Metodologia i materials

As mentioned previously, GIS and MCDA are two useful support tools that are used in many parts of the world for land evaluation. However, procedures and ways of application, as well as their effectiveness vary from place to place, depending on specific conditions. This section provides an overview list of applications developed so far, concentrating on agricultural land evaluation (Corona et al., 2008).

Table 3.3 shows that GIS and MCDA tools are applied widely for land assessment and have been for a long time in many parts of the world. They can be used for specific studies in certain regions such as evaluating land suitability for a selected crop (single land use type), and used for complicated studies like classifying or evaluating land

suitability for multi-farming systems (multi-land use types) and compound land use types15, as well as studies that predict the agricultural capability. Applying GIS and

MCDA together allows the consideration of and integration of multi-disciplines in land evaluation. Moreover, interrelationships and interactions between bio-physical, socio-economic, and other land characteristics are weighted equally with respect to the performance of a specific land use.

Obviously, GIS and MCDA have a major function and have played a much more important role in land evaluation so far because of the development of new AHP versions and GIS software, associated with the development of other decision support systems. They help land evaluation procedures to be more effective, appropriate, and undertaken at a lower cost. However, the GIS or MCDA tool, itself, does not cover all tasks in land evaluation. They should be linked together, or with other tools, to perform the function because land evaluation requires the involvement of a range of multi-disciplines, and is dependent on different conditions in local areas.

The AHP linked with the GIS tool, as used for land capability assessment in this study, is presented and interpreted in Chapter 6 of this thesis.

Table 3.3: Examples of GIS-based and (or) MCDA-based land evaluation

Author (s) Purpose Support tools used Data layers Outputs

Liengsakul et al.

(1993) Comparing GIS + digital remote sensing with soil inventories, and the use of soil and other data to locate new sites for cropland and settlements

GIS + remote sensing Satellite image interpretation (geological, topographic, and landform), land use/cover, soil map, terrain, accessibility

GIS and remote sensing present to planners and decision makers potentially suitable and accessible locations (based on selected criteria) for permanent cropland in highland areas that are not yet used at present.

Wandahwa and van

Ranst (1996) Assessing qualitative land suitability for pyrethrum (Chrysanthemum

cinerariaefolium)

Computer-captured expert knowledge and GIS

Climatic, soil and landform (drainage, soil texture or structure, flooding, coarse fragments, soil depth, calcium carbonate, water pH, organic carbon, and CEC

Land suitability maps for pyrethrum cultivation

Delli et al. (1996) Evaluating land suitability

for rainfed winter wheat Satellite interpretation image and attribute data analysis

Climate, geomorphology, soils, vegetation, socio- economic such as labour intensity, capital intensity, market orientation, infrastructures.

Yield potential map of wheat

Bydekerke et al.

(1998) Land suitability assessment for cherimoya (Annona cherimola Mill.) in southern Ecuador

GIS and expert method Climate, soils, landforms Land suitability map for cherimoya

Ahamed et al.

(2000) Assigning suitability for crops in the land Kalyanakere sub-watershed in Karnataka, India

Linkage of MCDA and

GIS Texture-surface, subsurface, soil pH, drainage, texture- CEC, gravel-surface, gravel- subsurface, and base saturation

Land suitability maps for paddy, ground nut, and finger millet

Table 3.3: Examples of GIS-based and (or) MCDA-based land evaluation (continued)

Author (s) Purpose Support tools used Data layers Outputs

Store and Kangas

(2001) Improving suitability evaluation over habitat large areas to produce habitat suitability maps for old-forest polypore (Skeletocutis odora)

Spatial MCDA and expert knowledge integrated for GIS-based

Soil fertility, slope direction, soil moisture, density of growing stock, stem volume of spruce, and age of spruce

Land suitability maps for Skeletocutis odora

Kalogirou (2002) Implementing a land suitability evaluation model by combining GIS and expert-systems

GIS and expert-systems Physical FAO (1976) land classification for crops such as soil toxicities, rooting conditions, excess of salts

Suitable areas for agriculture and a group of selected crops: wheat, barley, maize, seed cotton, sugar beet)

Prakash (2003) Extending potential of the Fuzzy AHP into land suitability decision-making

Integration of GIS and MCDA (AHP, Ideal Vector Approach-IVA, and fuzzy AHP)

Soil, climate, topographic, socio-economic, market- infrastructure, and irrigation facilities

Suitability maps for Rice from AHP, IVA, Fuzzy AHP

Ceballos-Silva and López-Blanco (2003)

Identifying land suitability for the production of maize and potato crops in Central Mexico

Integration of the GIS and Multi-criteria evaluation techniques

Climate, relief, and soil

databases are involved Comparison of current and potential land suitability areas for maize and potato cultivation

Boonyanuphap et

al. (2004) Evaluating land suitability for Musa (ABB group) plantation

GIS and GPS Soil texture, depth, drainage, pH, CEC, total C, slope, elevation, rainfall

Land suitability classification map for Musa, maps of possible area for new Musa plantation based on land use types and based on soil series characteristic

Sicat et al. (2005) Classifying land suitability

for crops Fuzzy modelling of farmers’ knowledge combined with GIS

Cropping season, soil colour, soil texture, soil depth and slope

Land suitability maps for optimum land-use planning.

Table 3.3: Examples of GIS-based and (or) MCDA-based land evaluation (continued)

Author (s) Purpose Support tools used Data layers Outputs

Liu et al. (2007) Developing an integrated GIS-based analysis system for supporting land-use management of lake areas in urban fringes in China

Incorporation of MCDA

and GIS Geology and topography, hydrology, ecology, population, economics, environmental impacts, economic location, and transportation location

Two scenarios for potential land use changes from 2006 to 2020 are generated

Baniya (2008) Evaluating land suitability for vegetable crops in Nepal

GIS and AHP Temperature, soil texture, fertility, soil pH, irrigation, soil depth, slope, service

Current land suitability maps and potential land suitability maps for vegetable crops

Santé-Riveira et al.

(2008) Developing a planning support system for rural land-use allocation

A Multi-objective linear programming model (LINDO optimum software, hierarchical optimization, ideal point analysis, and an algorithm) GIS-based

Agronomic, management, socio-economic, and environmental impacts

A support tool for rural land-use planning is formed

Bandyopadhyay et

al. (2009) Assessing land suitability potentials for agriculture GIS and remote sensing Soil texture, erosion, slope, depth, organic carbon Agricultural land suitability map Reshmidevi et al.

(2009) Introducing integrated fuzzy rule-based a GIS- inference system for land suitability evaluation

GIS and fuzzy model Land use, soil texture, terrain slope, drainage density, soil depth, pH, CEC, OC, salinity, rainfall, elevation

Land suitability maps for paddy, propose weighted attribute aggregation methods for land evaluation

Hossain et al.

(2009) Identifying suitable sites for carp farming development in urban water bodies in Bangladesh

GIS-based Multi-Criteria

Evaluation Water, soil and infrastructure database Suitable maps for carp farming are created Hossain and Das

(2010) Identifying appropriate site for the farming of giant prawn (Macrobrachium rosenbergii) in Companigonj of Noakhali, Bangladesh

GIS-based Multi-Criteria

Evaluation Twenty base layers of quality, soil characteristics and infrastructure facilities

Suitable land maps for prawn farming