Soil Type Map Research Articles

PEMETAAN SEBARAN TINGKAT BAHAYA EROSI DI WILAYAH SUB DAS LEMPAKE

This research was aimed to predict the erosion hazard level based on the Universal Soil Loss Equation (USLE) formula and to create distribution mapping of erosion hazard level at Lempake sub-watershed area. This research was conducted by overlay four types of maps, i.e: rainfall, soil, slope, and land cover maps. The results showed that the process of overlay from a topographic map, map of soil types, vegetation maps and rainfall map was 36 land units about 583.108 ha area. Annual rainfall in the sub-watershed of Lempake during about 10 years old from the year of 2008 to 2017 amounted was 2445.8 mm. The soil type of dominant was podsolik kandika bout 1724 ha area. The most of topography of the Lempake sub-watershed was dominated by the slope class of 15-25% (rather steep) which is 1218.34 ha. Land covers were dominated by shrubs with an area of 830.27 ha. An overlay process was done to get the final result, i.e. erosion hazard level prediction. The level was classified into five categories those were very light, light, medium, heavy, and very heavy. The results showed that the distribution mapping of erosion hazard level at Lempake sub-watershed area ranged from very light to very heavy, with the percentage soft he affected areas are 20.39%;10.87%; 3.93%; 36.87%, and 27.9% respectively. The results can be used as a database to make a good planning watershed area management.

The Scale Effect of Double-Ring Infiltration and Soil Infiltration Zoning in a Semi-Arid Steppe

The double-ring infiltrometer is widely used to measure soil unsaturated hydraulic conductivity in the field. The scale effect of the inner and outer ring size (especially the inner one) affects the measurement results. In the semi-arid steppe, where water is scarce and transportation is inadequate, studying the scale effect caused by the inner-ring diameter of the infiltrometer can reduce the test consumption on the premise of ensuring the test accuracy. In this paper, a total of 190 double-ring infiltration tests with different inner-ring diameters (15, 20, 25, 30, and 40 cm) and 0.33 times outer buffer index were carried out at 38 sites with five soil types in the Xilin river basin, China. Results showed that: (1) When comparing the simulated parameters of six infiltration models, parameters increased with the increase of the infiltrometer inner diameter, but the trend gradually slowed down, indicating that the increase of the infiltrometer inner diameter would weaken the influence of the infiltrometer scale effect. However, the infiltrometer with an inner diameter of 40 cm is not enough to completely overcome the scale effect. (2) Through principal component analysis, the infiltration process is mainly affected by the particle size and the initial moisture content. (3) The soil infiltration map based on infiltration tests was more practical than the soil type map, which can provide a theoretical basis for ecological and soil restoration in the future.

A review of the global soil property maps for Earth system models

Abstract. Soil is an important regulator of Earth system processes, but remains one of the least well-described data layers in Earth system models (ESMs). We reviewed global soil property maps from the perspective of ESMs, including soil physical and chemical and biological properties, which can also offer insights to soil data developers and users. These soil datasets provide model inputs, initial variables, and benchmark datasets. For modelling use, the dataset should be geographically continuous and scalable and have uncertainty estimates. The popular soil datasets used in ESMs are often based on limited soil profiles and coarse-resolution soil-type maps with various uncertainty sources. Updated and comprehensive soil information needs to be incorporated into ESMs. New generation soil datasets derived through digital soil mapping with abundant, harmonized, and quality-controlled soil observations and environmental covariates are preferred to those derived through the linkage method (i.e. taxotransfer rule-based method) for ESMs. SoilGrids has the highest accuracy and resolution among the global soil datasets, while other recently developed datasets offer useful compensation. Because there is no universal pedotransfer function, an ensemble of them may be more suitable for providing derived soil properties to ESMs. Aggregation and upscaling of soil data are needed for model use, but can be avoided by using a subgrid method in ESMs at the expense of increases in model complexity. Producing soil property maps in a time series still remains challenging. The uncertainties in soil data need to be estimated and incorporated into ESMs.

Application of USLE and GIS to predict erosion loss at Brantas Watershed

Erosion processes are still the dominant factor affecting land degradation. The rapid calculation of erosion loss is urgently required for conservation planning and management at the watershed level. This paper is reporting the use of USLE method and GIS at Brantas Watershed. The digital layer data of rainfall from 2005 to 2014, soil types, land use, and DEM (from ASTER GDEM2) were used as the main input. The research procedures consist of (1) data inventory dan preparation, (2) calculation of the erosion factors (R, K, LS, CP), and (3) calculation and classification of the erosion hazard. The erosivity factor (R) is calculated from the analysis of annual rainfall data. The erodibility factor (K) is obtained using analysis of soil type map. The length and slope factor (LS) is calculated from the DEM and Soil layer data. The crop cover and conservation activities (CP) is interpreted from RBI maps year 2014. The results showed that the erosion hazard in Brantas Watershed dominated by very low with predominantly the erosion yield of 0,96 ton/ha/year. Thus required conservation and watershed management activities to prevent an increase erosion hazard in the Brantas Watershed.Keywords: erosion yield, USLE, GIS, Brantas, Watershed

Predicting soil types and soil properties with limited data in the Uasin Gishu Plateau, Kenya

Digital soil mapping (DSM) approaches can be used to create new soil maps or enhance existing maps, particularly in areas where only general soil maps are available. In this study, we utilized a knowledge-based inference soil mapping approach to develop a first-generation digital soil map for part of the Uasin Gishu Plateau in western Kenya. We calculated the following environmental covariates from the Shuttle Radar Topographic Mission (SRTM) 30 m digital elevation model (DEM): slope gradient, multi-resolution valley bottom flatness index (MrVBF), multi-resolution ridgetop flatness index (MrRTF), topographic position index (TPI), elevation, and profile curvature. These covariates were then used along with existing soil information and expert knowledge from soil scientists familiar with the area to produce new raster-based maps of soil types, effective soil depth, soil moisture storage capacity and soil drainage class. The soil type maps predicted using clustering analysis and fuzzy logic methods showed good agreement with field observations based on the overall accuracy values. The fuzzy logic map performed slightly better (kappa coefficient (k) = 0.68; overall accuracy = 0.76) than the map based on clustering analysis (k = 0.59; overall accuracy = 0.68). The accuracy for the effective soil depth fuzzy logic map was higher (R2 = 0.56; RMSE = 11; ME = 1.1) compared to the existing soil map (R2 = 0.34; RMSE = 27; ME = 8). Seven major soil types occur in the study area: Ferralsols, Nitisols, Gleysols, Luvisols, Acrisols, Cambisols and Regosols, according to the World Reference Base soil classification system. This study generated detailed and improved predictions of soil types and properties at 30 m grid resolution. These maps should be more useful for soil, crop and land use management decisions than existing maps.

FORAGE POTENTIAL AND ADAPTATION OF Alysicarpus vaginalis IN BALI PROVINCE

Climate change that has hit the world requires to make adaptation efforts so that agricultural productivity can be maintained. Alysicarpus vaginalis is one of the local variety forage that can grow in a various of environmental conditions. In this regard, a survey research has been carried out to study various types of local forages throughout Bali. The aim of the research is to obtain forages that have superior properties and can be developed in various regions in Bali. The survey sampling location refers to a map prepared specifically for that by overlaying a map of soil types, land use maps, and climate maps. Based on the results of the survey, several species of local forages that have superior characteristics have been found. One of them is Alysicarpus vaginalis plant as a forage superior, Alysicarpus vaginalis forage production as much as 46,302 kg DM ha-1 with 0.21% botanical composition.
 Keywords: Alysicarpus vaginalis, superior legumes, tropical forage

A Random Forest-Based Approach to Map Soil Erosion Risk Distribution in Hickory Plantations in Western Zhejiang Province, China

Increasing agroforestry areas with improper management has produced serious environmental problems, such as soil erosion. It is necessary to rapidly predict the spatial distribution of such erosion risks in a large area, but there is a lack of approaches that are suitable for mountainous regions. The objective of this research was to develop an approach that can effectively employ remotely-sensed and ancillary data, to map soil erosion risks in an agroforestry ecosystem in a mountainous region. This research employed field survey data, soil-type maps, digital elevation model data, weather station data, and Landsat imagery, for extraction of potential variables. It used the random forest approach to identify eight key variables—slope, slope of slope, normalized difference greenness index at leaf-on season, soil organic matter, fractional vegetation at leaf-on season, fractional soil at leaf-off season, precipitation in June, and percent of soil clay—for mapping soil erosion risk distribution in hickory plantations in Western Zhejiang Province, China. The results showed that an overall accuracy of 89.8% was obtained for three levels of soil erosion risk. Approximately one-fourth of hickory plantations were at high-risk, requiring the owners or decision makers to take proper measures to reduce the soil erosion problem. This research provides a new approach to predict soil erosion risk, based on the primary variables that can be extracted directly from remotely-sensed data and ancillary data. This proposed approach will be valuable for other agroforestry and plantations, such as Torreya grandis, eucalyptus, and the rubber tree, that are playing important roles in improving economic conditions for the local farmers but face soil erosion problems.

Land suitability evaluation of shallot (Allium ascalonicum L.) at production centres in Losari District, Brebes

The demand for shallots is getting higher as the population grows. Indonesia targets to become a self-sufficient country of onion and the largest exporter of shallots in ASEAN by 2045. One of the shallot production centres is Losari District, Brebes, but the shallots productivity has decreased, so it is necessary to know the cause and the improvement effort to overcome it. The research was a land survey and evaluation to determine the current and the potential land suitability classes for the shallot. Data analysis using LMU (Land Map Unit) as the unit of analysis, which is the result of an overlay of soil type map, slope map and land use map using ArcGIS 10.3. The sampling method was purposive sampling and data analyzed using the matching method between the results of land characteristics data with the requirements of shallots growing. Results showed that even in production centres, the current suitability classes are marginally suitable (S3) as the heaviest limiting factors are very high rainfall. Improvement efforts to overcome this can be done by using suitable varieties, making gully drainage and using mulch/shade so that the potential land suitability class increases to be moderately suitable (S2).

Run-off\u2013erosion modelling and water balance in the Epit\xe1cio Pessoa Dam river basin, Para\xedba State in Brazil

Water scarcity and sediment yield scarcity are major environmental problems in the Brazilian semi-arid region that influence the quantity and quality of water used for water supply. Thus, the aim of the paper was to analyse the water balance and the sediment yield in the Epitácio Pessoa Dam river basin using the Soil and Water Assessment Tool model. Rainfall, streamflow, air temperature, air humidity data from 1970 to 1993, a soil type map, a land cover map, and a digital elevation model were used in this study. The model was calibrated and validated by comparing simulated mean monthly streamflow with observed long-term mean monthly streamflow for the Poço de Pedras and Caraúbas streamflow gauges after sediment yield values were estimated. The Soil and Water Assessment Tool model results indicated good performance by the model during the calibration, with an observed mean streamflow of 6.86 m3/s and a simulated streamflow of 5.68 m3/s for Poço de Pedras and 9.33 m3/s for Caraúbas. The mean sediment yield was 3.91 ton/ha/month. The results of the water balance analysis indicate a high rate of evapotranspiration in the basin (68% evapotranspiration), and 7% of the rainfall was converted to streamflow (5% streamflow and 2% base flow). Therefore, this study found that Soil and Water Assessment Tool could be effectively used for assessing the water balance components and sediment yield of the Epitácio Pessoa Dam river basin, Paraíba State, Brazil.

Land Suitability Evaluation for Upland Rice in Tirtomoyo District, Wonogiri Regency, Indonesia

Food cultivation, especially upland rice is needed to fulfill the needs of dryland food. It is necessary to evaluate the suitability of the land so that it can overcome land constraints to increase the productivity of upland rice in Tirtomoyo Regency. The unit of analysis is Soil Mapping Unit based on soil type map using ArcGIS 10.1 and determination of sample point based on purposive sampling method. Data analysis was done by matching between the result of soil characteristic which has been obtained with growth requirement of the upland rice. Based on the results, District Tirtomoyo divided into 4 Soil Mapping Unit. The actual land suitability class for upland rice is moderately suitable (S2) and not suitable (N). Limiting factors include rainfall, slope, erosion hazard, basic saturation, CEC, C-organic, N-total, K<sub>2</sub>O. Improvement efforts are done by arranging cropping pattern, drainage management, a making of terracing, cover crop planting, implementing organic material, and fertilizing. The suitability class of potential land of upland rice is highly suitable (S1) and marginally suitable (S3).

Application of light detection and ranging and ultrasonic sensors to high-throughput phenotyping and precision horticulture: current status and challenges

Ultrasonic and light detection and ranging (LiDAR) sensors have been some of the most deeply investigated sensing technologies within the scope of digital horticulture. They can accurately estimate geometrical and structural parameters of the tree canopies providing input information for high-throughput phenotyping and precision horticulture. A review was conducted in order to describe how these technologies evolved and identify the main investigated topics, applications, and key points for future investigations in horticulture science. Most research efforts have been focused on the development of data acquisition systems, data processing, and high-resolution 3D modeling to derive structural tree parameters such as canopy volume and leaf area. Reported applications of such sensors for precision horticulture were restricted to real-time variable-rate solutions where ultrasonic or LiDAR sensors were tested to adjust plant protection product or fertilizer dose rates according to the tree volume variability. More studies exploring other applications in site-specific management are encouraged; some that integrates canopy sensing data with other sources of information collected at the within-grove scale (e.g., digital elevation models, soil type maps, historical yield maps, etc.). Highly accurate 3D tree models derived from LiDAR scanning demonstrate their great potential for tree phenotyping. However, the technology has not been widely adopted by researchers to evaluate the performance of new plant varieties or the outcomes from different management practices. Commercial solutions for tree scanning of whole groves, orchards, and nurseries would promote such adoption and facilitate more applied research in plant phenotyping and precision horticulture.

EVALUASI KESESUAIAN LAHAN TANAMAN CABAI PIPER RETROFRACTERUM di KECAMATAN KAMANG MAGEK KABUPATEN AGAM

This research was conducted on Kamang Magek Subdistrict, Regency of Agam, in December 2016 aimed to get data and information about (1) Characteristic of land related to the requirement of growth of chilli plant (2) Land suitability of chilli area area in research area. The research includes descriptive research type, the sample is taken from the map of the unit of land form obtained from the overlay of landform map with slope map, soil type map, geological map, land use map. Data analysis techniques used to determine land characteristics and land suitability is the method of matching or matching each land characteristic. The results showed (1) The level of land suitability consisted of the corresponding level (S2) of three units of land. (2) Land suitability characteristics in the study area have varying slopes from flat (0-8%), ramps (8-14%), steep slopes (8-14%), steep slopes (25-40%), very steep (> 40%)., Clay. Soil pH ranges from 5.05 to 6.75. Permeability between 2.91-axis (infinity). Rainfall 1898,5 mm / yr. The dry season is 8 and the temperature is 210 C. It consists of 3707.51 ha of forest, mixed plantation with an area of ​​511.67 ha, the moor has an area of ​​624.48 ha, the bush has an area of ​​1877.44 ha, the rice field has an area of ​​1877 , 44 Ha and the settlement has an area of ​​369.54 Ha.

Evaluasi Kesesuaian Lahan Untuk Tanaman Kopi Arabika (Coffea Arabica) di Kecamatan Pollung Kabupaten Humbang Hasundutan

The aims of this study was to evaluate the suitability of land for Arabica coffee crops in Pollung District of Humbang Hasundutan Regency. There are sixteen land map units (SPL) determined based on the soil type map, slope map and altitude map resulting from topographic map with scale of 1: 50.000, then grounding on soil type map data, slope map, and altitude map (overlay). Assessment of land suitability class based on the criteria from Bogor Land Research Center. The land evaluation method is the matching method. The results showed that the highest potential land suitability class on Arabica coffee plant was SPL 7 very suitable (S1) and SPL 3, 4, 5, 8, 9, 10, 12, 15, 16 suitable with marginal condition with limit factor is rooting medium (S3rc)

Mapping of landslide hazards prediction using geographic information system in Solok District

Solok District is one of the areas prone to the landslide in West Sumatera Province. Generally, landslides are caused by natural and human factors. The aims of this study are to predict the location of the highest landslide hazard distribution in Solok District and to know the level of vulnerability of landslide hazards in Solok District. This study consists of preparatory steps, field survey, analysis and processing of the data based on 4 types of maps, i.e. rainfall, soil type, geological, and slope maps. These maps then scoring in 5 types of vulnerability levels. As the results of this study, it is known that the sub-districts are on the highest prediction of the landslide are Pantai Cermin, Lembah Gumanti, Hiliran Gumanti, Lake Kembar, Mount Talang, Payung Sekaki, Tigo Lurah, Bukit Sundi, Kubung, X Koto Singkarak and Junjung Sirih. The level of vulnerability prediction of landslide hazard in Solok District is divided into 5 levels, which is very low 44511,71 Ha with percentage of 11,91%, low of 69179,34 Ha with percentage 18,51%, while 89894.35 Ha with the percentage of 24.05%, height of 86307 Ha with the percentage of 23.09%, and very high 83907,60 Ha with the percentage of 22.45.

Spatial Characteristic of Coal Mining in Kutai Kartarnegara Regency, East Kalimantan Province

Coal mining activities in Kutai Kartanegara Regency conducted in an open way. Number IUP announced by the Directorate General of Mineral and Coal, Ministry of Energy and the results reconciliation of Mineral Resources IUP with the 210 status Clean and Clear (C & C). The purpose of the study is to identify the characteristics and patterns of coal mining in Kutai Kartanegara Regency based landform units in order to see the distribution pattern of its spread. The method used the construct maps of landforms unit in Kutai Kartanegara Regency derived from Satellite Imagery Landsat 7 ETM + in 2012, A sheet of study area Indonesia Map, Geological Map, Soil type and field surveys Map using ArcGIS 9.3 facilities. The results showed that the characteristic of the coal mining in Kutai Kartanegara Regency is implemented by way of an open mining. With the status of the production details 151 IUP (72 %) and the exploration 59 IUP (28 %). Condition of the land of post coal mining in some areas showed low implementation of the rules set by the government for land reclamation, thus causing in high environment such as erosion, flooding and landslides. Unit landform with majority in the coal mining activities is wavy tectonic cluster. The cause of the pattern of coal mining activity tend to cause factors of the position / location of relatively shallow or have undergone a process of outcrops to the surface between 0-30 meters, easy access from the mine to the port. The research result recommendations is conducted anticipation program from the dangers of impact that occurs as erosion and sedimentation, water quality and soil (land potential), The licensing selection strictly refer to the legislation and in depth learning to identify a variety of potential post-mining land to be developed on the post-mining unit of the shape according to the character of the land

Delineation of groundwater potential zones using remote sensing, GIS, and AHP technique in Tehran–Karaj plain, Iran

Evaluation of groundwater resources in dry areas without enough data is a challenging task in many parts of the world, including Tehran–Karaj plain in Iran, which includes Tehran, the capital city of Iran and Karaj, one of Iran’s biggest cities. Water demand due to increasing agricultural and industrial activities caused many problems in the field of water resources management. In this study, the potential of groundwater resources was evaluated using remote sensing, geographic information system (GIS), and analytic hierarchy process (AHP) for the first time. Digital Elevation Model from Shuttle Radar Topography Mission was used to generate a slope map and drainage density map. Three Landsat-8 satellite images were utilized to provide lineament density and land cover/land use maps. Geological and soil type maps were provided from the Geological Survey and Mineral Explorations of Iran (GSI). Tropical Rainfall Measuring Mission data were used to prepare average annual precipitation map. Discharge values from 102 pumping wells in the time period of 2002–2014 were used to evaluate the results. Seven data layers were prepared, and the geodatabase was made in GIS. The layers and their classes were assigned weights using AHP method. Finally, the layers were overlaid based on their weights, and the potential map of groundwater resources was generated. The area was classified into five zones with very high, high, moderate, low, and very low potentials. The zones covered 5.95, 32.90, 22.70, 10.20, and 28.25% of the study area, respectively. The results showed good agreement with the field data obtained from discharge wells.

Perhitungan Kecepatan Sedimentasi Melalui Pendekatan Usle dan Pengukuran Kandungan Tanah dalam Air Sungai yang Masuk ke dalam Waduk Sermo

Dam is one of the essential man-made buildings which was developed to various beneficialy purposes such as irrigation, fresh water supply, flooding and drying control, and also tourism. Due to those mentioned functions, condition of the dam has to be maintained continuously especially from sedimentation. Sedimentation is being a serious threat for the continuity of dam services. Protecting dam from sedimentation is not only managing dam area, but also we have to care all watershed area, because the sedimentation is caused by erotion on the area. In order to know the rate of the sedimentation within the dam, measurement and prediction must be done. One of methods to predict and measure the sedimentation is by analyzing geospatial data using USLE Approach, and analyzing suspended sediment in river’s water toward to the dam. By those both analysis, rate of sedimentation happened within the dam can be calculated. This paper try to use geospatial (GIS) based analysis to estimate the sedimentation rate using USLE approach within Ngrancah Watershed. The USLE Formula requires four types of maps, they are soil type, slope, land cover, and rain erosivity maps. Each of maps is classified to the specific standards, then will be analized by overlaying to another map. Another method will be used to estimate these dimentation rate is the suspended sediment measurement. This method was determined using sediment transport formula. The data used are samples of river water ing Ngerancah Watershed that was flow toward to the Sermo Dam, and daily volume of inflow water. Those resulted values, then were compared each other. Based on the calculation, sedimentation rate resulted using USLE Approach is 276.100,917 m3 per year or 8,675 mm thickness per year. While the calculation based on the measurement of suspended sediment in river’s water is 270.206,363 m3 per year or 8,490 mm thickness per year. The difference value between the both methods is 5894,555 m3 per year or 0,185 mm thickness per year. Based on the watershed monitoring guidelines published by The Ministry of Forestry of Indoensia, the Sermo Dam sedimentation rate is categorized in poor class, because the sedimentation rate is exceeding 5 mm per year, as the safe limit of dam sedimentation rate.

137Cs activity in Sweden after the Chernobyl Nuclear Power Plant accident in relation to quaternary geology and land use

After the Chernobyl Nuclear Power Plant accident 137Cs was deposited in Mid-Sweden, with the highest activity in Gävle municipality. We compared aerial measurements of 137Cs on the ground over time in Gävle municipality since 1986. Maps of soil types and land use were used to analyse the decrease in activity of 137Cs. A spatial pattern was identified where the reduction of activity was greater in sand than in organic soil. For land use the reduction was greater in urban areas than in forests, with agricultural land in between. Long-term external radiation from 137Cs depends not only on the physical decay of 137Cs but also indirectly on geology, and this should be considered when calculating external radiation doses to individuals in epidemiological studies.

Ecological water requirement of plant–soil systems along the Silk Road Economic Belt: A case study of the Guanzhong–Tianshui region, China

“The Belt and Road” refers to the Silk Road Economic Belt and the 21st‐Century Maritime Silk Road. In this paper, the Guanzhong–Tianshui region is selected as a case study, which is located at the starting point of the Silk Road Economic Belt. First, the spatial distribution maps of plant and soil types are obtained based on the TM remote sensing images and the soil texture data. The boundaries of the third‐level watershed are extracted based on the digital elevation model data. Then the corresponding mathematical models are used to evaluate the ecological water requirements of the plant–soil systems. Also, the spatial distribution characteristics are analysed at the landscape scale and the third‐level watershed scale. The results show that the spatial differences of ecological water requirement in the Guanzhong–Tianshui are obvious. At the plant–soil landscape scale, the ecological water requirement per unit area of the woodland‐clay loam is the highest, about 0.4777 m3/m2, while that of the grassland‐gravel loam is the lowest, about 0.2813 m3/m2. At the third‐level watershed scale, the ecological water requirement per unit area in the Weihe watershed (Jinghezhangjiashan above) is the highest, about 0.4123 m3/m2, while that in the Weihe watershed (Longmen to Sanmenxia) is the lowest, about 0.3002 m3/m2. The study offers scientific references for the regional ecological environment protection and ecosystem management.

Soil depth spatial prediction by fuzzy soil-landscape model

Soil depth is a soil property that influences land use, land suitability, and earth surface processes. This article presents a simple method for predicting soil depth by constructing a membership function based on fuzzy C-means. This paper incorporates the soil type map, the land use map, and one type of DEM data to construct a soil-landscape model for soil depth prediction. It compares a fuzzy C-means classifier that includes expert judgment with a conditional autoregressive (CAR) model. Prediction efficiency was evaluated in the Three Gorges area of China using the root-mean-square error (RMSE) and the agreement coefficient (AC) of predictions at validation points. The prediction stability of soil depth values from the fuzzy model is close to the regression model; the AC value indicates a better agreement by the fuzzy C-means method (0.428) than when using the regression model (0.420). The purposive sampling approach was provided by our method by the centroid where the fuzzy membership value is above 0.85, which improves the efficiency of the field sampling. The expansibility of our method is limited as the typical centroid sample location is dependent on the study area. The fuzzy membership value must be recalculated to provide a new typical centroid for field sample when enlarging the study area. The results indicate that the soil-landscape model constructed by the fuzzy membership value with fuzzy C-means method and the conventional soil map provides better quality soil depth spatial information on soil depth.