LSGI 4321 Essay TopicCritics have argued that the roof of the current high housing price is the result of a mismatch of supply and demand. Discuss how GIT can help facilitate a steady housing land supply to meet the demand.

Tang Wing Yee Peony 09113226D

Introduction

The housing price in Hong Kong nowadays is continuously increasing. Although the government has introduced some new housing policy and increased the restriction on property transaction and the economic environment is still full of uncertain factors, the increasing in property price is still having an adorable raise. Therefore, both the middle and lower income classes can hardly afford to buy a place for living and it leads to social disharmony.

Some said that if the government can ensure a steady land supply, the current housing price may be reduced. In this essay, I will discuss how Geo-Information Technology (GIT) can help facilitate a steady housing land supply to meet the demand.

Defining GIT

GIT is a mean for spatial analysis. It consists of both specialized information and communication technology. Data includes resources, landscape features and socio-economic characteristics of an area will be collected, managed and analyzed. It can then visualize the spatial data for communication, dissemination and knowledge sharing. Its major tools are Geo-Information System (GIS), Geo-positioning System (GPS), remote sensing and web-based tools.

Defining Land Supply, Land Capacity and Demand

Naturally, the contentiousness of a highly politicized process that helps shaping the decisions of the development of urban increase according to the relative scarcity of land deemed “developable.” This need to establish “definitions of available land supply agreed on by both private interest and the government” continues to be a major issue with land monitoring.

Typically, buildable lands are classified as vacant, partially utilized or underutilized. Vacant land is land without any significant uses. Partially utilized land is improved parcel that are sufficient vacant and allow additional new construction without changing the existing structure. Underutilized land is property that already developed over most area, but considered likely to undergo demolition and replacement or

significant alteration of structure to yield more intense, more highly valued, or altogether different uses, usually means lands having redeveloping potential.

Although adequate land supply is always assessed relatively to demand, it technically does not have to be considered in determining the land supply and estimating the land capacity. However, if possible, we should also consider the consumer preferences for housing type, sectoral employment growth, and changes in construction and land development practices as well as dwelling unit versus employment growth.

As for Hong Kong, the land supply mainly sourced from government vacant land and renewal project, while the purchasers of the housing are usually investors and residents.

Trend of using GIT in monitoring land supply

Recently, there is increasingly more concern on the impacts of future urban development through growth-conscious planning and the development of GIT become more rapid, which helps doing the functions of planning and management. Since GIT is capable in perform several of functions that help doing sophisticated analyzes, modeling and visualizing, use of GIT in monitoring land supply becomes more common and popular.

How GIT facilitate the land supply

Data Capture

Before the processing, we need to develop a comprehensive land supply database, conduct an inventory of the buildable land supply, estimate development capacity and apply land supply and capacity information to plan-making and plan implementation processes.

Since the data collected are useful to other general planning activities and other government functions, also the monitoring and analysis approach may change over time, so it is important to separate the database from the buildable land supply inventory and analysis. The database should be as completed and comprehensive as possible, if not the outcome may not be reliable and convincing.

Generally, the database should include the following data types such as existing and planned land uses, zoning, other regulations that impose limits on density and use (usually imposed by the planning departments of the government to ensure a sustainable city development), land ownership information, environmental conditions, existing planning and infrastructure, etc.

Remote sensing, one of the essential GIT tools, is definitely capable in collecting most of the above information. Remote sensing is the art and science of obtaining information about object, area, or phenomenon through the analysis of data acquired by a device that is not in contact with the object, area, or phenomenon under investigation.

Using remote sensing, we can do land use classification, land use monitoring and environmental observation.

By image interpretation, we can do land use classification according to their shape, size, pattern, tone or hue, texture, shadow, site and association. For instance, texture helps distinguish urban and rural land use. Shape helps recognize recreational land use such sport ground and swimming. Site, which is the geographic location of the features, can help recognize commercial land use such as Central. Pattern helps us to distinguish residential and industrial land use. We can also recognize transportation land use such as roads and bus stations using pattern and association. More, it definitely helps us to identify the vacant land and partial utilized land.

By image interpretation, we can able to monitor the current use of land. This is really important, since if the land is used not correctly, the planning that done previously will be meaningless and the ordinary land supply strategy would be ruined. For instance, illegal farming activities on government land like mountain or national park can easily be recognized using aerial photo using pattern. Another example is that previously, that was news reported on July that some riches built the gate of their houses on government land and it shows clearly on aerial photo and posted on newspaper and TV program. (For more information, please visit the following website: http://www.hkatvnews.com/v5/news.php?id=151601&d=2011-07-18&cn=0)

Another application is that using different bands, we can able to observe the natural environment in many different aspects. For instance, using visible blue band, we can illuminate materials in shadows, observe the water penetration of bathymetry, soil and vegetation differentiation and deciduous and coniferous differentiation. Using visible green band, we can observe water penetration for bathymetry, clear and turbid water contrast, discrimination of oil on water and the green reflectance peak of healthy vegetation. Using visible red band, we can observe the vegetation differentiation and chlorophyll absorption.

Data Processing and output

By inputting the information captured to GIS, the system will do visualization according to the spatial data. User can choose to build 2D or 3D model depends on their need.

After developing a comprehensive land supply database, we can then conduct an inventory of the developable land supply by delineating the

geographically specific and unit of land. As some lands may be excluded from the buildable land supply even they are vacant, partial utilized and underutilized land. These constraints include environmental or physical factors, land ownership and lands that use for specific purpose. Recently that is a buildable land that its development is for prohibited since this land is being classified as a historical heritage. By inputting all these requirements of buildable land and set up the formula, GIS would perform the data analysis and it will able to identify the buildable land and select them in the model. Since the model is visualized, it is possible for user to locate the buildable land easily and provide you the estimated development capacity.

GIS is also useful in doing model simulation. As to lower the housing price, the government has been introducing new housing policies and adjusting the housing strategy. By changing the value such as changing in land ownership after ending of short tern tenant treaty, increasing the accessibility and infrastructure of a place, and then inputted them in GIS, the system can help visualize the new look of the studied area, do the analysis about the influences on different aspects such as sky view, ventilation, shadow, etc. as well as the increase in land supply in a fast way. Using this would be convenience for the government to introduce effective strategy or guidelines that increase the land supply but at the same time minimize the harm that caused to the surrounding areas.

Potentially, the land demand of Hong Kong will keep increasing, especially for residential and commercial uses. Since land resources are limited, therefore different land usages are competing with each other. Therefore, it is essential for the system to consider both factors. Since GIS can perform assessment of potential amounts, pattern, and locations of future development within sub regional areas of interest, it can definitely to forecast the future land demand and thus enable us to facilitate a steady land supply in long term.

Data Sharing

Web-based tools are very useful GIT tools for data sharing. They includes Google map, GeoInfo Map, etc. Using this information can be shared internal or to the general public. They would be spatial information like addresses and site annotation as well as analyzed result such as transportation path from one location to another and area of a building. Through this it is possible for everyone in the society in monitoring the land uses and comment on it. And the government may then able to

receive good and professional suggestion or recommendation from non-government institution such as the Hong Kong Building Environmental Assessment Method Society.

Another point is that some web-based tools can be running under an open-source system, which enables all people that able to access to the internet to alter and update the existing information. This is good for obtaining the latest information using less cost and time, thus, produce a system that reflect the current states for land supply monitoring. However, if the information is invalid, it would be time-consuming to detect it and it may affect the accuracy of the system.

Limitations and Challenges

One limitation of using GIT to facilitate a steady land supply is deal to the capability and the accuracy of the data. Since some information required may be confidential, private or lost, it is hard, costly and time-consuming to establish a completed and comprehensive database and so the updating. Also, the accuracy of the data collected may not be that precise, this is because the resolution of the digital image is bad that affect the image interpretation, the site knowledge of the image obtainer is low and the data captured may not be updated. All these will then affect the usefulness of the model in monitoring the land supply.

Another limitation is that resources should be continuously inputted for the system maintenance. Although the version of GIS system is being more and more advanced and providing users’ without more functions, it is very costly and the users’ may need time to adopt the new system.

Also, since human behaviors are difficult to predict as well as the market conditions. It is hard to define the term “steady land supply that meet the demand”. And the prediction of the future trend may therefore be less powerful and can poorly support the quantitative and qualitative analysis based on it.

More, it is difficult for the system to address both the cumulative and dynamic aspect of environmental impacts and constraints in urbanized areas. Although the responsiveness of the system to environmental condition can be increase by including mapping of pollution “shed” around future transportation and industrial concentration, monitoring land development within watershed, providing data to estimate the cumulative impacts of development on land cover and soil permeability, research is certainly needed in this area.

Conclusion

All in all, GIT would certainly help facilitate a steady land use that meet the demand. However, just researches and developments on GIT tools must carry on. And the problem of obtaining a completed and comprehensive database is still hard and seems impossible. Therefore, although people can use the analysis’s result of GIT as a supportive evidence in new policy that help increase the land supply, people should not fully depend on it and should do more consideration before any decision making based on the result.

References

Anne Vernez Moudon and Michael Hubner, 2000, Monitoring Land Supply with GIS

Lillesand and Keifer, 2009, Remote Sensing and Image Interpretation

Info resources, 2007, http://www.inforesources.ch/pdf/focus07_3_e.pdf