The study area is Gheshm Island, which is the biggest, and the most important island in Persian Gulf with 124 km length and between 10-35 km width. This island located in south of IRAN in Persian Gulf. It lies between 26,50′-27 N latitude and 55,15′-56, 15′ E longitude, were surrounded by limestone mountains. The average rainfall in this island is around 230mm per year and the average temperature is 24oC .
The forest region of the Island is covered by Mangrove plants, which according to climatical zone belongs to semi-tropical region. Mangrove forest were scattered from HORMOZ Isthmus to coast OMAN sea. These plants are grown up in salty water and change it to sweet. This forest is environmentally protected plant.
in this paper following steps were peformed:
- Collection of landsat satellite images TM (1989.5.21) and (1998.5.22), IRS satellite images.
- Collection available information such as topographic, geological, agricultural,hydrological and soil maps.
- Geometric correction of TM images by using topograghic map scale 1:50000 .
- Using false colour images (bands 4,3,2).
- Enhanceing of images,stretching ,filteing to improve interpret.
- Then on supervised classification (MLC) is applied to accomplish 2 maps
1- Classicifation of GHESHM Islan are revealed 11 differents landuse as follow:
- native vegetation
- range land 1
- range land 2
- range land 3
- salty land
- bad land
- wet land
- Gheshm city
2- Classification of Mangrove forest in this map 7 major classes have been classified and recognized as follow:
- deep water
- medium water
- shallow water
- wetland with vegetation
- high density forest
- low density forest
As considered in the map, Mangrove forest were grown up in northeast of Island on the soils that were eroded by water and exposed to tidewater, with nearly 3 meters high and their leaves are ellipse shape. Due to available ecology condition many birds such as Heron and Flaminco live there. But in 1998 this plants were damaged due to uncontrolled grassing.
Based on multi-phase TM data, we can compare the change of forest distribution at different time. This is very useful for the controlling of resource and planning of management measures. This Islan special Mangrove forest have an available ecological condition with great biodiversity abundance . We can survey and research of fauna and flora and their living environment. With this survey and monitoring and landuse planning of forest providing decision support for biodiversity conservation and sustainable use of natural resources.