Estimating the area and delineating the boundary of a land-use category for greenhouse gas inventory and of area dedicated for a proposed project is the first basic step in preparing a carbon inventory. Methods ranging from field measurements, such as a physical land survey, to more complex methods involving the use of a satellite available for estimating land area and marking its boundary are presented in this chapter. The need for stratification of land area to increase the accuracy will be highlighted (methods for stratification are described in Chapter 10). These methods could be used in preparing greenhouse gas inventories of different land-use categories for use in carbon mitigation or roundwood production projects. Estimating the project area and the boundary is very critical for carbon inventory since this determines the following:
(i) The total project area directly impacted by the project activity.
(ii) The area from which leakage of carbon stocks occurs and can be estimated.
(iii) The area from which areas sample plots for carbon inventory can be taken.
(iv) Whether the project boundary is fixed or changing (the boundary can change over time due to additional area added to the project activity or new areas subjected to leakage).
(v) Whether the project activity comprises a single contiguous unit or dispersed multiple units.
These features will have implications for sampling and for the cost of preparing the carbon inventory. Any change in project area may require additional sampling units, and multiple parcels dispersed over the project area may need more sampling plots. Describing and listing the features of land uses and land cover of the area can serve as the basis for estimating land areas used in a project. It is good practice to define a land-use system at a disaggregated level to enable its stratification into homogeneous subsystems. The land-use types could, for example, be described as forest land, cropland, grazing land, barren land or grassland. These types can be further disaggregated, such as forest land being split into natural primary forest, degraded forest, eucalyptus plantation or regenerated forest. Each one of these different land-use systems or subsystems of a project can be found as a single unit or in multiple units dispersed over different areas, such as villages or landscapes. These land-use systems and subsystems should be presented spatially on a map.
It is possible to visualize two situations: one in which information and maps aie available for the land-use category or project area describing the land-use and cover features, vegetation status and latitude and longitude. The other in which not much information is available, and even a map may be lacking. For some locations, satellite maps may be available. Therefore, the extent of effort involved in defining the area and boundary depends on the status of preliminary information availability and the access to it.
Broad methods Two broad methods are available for land area measurement and boundary marking:
1. Ground methods
(a) Physical measurements
(b) GPS approach
(c) Participatory rural appraisal
2. Remote sensing methods
• Aerial photography
• Passive and active satellite imagery
Practical issues in choosing a method Selection of a method depends on several factors such as size of the project, resources available and technical capacity, and these factors should be evaluated in making a choice.
• Type of the project Different types of land-use projects will demand different kinds of methods to get the required information.
• Size of the area Size is critical because large projects extending to tens of thousands of hectares may need remote sensing techniques for monitoring changes in the area, while small, village-scale community projects may be adequately served by measurements in the field.
• Level of accuracy Coarse-resolution satellite data will give generalized information over each unit at a pixel level, whereas fine-resolution satellite data offer greater details leading to greater accuracy in interpretation.
• Technical capacity Trained field staff is needed for ground measurements whereas computer hardware and software expertise is needed for making the best use of satellite imagery.
• Cost Resources available determine whether aerial photography or physical measurements are used for a given project, small or large.
• Physical access Remote areas in dense forests or high up in the mountains are hard to reach, which makes field measurements difficult, and remote sensing methods may be the only choice.
Project area estimation and boundary marking is the first step in project development as well as implementation. Estimation of the project area as well as its composition, that is whether it comprises a single unit or multiple units, is required for estimating the total carbon stock gains. The approaches to selection involves the following steps:
Step 1: Identify the land-use category or land-use systems and the location selected for the project, along with the size of the project. Step 2: Obtain all the maps available for the project location such as a topographical map, soil map, land-use map and maps derived from remote sensing data. Step 3: Collect information related to current and historical land-use patterns, land tenure, human settlements, livestock grazing locations, source of fuelwood and timber and locations and areas of implementation of different programmes such as afforestation, soil conservation and grassland reclamation. Step 4: Collect detailed information on proposed project activities such as area planned for afforestation, soil conservation and forest protection and phasing of these activities, particularly the area to be brought under project activities annually and locations of different project activities. Step 5: Evaluate all the currently available maps and information as well as the details of the proposed project activities along with the resources available for monitoring to take a final decision on the method to be adopted for measurement and monitoring of project area and activities.
Examples of methods for different land-use categories and project activities are presented in Table 8.1. Normally ground methods are used for small-scale and dispersed location projects in landscapes consisting of a mosaic of multiple land-use
Table 8.1 Methods for estimating and monitoring of project area and boundary for different land-use categories and project activities
Status of land and vegetation
Scale of project
Natural forest converted to degraded forest or other land uses
Preserving natural forest
Physical Remote sensing measurements
- Grassland remaining grassland and subjected to degradation
- Grassland reclamation
Physical measurements GPS
Physical measurements Aerial photography
Cropland remaining cropland
Physical measurements GPS Physical measurements GPS
Aerial photography systems. Aerial photography and remote sensing techniques are used for large-scale projects with adequate financial and technical resources. Remote sensing techniques are still evolving, particularly for application in small-scale projects. Participatory rural appraisal techniques could be effectively used to supplement other methods particularly for small-scale projects in and around human settlements.
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What you need to know about… Project Management Made Easy! Project management consists of more than just a large building project and can encompass small projects as well. No matter what the size of your project, you need to have some sort of project management. How you manage your project has everything to do with its outcome.