Analysis of Changes in Vacant Land and Fair Market Land Prices to Determine Direction of Settlement Development in Tembalang District Period 2010 and 2016

Semarang city is the capital of Central Java province. As the capital city, Semarang experiencing rapid physical development. These conditions make the Semarang city over bounded indicating the construction of the city to the suburban or rural area. Tembalang District is one of the districts on the suburban of the Semarang city with very rapidly development progress. The one implication is the number of land use changes, including settlement construction and other physical structures. The development requires vacant land, so that information about the availability of vacant land and the fair market land prices is required. The data used is the Quick bird satellite imagery in 2010 and 2016 as well as information on the fair market land prices in 2010 and 2016. The data processing is done using remote sensing and Geographic Information Systems. It is also necessary field surveys to obtain information on the fair market land prices and for the validation to identify vacant land that has been done so that the results obtained identification in accordance with the real conditions in the field. The results of this study is the widespread availability of vacant land and build up land area in each villages in the Tembalang district is changes during the period 2010 to 2016. Type vacant land that decreasing the number of vacant land availability is the vacant land not allocated, while vacant the value of vacant land already allocated does not change at 653.351 Ha. Availability of vacant land not allocated amounted to 704,873 Ha in 2010 and amounted to 630,512 Ha in 2016. As the reduced availability of land, the land value was also increase by more expensive.


Introduction
The physical growth of the region is a major problem for some developing countries. One of them is Indonesia, which experienced serious problems in terms of population distribution that requires the land to support these activities. Growing regions will require space in this land as the land's physical development. This is a problem faced by big cities in Indonesia, as Semarang which is currently implementing the system in the development of suburban areas in order to achieve equitable development. So that information about the availability of land is needed both in terms of location, size, and the land value. But as the development of land areas that require the availability of land for development should be identified. One of them carried out in this study, which is located in Tembalang District, Semarang is to determine the availability of vacant land in the Tembalang District, Semarang in period 2010 and 2016. In addition, this study aims to determine the changes in the availability of vacant land and land value changes in the Tembalang District, Semarang and identify how to influence the availability of vacant land to the development of the area in Tembalang District, Semarang, Central Java Province. In Tembalang District, vacant land availability is always changing in every year due to the impact of residential growth and development policies in the Semarang City suburb to be developed.
With the development and changes in the availability of land for development purposes, then fair market land prices will increase. The fair market land prices are very sensitive to changes in surroundings. Things to give effect to changes in the fair market land prices called the factors that affect the price. It may increase or demean the fair market land prices [1]. Von Thünen in distance decay theory principle from the center suggests that land values would be higher if the closer to the city center [2]. In the journal of the American Institute of Real Estate Appraisers, said four factors that can affect the land value, among others, economic factors, social factors, government factors and physical factors [3]. Meanwhile, according to Pusat Badan Pertanahan Nasional there are 4 components or strategic and important factors that affect the land value, namely, land status, usefulness, accessibility, and institutional [4].

Studi area
The area study of this research is in Tembalang District, Semarang city, Central Java, Republic of Indonesia. The area is located on the outskirts of the city and is at an average altitude of 300 meters above sea level. Tembalang District located in the most southern region of the Central Government of Semarang city with hilly topography and residential areas.  The spatial data are high-resolution rectified satellite imagery in period 2010 and 2016, administrative maps, and maps of the initial zone Tembalang District, Semarang to identify the availability of vacant land that has the potential to be built into a variety of land use. In addition to spatial data, used also non-spatial data that is data of land value that approach in 2016. The classification of vacant land includes vacant land not allocated thats consist of bush and vacant land and vacant land already allocated thats consist of moors. Vacant land classification method using a high-resolution image interpretation methods and methods to assess changes in the availability of vacant land is overlaying the data from 2010 and 2016.

Data processing
This research first data processing is digitization on the satellite imagery and data processing analysis of land value to stage the availability of vacant land and changes in land value Tembalang District. The identify method of vacant land is the visual interpretation and digitization process on Quick bird imagery which has been rectified then visually interpretation by its characteristic appearance of the surface of the land use and digitization to obtain the distribution of the vacant land. Visual interpretation aims to distinguish one theme to another theme based on the appearance depicted in the data imagery. The parameters used in the visual interpretation is the hue or colour, the roof shape, size, texture, associations (density between buildings), location or site, the pattern of land.
The fair market land prices data collect in 2010 and 2016. Before conducting field surveys must first do manufacture polygon (initial zone) on the satellite imagery available. In this study uses data initial zone that already exists for the Tembalang District obtained from BPN Semarang. At the beginning of the zone is divided into 82 zones for the District Tembalang. The data collection was conducted using a sample. The samples referred to in the survey and mapping of the value of land is registered plot / land that provides the bid price or transaction information field of the land during the period of 24 months for non-agricultural and 48 land last month for farmland. Attempted transaction price or offer in question is the buy or sale price. If no sale price (offer and transactions) can be used in the land rent. Samples have not less than 30 parcels of land by district with purposive technique, which is based on considerations of the characteristics of the village or district, in proportion to the land-use residential, commercial and agricultural in the land value is reflected in the zone of land value with a minimal number 3 (three) samples for each zone of the land value, whereas for the above zones 10x10 cm, a sample of at least 5 (five). For each 10x10 cm excess number of samples plus 2 (two) and so on every multiple of 10x10 cm. Selected samples sought in the form of an empty plot which refers to the base map used as a map of the existing work.
This research using 70 land value zones, with 198 sample of land parcels thats already direct surveys in period 2010 and using 82 land value zones, with 223 sample of land parcels thats already direct surveys in period 2016. The Land value data obtained from direct surveys need to get correction. The correction data in land values is to conduct market value analysis done to get the market land value of the transaction data. All data and purchase transactions are set at a certain valuation date, then the correction of the type and time correction data transactions of buying and selling to get a price estimate of land value. : time transaction Appraisers are allowed to have their own considerations in determining the amount and direction of the percentage value of each adjustment. If the assessors choose magnitude or direction of adjustment beyond the range described above must in information coloumn with regard socioeconomic conditions of the region [5].

Results and discussion
The result of the vacant land availability on the digitized imagery in 2010 and Field survey results and data processing of fair market land prices in 2010.
The results from digitization of vacant land availability classified as vacant land not allocated and vacant land already allocated. The results of field survey and data processing of fair market price of land in 2010 obtained the average indication price or NIR. The NIR price of each zone of fair market land price is taken at its maximum price. The area of vacant land availability digitized imagery results and fair market land price in the Tembalang District shown in Table 1 below. The result of the vacant land availability on the digitized imagery in 2016 and Field survey results and data processing of fair market land prices in 2016.
The results from digitization of vacant land availability classified as vacant land not allocated and vacant land already allocated. The results of field survey and data processing of fair market price of land in 2016 obtained the average indication price or NIR. The NIR price of each zone of fair market land price is taken at its maximum price. The area of vacant land availability digitized imagery results and fair market land price in the Tembalang District shown in Table 2 Table 3 below.  Vacant land changes leading to reduced availability of vacant land is largely due to the transition of land into settlements. One example of a change to see vacant land to residential use is shown in Figure  7 and Figure 8   The decline in the number of vacant land availability that most are in Tembalang Subdistrict with a total area change of 559,198.7 square meter with percentage 33.3%. This happens because the vacant land change for the construction of settlements. As the decline in the number of vacant land availability from period 2010 and 2016, the land value is also increasing, it can be seen in the increase in land value in all areas of research. So it can be identified that the development of the region and physical development in Tembalang District, Semarang most are in Tembalang Subdistrict, it can be seen on the vacant land use changes that occur in the region. Phenomena that occur is the existence of an education facilities like university in rural areas, one of which occurred in Semarang, that is placed Diponegoro University in Tembalang (the upper region of Semarang). The existence of Undip in this suburb as a form of the development of the city that was equitable development with the spread of urban facilities. The Results of this research that is the existence of Undip influenced the development of settlement in Tembalang Village and Pedalangan Village. For the whole region in Tembalang Village is affected by the existence of the Undip. For the development of settlement in Pedalangan Village is divided into two parts, that is the development of the northern part of physical and non-physical areas affected by the existence of educational activities such as the existence of the Undip College, then the existence of Politekkes and other educational activities.