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Settlement Accesssubility: A
case study in the south east part of chiangmai city, Thailand
Suharyadi
Gadiah Mada University,Yoayakarta, Indonesia
Gadiah Mada University,Yoayakarta, Indonesia
Abstract
A settlement accessibility survey based on aerial photographs as main data sources and using a scoring has been applied in chiangmai city. Panchromatic aerial photographs scale 1:10.000 made in were used tom carry aerial out the survey .two different t yes of data are derived from photo interpretation settlement an medium pattern and density as a mapping unit in graphic data and parameters of settlement accessibility as attribute data. So parameters are used in the width of minor local sterol quality of major street width of minor local street distance to public transport line distance to railway station and distance to main road for analyses data about settlement accessibility from photo interpretation and field survey are normalized with value. The value training from 1to 8 to reflect the relative important of the parameter are used weighting factors. Data process and analyses were carried out with the help of a geographic information system CILWIS software package the result of the sunrise are combination graphic and attribute data bases in table and map form.
Introduction
The is the second largest city of Thailand .The city growth has been rapid in the last two decades as a result .the city plan and administrations have to deal with problems related to the increase in demand of improvement maintenance infrastructure and facilities in the city.
In leap up with the growth the city planners and administrators need accurate detailed information on urban problems with in shell time. The type of information useful for planning is settlement accessibility data over the city this data would illustrate facilities related to accessibility available in the city.
In many cases there are difficulties in providing the data due to financial and time constrains. Especially when conventional filed survey should be considered as an alternative aerial survey can provide most of the needs planners rapidly with relative economy and accuracy.
Data collection is not the only step also data processing and analysis have to take palace as soon as possible by using geographical information system it is possible to increase speed in data processing and analysis.
Study Area
The whole should be covered in a study like this accessibility of the different part of the city could be detected and areas indicated where are necessary but due to time constrains only part of the city was selected. the survey has been carried out in the south east part of damages background for selection this study are conditions of settlement and Varity of facilities available there the boundaries of the area are there road for the pattern ping river for the western super high way for the western and municipality boundary as south boundary as south location of study area.
Objectives of the survey
The details of models of settlement accessibility using are photoing as main source of data in aerial the like of settlement accessibility in south east and CHAINGMAI city. Base on the model. In areas the use frames of aerial photographs for providing data in settlement accessibility survey.
Concepts Used.
Settlement area with an inform pattern and density uniform is residential an be regular and on semi replay pattern can be regular represents comparison of roof cover and land occupied density represents comparison of settlements are grouped in three class i.e. a the density of settlements has more 70% roof cover semi dense is 40% and low than 40%.
Parameter of settlement accessibility.
Width of major quality of major street width of minor local street quality of local street distance to public local street transportations distance to railway station and distance to main whole most of the parameter are provider by interpretation of photographs information on public transport line is taken from secondary data for checking of the photo interpretation and providing additional data a field survey took place in the study store.
Method of the survey.
The method survey in brief can be in the flow chart on the figure. 2 aerial photographs panchromatic scale (f : 10.000)made in 1987 were used to carry out the two different of data are derived from photo interpretation settlement with a uniforms pattern and density as mapping unit in graphic data. And data of settlement accessibility attribute data.
Figure.1 Location of study area
Figure.2 Flow chart of the survey
The procedure to get data is as follow three general groups of land use are identified in the study area base on photo interpretation these are settlement built up area non settlement and non built area with in the settlement delineations a detailed delineations is made according uniformity of the pattern and density of house with assumed that a settlement with and density of house with uniform pattern and density is homogenous in facilities related to accessibility settlement with an uniform pattern and density than are used as mapping unit in data consuming data base interpretation and measurement of data concerning settlement accessibility through the aerial photographs quality of street for both major and local main road distance to railway station .
This ILWIS software was used to create a graphic and attributes data base first the lineation from aerial photographs were transport to a base the settlement delineations are stored in rasher format the attribute data base is created based on the interpretation of aerial photographs and secondary data transport.
After finishing interpretation a field survey took place in the study area these are two aims in the field survey check and improve data from interpretation of aerial photographs and collect additional data that can not gathers from aerial photographs for instance public transport line.
The technique used for field checks in the study area is a combined random sampling this means checking of all settlements as mapping unit and in each settlements of the parameters are checked randomly
The data base of settlement accessibility after the field survey are indicated in future and table data about pattern density of houses in the mapping unit are also incident density of houses in the mapping unit are also included this data wilt be used to fid correlations between accessibility and type of settlement.
Accuracy Test
Comparison of the result of the photo interpretation and the actual situation the field interpretation about the accuracy of interpretation in general after checking in the accuracy of interpretation appeared to be accurate for instance the accuracy for the parameter width the street are about 80% for both major and local street and for their quality is also about 80% for major street and less than 70% for local street.
Width of street was measured directly from the photographs by using a magnifying glass with millimeter scale. Most in accuracy in measurement on photographs occurred because the edges of the street were not easily describable especially when not located on an open area other in accuracies in the measurement are caused by radial displacement of aerial photographs are occurred by high objects because of the displacement.
Quality of street is identified based on three main keys lone pattern and texture for instance surfaces street are mostly regular pattern smooth texture and dark tone asphalt or light tone for concrete material but it is not easy to different between payment street with surfacing and without different between payment street with surfacing and incorrect interpretations of the quality of street in a shadow area most street is caused by shadow of high objects on the street others are caused by some new streets they have same the tone as payment street.
Value of the parameters
For analysis data settlement accessibility from photo interpretation and field survey are normalized with values. The value range from 1to3. To desire the value of the parameters two approaches were used to decades on street consist width and quality of street in both major and local are determined with general street approach and the scale condition and payment with surface is better than others values are according to the class conditions the higher value the better condition class and values of the parameters are presented in table 1 to 3
Table 1: Class and value of parameter width of
Major Street
Table-2 Class and value of Parameter quality of Major Street
Table-3 Class and Value of Parameter width of Local Street.
| Class | Width | Value | Remark |
| 1 | > 7.9 | 3 | two ways street for most of car |
| 11 | 5.0-6.9 | 2 | two ways street for small car |
| 111 | < 4.9 | 1 | one way most car |
Table-2 Class and value of Parameter quality of Major Street
| Class | Quality | Value | Remark |
| 1 | Payment with surfacing | 3 | Most comfortable to pass |
| 11 | Payment without surfacing | 2 | Comfortable to apses |
| 111 | Un Payment | 1 | less comfortable to pass |
Table-3 Class and Value of Parameter width of Local Street.
| Class | Width | Value | Remark |
| 1 | > 5.0 | 3 | two ways street for most of car |
| 11 | 3.0-4.9 | 2 | most of car can pass |
| 111 | 2.9 | 1 | most of car not pass |
To decide the value of the parameters, two approaches were used. Conditions on street parameters, consist, width and quality of street for both major and local are determined with qeneral opinion approach, and the scale of the value is 1-3. In general the wider street reflect the better condition, and pavement with surfaceing is better than others. Value, the better condition. Class and value of the parameters are presented in table1 4
| Class | Quality | Value | Remark |
| 1 | Payment with surfacing | 3 | Most comfortable to pass |
| 11 | Paymentwithout surfacing | 2 | Comfortable to pass |
| 111 | Un Payment | 1 | less comfortable to pass |
Value of the parameters distance to railway stations and distance to main road are determined by statistic approach first, maps with equal distance determined to parameters are created by computer the maps are then interval to parameters are created classified in three classes each covers approx one third of the total study area class `1 is close to the parameters is and get the highest value by over laying the distance maps and their unit the value in each mapping unit was obtained. Class and value of distance parameters can be scan in table 5 to 7.
Table 5 Class and value of parameter distance to
public transformation
Table 6 Class and Value of Parameter distance to railway statics
Table 7. Class and value of Parameter distance to Main road
| Class | Distance to Public Transport | Value |
| 1 | <200m | 3 |
| 11 | 200-600m | 2 |
| 111 | >600m | 1 |
Table 6 Class and Value of Parameter distance to railway statics
| Class | Distance to Railway Station | Value |
| 1 | <900m | 3 |
| 11 | 900-2000m | 2 |
| 111 | >2000m | 1 |
Table 7. Class and value of Parameter distance to Main road
| Class | Distance to main road | Value |
| 1 | <200m | 3 |
| 11 | 300-800m | 2 |
| 111 | >800m | 1 |
Weight factors.
Weight factors used to reflect the relatives importance of the accessibility parameters weighting factors in the surveys are derived from field observations some parameters are determining in accordance with frequency of use other parameters are determined base on general make options due to lacks of time for the filed details did not make any differentiate weighting factors in details conditions of street parameters for instance are base general opinion and their weighting factors are 2 for both major local street and 1 for their quality the reason width street is more difficult to improve than its quality.
The weighting factors for distance parameters are derived on frequency do use of people that use public transport daily in the city public the number of passenger using public transport bus and because bus city and re-cars carry about 90,000 people it can be part on public it can be conclude that the population and bus pf CJHANGMAI depend for large part on public transport number of people that and public use main inroad daily can be concluded that vehicles in the city and public transport area are parameters that are used almost daily and public transport in the city so the distance factors for both area 2 the weighting factors for distance to railway station is base on the assumption that people from the study area use in train as the transpiration even thought the high table 8 below shows the weighting factors of the parameters.
Level Accessibility
Level of accessibility is derived by multiplying the value of parameters and their weighting factor adding them in each mapping unit for example mapping unit number its score is. In see the distribution of the accessibility in the study area the final score a highest score in attribute database combined with that mapping unit in the graphic database.
Final score of the value of each parameters mapping unit showed a highest value is 33 and lowest value is 15 for make if easy to comparison mapping mail the final score are classified in 5 classes.
The distributions of the local of accessibility in study area after classification is shown in figure settlement class with very good accessibility are found in the northern part of study area good accessibility are along charwomen Mutant Road.
Most settlement with fairly bad accessibility settlements are located in the centre of the study area settlements class v settlements with bad accessibility are settlements that need all improvement in accessibility.
Table 8. Weighing Factors
Table 9. Class of Settlement Accessibility
| Class | Parameters of Settlement Accessibility | Weightr Value |
| 1 | Width of Major Street | 2 |
| 2 | Quality of Major Street | 1 |
| 3 | Width of minor local street | 2 |
| 4 | Quality of local street | 1 |
| 5 | Distance to public transport line | 2 |
| 6 | Distance to railway station | 1 |
| 7. | Distance to main road | 2 |
Table 9. Class of Settlement Accessibility
| Class | Score | Remark |
| 1 | >30 | Very good accessibility |
| 11 | 20-30 | Good accessibility |
| 111 | 24-27 | fairly good accessibility |
| IV | 20-23 | fairly bad accessibility |
| V | <20 | Bad accessibility. |
Correlation between type of settlement and the accessibility
In the survey an attempt is made to get an impression about 4 the correlation between the accessibility types of settlements are reflected by pattern and density of houses. Two types of settlements are considered in the survey these are settlement with regular pattern and low density and settlement with irregulars and highly density settlement and type 8 is a of unplanned settlement.
The hypothesis was tested based on computing correlation value between settlement planned settlement class I to II and settlement type with settlement class IV class V.
The correlation coefficient was computed based on product moment correlation technique the correlation coefficient settlement type a with accessibility is correlation between these variable and the correlation coefficient settlement type it with accessibility is coefficient settlements weak because the correlation as conclusion both are close to 0 we rejected the hypothesis and as conclusion there is no different between for both type planned settlement in accessibility.
Conclusion
- The model of settlement accessibility based on 7 parameters and using aerial photographs as the main data source cam is applied as a model of settlements accessibility survey in southeast part of CHANGMAI city. Of the parameters can be derived from photo interpretation except parameters of public transport line by using geographical information system it possible to increase sped in data processing and analysis.
- Settlement that very good accessibility is settlements are located in northern part of study area. Settlement class V should be improving.
- Aerial photographs scale 1:10,000 can be used out the survey with sufficient accuracy parameters from photo interpretation have good accuracy when be checked in the filed with the exception of quality of local street radial displacement of aerial photograph lead to in a accuracies in the measurement of objects in the edge of photographs.
- In the study area there is no relationship between type of settlement type of settlement and the accessibility.
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