Identification of land use change on rice fields in Tangerang District using landsat 8 imagery

Tangerang District is a suburban area located around DKI Jakarta that has undergone significant development, resulting changes in natural resources. Rice fields are one of the natural resources in agriculture. The conversion of rice field areas into another land uses can indirectly cause several problems, such as food scarcity. The study aims to identify changes in the rice fields area of Tangerang District, using Landsat 8 imagery with supervised classification method. Based on the research findings, the rice fields in Tangerang District have transformed into residential areas, industrial zones, open fields, bodies of water, plantations, and green open spaces. The rice field area decreases every year. The conversion of rice fields into open land is the most dominant change due to the increasing demand for land for industrial and residential purposes in Tangerang District. The rice fields are drained before being converted into residential and industrial areas to compact the soil, ensuring it does not pose a threat to the construction on the land. The continuous and uncontrolled reduction in rice field areas can have an impact on food scarcity in Tangerang District.


Introduction
The transformation of land use and land cover can occur as an environmental response to changes in global and local conditions [1].Land use changes can impact ecosystem services by altering ecosystem structure and function within a varied context of land use scale, type, and intensity [2].The interaction between human activities and land resources results in land use change, a fundamental impact that affects human survival [3].Studying land use changes can reveal unique mechanisms between humans and the environment, reducing conflicts and promoting sustainable development in a region [4].Many studies show the importance of conversion and proper land use regulation to mitigate massive climate change and environmental pollution [5].Analyzing environmental issues caused by changes in land use has become highly urgent due to the increasing trends in land use changes [6].
The rapid global acceleration of social and economic development, particularly in the urbanization sector, has led to significant land-use changes [7].According to research conducted by [8], more than half of the world's population resides in urban areas due to the expectation that these areas will continue growing in the future.The continued changing of land use indicates the occurrence of a "Dynamic Urban 1314 (2024) 012038 IOP Publishing doi:10.1088/1755-1315/1314/1/012038 2 Sprawl" phenomenon, which is the expansion of urban areas indirectly altering various types of land use [9].
Indonesia has experienced significant land use changes, particularly with the expansion of industrial and residential areas.[10][11][12][13].The expansion of industrial and residential areas in Indonesia was driven by the country's growing economy and population [12] [13].The demand for industrial and residential areas has increased due to economic and population growth, however the land availability is not proportional with the demand [12,14].As a measure to fulfill the demand for industrial and residential areas, land use change or land conversion is carried out, especially on forest and rice fields area [12,13,[15][16][17].The land use changes generally result rapid transformations on several cities including changes in social, ecological, and economic life [18].The Greater Jakarta Region is the largest metropolitan area in Indonesia, it consists of several cities and district, including DKI Jakarta, Bekasi, Depok, Tangerang, and Bogor, and is currently rapid transformations [19] [20] [11].The Greater Jakarta Region plays a significant role, especially in the sector of the Indonesian economy which can generate an average income of more than IDR 1,500 trillion (USD 113.52 billion) [21].
Tangerang District is located in the Greater Jakarta Region, which has a relatively flat topography with an average slope of 0-8% down to the north [22].Tangerang District is also known as the "City of a Thousand Industries."Because the Tangerang District was home to several large industrial estates in Indonesia [23].From the 20th century, there has been a flourishing of housing development, urban design, and urban planning in Tangerang District [24].Currently, many areas in Tangerang District have transformed into residential and industrial areas [25].The existence of this phenomenon (land use changes) harms the environmental composition, including a decrease in green areas and agricultural land.The land use changes in Tangerang District can lead to an increase in urban air temperature and a reduction in rice field area [12,16,26].Significant land use change can cause several problems on a large scale, such as affecting biosphere-atmosphere functions, biodiversity, ecosystem function, energy balance, and biogeochemical cycles, food scarcity, which can hinder sustainable development goals [25].The uncontrolled reduction of rice fields can lead to food scarcity since land availability is inversely proportional to increasing food demand [12,13].
From the explanation, it seems the importance of land use change study especially in Tangerang District as a growth city.Studying land use changes that have occurred, can provide appropriate input to policymakers in designing spatial planning that is effective and sustainable for the environment [27], especially in the Tangerang District area.The research aims to identify land use changes in rice fields in Tangerang District, so it can help stakeholders determine spatial planning policies concerning the balance of social, economic, and environmental land use so that changes in land use that occur can be controlled according to social and eco-friendly functions.
The study utilized a spatial approach that involved a supervised classification of the image data analysis technique.Various sources of data were used, including Landsat 8 imagery from the years 2017, 2020, and 2022, and Shapefile of Tangerang District Administrative Boundaries.The data sources were obtained from the USGS website, and the Geospatial Information Agency.The high-resolution 30meter/pixel on the Landsat 8 imagery makes it particularly effective for identifying various land use types with great detail [14,32].The Landsat 8 has a revisiting time of approximately 16 days, which allows for monitoring changes in land use.Landsat 8 also possesses a historical data archive since its first remote sensing mission, enabling the analysis of historical land use and changes over time [33].

Figure 1. Map of Research Location
Data analysis and interpretation of Landsat 8 OLI imagery are performed using Geographic Information System (GIS) software because it can process and analyze data spatially [34].The data processing process begins with cropping Landsat 8 satellite images from the years 2017, 2020, and 2022 to the administrative boundaries of Tangerang District.The images are processed using the supervised classification method to generate land use data [5,35].The result interpretation of Landsat 8 imagery will classify into seven types of land use: rice fields, residential areas, industrial areas, open fields, water bodies, green open spaces, and plantations.
The next step is to perform data analysis in order to obtain information regarding changes in land use in the rice field area from 2017 to 2022.The analysis will involve a data clipping process, with the primary data being the 2017 rice field data.The data will be sequentially processed along with the data from 2020 and 2022.The data clipping process will help focus the analysis on the relevant rice field areas to understand changes in land use during that time period.The result of validation process involves field ground-checking activities, and interviews.Accuracy testing will be conducted after field validation using the Overall Accuracy formula based on the approach proposed by Thomas M. Lillesand in 1993 [23].

Results and Discussions
Based on the data processing of Landsat 8 using the Geographic Information System, the land use in Tangerang District from 2017 to 2022 can be categorized into 7 types, namely Rice Fields, Residential Areas, Industrial Areas, Open Fields, Water Body, Green Open Spaces, and Plantations (figure 2).Each land use contained in Figure 2 has a different color and area from one another.In Figure 2 Tangerang District underwent significant changes in land use from 2017 to 2022.In Figure 2 it can be seen that each land use has changed in area, namely increasing or decreasingly.The changes in land use that occur in Tangerang District can be attributed to the influence of the area's proximity to DKI Jakarta.Jakarta, as the capital city of Indonesia, has become the largest metropolitan area in Indonesia and Southeast Asia [23].Economic, residential, and industrial activities are mixed together in Jakarta making it a crowded [23] [36].The economic and population growth, which was originally centered in DKI Jakarta, has now spread to the surrounding regions, including Tangerang District.According to [37] the growth of suburban areas can be attributed to uncontrolled population growth in the city center, transportation facilities, and the availability of better infrastructure in the sub urban area.Figure 2 show that, Rice fields are the most affected land use due to the growth occurring in Tangerang District (Figure 2).From 2017 to 2022, the rice field area in Tangerang District consistently decreased each year (Table 1).In 2017, the utilization of rice fields still dominated the district, as indicated by the light green color covering an extensive area, accounting for 36.19% of the total area.In 2020 and 2022, the rice field area continued to decline.Specifically, in 2020, the area designated for rice fields experienced a significant reduction, decreasing to just 34.03%.In 2022, the rice field area continued to decrease, covering only 27.70% of Tangerang District's total area.From Table 1, it can be observed that the rice field area experienced a decrease of 8.48%, which is equivalent to 8,140.85 hectares from 2017 to 2022.The reductions in the rice field area vary, with detailed figures as follows: from 2017 to 2020, there was a decrease of 2,067.48hectares, approximately 2.15% of the 2017 rice field area.From 2020 to 2022, there was a reduction of 6,073.37 hectares, or about 6.32% of the 2020 rice field area.The decline in the rice field area that occurred between 2020 and 2022 represents the largest reduction in the rice field area of Tangerang District (Table 1).An additional study conducted by [12] indicated that in Serang Regency, there was a notable decline in rice fields from 2006 to 2008, with a reduction of 6,107.32 hectares.In contrast, the built-up area expanded, showing an increase of 8,321.09hectares during the same period.in the DKI Jakarta area also showed similarities, where rice fields are the most affected by land use change or land conversion, with the results indicate a decrease in the rice field area in Jakarta from 2,386 hectares in 2010 to 1,520 hectares in 2016 [36].
The reduction in the rice field area of Tangerang District is attributed to the conversion of rice field areas into other land uses such as residential areas, industrial areas, green open spaces, and other land uses (Table 2).From 2017 to 2020, the land use changes in the rice fields area of Tangerang District were predominantly shifted to open field and green open spaces, with each land use gaining an increase in area by 3.4% and 0.9%, respectively, compared to the rice field area in 2017.Industrial areas, residential areas, plantations, and water bodies also experienced expansion in their respective areas, residential areas received additions of 0.65% and 0.51% for industrial areas (Table 2).The expansion in plantation and water bodies area was relatively smaller than other land uses.Another study conducted by [12] indicates that the rice field area in Serang Regency has also experienced a decrease, while open land dominates land use, amounting to 173,949 hectares in 2000, which then increased to 183,231 hectares in 2018.
From 2020 to 2022 the land use for Residential Areas and Industrial Areas also experienced a significant increase.In Table 2, it can be seen that the residential area has increased nearly threefold compared to the increase in 2017 to 2020, whereas the industrial area has expanded almost four times compared to the increase in land area in the previous period.The conversion of rice field land into developed land in Tangerang District can be attributed to the lower land value of rice field land compared to developed land.The statement is in line with [12] assertion that land use changes in rice fields area into developed land can occur because the land value of the built land tends to be higher than when it became rice fields.The value of rice fields area was lower than non-rice fields area, rice fields will be converted into non-rice fields to increase their value [38].
Open fields and green open spaces have also expanded in size and continue to dominate the conversion from rice fields.In the period between 2020 and 2022, more rice fields have transformed into open fields, with a total area of 2,616.83hectares.The increase in open field area is illustrates in the figure 3, that show significant expansion of the yellow areas in 2022.The expansion of open land can be attributed to the conversion of rice fields into built-up land.The conversion of rice field area into built-up land requires several processes due to its relation to the condition of rice fields containing a significant amount of water.Before commencing building construction, the rice fields are first drained to compact the soil, ensuring its stability and preserving the building's foundation.The statement can be proven by several areas that in 2020 turned into open fields, then in 2022 changed to residential areas and industrial areas.The changes of residential and industrial areas can be observed in Figure 3, where some yellow areas in 2020 have changed to red, and orange areas in 2022  The expansion of residential areas and industrial activities to suburban areas such as in Tangerang District can certainly have an impact on the decrease in the rice fields area.The same thing is also found in the eastern part of Serang Regency which has changed land use into residential areas which were originally rice fields area [12].In the Sub-Urban area of Pekanbaru, there are also many changes in land use into residential areas [35].Another study reveals that in Karawang Regency, there was a decrease hectares in that time period.The decline occurred as a consequence of the shift in the development focus from the agricultural sector to the industrial sector [15].The Land use changes are strongly influenced by human factor, such as high population growth rates [39].The demand for residential areas such as in the Tangerang District is due to the lack of residential area and industrial area in DKI Jakarta.Land use changes can occur as a result of natural factors, socio-economic conditions, and how humans utilize the area [40].
The Data that presented in Figure 3 underwent validation through ground checking activities and interviews with residents at the validation sites.Ground checking activities were conducted at various locations in Tangerang District to corroborate the outcomes of Landsat 8 data processing with information collected in the field.A total of 35 ground checking points were utilized as benchmarks to evaluate the validity and precision of the data.Following the field validation, accuracy calculations for the data were performed to assess its level of precision.The outcomes of the Ground checking activity are outlined in From Table 2, the overall accuracy is calculated by summing the correct samples and dividing it by the total predetermined samples.The number of correct samples is 31, and the total number of samples is 35.The accuracy test results indicate a value of 88.57%.The results of this calculation show that the accuracy level of the Landsat 8 image data processing and analysis is 88.57%, it can be concluded that the processing data is valid and consistent with the actual conditions in the field.

Conclusion
The processing of Landsat 8 satellite imagery using Geographic Information Systems with a supervised classification method has revealed significant changes in land use in Tangerang District from 2017 to 2022, with rice fields being the most affected.The conversion of rice fields into other land uses, such as residential areas and industrial zones, has been driven by factors like the lower land value of rice fields compared to developed land.The transformation has resulted a continuous reduction in the area of rice fields, leading to food scarcity.As a preventive measure, several appropriate strategies are required to maintain food security.Sustainable farming practices, efficient water management, and innovative landuse planning can be employed to ensure balanced urban development and food security in the future.
, the representation of land use is depicted as follows: rice fields are indicated by the light green color, residential areas are marked in red, factories are depicted in orange, open lands are represented in yellow, plantations are shown in green, water bodies are illustrated in blue, and Green Open Spaces are denoted by the dark green color.

Figure 3 .
Figure 3.The Map of Change in Rice Field Area to Another Land Uses in 2017, 2020, 2022

Table 1 .
Land use area in Tangerang District 2017 -2022

Table 2 .
The Change in Rice Field Area to Other Land Uses (Compared Rice Field area in 2017)

Table 3 Table 3 .
Results of Land Use Ground Verification Land UseType