APPLICATION OF GEOGRAPHIC INFORMATION SYSTEM (GIS) 
AND REMOTE SENSING TO LAND ASSESSMENT IN THE PHILIPPINES 
Julius P. Maling 
Chief Remote Sensing Technologist 
National Mapping and Resource Information Authority (NAMRIA) 
Metro Manila, Philippines 
ISPRS Commission IV 
Fort Bonifacio, Makati, 
Abstract: 
GIS and remote sensing are currently being utilized in the Philippines for assessing 
various land concerns such as soil erosion, upland utilization and property values. These 
national resource, which is land. Three (3) 
TYDAC SPANS and CRIES) in the overlay anal 
use they deal with the single most important 
types of GISs are being used (e.g., ARC INFO, 
extent using remote sensing techniques. 
considerations for the effective management of sloping lands, and more importantly, for 
revenue collection in prime agricultural lands. 
ysis of attribute maps, produced to a large 
The resulting decision maps are basic 
Key Words: GIS/LIS, Remote Sensing Applications, Land Applications, Mapping. 
1. INTRODUCTION 
About 50% of the Philippines’ total land 
area of approximately 30 million hectares 
is arable. With a population of 65 
million, the pressure to open forestlands 
to agriculture, and to devise ways and 
means of effectively utilizing available 
land resources is expectedly great. 
There are three (3) main concerns involving 
land in the country today: determining 
additional areas for cultivation, 
preventing further degradation of land 
resources mainly through soil erosion, and 
collecting the proper revenue from the 
citizen's use of the land. Such a wide 
Scope of interest necessitates the use of 
modern evaluation methods, such as remote 
sensing and GIS, which could give quick 
and accurate results. 
Practically all of the arable lowland areas 
are already under cultivation, or are 
subject to private rights. As a 
consequence, new sites for agriculture must 
come from the uplands. This is a very 
sensitive issue, since forests and 
watersheds must be protected for obvious 
ecological and environmental reasons. The 
delicate task of determining upland areas 
suited to agriculture, taking into account 
as many considerations as possible, can be 
easily accomplished through the use of a 
computer-based evaluation System, such as 
a GIS. 
The opening up of sloping lands to 
agriculture, as well as other human 
activities in these areas such as logging, 
has the immediate consequence of increasing 
soil loss through erosion. A secondary 
effect of this is the accompanying 
siltation and sedimentation of waterways, 
continuing onto coastal reef areas. 
Therefore, the same GIS must be able to 
address the need to map areas which are 
susceptible to erosion in various degrees. 
Finally, as income is derived from 
subjecting the land to agricultural and 
other uses, proper assessment must be made 
for taxation purposes. In many instances 
in the country, this effort is hindered by 
the absence of maps showing property 
781 
boundaries. Provisional lot plans can, 
however, be plotted by photogrammetric 
means, which could then be incorporated 
into a GIS. 
These photo-based maps can be the practical 
basis for tax assessment in many areas in 
the country where cadastral surveys have 
not been undertaken. When more accurate 
maps or lot plans become available later 
on, the GIS database consisting of 
digitized photo-based maps could then be 
easily revised or updated. 
This paper presents the techniques used by 
the various projects of the GIS 
Applications Development Division of the 
National Mapping and Resource Information 
Authority (NAMRIA), the central mapping 
agency of the Republic of the Philippines, 
in applying GIS and remote sensing for land 
assessment as stated above. 
2. DESCRIPTION OF PROJECTS AND THEIR 
STUDY AREAS 
Upland 
2.1 Determination of Suitable 
This project was initiated in 1988 with the 
town of Tuba, in the province of Benguet, 
as the study area. Benguet has a 
mountainous terrain, and contains the 
highest peak in the island of Luzon, Mt. 
Pulag, whose elevation is about 2,900 
meters above sea level. The province is 
located about 250 kilometers north of 
Manila. 
The project aims to determine which areas 
in Tuba are suited to agricultural use 
based on such parameters as slope, soil 
type, availability of water, accessibility, 
and existing land use. ARC/INFO GIS was 
used for this purpose. 
The project also commenced in 1988, with 
the Tamlang River Watershed, in the town of 
Brookes Point, island-province of Palawan, 
as the study area. Palawan is a long, 
narrow island located about 300 kilometers 
southwest of Manila, and is one of the few 
areas in the country where the environment