Application of remote sensing technique in biomass change detection: a case study of Bromley and Chihota, Zimbabwe

Abstract

Biomass is defined as the total mass of living plant matter in a given unit of an environment area.  Several factors influence the change in biomass content of an area. The rate of change varies from mass seasonal drying of grasslands to gradual degradation of forestry area.  It is in the interest of environmental monitoring and sustainable development that biomass change be constantly determined. There are various field methods used worldwide to determine density of forest resources but have several limitations because of the nature of factors influencing biomass change.  These include seasonal changes, human activities, forest fires etc.  Remote Sensing as an enabling technology provides an efficient avenue of assessment of biomass content of any area.  This research focused on biomass content that constituted forest resources. Two main methods used were qualitative analysis involving visual image interpretation relying on knowledge of spectral reflectance characteristics of ground cover types and quantitative analysis involving use of mathematical capacity of the computer to extract information on pixel digital number The techniques employed in these methods were complementary and were combined in a systematic manner to optimize the potential of remotely sensed data in biomass change. Comparison of two methods information, revealed that biomass content obtained from the remotely sensed data from the two study areas were almost identical. Extra ancillary data like population information and detailed land use data, can be integrated into GIS together with results from remote sensing analysis to enhance the decision making process.

Keywords:  Biomass, Forest, Image, Interpretation, Qualitative, Quantitative