Delineation and incorporation of socio-infrastructure database into GIS for land use planning: A case study of Tan Phu Thanh village, ChauThanh District, Cantho Province

Delineation and incorporation of socio-infrastructure database into GIS for land use planning: A case study of Tan Phu Thanh village, ChauThanh District, Cantho Province

3.3. Socio-insfrastructure evaluation
This evaluation is applied for the study area as a method development for evaluation of land use types under the socio-infrastructure conditions, in which criteria and weights are applied for factors to check for the ability in using of GIS in suitability assessment which the limiting factor method is limited due to the problems of important levels of factors. The methodology of this method is following the steps as follows

Criteria development
Because of the different scales upon which criteria are measured, it is necessary that factors be standardized before combination using the fomulas, and that they be transformed, if necessary, such that all factors maps are possitively correlated with suitability.

Criterion weights
Matching of agro-hydrologcal characteristics and requirements to assess the suitability of a map unit for a cropping pattern is carried out for diferent methods, although a variety of techniques exist for the development of weight one of the most promissing is that of comparisons developed by Saaty (1977) in the context of a decision making process known as the Analytical Hierachy Process (AHP). The first introduction of this technique to a GIS application was that of Rao et al (1991), although the procedure was developed outside the GIS software using a variety of analytical resources. In the procedure for multi criteria evaluation using a weighted linear combination, it is necessary that the weights sum to one. In Saary’s technique, weights of this nature can be derived by talking the principle eigenvector of a square reciprocal matrix of pairwise comparisions between the criteria. The comparisons concern the relative importance of the two criteria involved in determining suitability for the stated objective. Ratings are provided on a 1 point continous scale.

However, in this research, the Arithmetric procedure (FAO, 1986) is used as the method of matching of factors, in which the indivitual assessments, expressed numerically, can be combined by multiplication (or by addition). In this method, each suitability class is assigned a value ranging from 1.0 to 0.0 depending on the level of importance and the suitability classes (Table 2). Once a suitability map has been prepared, it is common to undertaken a step of deciding upon which cells belong to the set that meets a particular land allocation area target (the decision set).
Table 2 : Assigned value for different suitability classes of difference level of impotance

Level of Importance	Suitability classes
Level of Importance	S1	S2	S3	N
Very Importance	1	0.7	0.4	0
Moderately importance	1	0.8	0.5	0
Less Importance	1	0.9	0.6	0

The diagnostic factors for of socio-infrastructure characteristics for different land use types in the Tan Phu Thanh village are based on the accessibility to the different infrastructure which affected to the socio-economic aspect, these factors including

Accessibility to main road
Accessibility to main rivers
Accessibility to main market
Accessibility to agricultural product processing factory
Accessibility to seed supply (Animal, Fish, crops)
Accessibility to Agricultural materials supply

The distance for different classes of all land use types applied in the research is showed in Table 3.
Table 3: Accessibility suitability classes of all land use types in the research area

Factor rating	Suitability Classes
Factor rating	S1	S2	S3	N
Accessibility classes	<1000	1000-5000	>5000	-

Depending on the type of infrastructure, the accessibility to different infrastructure types will also affect to systems at different levels, since, the weight of different accessibility classes is also different for different infrastructure types. The next step will be done by assigning the weighted value for each suitability class and depending on the importance of factor, the weight value will be assigned from 0 to 1, hightly suitable will assign the value 1, moderately suitable will assign the value from 0.7 to 0.9, marginally suitable will assign the value 0.4 to 0.6 and Unsuitable will assign value 0.0. The weight assigned for different suitability classes is applied as the same methodology of FAO (1986). Detailed of assigned weight for diagnostic factors of different land use types is showned in below table, in which the S1 has the weight of 1 and S1 has the weight from 0.7 to 0.9 depending on the important level, S3 and N are not applied for the study area.
Table 4: Assigning weight for diagnostic factor of socio and insfrasctructure conditions for different Land use types in the Tan Phu Thanh village.

Factor rating	Suitability classes
Factor rating	S1	S2	S3	N
Lut 1: Rice (DX) + Rice (HT) – Fish
Accessibility to main road (m)	1	0.7	-	-
Accessibility to main rivers (m)	1	0.7	-	-
Accessibility to main market (m)	1	0.8	-	-
Accessibility to agricultural product processing factory (m)	1	0.9	-	-
Accessibility to Animal, Fishery food suppy (m)	1	0.9	-	-
Accessibility to Animal, Fishery hachery suppy (m)	1	0.9	-	-
Accessibility to plant supply (m)	1	-	-	-
Accessibility to Agricultural material supply m)	1	0.9	-	-
Lut 2: Rice (DX) + Rice (HT) + Rice (TD) – Fish
Accessibility to main road (m)	1	0.7	-	-
Accessibility to main rivers (m)	1	0.7	-	-
Accessibility to main market (m)	1	0.8	-	-
Accessibility to agricultural product processing factory (m)	1	0.9	-	-
Accessibility to Animal, Fishery food suppy (m)	1	0.9	-	-
Accessibility to Animal, Fishery hachery suppy (m)	1	0.9	-	-
Accessibility to plant supply (m)	1	-	-	-
Accessibility to Agricultural material supply m)	1	0.9	-	-
Lut 3: Rice (DX) + Upland crops (XH) + Rice (TD) – Fish
Accessibility to main road (m)	1	0.7	-	-
Accessibility to main rivers (m)	1	0.7	-	-
Accessibility to main market (m)	1	0.8	-	-
Accessibility to agricultural product processing factory (m)	1	0.9	-	-
Accessibility to Animal, Fishery food suppy (m)	1	0.9	-	-
Accessibility to Animal, Fishery hachery suppy (m)	1	0.9	-	-
Accessibility to plant supply (m)	1	-	-	-
Accessibility to Agricultural material supply m)	1	0.9	-	-
Lut 4: Upland crop (DX) + Upland (XH) + Rice (TD) – Fish
Accessibility to main road (m)	1	0.7	-	-
Accessibility to main rivers (m)	1	0.7	-	-
Accessibility to main market (m)	1	0.8	-	-
Accessibility to agricultural product processing factory (m)	1	0.9	-	-
Accessibility to Animal, Fishery food suppy (m)	1	0.9	-	-
Accessibility to Animal, Fishery hachery suppy (m)	1	0.9	-	-
Accessibility to plant supply (m)	1	-	-	-
Accessibility to Agricultural material supply m)	1	0.9	-	-
Lut 5: Upland crops
Accessibility to main road (m)	1	0.7	-
Accessibility to main rivers (m)	1	0.7	-
Accessibility to main market (m)	1	0.8	-
Accessibility to agricultural product processing factory (m)	1	-	-
Accessibility to Animal, Fishery food suppy (m)	1	-	-
Accessibility to Animal, Fishery hachery suppy (m)	1	-	-
Accessibility to plant supply (m)	1	-	-
Accessibility to Agricultural material supply m)	1	0.9	-
Lut 6: Fruit tree- Fish
Accessibility to main road (m)	1	0.7	-	-
Accessibility to main rivers (m)	1	0.7	-	-
Accessibility to main market (m)	1	0.8	-	-
Accessibility to agricultural product processing factory (m)	1	0.9	-	-
Accessibility to Animal, Fishery food suppy (m)	1	0.9	-	-
Accessibility to Animal, Fishery hachery suppy (m)	1	0.8	-	-
Accessibility to plant supply (m)	1	0.9	-	-
Accessibility to Agricultural material supply m)	1	0.9	-	-

Matching for suitability classification
Once the weight value assigned for each class of each map, all of maps of factors for each land use type will be multiplied together, its means these values are multiplied for all moderately or very importance land qualities. The product is converted back to an over all suitability by assigning above value. The output will be the suitability map for the land use type with the value from 0 to 1.0. The final reclassified map is the suitability map of selected land use type.

In oder to classify for the suitability classes, the GIS reclassification method will be applied, which :

S1 : Highly suitable	assigned for all of value greater than 0.6
S2 : Moderately suitable	assigned for all of value from 0.4 to 0.6
S3 : Marginally suitable	assigned for all of value from 0.2 to 0.4
N : Unsuitable	assigned for all of value less than 0.2

However, a structural problem with this procedure is that the large the number of qualities considered (other than with S1 suitability), the lower is the product. Therefore the same number of qualities must be used in all calculations that are to be compared; even if some of the qualities are not needed they are automatically given an assessment. There have been a number of studies in which, for a particular local area, good correlations have been obtained between overall suitability ratings obtained by this procedure and observed crop yields. If transferred from one area to another, however, the ratings will usually require adjudment, or calibration in relation to crop yields.

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