Analysis of population density and land use in Karangmalang Subdistrict, Sragen Regency in 2013 and 2022

Increased population growth is one of the driving factors for land use change because it is to meet the needs of the population, especially in settlements or residences. Land use changes occur as a result of improving the quality of human life which has an impact on land use changes that are difficult to control. This study aims to analyze the distribution of land use in 2013 and 2022, and analyze the relationship between population density and land use change. The research method used is the Overlay Method and Liner Regression. The results of this study show that land use change in Karangmalang Subdistrict in 2013 and 2022 amounted to 197.7 hectares, dominated by residential land of 154.4 hectares. There was an increase in population in 2013 and 2022 of 2,280 people/square kilometer. The results of the linear regression calculation show an R2 value of 0.697 which means that there is a positive relationship between land use change and an increase in population density.


Introduction
According to the FAO (Food and Agriculture Organization), land encompasses various recurring elements of the biosphere, extending above and below its surface.This includes the atmosphere, soils, geology, hydrology, plants, animals, and the influence of past and present human activities.These features play a significant role in human land utilization [1,2].Land use has played a significant role in human society throughout history.In the past, changes in land use occurred gradually, driven by individual decisions.However, in today's densely populated and complex world, land use changes are formally guided by land use planning.The primary goal of this planning is to discover productive and innovative ways to utilize environmental resources.Essentially, changes in land use are no longer inevitable.Rapid population growth and the increasing demand for land by communities lead to a mismatch between land use and its zoning [3,4].Rapid population growth, coupled with swift development in various sectors, results in an increased demand for land.However, land is a finite resource, and its supply can only be expanded through processes like land reclamation in areas such as the sea, lakes, or riverbanks.Without a careful and judicious approach to land use, this surging demand for land can lead to various issues, particularly land conversion.The rapid population growth contributes to the conversion of land use, primarily impacting the transformation of agricultural land into nonagricultural uses [5].
Rapid population growth and development activities across various sectors often stimulate land conversion.As Arsyad and Rustiadi (2008:78) note, land conversion is a logical outcome of increased human activity, population growth, and other development processes.Land conversion, at a certain stage, is a natural occurrence; however, when left uncontrolled, it can escalate into a problem [6].According to data from the Central Bureau of Statistics in 2017, Indonesia's population was recorded at 261.4 million people, and it was projected to increase to 275.8 million people by 2022, with a growth rate of 1.17%.The population density in 2017 was 146 people per square kilometer [7].As the population grows rapidly, the demand for land for various purposes, including settlements, housing, and economic activities such as factories, shops, and markets, has also surged.However, the supply of land is limited, and the number of inhabitants continues to increase each year.This trend has negative consequences for the surrounding environment [8,9].
Karangmalang is one of the districts in Sragen Regency that has experienced dynamic regional development, primarily due to its close proximity to the urban area of Sragen, the capital, which is only about 2.7 kilometers away.The Karangmalang district spans an area of 4,298 hectares or 42.98 square kilometers, with the majority of its terrain being flat land at an elevation of 86 meters above sea level, dominated by areas with slope classes ranging from 0-2%.This geographical characteristic allows for changes in land use.Furthermore, Karangmalang's strategic location in the vicinity of the Sragen Regency's Strategic Economic Growth Area, as defined by Regional Regulation No. 11 of 2011 concerning the Spatial Planning of Sragen Regency for the period 2011-2031, contributes to its development [10].
The rapid development of the urban areas in Sragen can be characterized by the increasing population density, closely packed buildings, expanding residential areas, and the growth of social and economic facilities supporting the activities of the population [11].The rapid development of urban areas is not limited to the city center but also extends to the suburban or hinterland areas.This is a natural consequence of changes in land use that result from the development of a region [12,13].One of the regions in Sragen Regency affected by the development of urban Sragen is the Karangmalang Subdistrict.It is situated in the southern hinterland of urban Sragen and plays a strategic role in the economic growth of Sragen Regency.Geographically, the Karangmalang Subdistrict is characterized by predominantly flat terrain with slopes ranging from 0-2%.Its proximity to urban Sragen makes it susceptible to changes in land use.
The changes in land use in the Karangmalang Subdistrict are evident in the reduction of land types between 2014 and 2019.Wetlands decreased by 0.21%, agricultural drylands decreased by 5.0%, and non-agricultural land increased by 5.21% [14,15].These changes in land use in the Karangmalang Subdistrict are in line with the increasing population, which directly impacts the growing demand for land [16].This is supported by data from the Sragen Regency Central Statistics Agency, which states that the average population growth in the Karangmalang Subdistrict from 2013 to 2020 was 1.79%, with an average population of 65,160 people, which, of course, has implications for the surrounding environment.This is further reinforced by previous research indicating that nearly every community is involved in land use, and as the human activities increase rapidly, land becomes a scarce resource.The decision to change land use patterns can result in significant benefits and drawbacks, both in economic terms and in terms of environmental changes [17].Other research states that changes in land use in the North Bandung region during the period 2015 to 2018 led to a 1.14% increase in critically conserved areas [18].
Based on the issues described, the purpose of this research is to analyze the changes in land use in the Karangmalang Subdistrict over the past decade, specifically between 2013 and 2022.This is of utmost importance as the subdistrict is a strategic economic growth area in Sragen Regency and is also a part of Sragen City's hinterland.Furthermore, the research aims to examine the relationship between population density and changes in land use.

Study Area
This research was conducted in Karangmalang Sub-district, Sragen Regency, Central Java Province.Karangmalang Sub-district is located next to Sragen Urban Economic Growth Strategic Area, which is crossed by a main collector road (Figure 1).This strategic location causes the development of Karangmalang Sub-district to be rapid, which has an impact on population density and land cover.
Mathematically, the accuracy test is expressed using the following equation: 2 3

Overlay Data.
Overlay is a method of spatial analysis that is used to combine different types of spatial data to create new spatial data information [20].To produce land use change, satellite imagery was digitized to identify the land cover of Karangmalag Subdistrict in 2013 and 2022, then the results of land cover were overlaid to produce land cover change in Karangmalang Subdistrict.

Population Density.
Population density is the ratio of the number of people in an area to the area per square kilometer.The formula for calculating population density is as follows:

Simple Regression Method.
Simple linear regression analysis is a linear regression analysis involving only two variables, an independent variable and a dependent variable.It is called simple linear because the dependent variable is assumed to be linear in parameters and linearly related to the independent variable.This method was chosen because it examines the relationship between land use change (independent variable) and population density (dependent variable) [21,22] with the following equation: ŷ : Line Regression / Variable Response a : constant (intercept), intersection with the vertical axis b : regression constant (slope) X : independent variable/predictor

Land Use Classification in 2013 and 2022
Based on the results of digitizing satellite images of Karangmalang Subdistrict in 2013 and 2022, there are 7 land use classifications consisting of waters/water bodies, plantations, settlement/built-up land, vegetation, irrigated rice fields, moor, and rice fields (Table 3).Based on

Land Use Accuracy Test
The results of the calculation of the accuracy of the results of aerial photography classification with field data using 42 reference points consisting of the calculation of user accuracy (UA), procedur accuracy (PA), overall accuracy (OA), omission error (OE), and commission error (CE) which are put together into one matrix, namely the error matrix or called the confusion matrix (Tabel 3).Based on the calculation of the accuracy test, it can be seen that the user accuracy (UA) value is the possibility of a pixel on the map that is correctly represented by the class found in the field.land use classification results based on the UA value with the largest value found in the Settlements / Built-up Land class with 100% means that the results have been classified correctly.Meanwhile, the smallest UA is obtained in the Plantations and Vegetation classes with 33.3%% each that has been mapped.While 50% of pixels are not successfully mapped according to their class, this is due to entering a class that should be removed from a particular class or commission error (CE).The results of the confusion matrix of land use in Karangmalang sub-district based on the  y value of 64%, so that the accuracy test of the confusion matrix is close to the actual field situation.

Land Use Change
The results of the overlay of land use in 2013 and 2022 in Karangmalang sub-district show that the use of Residential Land / Built-up Land has increased significantly compared to other land uses (Table 4).Irrigated agricultural land experienced a change of 156.4 hectares, then plantation land of 23.1 hectares, and Moor of 12.0 hectares.One of the villages in Karangmalang sub-district that experienced a significant change was Plumbungan by 55.8 hectares.

Relationship between population density and land use change
Based on the results of calculating the population density level in Karangmalang Subdistrict, it shows an increase in population density from 2013 to 2022 with an average of 288 people/square kilometer (Table 5).The table 5 shows that there are 3 villages that experienced significant changes in population density, including Plumbungan Village with 466 people/square kilometer, Puro with 463 people/square kilometer, and Kryo with 337 people/square kilometer.The population density map (Figure 6) shows that the distribution of density in Karangmalang subdistrict is centered in several villages, namely Plumbungan, Puro, Kroyo, and Guworejo villages, if closely Figure 6 shows that the population density decreases as one moves westward.that the population density has decreased in the western area of Karangmalang subdistrict, which includes Saradan, Plosokerep, Jurangrejo, and Kedungwaduk villages.

Figure 6. Population Density Map
Table 6 shows the impact of population density on land use change, one of the factors for land use change is population, the increasing population in an area causes land use change to expand.Population density in Karangmalang sub-district has resulted in the conversion of several land uses into residential/built-up land because the population's need for a place to settle is increasing.The relationship between population density and land use using the simple linear regression method shows that land use change has a positive relationship with population density, the R-squared value of 0.697 indicates that land use change affects the increase in population density by 0.697 or 69.7%, and the rest is influenced by other factors (Figure 7).A closely related human-induced factor that affects land change is population growth.The faster the population growth in an area, the greater the demand for housing and the impact on land change.In the last 10 years, Karangmalang Sub-district has experienced an increase in population density in each village, which explains that the village with the highest increase in density is Plumbung Village, which is 466 people/square kilometer, while Saradan Village is the village with the smallest increase in population density at 64 people/square kilometer.This is supported by research by Laka et al. (2017), which shows that high population density in an area encourages residents to open up new land for settlement or cultivation.
This suggests that there is a close relationship between increasing population density and changes in land use functions.An increase in population density in Karangmalang sub-district of 2,880 people/km2 and a change in land use to settlements of 197.7 ha, when viewed from the results of simple regression calculations, shows a positive relationship between the level of population density and land use change of 69.7%.Areas with large increases in population density also have large changes in land use, and conversely, areas with small increases in population density also have small changes in land use.Plumbungan Village is one of the villages that experienced a large increase and also a large land use change, while Saradan Village is one of the villages that experienced a small increase in population density and also a small land use change.

Conclusions
Karangmalang sub-district experienced a land use change of 197.7 ha in a period of 9 years from 2013 to 2022.The largest land use change is from rice fields to settlements amounting to 156.4 ha, most of which occurred in Plumbungan village (55.8 ha), while Jurangrejo village experienced the smallest land use change (1 ha).An increase in population density has a positive relationship with land use change.An increase in population density has an effect of 0.697 on land use change.

Figure 3
Figure3 and 4shows that the land use in Karangmalang sub-district is dominated by rice fields and residential/built-up land.In 2013, the area of irrigated rice fields was 3,012.6 hectares and settlements/built-up land was 1,172.2hectares.In 2022, the area of rice fields decreased to 2,856.2 hectares while settlements/built-up land increased to 1,369.8 hectares.

Figure 5
Figure 5 shows that most of the land use in Karangmalang sub-district, such as plantation land, vegetation, rice fields and Moor, has been transformed into built-up areas, especially in areas close to Sragen urban area, namely Plumbungan, Kroyo and Puro villages.

Figure 5 .
Figure 5. Land Use Change in Karangmalang Sub-district

Figure 8 .
Figure 8. Population Density and Land Use Change 3.5.Discussion Land use in Karangmalang sub-district is divided into 7 land uses, including: irrigated rice fields, rainfed rice fields, plantations, grass, settlements, buildings, fields and water bodies.The most dominant land use in Karangmalang sub-district is the use of rice fields in 2013, amounting to 3012.6 ha.However, in 2022, the use of paddy fields will decrease to 2856.20 ha.Meanwhile, residential land in 2013 amounted to 1,172.2 ha, changing to 1,369.8 ha in 2022.The need for residential land has led to land conversion, where land originally designated for rice fields has been converted to residential land.Although rice fields have decreased, rice fields remain the most dominant land in Karangmalang sub-district.The land use change into settlements that occurred in Karangmalang sub-district in the period of 9 years amounted to 4.28%, which is 197.7 ha.Based on this data, the largest land use change occurred in paddy fields into residential land with an area of 156.4 ha, while plantation land and dry land were only 23.1 ha and 12 ha respectively.Almost all villages in Karangmalang subdistrict experienced land use change, Plumbungan village experienced a land use change of 55.8 ha, while the village with the smallest change was Jurangrejo village with a size of 1 ha.This is supported by the study conducted by Wahyuni et al. (2014), which stated that the change in function from paddy fields to residential land was caused by urbanization, increasing population, social conditions, and economic factors in the area.Land use change in Karangmalang sub-district is caused by natural and human factors [4,23].According to Darmawan (2002), one of the factors that cause land use change is socio-economic factors related to the needs of human life, especially the people around the area.A closely related human-induced factor that affects land change is population growth.The faster the population growth in an area, the greater the demand for housing and the impact on land change.In the

Table 1 .
[19]al photography data of Karangmalang sub-district in 2013 and 2022, interpretation was carried out to obtain land use classification by using digitation on screen with GIS.The results of aerial photo interpretation show that there are 7 land use classifications, namely water/water body, plantation, settlement/built up land, vegetation, irrigation field, swamp and paddy field.1314(2024)012076 Data Accuracy Test.The classification results tested were the land use classification of Karangmalang Sub-district in 2013 and 2022.The percentage used to see the accuracy value of the classification results consists of producer accuracy, user accuracy, and overall accuracy[19].following is the Confusion Matrix Calculation of the accuracy test: Confusion Matrix Calculation

Table 3 ,
Settlement/Built-up Land Use increased by 197.6 hectares or 4.3% from 2013 to 2022, while other land uses such as Irrigated Rice Fields decreased by 3.4% or 156.4 hectares.

Table 2 .
Land Use Classification in Karangmalang Subdistrict 2013 and 2022

Table 4 .
Land change to residential/built-up (ha)

Table 5 .
Population Density in 2013 and 2022

Table 6 .
Changes in land use and population density