various humans in the environment, environmental potential, and setting.
2. 2)   Forming the environment by maximising site potential.
3. 3)   Solving regional space accessibility problems.
4. 4)   Enriching the quality of the environmental setting, for example, is sufficient green open space and public space.
5. 5)   Improving the quality of people’s social life.
6. 6)   Increasing the flexibility of urban space.

Human behaviour in a physical setting (open space) takes place, and it is consistent according to time and situation. Hence, the typical pattern of behaviour for settings in the physique can be identified. In other words, this approach looks at different aspects of norms, culture, and society, producing different concepts and forms of space (Liu et al., 2021; Rapoport, 1969).

Palu City Public Space Utilization Problems

Humans have their uniqueness, and the uniqueness of each individual will influence the surrounding environment. On the other hand, the uniqueness of the environment also influences behaviour. The environment is not only a place for humans to carry out activities but also an integral part of human behaviour.

Based on the results of field observation, the existing public space function criteria have not been achieved optimally, especially the democratic space function criteria, which include protection for the rights of public space users, such as ease of physical, visual (freedom of view), symbolic accessibility, freedom of activity, and a sense of belonging, and occupy. The availability of public space feels inadequate because it is not well organised, and there is no easy physical and visual accessibility, freedom of activity, or sense of belonging. Besides, the criteria for responsive public space, such as the need for comfort, relaxation, and communication, have also not been achieved optimally.

Several factors that influence the non-optimal use of existing public spaces are generally influenced by cultural factors, environmental perception, spatial cognition, and spatial behaviour. Factors that specifically affect the non-optimal use of public spaces are spatial limitations, user behaviour, and regulations/policies.

Spatial Limitations

The variety of activities that develop in public space requires fulfilling the need for more complex space. Due to various excesses caused by shopping, tourism, and cultural or historical activities, activities and users of public space are growing. These activities and users will continue to increase until the demand to form a new space for carrying out these activities rises. Unfortunately, the size of the available space areas has not been expanded. In other words, the higher the need for space, the smaller the available space is.

One of the factors that causes public space not to be optimal is the limited space to carry out various activities, which is increasing daily. As a result of these limited spaces, public space users try to continue exploiting the existing space, even though it often results in space conflicts in various forms.

User behaviour

Community behaviour in public space greatly influences the development of existing public space because it can influence all forms of activity and the use of existing space. User behaviour can be one of the factors that cause the inadequate function and use of public spaces. It is such that marking and personalising specific spaces triggers other space users to respond with defensive behaviour and even aggression to control the space they perceive as their territory.

Regulations/Policies

One factor that can also cause the inadequate use of public space is the lack of clear rules for utilising existing public space. The government can make the rules as an institution that issues policies and regulations. Many violations and forms of space violation that occur in the use of public space are caused by the absence of clear regulations, including utilisation permits, limits, and utilisation times. The existing rules do not describe the rewards and punishments for space users if they follow the rules or do not follow the existing rules. Besides, there also needs to be firmness in taking action against parties who do not follow the rules, which can negatively impact and harm other parties.

Formulation of Criteria for Structuring and Development of Public Spaces

It is necessary to identify the potential and availability of city space based on area and location to analyse and develop public space in Palu City, which will then carry out a hierarchical process and determine the direction of public space development. The following is the availability of existing city space based on Green Open Space, area, and location (Table 1).

Table 1. Potential for development of public space

No.	Type	Width (Ha)	Location
1	Urban Forest	56.330	Mantikulore subdistrict
2	City Park	3.390	Mantikulore
3	Sub-District Park	7.550	Tatanga 2,620 Ha, Ulujadi 3,087 Ha and di Palu Timur 1,843 Ha.
4	Production Forest Zone	5,215.783	Mantikulore 4.607,05 Ha, Palu Utara seluas 2,130 Ha
5	Smalholder Plantation	706.308	Ulujadi s 5,769 Ha, Tawaeli 688,577 Ha.
6	Coastal Border Zone	24.873	Ulujadi 16,671 Ha, Mantikulore 8,203 Ha.
7	River Border Zone	164.501	Ulujadi 9,190 Ha, Tawaeli 42,164 Ha, Tatanga 11,488 Ha, Palu Utara 16,647 Ha, Palu Timur 6,56 Ha, Palu Selatan 6,207 Ha, Palu Barat 4,479 Ha, Mantikulore 67,762 Ha
8	Liquefaction Memorial Park	232.560	Balaroa Village 44,603 Ha, Donggala Kodi Village 8,794 Ha, Duyu Village 0,687 Ha; Petobo Village 178,477 Ha.

From this process, it can be explained that the purpose of employing the AHP approach is to obtain new alternative public spaces for developing functional public spaces that meet the criteria of responsive spaces, democratic spaces, and meaningful spaces. Tables 2 and 3 are a table of codes, criteria, alternatives, and a hierarchical matrix for determining criteria and alternative goals.

Table 2. Public Space Development Code and Criteria

Code	Criteria	Description
K1	Responsive space	A space designed to meet the needs of physical comfort, relaxation, active and passive communication
K2	Democratic space	Space that can protect the rights of public space users, such as ease of physical, visual and symbolic accessibility, freedom of activity, and a sense of belonging and occupancy.
K3	Meaningful space	Provides users with a physical and social connection with the space, whether related to history, supporting various user activities, feeling safe and comfortable or related to other events

Table 3. Public Space Development Codes and Alternatives

Code	Alternative	Description
A1	Urban Forest	Space supporting natural ecosystems and forming an ecological unity; as a water catchment area; as a microclimate controller; as a place for limited social activities of the community; limiting the development of urban areas.
A2	City Park	Open land that has socio-cultural and aesthetic functions as a means of recreation, education or other activities aimed at serving the population
A3	Sub-District Park	A place for the growth of various types of vegetation and biodiversity; as a water catchment area; as a microclimate controller; as a place for community social activities; has a service radius of 2,500 m;
A4	Production Forest Zone	Forest areas/zones that produce forest products; has high vegetation diversity; carried out using an agroforestry approach; and/or forests outside protected areas/zones, nature reserve forest areas/zones, nature conservation forest areas/zones and bird parks
A5	Smalholder Plantation	The green cover is dominated by woody plants or other types; is not a monoculture plantation and has a diversity of local vegetation with complete stratification; carried out using an agroforestry approach;
A6	Coastal Border Zone	It has the main function of limiting residential growth or other activities so as not to disturb the sustainability of the coast. Coastal border green open space is a coastal protection area from damage or disasters caused by sea waves such as sea water intrusion, erosion, abrasion, strong winds and tsunami waves.
A7	River Border Zone	The green belt is located on the left and right of the river which has the main function of protecting the river from various disturbances that can damage the condition of the river and its sustainability
A8	Liquefaction Memorial Park	It is an open space located at the liquefaction location in Palu City, this area functions as a green open space.

Table 4. Criterion Pairwise Comparisons

	Responsive space	Democratic space	Meaningful space
Responsive space	1,000	5,000	6,000
Democratic space	0,200	1,000	5,000
Meaningful space	0,167	0,200	1,000
Number of Columns	1,367	6,200	12,000

Table 5. Number of Pairwise Comparison Column Consistency Values

	Responsive space	Democratic space	Meaningful space
Responsive space	0.732	0,806	0,500
Democratic space	0.146	0,161	0,417
Meaningful space	0,122	0,0.32	0,083
Number of Columns	1,00	1,00	1,00

Criteria and alternatives are carried out using pairwise comparisons (Table 4). A scale of 1 to 9 is the best scale for expressing opinions. The following are the resulting weights for criteria based on pairwise comparisons and the resulting weights are based on the main eigenvector of the decision matrix with a Consistency Index (CI) value with the formula CI = (λmax − n)/n of -0.440, Consistency Ratio with the formula CR = CI /IR is -0.393, and the Random Consistency Index is 1.12, it can be concluded that the consistency is high and meets the requirements (Tables 5).

Table 6. Number of Total Criteria Eigen Values

	Amount
Responsive space	3,476
Democratic space	3,203
Meaningful space	3,040
Average	3,240

From the results of the comparative analysis of public space criteria based on the AHP method, it can be concluded that the criteria for public space, which functions as a responsive space, is the one that best meets the criteria with an eigenvalue of 3.476, then a democratic space of 3.203 and finally a meaningful space of 3.040 (Table 6). Responsive spaces designed to meet people’s needs regarding physical comfort, relaxation, and active and passive communication best meet the criteria and are desired by the community.

Furthermore, to obtain alternative public space development based on existing potential, the criteria values obtained from the AHP method are compared with several alternatives that are compared in pairs with the existing criteria. The results of a comparative analysis of existing criteria and alternatives can be seen in Table 7.

Table 7. Pairwise comparison of total eigenvalues of criteria and alternatives

Alternative	Criteria
	Responsive space		Democratic space		Meaningful space
	A	E	A	E	A	E
Urban Forest	0,781	0,221	0,619	0,215	0,781	0,221
City Park	1,838	0,521	1,534	0,531	1,838	0,521
Sub-District Park	0,387	0,110	0,313	0,108	0,387	0,110
Production Forest Zone	0,356	0,101	0,288	0,100	0,356	0,101
Smalholder Plantation	0,166	0,047	0,134	0,046	0,166	0,047
Coastal Border Zone	1,235	0,350	1,046	0,362	1,235	0,350
River Border Zone	1,077	0,305	0,863	0,299	1,077	0,305
Liquefaction Memorial Park	1,265	0,359	1,166	0,404	1,265	0,359
TOTAL	3,528	2,014	2,888	2,065	3,528	2,014

Note: A= Amount, E = Eigen

The analysis result derived from the AHP method highlighted that the potential for developing public space is found in several functions of existing green public spaces. Table 8, ranking criteria and alternatives, shows that green open space and public space with the type of city park have the highest value, with a final value of 0.518, ranked first. The coastal border zone is ranked second with a value of 0.363. The liquefaction memorial park has a value of 0.350 as the third rank, the river border zone has a value of 0.313 as the fourth rank, and the urban forest has a value of 0.223 as the fifth rank. The sub-district park had a value of 0.111 as the sixth rank, the production forest zone had a value of 0.102 as the seventh rank, and the smallholder plantation zone was 0.047 as the eighth rank.

Table 8. Ranking of Criteria and Alternatives

	Responsive space	Democratic space	Meaningful space	Score	Rank
Eigen Criteria	0,679	0,241	0,079
Urban Forest	0,226	0,215	0,221	0,223	5
City Park	0,513	0,531	0,521	0,518	1
Sub-District Park	0,112	0,108	0,110	0,111	6
Production Forest Zone	0,103	0,100	0,101	0,102	7
Smalholder Plantation	0,048	0,046	0,047	0,047	8
Coastal Border Zone	0,364	0,362	0,350	0,363	2
River Border Zone	0,319	0,299	0,305	0,313	4
Liquefaction Memorial Park	0,330	0,404	0,359	0,350	3

Table 9. Criteria Data List

No	Criteria Code	Criteria	Weight	Type
1	C1	Sense of Space	0,2	Benefit
2	C2	Harmonious Environment	0,2	Benefit
3	C3	Width	0,1	Cost
4	C4	Accessibility	0.5	Benefit

Table 10. Decision Matrix (X)

No	Alternative	C1	C2	C3	C4
1	City Park	3	4	1	4
2	Coastal Border Zone	2	2	2	1
3	Liquefaction Memorial Park	3	5	5	5
4	River Border Zone	2	2	4	1
5	Urban Forest	3	2	4	4
Total		13	15	16	15

Table 11. Normalization Matrix (R)

No	Alternative	C1	C2	C3	C4
1	City Park	0.2308	0.2667	0.0625	0.2667
2	Coastal Border Zone	0.1538	0.1333	0.125	0.0667
3	Liquefaction Memorial Park	0.2308	0.3333	0.3125	0.3333
4	River Border Zone	0.1538	0.1333	0.25	0.0667
5	Urban Forest	0.2308	0.1333	0.25	0.2667

Furthermore, to obtain the best solution and determine the direction of public space development for the ideal ratio, the COPRAS method is used to make decisions that assume direct and proportional dependence on the significance level of alternative location uses. Furthermore, Complex Proportional Assessment (COPRAS) solves the problem of determining alternatives by producing 𝑄Max, the maximum relative value. The performance index value (Pi) obtains all alternative candidate rankings. From the results of these calculations based on existing criteria, sub-criteria, sub-sub-criteria, and alternative spaces, the calculation results obtained are depicted in Table 9 - 18.

From the results of the analysis (COPRAS), we can see several alternatives for developing public space based on the potential of green open space in Palu City; Memorial Park, a former liquefaction area, is one of the best alternative open space development with a utility value of 100 have a 1^st rank, then a city park with a value of 96, 9297 is the 2^nd rank, urban forest with a value of 75.3756 is 3^rd rank, the coastal border zone with a value of 39.3296 is 4^th rank, and the river border zone with a value of 35.3918 is 5^th rank.

Table 12. Weighted Normalisation Matrix

No	Alternative	C1	C2	C3	C4
1	City Park	0.0461	0.0533	0.0062	0.1333
2	Coastal Border Zone	0.0308	0.02667	0.0125	0.0333
3	Liquefaction Memorial Park	0.0461	0.0667	0.0312	0.1667
4	River Border Zone	0.0308	0.02667	0.0250	0.0333
5	Urban Forest	0.0461	0.02667	0.0250	0.1333

Table 13. Maximizing Value S+ (C1 C2 C4)

No	Alternative	C1
1	City Park	0.23282051282051
2	Coastal Border Zone	0.090769230769231
3	Liquefaction Memorial Park	0.27948717948718
4	River Border Zone	0.090769230769231
5	Urban Forest	0.20615384615385

Table 14. Maximizing Value S+ (C3)

No	Alternative	C1
1	City Park	0.00625
2	Coastal Border Zone	0.0125
3	Liquefaction Memorial Park	0.03125
4	River Border Zone	0.025
5	Urban Forest	0.025
Total		0.1

Table 15. Relative Weight of Each Alternative

No	Alternative	1/S-i	S-i * Total 1/S-i
1	City Park	160	2.2
2	Coastal Border Zone	80	4.4
3	Liquefaction Memorial Park	32	11
4	River Border Zone	40	8.8
5	Urban Forest	40	8.8
Total		352

Table 16. Relative Priority Significance Value (Qi)

No	Alternative	Qi
1	City Park	0.27827505827506
2	Coastal Border Zone	0.1134965034965
3	Liquefaction Memorial Park	0.28857808857809
4	River Border Zone	0.10213286713287
5	Urban Forest	0.21751748251748
MAX		0.28857808857809

Table 17. Quantitative Utility Value (Ui)

No	Alternative	Ui
1	City Park	96.429725363489
2	Coastal Border Zone	39.329563812601
3	Liquefaction Memorial Park	100
4	River Border Zone	35.391760904685
5	Urban Forest	75.375605815832

Table 18. Final Ranking

No	Alternative	Ui	Rank
1	Liquefaction Memorial Park	100	1
2	City Park	96.4297	2
3	Urban Forest	75.3756	3
4	Coastal Border Zone	39.3296	4
5	River Border Zone	35.3918	5

Table 19. Alternative types of green space as potential for public space development

No	Type	Width (Ha)	Location
1	Liquefaction Memorial Park	232,560	Balaroa 44,603 Ha
			Donggala Kodi 8,794 Ha,
			Duyu 0,687 Ha
			Petobo 178,477 Ha.
2	Urban Forest	56,330	Mantikulore

Figure 6. Orientation of Potential Development of public spaces

Based on the availability of sufficient space, the urban green space of the Likufaksi Memorial Park and the forest park can be an alternative for developing public space in Palu City, which also considers the function of public space as responsive space, democratic space, and meaningful space. Besides, several criteria are further explained below, with a sense of belonging to space, a harmonious environment, and accessibility as more specific considerations. The potential for developing public space from two types of green open space/public space, memorial park and urban forest, can be explained based on location and available area in Table 19.

Table 19 shows that the potential for developing existing public spaces is the former liquefaction area of Balaroa village, with an area of 44,603 Ha. It has significant potential to be developed into public space in Palu City, including the former liquefaction area of the Petobo sub-district, which has the largest area of 178,477 Ha. Besides, this type of urban forest, specifically in the Mantikulore sub-district cactus park area with a potential area of 56.33 Ha, can be developed into a public space for Palu City (Figure 6).

Based on the AHP and COPRAS analysis results, an alternative development of public space in Palu city was found, which leads to open space in the former liquefaction area of Balaroa village with a potential area of 44,603 Ha. The orientation of the Balaroa village as a potential memorial park green open space function is shown in Figure 7.

Figure 7. The Image of Balaroa Village, Palu Barat District

(Adapted from Spatial Plan of Palu City 2021-2041)

Provisions for limited and conditional permitted activities and land use in areas prone to very high liquefaction disasters consist of:

1. 1)   Green space supporting facilities (parking area, access road);
2. 2)   Special small and micro-scale business space for liquefaction survivors (e.g., canteen, souvenir kiosk), place of worship as a memorial and support for green space, as required the building construction is light and has a flexible foundation (e.g., pile dwellings), and is equipped with a well with a diameter of >1 ( one) meter, and depth >15 (fifteen) meters KWT maximum 10% (ten).

Discussion & Conclusion

The criteria for public space that can be utilised optimally must meet the adequacy of functions and supporting facilities. Functional adequacy includes physical comfort, ease of physical accessibility, freedom of activity, freedom of view, and support of various community activities. It fulfils the need for security relaxation and can accommodate active and passive freedom of communication. Public spaces must also contain meaningful aspects of space and have a clear identity that can provide educational and historical elements for the community (Lee, 2022).

Based on the results of the existing analysis, public space in Palu City can be developed in locations that do not have existing city parks to fulfil the need for public space. However, it can be developed in the former liquefaction area (memorial park) in Balaroa village and potential forest areas. A city that still has a very adequate area.

Based on the results of the existing analysis using the AHP and COPRAS methods, the alternative development of open space in Palu city is directed at the location of the former liquefaction (memorial park) in Balaroa village, which meets the adequate criteria for developing public space, in the Palu city which is also supported by the Palu city government policy regarding development area of green space (RTH). Developing public space in Palu City by combining a green planning approach with the genius loci concept accommodates the local wisdom of the Palu City area. The green design approach minimises the negative impacts and influences on humans and nature and produces a healthier living environment. Palu City community, located in a disaster-prone area, uses the concept of local wisdom as part of life. The developed process is collaborative, scale-independent, technologically dependent, data-driven, and iterative in nature. The process is helpful for both academicians and practitioners. It fills the gap by providing a rational quantitative approach in academics (Kapoor & Bansal, 2023)

The concept of developing public open space is addressed based on a green planning approach divided into three alternatives: firstly, it is based on a balanced distribution of green open space between regions and land use priorities. Secondly, it is based on a balanced distribution of green open space, priority land use, distance to settlements, the minimum area of 250 m^2, and the complexity of the landform. Thirdly, it is based on considerations of spatial patterns and control of regional assets. The concept underlying the green design/planning-based public space development approach in Palu City is influenced by several considerations:

1. 1)   The shape and pattern of Palu City are viewed from the figure-ground concept, which analyses mass cover (solid) and open space (void).
2. 2)   The concept of linkage as a link (path/pedestrian ways).
3. 3)   The place theory concept is public space as a marker (landmark/node).
4. 4)   Genius Loci or local wisdom in Palu city.
5. 5)   Public space activity patterns (active/passive), public space function patterns (ecological/socio-cultural), and hierarchy of service levels.

The green design concept in public space development in Palu City is divided according to service levels, from the city scale to the environmental level. On a city scale, public space is conceptualised as a landmark that can become a link between several other open space locations. The landmark concept creates a city identity that matches the figure-ground pattern. At the territory scale, neighbourhood to sub-district, public space is developed according to activity patterns (active/passive) and green space function (socio-cultural/ecological). In densely populated areas, built-up land (facade walls) is used as green open space in the form of pots/vines.

Green design/architecture focuses on the natural environment and its ecological effects, with ecology as its main interest. It uses the efficiency of buildings by using natural architectural energy wherever possible to respect the environment better. Green design/architecture consumes minimal natural resources, including energy, water, and materials. Then, it also has minimal negative impacts on the environment. Public space, which will be developed by utilising the potential of former liquefaction areas, can also be filled with plants, plants, and vegetation (endemic and introduced) to support ecological, socio-cultural, and architectural benefits that can provide economic benefits (welfare) for the surrounding community. Judging from the function of public space, which has a function that is ecologically, socio-culturally, aesthetically, and economically beneficial, It also can follow ecological patterns (clustered, elongated, spread out) and planning patterns that follow the hierarchy and structure of urban space.

The concept of Genius Loci in Palu City is related to naming places in specific locations. It illustrates disaster awareness and has long been known by the Kaili tribal community in the Palu Valley. The naming of places by the Kaili people is called Toponymy, the name of a place, origin, meaning, use, and typology, which refers to background elements of events, natural conditions, and culture (Sirajuddin, Fitriaty, & Shen, 2022). Meanwhile, previous parents gave many names of places in Palu that came from local languages, including Kaili. Several places in the Kaili language contain meanings related to geology, geography, ecology, and natural events that have occurred. Knowledge of regional names (Toponymy) and vocabulary that interpret natural events can be used to determine how prepared we are to reduce disaster risk.

Contributions

Conceptualisation, FZ; methodology, FZ; software, FZ, DS and N.A .; investigation, DS and NA; resources, FZ; data curation, FZ; writing—original draft preparation, FZ, DS and NA; writing review and editing, FZ; supervision FZ. All authors have read and agreed to the published version of the manuscript.

Ethics Declaration

The authors declare that they have no conflicts of interest regarding the publication of the paper. The authors confirmed that the paper was free of plagiarism.

Acknowledgments

The author would like to thank the Faculty of Engineering, Tadulako University, as well as the Palu City Government, for sharing data and information for data on the availability of green open spaces in Palu City.

Funding Statement

Faculty of Negineering, Tadulako University funded this researchthrough theDIPA 2023 research program.

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