Occurrence Of Land Subsidence Research Articles

Assessments of Land Subsidence in the Tehran Metropolitan Using Satellite Radar Interferometry Technique

Background and objective Many cities in the world have land subsidence problems because of environmental issues related to urban development. The arid and semi-arid climatic conditions prevailing in most of the interior regions of Iran and the need for the increasing industrial, agricultural, and drinking water exploitation from underground water resources, as well as urban development, have increased the occurrence of land subsidence in Iran, especially in the metropolis of Tehran. This study aims to assess land subsidence in Tehran, Iran, using the satellite radar interferometry (InSAR) technique. Method In this research, 31 images of Sentinel-1 were processed using the time series of persistent scatter interferometry (PSI) in 2022, and a map of the average annual rate of land subsidence in Tehran metropolis was prepared. Finally, after validating the results of interferometry with GPS station observations, the relationship between land subsidence and exploitation of underground water resources was examined as the most important factor in ground surface changes in the study area. Results The findings showed a decreasing trend in land subsidence from plain to urban areas. The highest land subsidence, with a rate of -43 mm per year occurred in the southern and southwestern parts of Tehran. Districts 10, 11, 12, 16, 17, 18, 19, and 20, which comprise about 26% of Tehran’s population, were experiencing land subsidence. The drop in the water level of observation wells was considerable in the areas where the highest rate of land subsidence occurred. Another finding of the research was the decrease of the underground water level from the north to the south of Tehran, indicating that the water depth in the southern areas of Tehran decreased due to human activities such as water pumping. Conclusion There is an increasing pressure in the aquifer through pumping water from wells in the study area for various industrial, agricultural and drinking water uses which has led to the increase in the occurrence of land subsidence.

The Community’s Understanding and Responses Regarding Land Subsidence, Waterlogging, and the Link Between the Two in Rural South-western Coastal Bangladesh

Land subsidence has triggered severe waterlogging problems in the southwestern coastal zone of Bangladesh, which affects the biodiversity as well as people’s lives, and livelihoods. The members of the affected community, however, appear to have a poor understanding of the nature of land subsidence and its consequences. This study, therefore, aims to assess the community members’ understanding of as well as the actions that they take to solve problems of this nature in the rural, southwestern coastal zone of Bangladesh. A qualitative comparative case study approach was employed in this study, where two rural communities from the southwestern coastal districts were selected as the cases. By subjecting the data to thematic analysis, the study found that, although a few civil society members and activists are, to some extent, aware of the occurrence of land subsidence and its linkage with waterlogging, however, most of the members of the communities lack adequate knowledge or an understanding about the nature, causes and consequences of the land subsidence issue and its connection to the waterlogging problem in their locality. Thus, it was found that they take no or very few measures to cope with the risk of land subsidence. The study’s findings imply that the policymakers should formulate a strategy for making the members of the community aware of the nature, causes, and consequences of land subsidence issues.

Impact of mining-induced seismicity on land subsidence occurrence

Mining-induced seismicity can damage buildings and surface infrastructure and cause fatalities. It is a growing concern, owing to the sudden occurrence of seismic events, lack of effective prediction capabilities, and associated consequences. In this study, we analyzed 13 high-energy mining-induced earthquakes from 2016 to 2020 in Poland's Legnica-Glogow Copper District (LGCD), based on data recorded by the Induced Seismicity-European Plate Observing System (IS-EPOS). We used European Space Agency (ESA) Sentinel-1 Copernicus satellite radar images, to study the co-seismic subsidence in the region. Additionally, we employed volumetric point source approximation and a Bayesian inverse modeling scheme to estimate the location and strength of subsurface collapses from the land subsidence data. Finally, we correlated the geological constraints with the land subsidence and earthquake source parameters. The interferometric synthetic aperture radar (InSAR) displacement maps portrayed maximum line-of-sight (LOS) displacements of −144 mm and − 124 mm in ascending and descending images, respectively, with maximum land subsidence reaching −142 mm. Notably, only a few earthquakes with large magnitudes caused land subsidence. There was a significant correlation between earthquake magnitude and land subsidence; the greater the thickness of the loose Quaternary strata, the smaller the land subsidence. According to the inversion results, the focal depths of the collapses associated with the earthquakes were 437–669 m. However, the estimated collapse depths were situated above the mining exploitation fields, within the rigid Triassic rock layers. The associated collapse energy was 1.62 times greater than the seismic energy, indicating aseismic deformation in the field. Additionally, we observed spatial discrepancy between the location of the earthquake epicenters and the maximum land subsidence. Thus, our study can improve the current understanding of the impact of mining-induced seismicity, the occurrence of associated land subsidence, and seismic mechanisms in mining areas.

Rainwater Storage Engineering based on Water-Sensitive Urban Design in Lapangan Pancasila, Semarang City

Lapangan Pancasila is a public open space that located in Jln. Seroja Dalam III no. 9 Semarang City. Flooding is often occurs at Lapangan Pancasila in rainy season. Floods in Semarang City are caused by the occurrence of land subsidence and water catchment area decreases. Rainwater harvesting system with water sensitive urban design(WSUD) basic, is one of plenty solution that can be applied to reduces flooding at Lapangan Pancasila. The research was conducted using a descriptive methodology which refers to the spatial and ecological approach. A spatial approach is used to determine the physical condition of the site, while an ecological approach is used to determine the components required for engineering rainwater storage. Based on the calculations that have been carried out, the discharge from the calculation of the planned rainfall is 0.003886 m3/s. Rainwater collection engineering at Lapangan Pancasila was built as a complex system that combines various components of rainwater treatment such as rainwater catchment areas, macro water filtration tanks, sand filter tanks to filter mud and purify water, clean water reservoirs, sprinkle landscape irrigation systems, and infiltration wells.

Measuring the Vulnerability of the Urban Fabric in the Face of Land Subsidence (Case Study: District 17 of Tehran)

Urban vulnerability is the probability of damage to cities and urban infrastructures against natural and unnatural events. In this regard, in the last half century, land subsidence has involved many countries as a potential risk for urban, industrial and agricultural areas. With the occurrence of land subsidence, the physical and structural characteristics of the structures built in the city are changed and show different behavior. For this reason, it is important to consider the effect of land subsidence on the urban fabric in which there are exposed and buried structures. The involvement of the 17th district of Tehran with the issue of land subsidence was the initial idea of the current research. Currently, the maximum land subsidence rate in this area is 25 cm per year. The present research has been carried out in the form of spatial studies and by implementing the analytical model in four steps. The results of the model implementation showed that the urban fabric of the 17th district is prone to high vulnerability due to features such as high population and building density, the presence of worn-out fabric, buildings with low structural strength and very low construction quality of buildings. In total, about 657 hectares (80 percent) of the built-up lands in the 17th district of Tehran are under the influence of land subsidence.

IDENTIFICATION OF THE HARD LAYER USING WENNER CONFIGURATION RESISTIVITY METHOD (CASE STUDY: JALAN SAMBOJA – SEPAKU)

Samboja – Sepaku road is a land transportation route that can be used from the cities of Balikpapan and Samarinda to the new capital city. There is a problem with this road. Namely cracks appear on several roads due to subsidence. This is because the layer of soil that supports this road is thick and has young sediment. The hilly topography and steep ravines that dominate this road area also contributed to the subsidence. Efforts that can be made to deal with the occurrence of land subsidence are geotechnical engineering, such as making siring. In the construction process, the siring foundation must be planted in a dense layer of soil that is not easily shifted or unstable, which is also known as a hard layer. Determining the position of the hard layer can be done by identifying the subsurface stratigraphy using the resistivity method. The results of the subsurface lithology depiction obtained two types of soil layers that dominate the roadside area, namely clay layers with resistivity values of 2.31 Ωm – 15.1 Ωm and sandy clays with resistivity values of 38.7 – 253 Ωm. The clay layer is the recommended layer as a hard layer at a depth of 15-20 meters.

Investigation of Ground Deformation around The Segments of Kendeng Fault in East Java 2017-2020 using Multi-Temporal InSAR Analysis with GACOS Correction Product

Multi-Temporal Interferometric SAR (MT-InSAR) analysis technique can provide spatially continuous measurements of the ground deformation and monitoring caused by the movement of four segments in the Kendeng Fault, East Java. Most ground deformation in these segments is indicated by the dominance of local thrust movements, folds, and the seismic density of earthquakes. In this study, ground deformation detection was carried out using the Small Baseline Subset Algorithm in the MT-InSAR process with the tropospheric correction from GACOS to determine ground deformation during 2017-2020. The percentage of change in the deformation velocity value resulting from applying the GACOS correction is up to 33.8% compared to without the tropospheric correction. The most significant troposphere effect correction is the area around the Cepu segments, which are dominated by high elevation thrust and folds. The results of the mean LOS velocity around the southern segments of Cepu, Waru, and Surabaya based on the Sentinel 1A SAR represent the occurrence of land subsidence in the south part of the area around segments with values ranging from 3.0 mm/yr to 6.0 mm/yr. Thus, the deformation effect causes land subsidence in the area around the delineation of the northern fault segment up to -3.0 mm/yr.

The effect of land subsidence on hydrodynamic conditions in Pekalongan coast

Due to land subsidence at Pekalongan, some areas at Pekalongan coast submerged at a rate up to 10 cm/year. This study was conducted to examine the effect of land subsidence on the hydrodynamic conditions in Pekalongan through a numerical model simulation using Delft3D. There are 2 scenarios for the numerical model, scenario 1 in 2016 and scenario 2 in 2021 after the occurrence of land subsidence at a rate of 10 cm/year. Model calibration was carried out on water level elevation and current velocity by comparing the simulation data and field data based on the variation of the Chezy number. The calibrated Chezy number parameter was 60 m0.5/s. The sensitivity test is carried out by changing the input parameters such as water level elevation, river discharge, and wave height. The sensitivity test results shows that the most sensitive parameter is wave height. The comparison of the simulation results of the two scenarios shows that the current velocity decreased by about 0.05 m/s to 0.1 m/s and the wave height increased by about 0.05 meters to 0.15 meters after land subsidence occurred. Land subsidence causes the waters in the study area to become deeper, and the results of the study show that current velocity tends to decrease and wave height tends to increase because of the land subsidence.

Numerical modelling of land subsidence effect on coastal sediment transport in Pekalongan

This study examines the condition of sediment transport on the Pekalongan coast by a numerical model computation using the Delft3D Flow module. The research was started by collecting and analysing field data both primary and secondary. Thus, the hydrodynamic and sediment transport model are then calculated in two scenarios which are representing the conditions before (2016) and after (2021) land subsidence by assuming a land subsidence of 10 cm/year. The numerical model is then calibrated and verified on the data of tidal water level elevation and current velocity, the best results are obtained at a chezy number of 60 m0.5/s, and sensitivity tests are carried out on changes in sediment grain size, wave height and wave direction in order to determine the characteristics of the numerical model. The sensitivity analysis of sediment grain size is the most sensitive effect to sediment transport characteristic. The results of the numerical model are then compared based on the scenarios before (2016) and after the occurrence of land subsidence (2021). The results indicate that after land subsidence, the sedimentation rate is increasing by 56.34%, whereas the erosion rate is decreasing by 3.98% after one neap-spring tidal cycle (around 15 days) in the study area.

Influence of Groundwater Heat Pump system operation on geological environment by Hydro-Thermal–Mechanical–Chemical numerical model

Groundwater Heat Pump (GWHP) systems have gained attention for space heating and cooling due to its efficiency and low installation costs. It is known that thermal transfixion and land subsidence are main geological environmental hazards in the application of GWHP. But few studies paid attention to groundwater quality. In this research, a three-dimensional Hydro-Thermal–Mechanical–Chemical numerical model was established based on Biot’s consolidation theory, solute and heat transport in porous media theory. The numerical model could evaluate geological environment from four aspects: hydraulic head, temperature, groundwater quality, and land subsidence. The coupling effect of building load and extraction–injection groundwater is considered to study land subsidence. The model is applied to a GWHP in Nantong, China. The results show that increasing the temperature change and decreasing the circulation ratio of GWHP will alleviate thermal accumulation, thermal transfixion, and freshwater salinization of the confined aquifer III. But it will aggravate the occurrence of land subsidence. The geological environment involves four factors. The development of shallow geothermal energy should be considered comprehensively. Optimizing operation scheme by changing the groundwater seepage field would alleviate geological environment deterioration.

Monitoring land subsidence induced by groundwater change using satellite gravimetry and radar interferometry measurements. Case study: Surabaya city, Indonesia

Land subsidence is considered a potential hazard often occurring in densely populated urban areas due to increasing freshwater demands from groundwater pumping. The Gravity Recovery and Climate Experiment (GRACE) satellite gravimetry combined with Sentinel 1 interferometric satellite radar measurement has provided the possibility to monitor land subsidence induced by groundwater change. This study monitored land subsidence induced by groundwater change through satellite observations over Surabaya City, Indonesia, from 2014 to 2019. Persistent Scattered InSAR (PSInSAR) measurement was used to monitor land subsidence by using 114 SLC pairs. As for the groundwater perspective, Global Land Data Assimilation System (GLDAS v.2.2), which contains the Groundwater Storage Anomaly (GWS) derived from GRACE satellite observation, was used to understand groundwater’s spatial and temporal variation. The results show a satisfactory agreement of satellite radar measurement with ground measurement (R = 0.96, RMSE = 4.92cm), while satellite gravimetry measurement showed reasonably good agreement with radar measurement as well (R = 0.25). Regarding the magnitude and occurrence of land subsidence over Surabaya City, the result shows that, over the past 5 years, the southern part of the city had the highest subsidence ranging from -10 mm/year to -40 mm/year. Therefore, the results conclude the capability of both satellite gravimetry and radar measurements to monitor land subsidence over an urban area. Thus, this information could be considered as an important decision-making process for disaster management purposes.

Using DInSAR to map ground deformation on road infrastructure (case study: North Buton, Southeast Sulawesi)

The mapping of ground deformation is an essential activity in the context of disaster mitigation. Road networks which susceptible to landslides due to soil surface instability need to be mapped as initial information for regular monitoring and maintenance activities. This information is also vital for the community to increase its capacity and preparedness in facing landslides. This study aims to map ground deformation on road infrastructure in North Buton regency, Southeast Sulawesi Province. We applied Differential Interferometric Synthetic Aperture Radar (DInSAR) method based on four Sentinel-1 single look complex (SLC) images from the 2019 and 2020 acquisition. Data processing includes the SLC co-registration, interferogram formation, phase unwrapping, and geocoding. From the research, we obtained the occurrence of land subsidence and uplift area in the study location. The land subsidence occurred -64 mm to -129 mm per year and uplift up to +65 mm per year. Conditions in the field obtained through direct surveys found landslides and cracks in the road body. From geology map analysis, the ground deformation probably influenced by the fault activity near the study location.

Monitoring and analysis of land subsidence in modern Yellow River Delta using SBAS-InSAR Technology

Modern Yellow River Delta has become one of the areas with serious land subsidence disaster in the plain area of Shandong Province. In this paper, Small Baseline Subsets - Interferometry Synthetic Aperture Radar (SBAS-InSAR) technology was used to process the Sentinel-1A data from August 2018 to October 2019 in the modern Yellow River Delta, in order to obtain the range and rate of land subsidence in the study area. At the same time, use the Leveling results of the same period to verify the accuracy. By selecting four larger land subsidence rate as feature points to analyze the characteristics of surface time series deformation, the influencing factors of land subsidence in this area are found out. The results show that during the past 2018-2019 years, the land subsidence in the the Yellow River Delta area was mainly distributed in Xianhe Town, southern the Huanghekou Town, Hubin Town, Guangrao County and its surrounding areas, DaWang Town, Yingli Town, Yangkou Town and the western part of Binhai Township, the most serious subsidence area is located in Xianhe Town, with an annual settlement rate of -204.7 mm/a. The land subsidence in the Yellow River Delta is mainly affected by groundwater overdraft, and the distribution characteristics of land subsidence funnel and deep groundwater depression funnel are basically consistent. In addition, natural factors such as consolidation of Quaternary loose sediments and regional tectonic movement also exacerbate the occurrence of land subsidence.

LAND SUBSIDENCE ANALYSIS OBSERVED BY PS-INSAR METHOD IN SOUTHERN PART OF BALI, INDONESIA (A CASE STUDY OF DENPASAR AND BADUNG AREA)

The utilization of groundwater unwise leads to problems for the life of sentient beings. The majority of environmental damage, mainly by groundwater utilization, is done or caused by human activities. The land subsidence, drought, seawater intrusion are some examples of damage caused by groundwater utilization unwise. This research aims to estimate land subsidence in southern Bali and analyze groundwater level reduction with land subsidence. The PS-InSAR technique to monitor land subsidence has been carried out in several regions in Indonesia and other countries. In this study, 38 images of Sentinel-1 taken from February 2015 to December 2018 are used to analyze the PS-InSAR technique. Land subsidence is found in Denpasar Utara district and Kerobokan district with deformation in -8 mm to -19 mm and velocity up to -5 mm/year. The utilization of groundwater causing land subsidence in Southern Bali is no significant relationship with coefficient correlation 0,16 and influenced only 2,7%. Limited groundwater data also influences the correlation between groundwater utilization and the occurrence of land subsidence.
 Keywords: Land Subsidence; Sentinel-1A; PS-InSAR; Southern Bali.

Contribution of SAR-driven displacement measurement in assessing the triggering factors of rainfall-induced landslides

Monitoring of landslides by computing the displacements gain importance in recent studies due to the accuracy in its measurements. Kerala-Karnataka landslides of August 2018, has led to severe loss of life and damages to both states. The study emphasizes the contribution of three major landslide-driving factors viz., rainfall intensity, land-use/land-cover and slope, towards the occurrence of land-subsidence, thereby to figure the crucial bounds of each causative factor that have induced landslides in the Idukki and Kodagu districts. The results identify and enunciate the vulnerable land-cover as the plantations and fallow/barren lands; the crucial rainfall intensity as 600 mm in Idukki and 1200 mm in Kodagu; and the critical slope angle as 20° to 35°, that are highly liable in triggering landslides. Identification of the crucial bounds in each causative factor of landslides aid in supporting the city planners and disaster management authorities to decide proper mitigation measures.

Land-subsidence susceptibility zonation using remote sensing, GIS, and probability models in a Google Earth Engine platform

Land subsidence causes many problems, including faulting of Earth's surface, damage irrigation systems, reduced soil fertility, misalignment and failure of the walls of wells, changes of river courses and roadways, and even damages in residential areas and agricultural lands. This study assesses groundwater changes using the Google Earth Engine (GEE) and land-subsidence susceptibility (LSS) on the Gharabolagh Plain in Fars Province, Iran, using two probabilistic models, evidential belief function (EBF) and Bayesian theory (BT). In extensive field surveys, the land-subsidence points identified in the study area were recorded by handheld GPS. A land-subsidence location map (LSIM) was prepared in ArcGIS 10.6.1. The sites were divided into two sets: 70% of the subsidence points locations to be used for modeling (calibration) and 30% to be used for testing (validation) of the models. Effective factors that promote land-subsidence occurrence (LSO) were selected and maps for each were prepared from several sources—topographical and geological maps, and satellite images. Changing groundwater level was determined from the GEE platform using GRACE satellite images from a 14-year period. Three methods—CSR (Center for Space Research at the University of Texas), JPL (Jet Propulsion Laboratory), and GFZ (German Research Centre for Geosciences)—were employed and show that the greatest changes in water depth in the study area are equal to − 16.55, − 17.77, and − 15.09 cm from CSR, GFZ, and JPL, respectively. The spatial relationships between land subsidence and the ten effective factors were assessed using the EBF algorithm and BT. Also, analysis of variables importance was done using the random forest model. Prioritizing these factors, it was revealed that excessive withdrawal of groundwater, elevation, and distance from rivers were the most important variables promoting subsidence. Finally, the LSS maps were prepared in GIS. The validation analysis of the two probability models by ROC curve revealed that EBF had 93.2% accuracy and BT was 99.8% accurate. The maps generated with both models can effectively indicate LSS for managers of groundwater and can be used to prevent fatalities, financial losses, and damage to property caused by this phenomenon.

A comparative study of land subsidence susceptibility mapping of Tasuj plane, Iran, using boosted regression tree, random forest and classification and regression tree methods

Land subsidence occurrence in the Tasuj plane is becoming more frequent and hazardous in the near future due to the water crisis. To mitigate damage caused by land subsidence events, it is necessary to determine the susceptible or prone areas. This study focuses on producing and comparing land subsidence susceptibility map (LSSM) using boosted regression tree (BRT), random forest (RF), and classification and regression tree (CART) approaches with twelve influencing variables, namely altitude, slope angle, aspect, groundwater level, groundwater level change, land cover, lithology, distance to fault, distance to stream, stream power index, topographic wetness index, and plan curvature. Moreover, by implementing the Relief-F feature selection method, the most important variables in LSSM procedure were identified. The performance of the adopted methods was assessed using the area under the receiver operating characteristics curve (AUROC) and statistical evaluation indexes. The results showed that all the employed methods performed well; in particular, the BRT model (AUROC = 0.819) yielded higher prediction accuracy than RF (AUROC = 0.798) and CART (AUROC = 0.764). Findings of this study can assist in characterizing and mitigating the related hazard of land subsidence events.

Hydrogeochemical processes controlling the mobilization and enrichment of fluoride in groundwater of the North China Plain

Fluoride enrichment in groundwater at the North China Plain (NCP) is posing a potential health risk to human being. To better understand the enrichment mechanism of fluoride in the groundwater systems, the groundwater, sediments samples and pore water compacted from clayey sediments were collected to perform the chemistry analysis and geochemical inverse modeling. The results showed that fluoride concentration in groundwater from the NCP has a range of 0.38–7.35 mg/L, and 67.8% of groundwater samples have the fluoride concentration higher than 1.5 mg/L. High fluoride groundwater was mainly distributed in the central plain and coastal area of the NCP, and characterized by the Na-HCO3 or Na-Cl type water, lower Ca and higher TDS concentrations. Along groundwater flow-path from the mountainous to coastal areas, several hydrogeochemical processes control the mobilization and enrichment of fluoride in groundwater, including cation exchange between Ca and Na on the surface of clay minerals, precipitation/dissolution of carbonates, dissolution of fluorite, marine transgressions, and release of pore water trapped in clayey sediments caused by land subsidence. The fluoride concentrations in the pore water compacted from the sediments ranged from 2.92 to 4.48 mg/L. At the central plain and coastal area, the wide occurrence of land subsidence resulted from the groundwater over-exploration leads to the release of pore water rich in fluoride into surrounding aquifers, thereby elevating the concentration of groundwater fluoride. The resulted groundwater environment with high salinity and some newly-introduced ions, such as Mg, promote the dissolution of fluorite, which was under-saturated in the groundwater samples from the NCP, further enhancing the fluoride enrichment in the groundwater at the coastal area. The findings of this study will provide new insights on the generation of high fluoride groundwater.

Application of Time Series InSAR (SBAS) Method using Sentinel-1A Data for Land Subsidence Detection in Surabaya City

We studied land subsidence occurrence in Surabaya, considering the rapid urban growth in the city. It is evidenced by the increasing number of buildings (e.g., houses, apartments, offices) that have been realized before 2015 and the increasing transport activities in the industrial area. Land subsidence is a vertical deformation on the land surface that can be caused by landslides, earthquakes, soil consolidation process, or even human-made activities, depending on the material characteristics of the area. In this study, Time-series InSAR (TS-InSAR), specifically the Small Baseline Subset (SBAS) method, is applied to obtain the Line-of-Sight (LOS) velocities and time-series LOS displacements in Surabaya between May 2015 and September 2017. We used 28 Sentinel-1A data (IW mode) acquired by using Terrain Observation with Progressive Scan (TOPS) operation with the spatial resolution of 5 ´ 20 m and covers the area of 250 km2. DEM SRTM with 30 m spatial resolution was used to reduce topography effect contribution in the interferograms. Based on the SBAS method, interferogram pair selection is applied with the maximum value of 150 m for the perpendicular baseline and 100 days for the temporal baseline. The DInSAR process successfully generated seventy-four (74) interferogram pairs, and then by using SBAS algorithm, the LOS velocity and time-series LOS displacement were estimated. The results showed the varying displacements respond with the significant subsidence occurred in the North, East, and Southeast part of Surabaya. The SBAS result confirmed that the LOS velocity over the Surabaya area between May 2015 and September 2017 ranges from -40 to +30 mm/year. Significant land subsidence occurred in the Asemrowo area (North Surabaya) with the value of LOS displacement velocity up to -45 mm/yr.

Modeling the Influence of Groundwater Exploitation on Land Subsidence Susceptibility Using Machine Learning Algorithms

Groundwater over-exploitation in arid and semiarid environments has led to many land subsidence cases. Immense economic losses incurred from land subsidence occurrences prompted many scientists to model this phenomenon. To this end, we used three machine learning models, boosted regression trees (BRTs), generalized additive model (GAM), and random forest (RF), together with four anthropological and geo-environmental predictors, to produce a spatial prediction map across land subsidence-prone area in the south of Iran. The inventory map and preparatory thematic layers were generated through extensive field surveys, using Google Earth images, local information, and organizational archives. The results revealed that the GAM significantly out-performs the BRT in terms of high goodness of fit (84.3% vs. 80.2%) and predictive power (81.6% vs. 70.1%). The RF model, as a benchmark model, showed slightly higher goodness of fit (85.45%) compared to the GAM; however, its prediction power was evidently lower than the GAM. Hence, the GAM was found as the best susceptibility model in the study area. According to the relative contribution test, the drawdown of groundwater level with 77.5% contribution was found to be the main causative predictor of land subsidence occurrence, followed by lithology (19.2%), distance from streams (2.5%), and altitude (0.8%). The results of the GAM suggest that almost 31.6% of the study area is highly susceptible zone to land subsidence occurrence, which can be of interest for further pragmatic actions.