Supachai Skawsang. The application of geographic information system and remote sensing to the distribution of earthworms in Ong Chu-Na Suan subwatershed Srisawasdi district Kanchanaburi province . Master's Degree(Appropriate Technology for Resources and Environmental Development). Mahidol University. : Mahidol University, 2003.
The application of geographic information system and remote sensing to the distribution of earthworms in Ong Chu-Na Suan subwatershed Srisawasdi district Kanchanaburi province
Abstract:
The purposes of this thesis are to study the characteristics of the earthworm,
the relationship between some environmental factors and earthworm distribution in
different land use patterns of Ong Chu-Na Suan Subwatershed, Srisawasdi District,
Kanchanaburi Province. The technology of a geographic information system and
remote sensing were applied to study and create a prediction map of earthworm
distribution.
Results of the study indicated that there were two earthworm genera
belonging to the Family Megascolecidae, including Amynthas sp. and Metaphire sp.
The highest density and biomass of these genera were found in evergreen forest,
deciduous forest and agricultural land, respectively.
The plant litter and soil moisture factors had the most influence and
importance of environmental factors that effected earthworm distribution.
The result of the prediction of soil moisture showed that Digital Numbers
(DNs) of the sixth channel (low gain) of the Landsat 7 ETM+ was significantly
correlated with the level of soil moisture calculated by exponential equation.
However, the efficiency of the prediction was quite low (R2 = 0.10).
The prediction map of spatial distribution of the earthworms can be divided
into four levels of earthworm distribution at low, moderate, rather high and high
level. The moderate level was approximately 8-16 ind/m2 of earthworm and
covered the most common study areas accounting for 55.74 km2 or 76.37 % of the
total area which were mostly deciduous forest and evergreen forest