5 subsets of land used for estimation and reporting according to definitions
agreed in the Marrakesh Accords for Parties to the Kyoto Protocol. 4.
The approaches should be transparent, i.e., data sources, definitions,
methodologies and assumptions should be clearly described.
By considering the general characteristics above, IPCC has defined six land use categories that can be applied in most countries and to accommodate
differences in national classification systems. The top-level land use categories are shown in Table 1 below.
Table 1. Top-level Land Use Categories
No. Land Use
Category Description
1 Forest land
This category includes all land with woody vegetation consistent with thresholds used to define forest land in the
national GHG inventory, sub-divided into managed and unmanaged, and also by ecosystem type as specified in the
IPCC Guidelines. It also includes systems with vegetation that currently fall below, but are expected to exceed, the threshold
of the forest land category.
2 Cropland
Includes arable and tillage land, and agro-forestry systems where vegetation falls below the thresholds used for the forest
land category, consistent with the selection of national definitions.
3 Grassland
Includes rangelands and pasture land that is not considered as cropland. It also includes systems with vegetation that fall
below the thresholds used in the forest land category and are not expected to exceed, without human intervention, the
threshold used in the forest land category. The category also includes all grassland from wild lands to recreational areas as
well as agricultural and silvi-pastural systems.
4 Wetlands
Includes land that is covered or saturated by water for all or part of the year e.g., peatland and that does not fall into the
forest land, cropland, grassland or settlements categories. It includes reservoirs as a managed sub-division and natural
rivers and lakes as unmanaged sub-divisions.
5 Settlements Includes all developed land, including transportation infrastructure and human settlements of any size, unless they
are already included under other categories. This should be consistent with the selection of national definitions.
6 Other lands
Includes bare soil, rock, ice, and all unmanaged land areas that do not fall into any of the other five categories. It allows the
total of identified land areas to match the national area, where data are available.
Source: IPCC 2003
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2.1.2 Land Use Change Detection
Land use change is an important research area in global environmental change research that attracts broad attention, since it can produce significant
ecological impacts to the environment Chen et al. 2003; Fang et al. 2006. Change detection is the process of identifying differences in the state of an object
or phenomenon by observing it in different times and identifying the differences of land use in different time may be very useful for the policy makers in order to
maintain and improve ecosystem Singh 1989; Fang et al. 2006. Land use change detection can be analyzed by using remote sensing
technology through extracting changes in radiance values of multi-temporal satellite image. The basic premise in using remote sensing data for change
detection is that changes in the object of interest will result in changes in radiance values or local texture that are separable from changes caused by other factors,
such as differences in atmospheric conditions, illumination and viewing angle, soil moisture, etc. It may further be necessary to require that changes of interest be
separable from expected or uninteresting events, such as seasonal, weather, tidal or diurnal effects Deer 1995.
The U.S. Geological Surveys USGS Urban Dynamics Research UDR program defines that the geographic understanding of land use change in urban
areas is a key aspect of the UDR program. The analysis requires understanding a regions land use history. Population data, timelines of historical events, and
related information are all used to explain the mapped changes. Population data are correlated with the temporal database so that human movement can be tracked
and factored into these interpretations. Population increases suggest economic growth and the availability of jobs in an area, and population declines suggest a
decline in livability or economic issues that cause people to leave a region. Timelines of past events and other historical compilations aid in identifying the
issues that affected the development of the region. In addition to gathering statistical and historical information, scientists must have a physiographic
understanding of the place and its greater region. Topographic features, climate, and adequate supplies of water and other natural resources can limit or encourage
growth and change USGS 1999.
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2.2 Remotely Sensed Image Classification
2.2.1 Remote Sensing
Remote sensing is the science and art of obtaining information about an object, area, or phenomenon through the analysis of data acquired by a device that
have no any contact with the object, area, or phenomenon investigated Lillesand and Kiefer 1993. Earth observation by remote sensing is the interpretation and
understanding of measurements made by airborne or satellite-borne instruments of electromagnetic radiation that is reflected from or emitted by objects on the
Earth’s land, ocean, or ice surfaces or within the atmosphere, and the establishment of relationships between these measurements and the nature and
distribution of phenomena on the Earth’s surface or within the atmosphere Mather 2004.
The characteristics of imaging remote sensing instruments operating in the visible and infrared spectral region can be summarized in terms of their spatial,
spectral and radiometric resolutions. The spatial resolution of an imaging system is not an easy concept to define, because it can be measured in a number of
different ways, depending on the user’s purpose. Most sensors operating in the visible and infrared bands collect multispectral or multi-band images, which are
sets of individual images that are separately recorded in discrete spectral bands, and the term spectral resolution refers to the width of these spectral bands
measured in micrometers μm or nanometers nm. Radiometric resolution or
radiometric sensitivity refers to the number of digital quantization levels used to express the data collected by the sensor. In general, the greater the number of
quantization levels, the greater the detail in the information collected by the sensor Mather 2004.
An important principle underlying the use of remotely-sensed data is as follow different objects on the Earth’s surface and in the atmosphere reflect,
absorb, transmit or emit electromagnetic energy in different proportions, and that such differences allow these components to be identified Mather 2004. The great
advantage of having remotely-sensed data available digitally is that it can be processed by computer either for machine assisted information extraction or for
