Agricultural Land Use Planning on Sustained Basis Using Landform and Land Evaluation Approach with Geospatial Analysis (a case study in East Barito District, Central Kalimantan Province)

Spatial planning for agricultural land use is required since the region with its land resource has an opportunity to be opened and cultivated. On the other side, balanced environment should be maintained in order to achieve sustainability for future use. Land resources information can then be used as basic information and prerequisite for analysis and evaluation in planning process. Because of the lack of data, this study was conducted to generate and provide land resource information. Landform approach using raster surface analysis and slope classification derived from digital elevation model (DEM) was then used to determine agricultural land regions. Procedure of land suitability evaluation in addition to geographic information system (GIS) technology were applied to define specific kind of use for lands. In the case of East Barito as study areas, mainly on the basis of landform analysis, the region can be classified into 6 slope classes i.e. <3%; 3-8%; 9-15%; 16-25%; 26-40%; dan >40%. The result of land suitability evaluation integrated into GIS environment establish that arable lands is still available with total area of 226,211 hectare (59.11%) of total study areas. Furthermore, the region can then be delineated for group of commodities involving food crops, estate crops, and forest as well with each total area 62,291 hectares (17.96%), 183,107 hectares (52.78%) and 101,513 hectares (29.26%), respectively. Several restrictive factors that should be considered include slopping lands and peat depth. Any appropriate and specific programs for agricultural development can then be formulated in land use planning process.


Introduction
In spatial planning process, proper and proportional allocation of land should be taken into account because not all areas in the view of land resources can be utilized for agricultural development purposes [1].In order to achieve sustainable development, appropriate land use should be implemented through proper and systematic land use planning referring to its land capability and suitability.The region with the existence of its lands should be then assessed systematically in order to delineate and determine land use options [2,3].Therefore, the proper land use can determine and indicate areas of lands that suitable for specific kind of land use while at the same time safeguarding balanced environment.In the term of sustainability, in addition to plays an important role in developed areas, it also leads to the protection and enhancement of the environment being used for future utilization with proper guide human activity and intervention [4,5].
In the case of East Barito District, Central Kalimantan Province, based on pre-eliminary study, the region was mainly covered by forest and local plantation that has been performed since a long time such as rubber with local varieties.While for farming, the land has been utilized for upland rice and horticulture with small scale [6,7].Based on satellite imagery interpretation, forest and bush occupy almost 283,384 hectares or 81.69% of total area of region.Meanwhile opened lands for farming activities are only 63,527 hectares (18.31%).This indicate that the potential of land resources is still available for specific kind of use such as agricultural development.In addition to local government policy support especially for food security, this region geographically has important access to others nearby provinces such as South Kalimantan and East Kalimantan province.Moreover, local government policy has established that agricultural sector development should be accelerated in order to support the existence of New Capital City of Nusantara (IKN) that located close to this region administratively.
The availability land resource information is important requirement in land use planning process [8].The main problem in relation to agricultural development in this region include the availability of land resources information.Furthermore, the availability has been widely used for planning purposes.It should be then generated and available for land assessment and geospatial analysis purposes [8,9].This study was conducted in the view of data scarcity and it was conducted to generate land resource information based on landform approach for identification and evaluation of the areas including the lands that suitable for agricultural development especially for food crops and estate crops.The output of this study can contribute the concept of land use planning especially for agriculture.In addition, the resulting data and information can then be used as basic reference and consideration in opening arable lands while at the same time still preserve natural environment in the scope of sustainability.

Data & Methods
This study was conducted in East Barito district, Central Kalimantan province with total area of 346,911 hectares.Geographically, this region is located below equator line with coordinate position 114˚55' 44"-115˚26' 38" East Longitude dan 1˚39` 10" -2˚22` 8" South Latitude (Figure 1).Spatial analysis procedure was used for evaluating topography of study areas based on landform data derived from digital elevation model (DEM) [10,11].The application of geographic information system (GIS) technology was used to produce spatial data and also to assist further spatial analysis including mapping process [11][12][13][14].
Land evaluation approach was used in this study in order to determine land suitability at class order [15],16].Several individual crops were selected representing group of commodities for food crops and estate crops i.e. rice (for food crop) and rubber (for estate crop).The result of evaluation was then integrated into GIS environment for further geospatial analysis.The general stages of methodology can be describe as shown at Figure 2.  Basic data used in this study involving information of digital elevation model (DEM) derived from SRTM 90 meters.It can then be used to produce topography and slope information [17].At the first stage of spatial land use planning in which data has not been widely available at regional level, soil information at reconnaissance with scale of 250, 000 can be used for spatial planning [18][19][20] and one of basic data that can be used for land identification and evaluation include landform information [17].Therefore, in this study, slope, as part of landform, is then considered in agricultural land use planning in addition to determine type of agriculture [21,22].Others relevant data used for land evaluation in addition to complete spatial data as basic spatial analysis include soil maps, land system maps, agroclimatic maps and administrative maps.

General Biophysical Environment of Study Areas
East Barito district located in Kalimantan Island, the same with other principal islands in Indonesia, has two monsoons.The wet monsoon usually starts from October to March, while dry monsoon occurs on April to September.By the end of 2022, based on the last ten years record, annual precipitation of this region is 2449 mm to 3229 mm.Period of consecutive wet months ranged between 10-12 months while dry months occur between 0-2 months.The high precipitation is influenced by temperature resulting in high evaporation intensity, causing water-saturated air conditions and potentially active rain cloud.For soil temperature and moisture regime, they have fairly homogeneous conditions for each climatic regime.
Based on land system information and soil maps, this region is spatially divided into 2 land typologies i.e. drylands and wetlands typology.Drylands typology is located in the central to the northern parts with several characteristics involving acidic, highly weathered, poorly buffered soils, and infertile.Meanwhile, wetlands typology that mostly found in the southern parts were dominated by peatlands and swamplands [23].There are several major soil types that occupy these land typologies.For drylands, these regions are dominated by orders of Ultisols.While at wetlands, they are covered by Entisols, Inceptisols, and Histosols.In the several parts, in the southern, order of Spodosols are also found [24].
Based on land system information and soil maps, the result of spatial analysis showed that the predominant drylands have total area of 276,219 hectares or 79.62% of total East Barito district region.Geographically, typology of drylands is mainly found in the central to the northern part.While for wetlands, they generally are located along the rivers in the southern parts with total areas of 70,692 hectares (20.38%) (Figure 3).For agricultural development, this information can be used as general description of land resource for policy program in supporting infrastructures, especially for transportation.

Topography Condition and Slope Classification
The result of landform analysis was focused on topography and earth surface feature including slope based on DEM data interpretation derived from SRTM 30 meters.As part of topography, slope is important factor of natural agro-environmental constraint for farming practices possibilities and it can be used to determine agriculture type.Therefore, it should be taken into account within agricultural land use planning process [21,22,24].As a result of interpretation, it showed that there are 6 slope classes i.e. <3%; 3-8%; 9-15%; 16-25%; 26-40%; and >40%.Spatial distribution of each slope class is provided at Figure 4.

Figure 4. Spatial distribution of slope classes in study areas
Slope class <3 and 3-8% with topography flat, gently and undulating are mostly found in western and southern part of East Barito district.Several locations especially for class <3% are located along the river streams and recognized as wetlands.In the central part, the region is occupied by slope classes 9-15% and 16-25% with topography undulating to rolling.While the remaining areas located in northern parts are dominated by slope classes 26-40% and more than 40% with topography condition moderately steep or even steep within land typology of dry lands.As an integral part of topography, slope parameter plays an important role in land management.In addition, for land use, it also can influence natural vegetation distribution including its diversity [26].For further land evaluation, slope classification is then implemented to establish appropriate region for specific kind of use [27].
For agricultural development purposes, the lands that can be cultivated falls into flat to middle slopes with slope class of >2% to 30% [15,28].Therefore, in this region, there are only four slope classes i.e. less than 3%; 3 to 8%; 9 to 15%; and 16 to 25% that can be allocated for arable lands.However, the lands that covered by soils developed from sandy soils and peat lands with peat depth more than 1 meter are not included and not suitable for farming practices [28].

Land Allocation for Agricultural Development
The result of land evaluation with the aid of GIS technology, delineation of appropriate slope classes and soil types for agriculture based on crop growth requirement can generate spatial information of agricultural land regions as shown at Figure 5.

Figure 5. Arable lands for agricultural development in study areas
The result of spatial analysis showed that land allocation for agricultural development in East Barito district mostly located in the central parts with total areas of 245,398 hectares or 70.74% of total region.Further spatial analysis based on the result of land evaluation then result in land use information for agricultural system that can be proposed to develop the region.In order to promote balanced environment and sustainability and to accelerate areas development for agriculture, this region can then be allocated in accordance with agriculture system as represent at Figure 6.
The spatial information in Figure 6 showed that in East Barito district as study area, there are three systems of agriculture i.e. food crops, estate crops and forestry with each total area 62,291 hectares (17.96%), 183,107 hectares (52.78%) and 101,513 hectares (29.26%), respectively.System of agriculture for food crops is mostly found at river stream areas in wetlands.However, there are some arable lands that occupy in drylands.While for estate crops, they are located in the drylands or uplands with topography undulating to rolling.
The development program of estate crops can be prioritized in this region and it can be followed by food crops development.On the other hand, the existence of forest areas should be preserved in order to achieve sustainability.Therefore, appropriate and policy program specific to location can be formulated in order to accelerate developing areas for agriculture.

Conclusion
At initial stage of agricultural land use planning with reconnaissance scale, landform approach with geospatial analysis can be implemented to interpret topography including slope classification for supporting balanced environment and sustainable agriculture development with ecological sound management.In the case study of East Barito district, there are 3 agriculture systems that have been delineated i.e. food crops, estate crops and forestry with each total area 62,291 hectares (17.96%), 183,107 hectares (52.78%) and 101,513 hectares (29.26%), respectively.

Figure 1 .
Figure 1.Location of study in East Barito district, Central Kalimantan Province

Figure 2 .
Figure 2. General Stages of Methodology

3 .
Result and Analysis

Figure 3 .
Figure 3. Spatial Distribution of Land Typology for Drylands and Wetlands in Study Areas

Figure 6 .
Figure 6.Land allocation for agriculture of food crops, estate crops and forestry in East Barito district as study areas.