Land use types have become more and more complicated along with growth in economic development and social changes. For effectively preventing illegal or improper development, various domestic competent target business authorities, such as Construction and Planning Agency of Ministry of the Interior (CPAMI); Soil and Water Conservation Bureau, Council of Agriculture, Executive Yuan (SWCB); and Water Resources Agency of MOEA (WRA), have individually conducted land use monitoring within their jurisdiction using satellite images and remote sensing technology for more than 10 years.

Satellite images obtained from different periods of time can be compared to determine points of ground feature changes and suspected illegal uses. Such kinds of information should be sent to the local governments, and competent target business authorities. Personnel will be then dispatched to conduct onsite inspections, and follow-up handling processes to objectively and effectively implement land resource management. In response to different business needs in the past, CPAMI, SWCB, and WRA each executed land use monitoring within their jurisdictions by employing different monitoring frequencies, reporting approaches, and satellite images with different resolutions according individual needs. Thus, it hindered governmental resource sharing.

To facilitate the integration of government resources, the Council for Economic Planning and Development, Executive Yuan (now National Development Council, Executive Yuan; NDC) convened the “Overall Establishment Plan of National Land Information System-First Review Meeting of 2013 Preliminary Operation Plan” on April 19, 2012. It concluded to determine that the Ministry of the Interior should act as the competent authority to coordinate and integrate monitoring plans of relevant agencies to avoid repeated investments of national resources. The Ministry of the Interior convened meetings beginning from 2012, and had reached to the conclusion that the National Land Surveying and Mapping Center (NLSC), Ministry of Interior (MOI) should integrate the existing monitoring plans of CPAMI, SWCB, and WRA beginning in 2014, and anew establish an integrated reporting system to be completed yearly.

Satellite remote sensing imagery is equipped with characteristics of short data acquisition period, quick overview of ground surface variation, wide coverage of image data, and lost cost. Therefore, it has been widely applied on environmental monitoring and collection of topography and geomorphology information. High resolution satellites such as the Formosa Satellite series has granted Taiwan exclusive edges in terms of image coverage and monitoring application.

National land use monitoring project is to utilize remote sensing technologies to capture high resolution satellite images which were then analyzed to locate differences of ground feature on images obtained from different periods of time. Those changes might indicate suspect illegal uses, such as illegal constructions, sand and gravel mining, waste dumping, and other illegal developments. All relevant data are then uploaded to the online reporting system and reported to relevant local governments, and other agencies. These agencies will then dispatch inspectors to perform onsite inspections.

Most of the images used for land use monitoring are from Formosa Satellite #2 (FORMOSAT-2), with additional images provided by the SPOT system. After geometric corrections, computerized comparisons of previously captured images and currently captured images are then performed. Differences in textures, shapes, and spectrum are marked by the system, and a staff will manually match these differentials with color aerial photographs, photographic base maps, land use maps, electronic map, and slope shades to screen for change areas with suspected violations.

The agencies (including sponsor, co-sponsor, and execution agencies) involved in the integration of national land monitoring works include local and central agencies. In addition to the agencies for managing reporting operations, there are also central agencies or competent authorities regularly receive inquiries of information of change areas. In order to avoid any deficiency or doubt during operations of these coordinating agencies, the principles of notification are established as shown below:

• When Change Areas are located within the jurisdiction of coordinating agency of this monitoring integration project, the coordinating agency must be notified to management the monitoring operation, or the information of change areas can be obtained via system inquiry.
• When Change Areas are not located within the jurisdiction of coordinating agency of this monitoring integration project, the change areas monitoring operation should be managed by the local agency with the administrative jurisdiction of the location of change areas notification.
• When change areas are located within the jurisdictions or more than 2 central agencies, these central agencies should be notified to manage the monitoring operations of such change areas.
• When change areas are located within the jurisdiction of both local and central agencies, in principle the central agency should be notified to manage the monitoring operation of such change areas.
• When change areas are located within the jurisdiction of both local and central agencies (receiving change areas for business reference), in principle the local agency should be notified to manage the monitoring operation of such change areas.

The integrated system has started the online service on December 3, 2015. All agencies can receive information of change area and feedback inspection result via such integrated system while providing an effective platform for cross-agency change area transfer and information communication to reduce the time consumption by administration procedure and official document delivery; agencies newly included in the monitoring integration can also directly use the integrated system to execute inspection and reporting without the need for developing each individual reporting and inspection system. Each land management agency can also receive change area information via the integrated system for the need of business management.

Land-Use Monitoring Report Process Flow

The overall integrated system aims at inputting results of land use monitoring systems in each period and the management of the follow-up operation procedure. A supporting function with the aid of applications for mobile devices in field investigations was added. A mechanism for a flexible system interface is also available. The reporting system also offers relevant statistics management and resulting analysis of the changes according to the requirements of individual units for the practical working situations. The system also provides open access for the public to browse dynamic databases of past satellite images and statistical results.

Example of change notification email.

The change area search and information download interface in the integrated system.

Authorization
check

Change areas
platform

Check and review
change areas

Change ares
report

Off-line
operational

After the launching of integrated system on December 3, 2015, in addition to email notices send by the integrated system to all reporting windows, the reports of change areas will also be issued in accordance with division of business after coordination; CPAMI, SWCB, and WRA remain responsible for the audit, inspection, supervision or evaluation of change areas reporting and inspection carried out by each executing unit. The reporting coordination units of change areas and monitoring scopes after integration are as shown in the table below.

Industrial zones and parks (such as Science Park, Biotechnology Park, etc.) play an important role in the history of industrial development in Taiwan. In recent years industries in Taiwan have been under the impact of globalization and post-industrialization changes, such that the supply and demand of industrial lands have also been changed. To fully understand the current status of land use within industrial zones and parks in Taiwan, the latest satellite images were divided into three categories of roads, buildings, and non-buildings based on object classification method and national land use investigation data to interpret building distributions in industrial zones and parks. Statistical analysis of the development rate was also conducted to elucidate the current status of physical development or non-development within these zones and parks.

An example of value-added application : Linkou Industrial Park Zone 1
Administrative District	Type
New Taipei City, Linkou District, Wugu District, Taishan District	County (city) Registered Industrial Zone
SPOT-6 : Mar 3, 2016

To implement the policy goal of “No more reduction of the ratio of natural shore”, a policy of the National Sustainable Development Commission, Executive Yuan, the Annual Tide Tables of Central Weather Bureau, Ministry of Transportation and Communications were used as a reference in conjunction with the water level data measured by all tidal stations. In addition, high resolution satellite images after fusion at a relatively high tidal level each day were collected and summarized to conduct shoreline change detection and digitalization operations. The changes to natural shoreline and artificial shoreline were calculated and summarized accordingly thereafter. The overlapped images of natural shoreline and artificial shoreline example are as shown below.

Natural Shoreline	Artificial Shoreline

With global climate change trends in recent years, the changes in intensity, time sequence, and distribution of rainfalls and the river flow would lead to prolonged dry seasons or abruptly increased river channel. Long non-flood seasons, fallow periods, and cultivation practices by farmers have led to depleted water sources and plantation coverage, thus exposing land with a high probability of erosion and dust emissions. The resulting establishment of river channel  and bare land are used as a reference for river governance, farm planning, and dike renovation. The deep groove results in flood season and non-flood season are as shown below.

Deep groove achievement of Xiu-Gu-Luan Creek in 2016
Flood Season	Non-Flood Season

CPAMI, SWCB, and WRA have accumulated considerable monitoring results in periods during the execution of past land use monitoring. To expand the application of these results, the distributions of change areas with violations based on reports over the years were summarized via spatial visualization or statistical charts. This summary can be provided to various agencies as a reference for rolling adjustment of the national land use monitoring execution plan and administration measures (such as national land planning, report punishment, and local advocacy). The examples of hot spots distributions of change areas with violations are as shown below.

Hot spots distributions of change areas with violations in the scope of slope land from 2000 to 2014

Overall Image

2000

In the events of emergency disaster, such as the interpretation of a collapsed barrier lake or a river management emergency, the emergency disaster response and relevant business requirements should be submitted in coordination with relevant authorities to arrange value-added applications based on satellite images. For example, after Typhoon Soudelor, Typhoon Dujuan, and the Tainan Earthquake,it has provided assistance in satellite image comparison and interpretation of land collapse results before and after the disaster, which can serve as a reference for relevant authorities. The results of emergency response are as shown in the figure below.

Disaster Analysis after Typhoon Soudelor — Nanshi River Region (Near Feitsui Reservoir)
Pre-Disaster Imagery (2015/3/14 - 5/30)	Post-Disaster Imagery (2015/8/11)