Expert classification for Land Cover Mapping of Bang Pakong Watershed, Thailand
STUDY AREA
The study area covers the Bang Pakong watershed which in the eastern part of Thailand. It
covers an area of Saraburi, Phatumthani, Chacherngsao, Nakhon Nayok, Prachinburi, and
Chonburi province. (Figure 1)
Figure1. Bang Pakong Watershed Area
METHODOLOGY
This study applied the unsupervised classification (ISODATA clustering method) and
knowledge-based operation which including spectral characters and GIS data (DEM and soil
moisture regime) and spatial models to classify the conditions for land cover categories
identification. The land cover categories are identified as residential and open space area,
abandoned land, mixed deciduous forest, mangrove forest and wetland, paddy field, other
vegetation, and water bodies. The detail steps and contents are described as follows:
Data Sources
Landsat satellite images are the main data sources which are the main basis of spectral
knowledge, while overlaid with other GIS data and DTM sources to assist for expert
classification.
Model Application
The application models were created and based on model spatial modeler for variables of
knowledge-based generation. It is a highly flexible tool when applying Model Maker together
with Spatial Modeler Language. The Spatial Modeler Language was a modeling language that
was linked internally by Model Maker to execute the operations specified in the graphical
models. The spatial models include clump model, NDVI model, mean NDVI per zone model,
WI model, mean WI per zone model, digital elevation model (DEM), slope model, and aspect
model. Ultimately, all variables, which included Landsat-7 (ETM+) imageries (band 1-5 and 7),
ISODATA clustering, clump model, NDVI model, mean NDVI per zone model, WI model,
mean WI per zone model, DEM image, slope model, aspect model and soil moisture image,
were used to generate the knowledge-based system for classifying the land cover categories in
