Application of Forest Canopy Density Map derived from FCD Model

Forest canopy density maps derived from FCD Mapper semi-expert system can be used for various purposes. Practical applications of FCD map have been demonstrated by taking two important forestry applications in the present study. In the first case, FCD maps derived from two data sets with an interval of 6 years i.e., 1996 and 2002 have been used for the detection of change in Sal (Shorea robusta) forest canopy density. Change detection assessment of this time interval shows that there is reduction in forest canopy in some isolated locations as shown in Fig. 15 indicated by red circle. The canopy density of > 80% reduced to 60 - 80% categories. This is a result of infestation Sal heart wood borer around the period 1998 to 2000. Most of the affected trees are removed from the stand and some trees lost canopy and became moribund which has crated openings in the Sal forest stand. However, some area shows development and expansion of the tree crown over 6 years as indicated with yellow circles in the same figure. These areas are unaffected by the insect infestation.

Some of the important forestry operations where forest canopy density map could be useful are listed below.

FCD model can used for following important forestry operations viz.,

• To plan afforestation and reforestation activities

Identification of forest canopy gaps for enrichment planting

Rehabilitation of encroached and logged over areas

Planning of operational silvicultural systems

Preparation of Working Plans (Maps at beet / coupe level)

Regeneration or Gap filling

Wildlife habitat management

Planned timber extraction

Can be used as a base line data for scientific work Detection of disease affected areas Change detection in forest and non-forest Predictive analysis of change in forest canopy density

In the second case, three data sets (1996, 1999 and 2002) are used to derive forest canopy map of the same study area. Change detection of 1996 to 1999, 1999 to 2002 and 1996 to 2002 have been carried out to assess the

Figure 15: Change in forest canopy density. Red ellipse on green area indicates reduction of forest density due to infestation of Sal heartwood borer

logged over area and reforested area. There was a forest as indicated by red ellipse in the Figure 16 which was removed around end of the year 1996. Change detection between the period 1996 to 1999 shows logged over area (Fig. 15). Same logged area was again replanted with high density Eucalyptus plantation in the end of the year 1999. Change map of the area between the periods 1999 to 2002 shows reforested area as indicated by red ellipse (Fig. 16). This kind of results help in management of forest cover in the local level.

Figure 16: Change detection of logged over area and reforested area from 1996 to 2002

Forest Canopy density is one of the most useful parameters considered in the planning and implementation of rehabilitation. Conventional remote sensing methodology is based on qualitative analysis of information derived from study area i.e. ground truthing. This has certain disadvantages in terms of time and cost required for training area establishment and also requires expertise. The JOFCA-ITTO semi expert system is useful tool for better management of forests. The model has been validated for its high accuracy. Compared to other methods, FCD Mapper has shown good results with respect to class interval, time taken for analysis and mapping accuracy. Cluster analysis of forest canopy density map derived from FCD Mapper and Conventional methods have showed similar trends with respect to percent area of forest and non-forest. Gregarious occurrence of bushy vegetation like Lantana poses problem in delineation of forest canopy density as their reflectance is similar to that of the forest. Further improvement can done to incorporate geographic coordinate system, map composition and one click data import facility so that user can get the full-fledged utility of the semi expert system.

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