Geographic and Potential Accessibility Measures

The location of Ampel city is rather central, but from Figure 7.1, we can see that Seboto and Kembang villages are also located in the central area and should be included in the Ampel city. Nevertheless, a geographic accessibility matrix must be constructed to justify whether the current five villages in the Ampel city are the most accessible villages within the Ampel sub-district. In constructing the geographic accessibility matrix, the distance is

not represented by just geographic distance. Table 7.2 shows the valued graph matrix¹³ that contains the distance between villages that is measured by the shortest route. The measure has taken into consideration the available road network.

Figure 7.1. Ampel Sub-district Map and Nodal Points

Source: Boyolali Agropolitan project, map album (2006)

To construct the geographic accessibility matrix, the valued graph matrix is transformed into Table 7.3 to allow for horizontal summation of distance in measuring the geographic accessibility. The total distances from each village are summed up to find the total distance. The higher the distance, the less accessible the village, and vice versa.

The results show that the five villages that are the most accessible villages from the highest to the lowest are as follows: Gladagsari (107 kms), Candi (121 kms), Tanduk (130 kms), Urutsewu (135 kms) and Kaligentong (135 kms). This measure is based on the road distance, and the two villages appearing to be accessible based on the quick map

13 A valued graph matrix is a matrix of distance (shortest route) between the nodes in the network (Rodrigue, 2004)

view are Kembang and Seboto. These have accessibility of 141km and 196km respectively. This justifies why they are not included in the Ampel city.

Table 7.2. Distance between Villages in Ampel Sub-District

Source: Statistical Yearbook of Ampel Sub-district (2003)

Table 7.3. Geographic Accessibility Matrix

Source: Author’s calculation

The village with the least accessibility is Jlarem, which is located in the northwest of Ampel city. Jlarem has accessibility of 405 kms, which is followed by Ngagrong with accessibility of 221 kms, followed by Sampetan and Ngargosari, both with accessibility of 217 kms. Other villages have accessibility between 140 kms to 197 kms. Thus, by looking at the geographic accessibility, the five villages constituting Ampel city are the most accessible villages within the Ampel sub-district area.

However, it is necessary that other aspects, apart from mere distance, be considered in measuring the accessibility. This is particularly important as one village may be more important than another one in terms of economic potential. Therefore, potential accessibility needs to be measured. In the case of Ampel, the potential accessibility is measured by two indicators. The first indicator is the working age

population in each village and the second indicator is the number of meat and milk cattle in each village.

The use of working age population as the indicator of potential accessibility is justified because working age population can serve as a measure of the potential labor force and the potential consumers of Ampel’s products and services. Under the assumption that only working age populations are earning, the purchasing power of the village will be determined by the number of working age population. This assumption would ignore the fact that more population means more demand for goods and services.

However, potential purchasing power is more important, because in the absence of purchasing power, residents are most likely to satisfy their needs through local resources not traded in the market.

In Table 7.1, the sum of the female and male working age population is the total working age population for each village within the Ampel sub-district. A good example of a village with low accessibility but large population is Sampetan with 1,545 working age males and 1,600 working age females. Sampetan village has the highest number of working age people. A contrasting example is Banyuanyar, a village with relatively high accessibility but small population. Banyuanyar village has 687 working age male and 770 working age female. Figure 7.4 shows the potential accessibility matrix that is constructed with working age population as the indicator. Unlike the geographic accessibility that is measured in a way that the lower the total distance the more accessible the node, the potential accessibility measure shows higher accessibility along with higher total value. The vertical summation in the Table 7.4 shows the potential accessibility measure.

From table 7.4, we can see that Kembang village has the highest potential accessibility with respect to the working age population. The village with the second highest potential accessibility is Gladagsari, followed by Candi, Candisari, Sampetan, Kaligentong and Urutsewu. Despite the high potential accessibility, the inclusion of Kembang village into Ampel city still depends on whether it is located adjacent to other accessible villages.

Table 7.4. Potential Accessibility Matrix based on Working Age Population

Source: Author’s calculation

From Figure 7.1, we can see that Kembang is located adjacent to the villages in Ampel city. Thus, it can be included in Ampel city based on its potential accessibility. In contrast, Tanduk village, which is located at the southern-most part of Ampel city and has very low potential accessibility, may be excluded from Ampel city.

This shows the possibility of altering the structure of Ampel city, if potential accessibility with respect to working age population is taken into consideration. However,

it is important to look at other factors in measuring the potential accessibility. The most important one is the number of livestock, which is the main produce of Ampel sub-district.

Table 7.1 shows the livestock of each village. The number of meat and milk cattle are summed up for each village to arrive at the total livestock. The total livestock is used to calculate the potential accessibility matrix. Table 7.5 shows the potential accessibility matrix based on the livestock in each village. From Table 7.5 we can see that Kembang, Sidomulnya and Seboto are the villages with the highest livestock, in particular meat cattle. The least livestock is found in Gondang Slamet and Ngampon villages.

Thus, the need to be accessible to Gondang Slamet and Ngampon villages is less important compared to being accessible to Kembang, Sidomulnya and Seboto.

Table 7.5. Potential Accessibility Matrix based on Livestock

Source: Author’s calculation

From Table 7.5, we see that Candisari has the highest potential accessibility, followed by Gladagsari, Candi, Kembang, Sampetan, Urutsewu and Kaligentong. It is important to note that Kembang, the top scorer for working age population based potential accessibility, is only ranked fourth, and Candisari, ranked fourth for working age population based potential accessibility, is ranked first. Gladagsari and Candi have second and third ranks, respectively, for both working age population based potential accessibility as well as livestock-based potential accessibility. Kembang, Sampetan and Candisari are consistently in the top five in the working age and livestock-based potential accessibilities but are not included in the current Ampel city. This is most likely due to the fact that these villages are not in the top five villages in terms of geographic accessibility. However, Tanduk village is out of the top five for both categories of potential accessibilities. Thus, its inclusion in the Ampel city is not justifiable when these two categories are taken into consideration.

All the five villages within Ampel city are also ranked the highest five in terms of geographic accessibility. However, only Candi and Gladagsari villages are also among the top five villages in the rankings of potential accessibility for both the working-age population-based score as well as livestock-based score. Candisari tops the score for potential accessibility based on livestock by a significant margin. Gladagsari is the second highest scorer. Kembang village, with a score of 18.4, is the top scorer for potential accessibility based on working age population. Unlike Candisari, which leads by a significant margin, Kembang village is closely followed by Gladagsari, with a score of 18.038.

In terms of consistency, Candisari as the top scorer for livestock based potential accessibility is only ranked fourth in working age based potential accessibility score and seventh in the geographical accessibility score. Kembang is only ranked fourth in the livestock-based potential accessibility score and sixth in terms of geographical accessibility. Sampetan, a village included in the top five for both measures of potential accessibility, is ranked in the bottom five for geographical accessibility. In contrast, both Gladagsari and Candi villages have displayed consistency by being ranked first and second respectively for geographical accessibility, second and third respectively for both measures of potential accessibility. These two villages are also among the five villages constituting the Ampel city.

The remaining three villages in the Ampel city, which are Tanduk, Urutsewu and Kaligentong villages, are not among the top five scorers for both measures of potential accessibility. However, both Urutsewu and Kaligentong are ranked among the top seven for both measures of potential accessibility, which may indicate a relatively high level of potential accessibility for both categories. On the contrary, Tanduk village is ranked low for both measures of potential accessibility, despite being ranked third in terms of geographical accessibility.

This leads us to the question of why Tanduk village is included in Ampel city instead of Kembang or Candisari village. Sampetan may be excluded from consideration since it has a very low score for geographic accessibility. In answering this question, it is important to go back to the basic nature of this research, which is to study the relationship between accessibility and urban growth. Although villages in Ampel city show a significant level of economic development, the current level of economic activities

among these villages varies. There is also a possibility that such variations can be explained by the differences in accessibility.

7.2.2. Investigating the Indicators of Economic Activities for the Most Accessible