LiDAR for Urban Planning in the Philippines: From Survey Data to Better Cities

Cities and municipalities are constantly changing. New subdivisions are developed. Roads are expanded. Buildings are constructed. Commercial centers emerge. Rivers and drainage systems interact with increasingly built-up environments. Areas that were once agricultural or undeveloped can look completely different within only a few years.

For urban planners, Local Government Units (LGUs), developers, and infrastructure agencies, keeping up with these changes presents a fundamental challenge: How do you plan for the future when you do not have an accurate picture of what exists today?

Urban planning involves much more than deciding where residential, commercial, industrial, or institutional areas should be located. Planners need to understand the physical environment supporting those decisions, including the terrain, existing development, road networks, waterways, property boundaries, infrastructure, and areas potentially exposed to natural hazards.

This is where surveying becomes an important part of the planning process.

As planning areas become larger and cities become more complex, LiDAR is becoming particularly valuable because of its ability to capture detailed three-dimensional information across large areas efficiently.

Why Surveying Matters in Urban Planning

Before deciding what a city or municipality should become, planners first need to understand what is already there. Surveying provides accurate spatial information about the physical environment. Depending on the methodology used, this can include:

• Ground elevations and terrain

• Existing buildings and structures

• Roads and transportation corridors

• Rivers, creeks, and other waterways

• Property boundaries

• Slopes and natural drainage paths

• Existing infrastructure

• Vegetation and other surface features

This information can then serve as a base for planning, engineering, GIS analysis, disaster risk reduction, and future infrastructure development. However, there is no single survey method that answers every planning question.

A cadastral survey, for example, serves a very different purpose from a topographic survey. Likewise, Aerial LiDAR provides a different level and scale of information from Mobile or Terrestrial LiDAR. The appropriate methodology should therefore begin with a simple question: What does the planner need to understand about the area?

From conventional land surveys and cadastral information to Aerial, Mobile, and Terrestrial LiDAR, different surveying technologies can provide planners with accurate geospatial information about the environment they are trying to manage. However, regardless of the specific planning problem, whether it involves flooding, land use, infrastructure, or development control, it is often essential to first have a complete and up-to-date overall view of the city’s current physical state. This requires a surveying approach capable of mapping large areas quickly, consistently, and accurately so that decisions are based on a unified understanding of the entire environment rather than fragmented or outdated information.

Different Planning Questions Require Different Survey Data

For understanding general terrain and elevations across a city or municipality, a Topographic Survey or Aerial LiDAR Survey may be appropriate.

If the concern involves property boundaries and land parcels, Cadastral and Relocation Surveys provide a different type of information.

For roads and transportation corridors, Mobile LiDAR can provide highly detailed information along existing road networks, while Terrestrial LiDAR can capture individual structures and localized areas in greater detail.

If rivers, reservoirs, or other waterways form part of the planning area, Hydrographic or Bathymetric Surveys may also be necessary to understand what lies below the waterline.

For flood studies, these methods may even need to be combined.

The objective is not to choose the most technologically advanced survey for every situation. It is to select the survey method, or combination of methods, that provides the information needed to make the planning decision.

Problem 1: Our Existing Maps Are Outdated

One of the most basic challenges in urban planning is that the environment changes faster than many planning maps are updated.

A base map created several years ago may no longer show recently constructed subdivisions, new buildings, widened roads, altered terrain, or other development that has occurred since the original survey.

Satellite imagery and existing maps can provide useful context, but when accurate elevation and current physical information are required, a new survey may be necessary.

How Surveying Can Help

An updated aerial survey can provide planners with a current representation of the city or municipality.

When LiDAR is acquired together with high-resolution aerial imagery, the resulting datasets can include both detailed elevation information and an orthophoto showing current visible conditions across the project area. Instead of planning based solely on historical maps, planners have a more current geospatial reference that can be incorporated into GIS and other planning workflows.

For LGUs, this information can provide valuable base data when preparing or updating planning documents such as the Comprehensive Land Use Plan (CLUP), subject to the other demographic, socioeconomic, environmental, legal, and policy information required in the planning process.

Problem 2: Why Does This Area Keep Flooding?

Flooding is not simply a question of whether an area is located near a river.

The shape of the surrounding terrain affects where water naturally flows and accumulates.

A road may unintentionally influence drainage. A community may sit within a natural depression. Water from higher terrain may converge toward an area that does not initially appear flood-prone when viewed on a conventional map.

How Surveying Can Help

Aerial LiDAR can provide detailed elevation information that allows the underlying terrain to be represented through a Digital Terrain Model (DTM).

From this terrain information, planners and engineers can better identify watersheds, slopes, depressions, natural drainage paths, and low-lying areas.

Initial terrain-based flood simulations can also be developed to visualize how areas may potentially be affected as assumed water levels rise. Where rivers and waterways are important to the study, topographic data may be complemented by hydrographic or bathymetric surveys to provide information about the submerged channel. This gives planners a more continuous understanding of the environment from the surrounding watershed into the waterway.

Terrain analysis does not replace a comprehensive hydrologic or hydraulic flood study. Rainfall, river discharge, drainage capacity, tides, land cover, structures, and other conditions may also need to be considered for detailed modelling. But accurate terrain provides an important physical foundation for understanding how water may move through an area.

Problem 3: Where Should Future Development Go?

Urban planning frequently involves deciding where future growth should be encouraged, controlled, or investigated further. But identifying land on a map is very different from understanding its actual physical characteristics.

Two undeveloped areas of similar size may have completely different terrain. One may be relatively flat and accessible, while another may contain steep slopes, natural drainage paths, waterways, or significant elevation differences.

How Surveying Can Help

Survey data provides planners with another layer of information when evaluating potential development areas. Terrain, slope, waterways, road access, existing structures, and surrounding development can be analyzed alongside other planning considerations.

LiDAR does not determine whether an area should become residential, commercial, industrial, agricultural, or protected land. Those decisions require much broader planning, environmental, socioeconomic, regulatory, and policy considerations. What it can provide is an accurate representation of the physical environment upon which those decisions are being made.

Problem 4: How Do We Plan Infrastructure Around an Existing City?

Planning infrastructure in an existing urban environment can be significantly more complicated than planning within an undeveloped site. Roads, buildings, bridges, sidewalks, drainage structures, vegetation, utilities, poles, and other infrastructure may occupy the same corridor.

The more developed an area becomes, the more important it is to understand existing conditions before proposing new infrastructure.

How Surveying Can Help

Different LiDAR platforms can provide information at different scales.

Aerial LiDAR can provide the broader view, capturing terrain and surface features across large areas.

Mobile LiDAR, collected from a moving vehicle, can provide detailed three-dimensional information along roads and transportation corridors.

Terrestrial LiDAR can capture highly detailed information around individual structures, facilities, and localized project areas. These technologies can complement one another depending on the required level of detail.

Rather than thinking of LiDAR as a single survey method, planners can think of it as a family of technologies that can be deployed differently depending on the environment and project requirements.

Problem 5: Different Departments Are Working with Different Maps

Another challenge is not necessarily the absence of data, but the existence of multiple datasets created for different purposes and at different times.

Planning departments may have one map. Engineering departments may maintain another. Disaster Risk Reduction and Management Offices may have separate hazard information. Assessors may work with property information, while individual infrastructure projects generate their own survey and CAD datasets.

Each dataset may be useful for its intended purpose, but integrating information becomes more difficult when datasets differ in age, coverage, accuracy, coordinate reference, or level of detail.

How Surveying Can Help

A current and properly referenced geospatial survey can provide a common physical base upon which different information can be overlaid and analyzed.

For example, terrain and imagery can be combined within a GIS environment with land-use information, road networks, hazard maps, property information, infrastructure records, and other datasets maintained by the LGU.

Surveying does not replace these datasets. Instead, it can provide an accurate spatial foundation that helps different information relate back to the same physical environment.

Why LiDAR Is Particularly Valuable for Large-Scale Urban Planning

Conventional surveying remains essential for many applications.

Property boundary surveys, control surveys, construction stakeouts, localized engineering surveys, and other activities may require surveyors to physically occupy and measure specific locations on the ground.

But the economics and logistics begin to change when the objective is to understand an entire city, municipality, watershed, or large development area.

Conventional topographic surveying requires field crews to physically access the project area, establish survey positions, move equipment between locations, and collect the measurements needed to represent the site.

For smaller areas, this can be practical and cost-effective. Across hundreds or thousands of hectares, however, collecting sufficient information becomes a much larger undertaking.

LiDAR Changes the Scale of Data Collection

An aircraft equipped with LiDAR can collect millions of measurements across large areas within a relatively short acquisition period. Instead of measuring only selected locations, LiDAR creates a dense three-dimensional point cloud of the surveyed environment. From the same properly planned acquisition, multiple deliverables can be generated.

• A Digital Terrain Model (DTM) can represent the ground and support terrain, drainage, watershed, and flood analysis.

• A Digital Surface Model (DSM) can represent buildings, vegetation, and other surface features.

• A classified point cloud preserves detailed three-dimensional measurements that can be viewed, measured, analyzed, and potentially revisited for future applications.

• Contours provide a familiar representation of elevation for engineering and planning.

• When a high-resolution camera is integrated with the LiDAR system, an orthophoto can provide a current visual representation of the project area and can also be used to add realistic color information to the point cloud.

The value of LiDAR for urban planning therefore isn't simply how quickly an area can be surveyed. It is how much reusable information can be collected from a single acquisition.

From Maps to Three-Dimensional Cities

For decades, urban planning has relied heavily on two-dimensional maps.

Those maps remain important, but LiDAR gives planners the ability to work with something more comprehensive: a measurable three-dimensional representation of the physical environment.

Terrain, roads, buildings, vegetation, waterways, and infrastructure can increasingly be represented spatially and analyzed together.

When accurate geospatial information is integrated with GIS, planning records, infrastructure information, environmental data, and other datasets, it can also provide part of the foundation for more sophisticated 3D city models and digital twin initiatives.

A digital twin involves considerably more than a LiDAR point cloud. It may incorporate operational information, asset data, sensors, simulations, and continuously updated datasets depending on its intended purpose. But every useful digital representation of a city needs one thing at its foundation:

An accurate representation of the physical city itself.

Better Cities Start with Better Information

Urban planning ultimately involves making decisions about a place that may affect how people live, move, work, and respond to future challenges for decades.

Surveying does not make those decisions. What it does is give planners, engineers, developers, and government agencies a clearer understanding of the physical environment those decisions will affect.

For small and localized requirements, conventional surveying may remain the most practical approach. For property boundaries and specific legal survey requirements, specialized land surveys remain essential.

But when planners need to understand large, complex, rapidly changing environments, LiDAR offers something fundamentally different: the ability to capture detailed, three-dimensional information across an extensive area and reuse that information for multiple planning applications.

At AB Surveying and Development, we approach urban mapping by first understanding what the client needs the data to accomplish. Our capabilities across Aerial, Mobile, and Terrestrial LiDAR, conventional land surveying, and hydrographic surveying allow different methods to be combined when the project environment requires it.

Because the goal should never be to use LiDAR simply because the technology is available. The goal is to collect the right information, at the right level of detail, to help planners make better-informed decisions about the places they are planning for.