Preparation of Indicative Land use Plans using GIS
J. Jayasinghe and W.M.M. Priyanthi
Land use Policy Planning Division
Ministry of agriculture, Land & Forestry
Abstract
- The land use Policy Planning Division (LUPPD) is presently engaged in the preparation of Indicative Land Use Plans (ILUP) of Provincial/District and Divisional Secretary (D.S) levels using GIS. ILUP classifies the land according to the intensity of land use.
- This paper outlines the procedure adopted in preparing an indicative Land Use Plan for the Bulathinhala D.S. Division in the Kalutara District. (Western Province)
1.0 Introduction
The major objective of the Indicative Land Use Plans are to draw attention to inappropriate uses of land, to highligh the environmental problems that could arise in continuing with present land uses and; to indicate opportunities for better and more intensive use of land. It is expectd that the plans will enable decision makers to provide at least some direction to the changes in land use taking palce at the district level.
At the start ILUP s were prepared manually by superimposing the soil types or slop clases on the undated and use map. This procedure was found to be very time consuming. Furthermore the accuracy of the plan depended on the skill of the cartographer. Because of the need to prepare a large number of plans for the country (all the D.S. divisions) within a reasonable period of time and with greater accuracy, it was decided to develop a computer based methodology to produce ILUP s quickly and accurately.
The methodology was initially developed for the Bulathsinhala D.S. division in the Kalutara District (western Province). This division was selected because the required data had been collected by the Surveyor General's (S.G.) office under the Planning Support Project.
2.0 System Used
The Hardware used comprised:
-
Sun Sparcstation 20 workstation with 1 GB Hard Disk
- The Calcomp digitizer (A0 size)
- Techject color plotter (Ali size)
Software:
The available software of the LUPPD, ARC/INFO Unix version 7.0.3 was used for the do GIS activities.
3.0 Methodology
3.1 Data Used:
There kinds of data were used in this system.
- The digital data generated by the S.G. office on land use. (1:20,000 scale)
- Digital topgraphic data obtained from the S.G. office. (1:50,000 scale)
- The data on land use changes gnerated by the LUPPD. These data were gnerated by updating the land use map prepared by the S.G. office using a revised legend. (appendix 1)
3.2 Steps Followed
1. the digital data provided by the S.G. Office were updated by utilizing the data on land use change generated by the Luppd.
2. A slope class map was prepared utilizing the digital data on topography (contours) generated by the S.G. Office. Six slope class were derived using DTM as follows:
| 1. |
0 - 8% |
| 2. |
8 - 16% |
| 3. |
16 - 30% |
| 4. |
30 - 0% |
| 5. |
40 - 60% |
| 6. |
> 60% |
3. The slope class coverage was overlaid on the land use coverage using 'UNION' command.
4. Land use intensity clases were derived by matching polygons in the land use coverage with the polygons in the slope class coverage. Four intensity clases were identified. (a) intensively used areas (b) semi intensively areas 9c) sparsely used areas (d) conservation areas. Each of the intensity classes were subdivided based on slope. These categories are indicated in appendix 2.
5. An AML (Arc Macro language) was prepared to print the map. (i.e. ILUP)
The ILUP for the Bulathsinhala D.S. Division was prepared using only the slope data because oher detailed data were not available. However it is hoped to use other physical and socio economic data wherever available to further refine ILUP s. such refinements will provide more detailed guidelines for the sustainable use of land resource in the country.
