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Forestry
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A Comparative Study on Relationships between Forest and Soil Series upon Different Topographies by GIS Technique at a Mae Huad Demonstrative Forest Plot, Lampang Province, Thailand
Peripherals
6.1.2. Digitizer Table A1 size
6.1.3 Colour plotter A0 size
6.1.4. Tektronix colour inkjet printer
Software
The software Spans (Spatial Analysis System) package version 5.3 of Typac company, Canada, consists of 14 Modules, Its main modules are Tiding mokule, Spans Map module and Spans GIS module employed incorporation with OS/2 operating system.
6.2 Methodology
6.2.1 Data Input: Before digitizing by tydig moduls. subdirectory was created in the computer, then tyding module was employed to take the point (node), are (line) from a topographic map (river, road). After digitized session, the outcome is digitized map containing several points and nodes (vector data). Refigitizing once more for forest cover and soil series data were made to show forest land cover map and soil series map (soil series map is a soil series appeared upon the different typographies ) So the final outcome is the digitized map containing several polygons (vecter data). After finishing digitized session insert topological (attributes by open spread sheet in spans Map module and then translate the vector data and raster data to Quarter which has been analysed by overlying between forest covers and soil types.
6.2.2 Data Storage
With Spans GIS module, study area has been identified to fix it mapping position in accordance with the variety of spatial data of different scale and projection combined.
6.2.3. Data Manipulation and Analysis
Bring quadtree type of data of a Mae Huad Demonstrative Forest Plot to analyse by overlaying method (soil series has been overlaid by forest landcover)) The analysis employs the overlay analytical technique which is imprerative for the Spans GIS module.
6.2.4 Output & Display
The area of 77.62 square kilometers out of 85.56 square kilometers shows completely the relationship between forest type. man made activities and soil series appeared on different topographies.
7. Result
The area of 77.62 square kilometers out of 85.56 square kilometers of Mae Huad Demonstrative Forest Plot shows completely the relationship between forest land cover and soil series appeared upon different topographies. It covers an area of the evergreen forest, dry dipterocarp forest ad old clearing area of which are soil series for example, M1. Li, Bg and other types appeared upon topographically dissected eosin surface including fans, and thin layered soils mixed with rock outcrops along the foot hill and upon the mountain top. Whereas, the mixed deciduous forest. teak plantation and agricultural area usually appeared on the specific topography which contains soil series Ks Tp etc. in old levee Ml Li Bg etc soil series within dissected erosion surface including fans and thin layered soils mixed with rock outcrops on hilly and mountainous area.
8. Discussion
The GIS technology brings Samuel on computer based set of procedures to store a manipulated geographical; referenced data ad displays them in the common and understanding media, such as,. mapping papers, thales of attributes, aerial photographs and satellite imageries.
Chart Showing the Process of GIS on a Mae Huad Decmonstrative Forest Plot, Amphoe Ngao, Lampang Province
Table Showing Overly of Forest Land cover and Soil Series on Different Topographies of Mae Huad Demonstrative Forest Plot
| Legend | Area (%) | Area (km2) |
| EF of DESIF | 1.49 | 1.16 |
| EF on HAM | 4.00 | 3.10 |
| MDF on OL | 0.14 | 0.11 |
| MDF on DESIF | 26.24 | 20.37 |
| MDF on HAM | 30.19 | 23.43 |
| DDF on DESIF | 0.62 | 0.48 |
| DDF on DESIF | 7.20 | 5.59 |
| TP on OL | 0.85 | 0.66 |
| TP on DESIF | 22.51 | 17.47 |
| TP on HAM | 2.28 | 1.77 |
| OC on DESIF | 0.90 | 0.70 |
| OC on OL | 2.27 | 1.76 |
| AA on OL | 0.15 | 0.11 |
| AA on DESIF | 0.57 | 0.44 |
| AA on HAM | 0.61 | 0.47 |
| Total of 15 classes | 100.00 | 77.62 |
Remark
EF: Evergreen forest
MDF: Mixed deciduous forest
DDF : Dry dipterccarp forest
TP : Teak plantation
OC: Old clearing area
AA: Agricultural area
DESIF: Dissected erosion surface including fan topography
MAM: Hill and mountain topography
OL: Old levee topography
References
- Burough, P.A. Principles of Geographical Information Systems for Land Resources Assessment. Oxford: Clarendon Press, 1986 .193p.
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Kaew Nualchawce. "Geographic Information Systems. Paper presented at the international Seminar on Human Resources Requirements for Natural Resources Information Management. AIT Bangkok 27-27 Auguse 1952. 11p
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