Heritage Smart City Mapping, Planning and Land Administration (Hestya)

Abstract

A smart city is a concept of urban development that requires different technologies to integrate all city elements into a sustainable city system. Land administration, including three-dimensional (3D) cadaster and planning, is a pre-condition for having a smart city. Land administration in the smart city will be more attractive when the city has a cultural heritage area that must be preserved for economic, social, and territory benefits. This paper describes the development of a multipurpose land administration system prototype of a city, especially in the cultural heritage area. The first activity of this development is to create a 3D city map for documentation and management of cities, especially for cultural heritage areas, and involve the role of the community in participatory mapping. The participatory mapping method is used to form a more detailed 3D building model using simple techniques for measuring the room distance on a building. Then, the 3D city model is stored in a spatial database and management system to visualize, analyze, and manage the data. This research uses the complex area of Kasepuhan Palace, Cirebon City, West Java, Indonesia, as a case study. That area is a cultural heritage area with complicated objects and unique information to document.

1. Introduction

Cultural heritage contributes considerably to promoting economic, social, and territory cohesion, as it enhances locals’ identity and appreciation for their land and its history. However, cultural heritage is exposed to multiple risks due to aging, adverse environmental conditions, and human pressure. Uncontrolled land development is also one of the causes of the disruption of cultural heritage. Therefore, the understanding of the cultural space is vital for the implementation of successfully integrated land-use policies.

Land use constitutes an essential form of cadastral data. It serves as the basis for taxation, supports urban planning, influences real property values, and affects land management procedures. The main rationale behind sustainable management of cities is the systematic and comprehensive credibility verification of the data being the basis for tax calculation—the information on land use contained in the cadastre. In many cases, such data are unreliable and outdated, causing significant tax losses in the budget of local government units over the years. However, modern geospatial technologies may facilitate regular verification of such data, providing the ground for the need for their update and reaping future economic benefits for local government units.

Indonesia has already had the 2D cadastral system. However, this system is not appropriate anymore. A 3D cadastral system is needed because of land dynamics resulting from population growth, which increases vertical development. Thus, multi-purpose land administration should accommodate data sharing and the 3D cadastre concept. As a result, the utilization of international standards and models for land administration is at the forefront. LADM is an international standard for the land information domain, supporting data sharing and the 3D cadastre concept. Nowadays, there is also a great deal of interest in the digital documentation and visualization of cultural objects, together with the quest for new technologies for efficient management. For example, developing a multi-purpose land administration system of a city with a cultural heritage area might use a 3D spatial information system that uses LADM, BIM, and 3D-GIS standards. IFC and CityGML are standard for a data model in BIM and 3D-GIS.

The three-dimensional (3D) city model is a representation of the city that can be used as input data to conduct land administration and 3D cadaster in the development of a smart city system that pays attention to cultural heritage areas. A smart city is a concept of urban development that requires different technologies to integrate all city elements into a sustainable city system [1,2]. This smart city system is useful in planning and construction and in the city maintenance process. Therefore, the 3D city model can integrate the interests of various stakeholders and experts from many diverse disciplines involved in urban planning and city management. In addition, a 3D city model can also facilitate the government in monitoring the progress of city development so that it complies with the existing laws and regulations. An example of improved supervision that can be done by the city government using the 3D city model is monitoring the change in total building area, which will affect land and building tax revenues, or the monitoring of the land-use changes that do not comply with the regulation.

Three-dimensional mapping techniques are required to create this 3D city model. The techniques used for mapping include photogrammetry, terrestrial and Unmanned Aerial Vehicle (UAV)/drone photogrammetry, and laser scanning [3,4]. All techniques can generate point clouds and can be used to document objects in 3D. However, mapping the city’s large areas requires a lot of human resources and an enormous amount of time. This research proposed a community-based mapping or participatory mapping method that involves the government and licensed surveyors and ordinary citizens in its implementation. Simple techniques and software will also facilitate an easy 3D digitization process. Based on the need for land administration to support smart cities, especially for cultural heritage areas, a 3D city model and city spatial information system are needed. This research aims to develop a multipurpose land administration system prototype of a city, especially in the cultural heritage area. To achieve this goal, a 3D city map was developed for documentation and management of cities, especially for cultural heritage areas. Then, the 3D city map is stored in a spatial database and management system to visualize, analyze, and manage the data.

A city consists of areas with different characters, including residential areas, vernacular, and historical/cultural heritage areas. The mapping process is relatively easier for areas with modern architecture than for the vernacular and cultural heritage areas, because it has simpler building forms. Moreover, cultural heritage areas, in general, have complicated objects and unique information to document. Heritage information is required to acquire knowledge, understand its meaning and values, promote interest and involvement, permit informed management, and ensure the long-term preservation of heritage places [5]. This need for information affects the mapping method used for heritage areas and surrounding areas.

2. Literature Review

Cultural heritage can be classified into monuments, groups of buildings, and sites. Monuments are architectural works, monumental sculpture and painting, elements or structures of an archaeological nature, inscriptions, cave dwellings, and combinations of features, which are of Outstanding Universal Value from the point of view of history, art, or science. Groups of buildings are groups of separate or connected buildings that, because of their architecture, homogeneity, or place in the landscape, have more value from the point of view of history, art, or science. Cultural heritage as sites are works of man or the combined results of nature and man, and areas including archaeological sites of value from the historical, aesthetic, ethnological, or anthropological points of view [6]. In Indonesia [7], cultural heritage was in the form of cultural heritage objects, cultural heritage buildings, cultural heritage structures, cultural heritage sites, and cultural heritage areas on land or in water. All records of cultural heritage in Indonesia need to be preserved because they have essential values for history, science, and culture. Education, religion, and culture through a determination process. Efforts to conserve cultural heritage areas through protection, restoration, and development, where all these activities need to be documented.

The cultural heritage documentation can be done by mapping techniques using photogrammetry and laser scanning. Photogrammetry enables many tools to give virtual casts of reality by showing it in the way of the point cloud. In Pulcrano et al. [8], the camera system documents the Church of Rosario di Palazzo. The system can be an alternative for heritage documentation, placed at an intermediate level between range-based and image-based traditional technologies. The close-range photogrammetry (CRP) also contributes to measured drawing, reconstruction, and restoration projects for historical buildings into 3D models [9].

The laser scanner technique was also used for cultural heritage [10]. For example, in Murphy et al. [11], parametric objects/components of heritage buildings based on 18th-century architectural manuscripts were constructed. These objects were stored as GDL objects collected in the library for HBIM. The object was then mapped or correlated to the point cloud from the laser scanner data so that a 3D model of the building can be obtained that can be used as an architectural document.

Some study areas use the combination of laser scanning and photogrammetry. The benefit of integrating these two technologies is to take advantage of the terrestrial laser scanner (TLS) capability to directly acquire dense colored point cloud with the flexibility of the photogrammetry to operate even in exceptional conditions [12]. For example, in Fawzy [13], the combination of TLS and CRP showed the optimum achieved accuracy for 3D digital documentation, and it is recommended for surveying instead of the traditional method. Furthermore, the model of cultural heritage building from laser scanners and photogrammetry can be visualized at different levels of detail and used Heritage Building Information Modeling (HBIM) for building maintenance [14].

Based on the data from the mapping process, the 3D models can be saved as a 3D Geographic Information System (GIS), Building Information Modeling (BIM), or the integration of both—the so-called GeoBIM. BIM is a digital representation that shares knowledge resources for information about a facility forming a reliable basis for decisions during its life cycle [15]. BIM working on a 3D model contains information via an intelligent database and can restore both geometric and semantic information [16]; rich semantic information such as material, height, and thickness. GIS is an information system with specific capabilities for working with spatially referenced data [15]. Due to the use of the data referenced by spatial or geographic coordinates, GIS can be used to model larger areas than BIM [17]. Three-dimensional GIS is an ideal tool for representing 3D geometry, semantic, and topology [16]. BIM and GIS are currently considered two different technologies and are challenging to integrate, even though they are necessary to model cities [17]. The 3D model in BIM has rich information supporting building facility management, but it works on local coordinates. On the other side, a 3D model in GIS with geographic coordinates can be used for spatial analysis in larger areas. The integration of those technologies can be beneficial for urban planning and evaluation.

Land administration has four primary functions: land tenure, land value, land use, and land development. These land administration functions are still managed separately in Indonesia. Multipurpose cadastre is capable of supporting all primary functions in land administration and should accommodate data sharing and 3D cadastre concept. LADM is an international standard for the land information domain, supporting data sharing and the 3D cadastre concept. In Safitri [18], the conceptual architecture of a multipurpose cadastre based on LADM with the country profile of Indonesia has been developed.

3. Materials and Methods

This project will use as a case study the urban heritage complex area in and around the Kasepuhan Palace, Cirebon, West Java, Indonesia. From the Building and Environment Plan (Rencana Tata Bangunan dan Lingkungan/RTBL) of Cirebon City, the area of Kasepuhan Palace is bordered by the red line (Figure 1). Kasepuhan Palace is one of four palaces in Cirebon; the other palace is Kanoman Palace, Kacirebonan Palace, and Keprabon Palace. The Kasepuhan Palace area was built in the 1500s and is currently surrounded by various other regional functions, including settlements, trade and services, and government offices. Kasepuhan Palace combines three cultural elements (Javanese, European, and Chinese) and three religions (Islam, Hinduism, and Buddhism) in its construction concept. Acculturation between Javanese, European, and Chinese cultures can be seen from the physical building; the ‘pendopo’ (gazebo-like building) represents Javanese buildings, and the ornaments attached have European and Chinese nuances. In general, the palace area represents the Islamic architecture of the archipelago, while the gates and walls of the palace using red brick structures are similar to Hindu and Buddhist architecture. The acculturation of culture and religion shows that intercultural and religious harmony is well maintained.

The method used in this research can be seen in Figure 2. The research method is divided into three activities, 3D city mapping and building model, 3D GIS-BIM integration, and 3D spatial data management and analysis. A detailed explanation of these activities can be seen in Section 3.1, Section 3.2 and Section 3.3. Three mapping methods are used in this study regarding the information needs that affect the mapping method. The first method is UAV-Photogrammetry to map cities, and the other two methods are used to map buildings. The two methods are distance measurement for building interiors and Close-Range Photogrammetry (CRP) and Terrestrial Laser Scanner (TLS), which produce a point cloud. The mapping results using CRP and TLS are used to validate the results of measuring the distance to the interior of the building and to complete the exterior model of the building.

3.1. 3D City Mapping and Building Modeling

Unmanned Aerial Vehicle (UAV) Photogrammetry technology is used to map the study area of Cirebon Palaces. It generates orthophoto, Digital Surface Model (DSM), and Digital Terrain Model (DTM) that can be used for creating the 3D city model. The 3D city model in this research can be made as Level of Detail (LOD) 1 or LOD 2. Using the concept of CityGML [19], the LOD 1 model only visualizes the building as building mass, and the LOD 2 model visualizes the structure with the shape of the roof in a simple way. The roof polygons are digitized manually from orthophoto and overlaid with DSM to create the LOD 2 model.

Data from measuring techniques, Close-Range Photogrammetry (CRP), and Terrestrial Laser Scanner (TLS) can be used to create the building model. The measuring techniques in this research use distometer and motion-based measuring technology, Moasure. Moasure is a commercial measuring tool based on motion sensor technology with an accelerometer, magnetometer, and gyroscope to measure indoor distance. Moasure boasts ease of measurement and gives measurements results almost directly or in real-time. Still, the maximum accuracy obtained is considered lower than the measurement results of laser sensors in general. Moasure can provide images directly, send and export measurement results directly in various formats, and help model and measure rooms faster and more efficiently [20]. The illustration of measuring the building’s interior can be seen in Figure 3. The measuring techniques can produce building plans as participatory mapping, which can create a 3D building model, especially for interior elements such as openings. CRP and TLS techniques generate the point cloud of building exterior and interior and are used as a reference for validating the building model.

3.2. 3D GIS and BIM Integration

The technology used for 3D modeling is Building Information Modeling (BIM) and 3D Geographic Information System (3D GIS). The 3D city model can be saved as a 3D-GIS model, and the building model can be saved as a BIM model. However, both models have their respective advantages and disadvantages, and there is a gap between the two. BIM and GIS are currently two different technologies and are challenging to integrate [21]. In this research, the city and building models’ integration uses georeferencing to integrate those models into one system coordinates and visualized together.

CMDBuild is an open-source web environment for configuring custom applications for Asset Management. Moreover, GIS features can be used to georeference and display assets on a geographical map (external map services) and/or on vector maps (local GeoServer and spatial database PostGIS) and BIM features to view 3D models (IFC format).

This Project is the source for experimental work of our research about Asset and Facility Management of Large and Complex Cultural Heritage Site using Open Source 3D-GIS and BIM. We utilize the advantage of CMDBuild, which has native mechanisms to model the database, design workflow, configure reports and dashboards, build connectors with external systems, geo-refer assets, and administer the system. Management of the Cultural Heritage Site can be implemented with this software environment and any applications such as construction management, smart campus, smart village, smart city, etc.

We also upgrade the two-dimensional (2D) map in CMDBuild to a three-dimensional (3D) map even to 3D Geographical Information System using 3DCityDB and CesiumJS. We are doing:

(a)

To adapt LADM into an integrated model, an integrated 3D land information management;

(b)

Data Model Designing for Asset/Facility Management of Large and Complex Cultural Heritage (CH) Site; it includes a temporal aspect that has not been established in CityGML yet;

(c)

Integrating or Mapping between CityGML scheme in 3DCityDB and IFC scheme in BIMServer;

(d)

Spatial Analysis Investigation that would be important in the management of CH asset/facility.

The system architecture of the prototype can be seen in Figure 4. The data on the server is managed using a single system resulting from the integration of several open-source software. The framework software is CMDBuild, where PostgreSQL/PostGIS support the database and, by default, is only capable of storing 2D spatial data (2D-GIS). In this research, the CMDBuild database is integrated with 3dCityDB to store 3D spatial data with the CityGML data model. The data stored can be in the form of LOD 0 to LOD 3 models, and, specifically for LOD 1 to LOD 3, can be integrated with interior geometries.

By default, CMDBuild is also connected to BIMServer. BIM 3D models that have been created using modeling software such as ArchiCAD or Revit can be saved in BIMServer. Therefore, any changes to the 3D model in the modeling software can be automatically synchronized with the 3D model in BIMServer. The IFC format is used to exchange model data between GIS and BIM. In this research, a mechanism is still being developed, namely synchronization between the 3D model in BIM-Server and the 3D model in 3DcityDB. This synchronization also performs geometric, semantic, and topological transformations because there are differences between IFC and CityGML in these three aspects. The synchronization is between the interior IFC and LOD 3 CityGML of the building. If the LOD 3 model can be built, generalizations are made for LOD 2, LOD 1, and LOD 0. If these generalizations can be made, the integration between the city map and the building model can be carried out to update the 3D city map.

3.3. 3D Spatial Analysis

In this research, urban spatial analysis and building spatial analysis were performed to the regulations. The regional regulation for this study is Building and Environment Plan (Rencana Tata Bangunan dan Lingkungan/RTBL) of Cirebon City [22]. The RTBL document contains various rules written to regulate the city of Cirebon. In addition, this document has some maps as the attachment and complements the regulations, which the maps are digitized to be used for 3D spatial analysis. One of the examples of digitized maps and regulation can be seen in Figure 5. This data can be used as a reference for 3D city analysis by comparing actual conditions with existing maps and regulations. The 3D spatial analysis for the city is about checking the maximum height of the building. The building’s maximum height is represented as the top building story, some area has four floors, and the rest has only two floors. The assumption for each story height is 5 m. The building spatial analysis carried out in this research is the natural room lighting evaluation.

Besides the RTBL document, Indonesia has a National Standard document for building Standar Nasional Indonesia (SNI). This document can be used as a reference for all of the buildings in this country, with detailed instructions and standards for construction and evaluation. In this research, the SNI 03-2396-2001 about natural room lighting and SNI 03-6572-2001 about room temperature are used for building evaluation. The element building for building evaluation can be computed from the 3D building model and compared with the standard. If the ratio between the building elements and the room meets the applicable standards, the building can be a reliable building.

4. Results and Discussion

4.1. 3D City Mapping

The results from aerial photo processing using the UAV Photogrammetry method are orthophoto and digital elevation model (DSM and DTM). The used horizontal reference is Universal Transverse Mercator (UTM) with Zone 49S; the vertical reference is Geoid EGM 2008. Orthophoto and digital elevation models can be shown in Figure 6, with the resolution 4 cm/pix.

The 3D city model LOD 1 can be created using orthophoto and digital elevation model when the LOD 1 model only shows the simplest form of city object. For example, the building models are visualized as a building mass without the roof. The LOD 1 model of the Cirebon Palaces area can be generated using two methods. First, the open share program 3Dfier and, second, using the 2D polygons as shapefile format data and extruding it into the 3D model using elevation value. The 3D city model LOD 1 can be shown in Figure 7. The LOD 2 city model was built using roof digitization data obtained from orthophoto and shown in Figure 8. LOD 2 visualizes building with the simple form of roof. Those city models are saved in City Geography Markup Language (CityGML) format.

4.2. Building Model

The 3D documentation of cultural heritage buildings in the Keraton Kasepuhan Cirebon has been carried out [23,24]. The paper described the workflow used in digitizing tropical vernacular architecture in the context of cultural heritage documentation. The works in those papers are part of this research, and some of the results can be seen in Figure 9.

Measuring using a distometer and moasure can generate the 2D building plan. In this research, the residence of Pangeran Arya Denda has been measured, and the building plan can be seen in Figure 10.

Based on the laser scanner data, the point cloud of the building exterior and interior can be seen in Figure 11. The detailed 3D model can be validated using this data and combined with the building plan to create a 3D building model. The laser scanner data is needed to complement building plan data because it has elevation value and the form of the roof. The building model of the Pangeran Arya Denda residence can be seen in Figure 12.

4.3. Spatial Database Management System

The 3D spatial database management for various purposes can be defined as an integrated land information system containing legal (e.g., tenure and ownership), planning (e.g., land use zoning), revenue (e.g., land value, assessment, and premium), and physical (e.g., cadastre) information. Therefore, the 3D spatial data management for various purposes should contain all information about tenure, taxation, land market, base maps, cadastral and survey boundaries, categories of land use, and streets addresses. It can support the spatially enabled government, private sectors, and society by expanding the process of visualization, organization, and management of useful land information. In brief, there are many advantages to implementing multipurpose land information. It benefits property inventory, project implementation and monitoring, utility management, population estimates, school management, census mapping, and urban and rural development.

The conceptual architecture of land data management is developed using geodatabase design. Therefore, geodatabase design is the main component of Geographic Information System (GIS) application production activity. Generally, the impact of data on system structure and procedure complexity caused by geodatabase design significantly influences the quality of the GIS model.

The adaptation of LADM into 3D land administration for Country Profile Indonesia can be seen in Figure 13. The implementation in Indonesia uses the 2D/3D hybrid cadastre. The concept of a hybrid cadastre is to preserve the current 2D registration and add a 3D component into the registration system. The ina_parcel is represented as a 2D geometry. This object is inherited from the current 2D registration system. While ina_buildingunit is represented as a 3D geometry. This object represents a property unit (3D) [20].

The geodatabase is then stored in 3DCityDB integrated with the CMDBuild application so that users can access it with interest in the area’s data, such as local government agencies. In addition, the CMDBuild front end can also visualize the 2D map, 3D map, and building models. For example, some user interfaces that display the map, the model, dashboard, and tabular data CMDBuild can be seen in Figure 14.

4.4. Urban Spatial Analysis

One of the urban spatial analyses in this research is maximum height building evaluation. The visualization of maximum height building evaluation can be seen by overlaying the LOD 1 city model with digitized maximum height building from RTBL (Figure 15). From the RTBL document, six zones have a different value of maximum height building. The analysis result can be seen in Figure 16, which shows the buildings that violate maximum height building. For example, the yellow zone is the residential area with a maximum height of 8 m, and the orange buildings are existing buildings.

Based on Figure 15, buildings with transparent colors have a height that complies with regulations, and several buildings marked with orange on the top of the building exceed the height tolerance limit for the yellow residential area. Buildings that exceed the block height have a height of more than 8 m. This report can be used for the government to decide which buildings should be renovated or demolished because of violating the regulation.

The other urban spatial analysis carried out in this research evaluates the building above the river and road by overlaying the LOD 1 city model with a layer of road and river from the digitized RTBL document. The river is represented by the blue polygon and the road using grey color. From the visualization of that overlay, there are some buildings above the river, as shown in Figure 17.

Buildings that are considered to violate regulations because they stand on a river are then re-examined using images. The image from Open Street Map can be used to re-examine those buildings. Based on the picture, it was found that the buildings deemed to have violated the regulations were only gates and bridges. This shows that the interpretation of the building roof from orthophoto can have errors, so it is necessary to re-check by looking at the condition of the building directly or through images.

4.5. Building Spatial Analysis

In this research, the building spatial analysis carried out is the natural room lighting evaluation. The diagram of lighting evaluation can be seen in Figure 18. Information is needed regarding the area of the room and the area of the opening in the room. Based on the generated building model, the window area information can be taken and used to compare with the room area. In this paper, only window area in the four rooms, as samples, is written in

Table 1. Room area and windows.

Zone to	Room Area (m2)	Windows Area (m2)
Room 4	18.18	0
Room 5	49.87	1.96 1.96 1.96
Room 6	13.82	1.96 1.96 1.96
Room 7	19.84	1.26 1.96

.

From Table 1, the room 5 area is 49.87 m² with a total opening area of 5.88 m². In the national standard, the reliable building with lighting evaluation is reliable if the ratio of room and the opening area is more than 15%. Room 5 has an area ratio of 11.79%, which means that room 5 is unreliable. For room 6, the ratio result is 42.54%, which means room 6 is reliable. For room 7, the ratio result is 16.2%, which means room 7 is reliable. For room 4, the room is not reliable because it does not have a window in the room.

Based on the results obtained, the building does not meet the requirements for occupancy based on existing regulations and standards. However, in this research, the building is a cultural heritage building, so the evaluation of the building is not necessarily the basis for further actions such as renovation or demolition. Instead, the building models can be used as documentation for cultural heritage buildings to carry out conservation in the future.

5. Conclusions

The main objective of this research is to develop a multipurpose land administration system prototype of a city, especially in the cultural heritage area. There are many advantages to developing the system, beneficial for city planning, monitoring, development, management, fiscal cadastre, and various spatial analysis. That objective was achieved by building a 3D city map, especially for cultural heritage areas, and storing it in a spatial database and management system to visualize, analyze, and manage the data.

The generated 3D city map can display multi-LOD based on different regional functions. For example, residential areas use LOD 1, government agency buildings use LOD 2, and cultural heritage buildings use LOD2, LOD 3, and LOD 4. The cultural heritage buildings are also stored in the BIM model because of the need for very detailed information in the documentation. The LOD 1 and LOD 2 city models can be used for urban spatial analysis; the example case in this study is the maximum height of the building. The building model can perform spatial analysis; one of the cases in this study is natural lighting room evaluation. From the urban spatial analysis result in the case study area, some buildings violate the regulation of maximum height building value. And from the building spatial analysis using natural lighting case, the residence of Pangeran Arya as the case study is not reliable.

From this research, participatory mapping using simple methods can create 3D building models for the interior. It can involve the role of the community in building the 3D city map for LOD 1 and LOD 2 with interior data. That model can be used for city management, including for tax purposes. The 3D models of buildings can also be integrated with city maps to update a more detailed city map. Synchronizing the 3D Model in BIM to GIS helps update the city map.

The 3D city and building model for heritage areas can be stored in CMDBuild, which is connected to 3DCityDB or BIMServer, to be able to visualize data that can be used for various purposes. The data can be used by some government agencies related to city planning and management and communities with limited access according to user needs. The data can be used for documentation and city planning, management, and development.

The actual implementation of this prototype needs synergy between National Land Agency (node network), Geospatial Information Agency (network node connector), and other government institutions (other node networks) to develop a multipurpose cadastre and National Geospatial Information Network.