Application of GIS to Identify Potential Areas for Aquaculture in Badulla District in Uva Province
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Date
2013
Journal Title
Journal ISSN
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Publisher
Uva Wellassa University of Sri Lanka
Abstract
Aquaculture is farming aquatic organisms including fish, mollusks, crustaceans and aquatic
plants (FAO, 1990). The main intent of the present study is to highlight the role Geographic
Information System (GIS) in identifying potential areas for aquaculture in Badulla district. The
study was carried out in Badulla district in Sri Lanka by the geographical coordinates of
longitude 80 .45 to 81 .15. Latitude 6 .34 to 7 .18. Data have been collected from secondary
sources and used to generate maps to identify fresh water bodies in Badulla district. Map of
seasonal tanks, reservoirs and tanks, stream network and rivers of Badulla district were
developed. Water availability (proximity to rivers), soil texture, soil pH, rainfall, temperature
and topography (slope, elevation) and land use factors were considered to identify potential
areas for aquaculture (pond culture). Protected areas are considered as constraints. Water
availability, soil texture, soil pH, slope, elevation, rainfall, temperature, land use/ land cover
thematic layers were created using ArcGIS 10.1 software. All these thematic layers have been
assigned the weights according to their relative influence on pond construction using Analytic
Hierarchy Process (AHP) and GIS approach. Finally, all thematic layers have been integrated in
a ArcGIS 10.1 environment to generate an aquaculture potential map. Thus, four aquaculture
potential areas have been Identified, viz. “Most suitable”, “Suitable”, “Fairly suitable”,
“Unsuitable”. The north part of the Badulla district is identified as most suitable and the
southern part of the Badulla district is identified fairly and unsuitable for aquaculture in Badulla
district.
Methodology
Data collection: Secondary data were collected from secondary sources.
GIS analysis: reservoirs and tanks, Rivers, Stream network of Badulla district were digitized
using Arc View 3.1 software. GPS coordinates of seasonal tanks were stored & developed a
map using ArcGIS 10.1 software to identify fresh water resources in Badulla district and all data
were stored in ArcGIS 10.1 environment and factor thematic layers were generated to identify
potential areas for aquaculture.
Analytic Hierarchy Process (AHP) - AHP is a multi-objective, multi criteria decision making
approach that employs a pair wise comparison procedure to arrive at a scale of preference
among a set of alternatives (Dai et al., 2001). Thematic layers were evaluated using scores and
each weighted according to their relative importance on the aquaculture using Analytic
Hierarchy Process (AHP) and GIS approach.
Map Generation -Each thematic layer was evaluated using the scores that were obtained
according to the weighted linear combination in ArcGIS 10.1 environment. Vector format was
converted to raster format. To reject the constraints the final result was multiplied by absolute
constraints. The protected areas were allocated a zero score. Finally, the potential areas for
aquaculture map was created and categorized into four levels: Most suitable, Suitable, Fairly
suitable, Unsuitable based on the total scores obtained from the weighted linear combination.
Description
Keywords
Aquaculture and Fisheries, Aquatic Resources, Aquatic Plant, Fish, Aquaculture