Occurrence Of Land Subsidence Research Articles

Prioritization of effective factors in the occurrence of land subsidence and its susceptibility mapping using an SVM model and their different kernel functions

This study attempted to map land subsidence susceptibility using a support vector machine (SVM) model and their different kernel functions in Kerman province, Iran. Initially, land subsidence locations were recognized using extensive field surveys and Google Earth images and, subsequently, a land subsidence distribution map was created in a GIS environment. Then, different effective factors in the occurrence of land subsidence in the study area including percentage slope, slope aspect, altitude, profile curvature, plan curvature, topographic wetness index (TWI), distance from river, lithological units, piezometric changes, land use and normalized difference vegetation index (NDVI) were selected as independent variables for the modeling process. Land subsidence susceptibility maps in the study area were produced using an SVM model and different kernel functions related to it such as linear, polynomial, sigmoid and radial basis functions. The results of model validation using 30% of the unused locations in the modeling process and receiver operating characteristic (ROC) showed that the maps of land subsidence susceptibility obtained from the SVM technique and kernel functions had the highest accuracy with AUC values of 0.894 to 0.857. According to the results of prioritization of effective factors, piezometric data (utilization of groundwater), NDVI and altitude were the most significant factors affecting the occurrence of land subsidence in Kerman province. Therefore, the results of spatial modeling of land subsidence and their susceptibility maps have a key role in the planning of land allocation and water resource management in the study area.

Land Subsidence Analysis of Reclaimed Land using Time-Lapse Microgravity Anomaly in Manado, Indonesia

Coastal area land reclamation is a policy with various benefits, including its potential to increase economic growth. However, reclamation also potentially has adverse impacts on the environment, including increasing pressure on biodiversity, natural resources and natural ecosystems, and the most common problem is land subsidence. This study uses time-lapse microgravity anomaly to ascertain the distribution of gravity and vertical gradient anomaly in order to map the subsidence characteristics occurring in the Manado reclamation area. From the research that has been previously conducted, the positive gravity anomaly is spread around Megamall-Multimart to the north of Monaco Bay and on the southern side of Manado Town Square (Mantos). Positive anomaly values range from 3 to 29.7 μGal. The negative anomaly values are scattered around the Mantos and Megamas separating bridge and at some points around the Whiz Prime Hotel, Menora Church and towards the Pohon Kasih Megamas area. The reclaimed areas generally experience subsidence accompanied by a reduction in groundwater mass (Megamall and Mantos) due to the use of the groundwater by the community in these areas. Uplifts also occur at some points in the reclamation area of Megamas as a result of the occurrence of land subsidence. Longer-term research is needed to determine whether there is an increase in the rate of land subsidence in the Manado reclamation area. Over a longer period of time it can also be established whether there are other factors which affect land subsidence. Other geodetic methods to monitor subsidence, such as levelling, InSAR and GPS survey, which have been conducted in other locations, are also needed to obtain more detailed information about the land subsidence in this area.

INSIGHT ANALYSIS ON DYKE PROTECTION AGAINST LAND SUBSIDENCE AND THE SEA LEVEL RISE AROUND NORTHERN COAST OF JAVA (PANTURA) INDONESIA

Land subsidence and the sea level rise is newly well known phenomenon around northern coast of Java Indonesia (PANTURA). The occurrence of land subsidence at least recognize at the first of the city or urban area development, while the sea level rise was recognize from several last decades corresponds to the global warming. Following the both phenomena, tidal inundation (in Javanese they call it “Rob”) is now becoming another newly well known phenomenon along PANTURA. In the recent years the tidal inundation comes not only at a high tide but even at the regular tide in some area. Sea level rise and the land subsidence are considered as the causes deriving the occurrence of tidal inundation. Dykes have been built against tidal inundation around PANTURA (e.g. in Jakarta, Blanakan, Pekalongan, Semarang, and Demak). Nevertheless, since the land subsidence and the sea level rise are believed to be continuing through times, insight analysis on these dykes “protector” is necessary. How long the dyke would effectively protect the land area would be highlight in this paper.

PERTAMBAHAN ESTIMASI KERUGIAN EKONOMI AKIBAT BANJIR DENGAN PENGARUH PENURUNAN TANAH DI JAKARTA

The land subsidences contributed to the widespread inundation of floods that occured in Jakarta. The purpose of this study is to calculate the increase in estimated economic losses due to floods that are affected by land subsidence. The main data used in this research is a Jakarta’s flood map. Calculation of loss estimation is done by combining flood map with land use map, and then adjusted to economic exposure value. This calculation is made with the assumption that there is no dynamics changes in the study area except the topography. The result of the calculation study shows that between 2007 to 2027 predicted that there will be an increase in economic loss of 15 T, from 21 T to become 36 T economic losses in 2027. It is necessary to take precautionary measures to reduce the occurrence of land subsidence in order to reduce the amount of economic losses due to the flood disaster.

Detection of Land Subsidence in Kathmandu Valley, Nepal, Using DInSAR Technique

Differential Synthetic Aperture Radar Interferometry (DInSAR) is a remote sensing technique that is capable of detecting land surface deformation with centimeter accuracy. In this research, this technique was applied to two pairs of Advanced Land Observing Satellite (ALOS) Phased Array L-band SAR (PALSAR) data to detect land subsidence in the Kathmandu valley from 2007 to 2010. The result revealed several subsidence areas towards the center of the valley ranging from a maximum of 9.9 km2 to a minimum of 1 km2 coverage with a maximum velocity of 4.8 cm/year, and a minimum velocity of 1.1 cm/year, respectively. The majority of the subsidence was observed in old settlement areas with mixed use development. The subsidence depth was found to gradually increase from the periphery towards the center in almost all detected subsidence areas. The subsidence depth was found to be in a range of 1 cm to 17 cm. It was found that the concentration of deep water extraction wells was higher in areas with higher subsidence rates. It was also found that the detected subsidence area was situated over geological formations mainly consisting of unconsolidated fine-grained sediments (silica, sand, silt, clay and silty sandy gravel), which is the major factor affecting the occurrence of land subsidence due to groundwater extraction.

Risk Assessment of Land Subsidence in Kathmandu Valley, Nepal, Using Remote Sensing and GIS

Land subsidence is identified as a global problem and intensive studies are being conducted worldwide to detect and monitor risk of this problem. Risk assessment of land subsidence is simply an evaluation of the probability and frequency of occurrence of land subsidence, exposure of people and property to the subsidence and consequence of that exposure. Remote sensing technology was used to extract information of land subsidence in Kathmandu Valley, Nepal. Also, Disaster Risk Index method and Analytic Hierarchy Process (AHP) along with Geographic Information System (GIS) tools were used to assess risk of land subsidence in Kathmandu Valley, Nepal. Subsidence volume for locations Central Kathmandu, Chauni, Lalitpur, Imadol, Thimi, Madhyaour Thimi, New Baneshwor, Koteshwor and Gothatar was calculated using a simple mathematical formula. The subsidence depth for these locations was found to be in a range of 1 cm to 17 cm and the maximum subsidence velocity was found to be 4.8 cm/yr. This study revealed that the location where maximum subsidence was observed (i.e. Central Kathmandu and Lalitpur) was found to be at high risk of experiencing land subsidence induced damage. Other location where subsidence was observed was found to be at medium risk and the rest of the Kathmandu valley was found to be at low risk with current data situation. This study can be considered as the first step towards other comprehensive study relating to land subsidence risk assessment. The outcome of this research provides a basic understanding of the current situation that can further assist in developing prevention and risk management techniques.

Spatial and temporal changes in flood hazard potential at coastal lowland area: a case study in the Kujukuri Plain, Japan

The spatial–temporal change in flood hazard potential in the coastal lowland area was analyzed in the Kujukuri Plain, Japan, where widespread occurrence of land subsidence, the expansion of urban area, and the change in land cover have been reported. The data on flood hazard potential factors (river system, elevation, depression area, ratio of impermeable area, detention ponds, and precipitation) at three different periods, i.e., 1970, 2004, and 2013, were integrated by using geographic information system. Main data sources used are airborne laser scanning data, leveling data, Landsat TM data, river watershed maps, and precipitation data from precipitation observation stations and radar precipitation data. The flood hazard assessment maps for each time were obtained by using an algorithm that combines the flood hazard potential factors with weighted linear combinations based on multicriteria decision analysis technique. By comparing each factor layer map and flood hazard condition maps of different periods, it was found that the changes in different factors were quite variable during different periods with different spatial distributions. From year 1970 to year 2004, most of the areas where flood hazard potential was increased were concentrated in the central and northeastern part of the study area. During the period from year 2004 to year 2013, the areas where flood hazard potential was increased moved to the north and east. This study provides a flexible method to study the spatial–temporal variation of the flood hazard and, hence, could help flood management and environment protection in similar coastal lowland areas.

Implications of Groundwater Depletion for Aquifer Geomatrix Deformation and Water Availability

Worsening water storage depletion contributes to environmental degradation, land subsidence and earthquake or even disrupts food production/security and social stability. There is also the need for efficient water use strategies in populated regions, especially when such regions also have intensive agricultural and industrial activities. The North China Plain (NCP) is one such region which is not only the seat of power, but also a major agricultural and industrial with a severe water storage depletion. Thus this study integrates satellite, model and field data products to investigate water storage depletion and land subsidence in the Beijing Environs of NCP. In the first step, GRACE (Gravity Recovery and Climate Experiment) mass rates are analyzed for water storage depletion in the region. Next, GRACE total water storage (TWS) is corrected for soil moisture storage (SMS) to derive groundwater storage (GWS) using GLDAS (Global Land Data Assimilation System) data products. The derived GWS is compared with GWS obtained from field-measured groundwater level to show water storage depletion in the study area. Then GPS (Global Positioning System) data of relative land surface change are used to show land subsidence due to water storage depletion. A total of ~96 near-consecutive months (Jan. 2002 through Dec. 2009) of datasets are used in the study. Based on GRACE mass rates, TWS depletion is 36.54±1.74 mm yr^-1 or 6.34±0.29 km³ yr^-1 for the 169 000 km² study area. Analysis of relative land surface change shows the occurrence of land subsidence at 7.29±0.35 mm yr^-1 in the Beijing Environ of NCP. About 7.50% (2.74±0.18 mm yr^-1 or 0.46±0.03 km³ yr^-1) of the depletion in TWS and 5.25% (1.52±0.07 mm yr^-1 or 0.26±0.01 km³ yr^-1) of that in GWS are attributed to storage reductions due to the land subsidence. Storage loss in the region justifies the current south-north water transfer efforts in the region. The concurrence of water storage depletion and land subsidence could have adverse implications for the hydrology, ecology, food security and social stability of the region. It is important to devise efficient measures to avert the negative effects of water storage depletion in the study area.

Numerical analysis to determine the impact of land subsidence on high-speed railway routes in Beijing, China

Abstract. More than 10 high-speed railway routes with top speeds of 300 km h−1 are expected to be operational from Beijing by the year 2020. However, the safety of these routes is affected by the occurrence of land subsidence. This paper focuses on the Beijing–Tianjin Intercity High-Speed Railway (BTR), the first high-speed railway in China, to analyze the operational safety of high-speed railway routes by analyzing both regional land subsidence and local differential subsidence caused by groundwater drawing. The Beijing construction stratum is mainly composed of cohesive soil, and the BTR has a maximum accumulative subsidence of > 800 mm and a maximum subsidence rate of > 80 mm a−1. In this paper, finite-element software ABAQUS is used to analyze groundwater drawdown and land subsidence caused by local water drawing, and its effect on the bearing capacity of railway bridge pile foundations and the orbit concrete supporting course. The analysis provides a technical basis for developing prevention and control engineering measures against land subsidence so as to guarantee the safe operation of these high-speed railway routes.

Has land subsidence changed the flood hazard potential? A case example from the Kujukuri Plain, Chiba Prefecture, Japan

Abstract. Coastal areas are subject to flood hazards because of their topographic features, social development and related human activities. The Kujukuri Plain, Chiba Prefecture, Japan, is located nearby the Tokyo metropolitan area and it faces to the Pacific Ocean. In the Kujukuri Plain, widespread occurrence of land subsidence has been caused by exploitation of groundwater, extraction of natural gas dissolved in brine, and natural consolidation of the Holocene and landfill deposits. The locations of land subsidence include areas near the coast, and it may increase the flood hazard potential. Hence, it is very important to evaluate flood hazard potential by taking into account the temporal change of land elevation caused by land subsidence, and to prepare hazard maps for protecting the surface environment and for developing an appropriate land-use plan. In this study, flood hazard assessments at three different times, i.e., 1970, 2004, and 2013 are implemented by using a flood hazard model based on Multicriteria Decision Analysis with Geographical Information System techniques. The model incorporates six factors: elevation, depression area, river system, ratio of impermeable area, detention ponds, and precipitation. Main data sources used are 10 m resolution topography data, airborne laser scanning data, leveling data, Landsat-TM data, two 1:30 000 scale river watershed maps, and precipitation data from observation stations around the study area and Radar data. The hazard assessment maps for each time are obtained by using an algorithm that combines factors with weighted linear combinations. The assignment of the weight/rank values and their analysis are realized by the application of the Analytic Hierarchy Process method. This study is a preliminary work to investigate flood hazards on the Kujukuri Plain. A flood model will be developed to simulate more detailed change of the flood hazard influenced by land subsidence.

Preliminary results of land subsidence monitoring project in Konya Closed Basin between 2006–2009 by means of GNSS observations

Abstract. One of the potential dangers that might arise as a result of bringing excessive amounts of groundwater to the surface of the Earth is land subsidence. Such surface deformations – these velocities may vary from a few millimetres to a few metres per year – do the greatest damage to infrastructure facilities and buildings in residential units. Agricultural lands, in which excessive irrigation is performed, and densely populated cities are more likely to suffer from land subsidence. Konya Closed Basin (KCB), where a rapid groundwater withdrawal has been observed during the last 30–40 years, is faced with such a threat. In this study, the possibility of the occurrence of land subsidence, related to groundwater withdrawal for the KCB, is assessed and the geodetic studies conducted up to now, with the intention of identifying land subsidence, are introduced. The vertical displacements of between -12 and -52 mm/year have been detected through GNSS observations collected on the 6-point test network. The land subsidence phenomenon has been developing in the areas where the groundwater is extensively used for irrigation and daily life. The results support the findings derived from the historical leveling records and point out the need of an extended study based on both GNSS and InSAR techniques for spatial and temporal mapping of land subsidence in the KCB.

Causes of Land Subsidence in the Kingdom of Saudi Arabia

The occurrence of land subsidence in the Kingdom Saudi Arabia is either natural or man-made. Natural land subsidence occurs due to the development of subterranean voids by a solution of host rocks in carbonate and evaporite terrains, over many areas of Saudi Arabia. Man-induced land subsidence is either due to the removal of groundwater in the agricultural areas or to wetting of unstable soils. Therefore, earth fissures and a lowering of the ground surface in unconsolidated sediments took place in alluvial plains and volcanic vent terrains. Unstable soils include Sabkha soils and loess sediments. These types of soils occur in coastal plains, desert areas and volcanic terrains. When this soil is wetted either during agricultural activities, waste disposal or even during a rain storm, subsidence takes place due to either the removal of salts from the Sabkha soil or the rearrangement of soil particles in loess sediments.

Some direct and inverse problems in land subsidence theory: V. Dimova, in: Land subsidence. Proc. international symposium, The Hague, 1995, ed. F. B. J. Barends & others, (IAHS; Publication, 234), 1995, pp 269–275

One of the effects of the underground human activities (geotechnological or civil engineering works) is the occurrence of land subsidence. The latter creates unfavourable conditions for the functioning of surface items (buildings, equipment, bands, etc.). In connection with this, the following two problems are considered and solved in this paper. (a) Direct problem the mining system is given; determine the equation of the land subsidence. This problem is reduced to the Dirichlet problem for Fourier's equation, (b) Inverse problem the equation of the mining subsidence is given, determine the underground operations from which the given subsidence is realized. This problem is of extreme importance in the cases when mining has to be done under built-up areas. In these cases the building standards dictate the land subsidence equation. This necessitates a more rigorous formulation of a new inverse problem in the land subsidence theory. The problem is reduced to an inverse Dirichlet problem for Fourier's equation. This is an incorrectly posed problem of mathematical physics in the sense of Hadamard. Its solution is obtained by Lions' quasi-inversion method. Some generalizations of the posed problems are discussed. The posing and solving of the unique inverse problem in the applied geosciences allows to speak about laying the foundations of a modern land protection geo-engineering field.

An extensive investigation of land subsidence in the Euganean geothermal basin, Italy: G. Gottardi, P. Previatello & P. Simonini, in: Land subsidence. Proc. international symposium, The Hague, 1995, ed F.B.J. Barends & others, (IAHS; Publication, 234), 1995, pp 21–30

In order to characterize the phenomenon of man-induced land subsidence taking place in the Euganean geothermal basin, an extensive investigation has been carried out at the University of Padova. This phenomenon was observed in the recent past and related to the with­ drawal of hot waters (85°C) from the subsoil. The currently exploited aquifers are located in the deep calcareous bedrock, hydraulically interconnected to the alluvial Quaternary deposits. In the 1960s the production of hot waters for mud bath treatments caused the progressive piezometric lowering (2.5 m year1) and the shallow layers cooling. A marked phenomenon of land subsidence thus developed, notwithstanding the deepening of draining wells. A 300 m-deep borehole was drilled and continuously sampled in order to investigate the geotechnical properties of the alluvial soils; at the same time an accurate measurement of water withdrawal and piezometric levels was also planned. The effects of high temperatures on soil parameters and on land subsidence occurrence are also taken into account in the paper.

Analysis of water level and land subsidence data from thorez open-pit mine, Hungary

The most important occurrence of land subsidence in Hungary caused by underground water withdrawal can be found in the NE of Hungary, in an area of open-pit mining at the foot of the Matra mountains. This paper presents the monitoring system of the underground water withdrawal, the processing method of achieving the underground water depletion and of the land subsidence as its indirect effect, as well as conclusions which can be drawn from the analysis of the observed data. The back analysis is illustrated by examples.

Land Subsidence Caused by Withdrawal of Oil and Gas in the Gulf Coastal Plain--The Houston, Texas, Case History: ABSTRACT

ABSTRACT The extensive network of geodetic leveling lines in the Houston-Galveston, Texas area, where at least 110 oil and gas fields have been developed, provides the most comprehensive opportunity in the Gulf Coast to search for the occurrence of land subsidence caused by withdrawal of oil and gas. Although the evaluation is complicated by regional subsidence caused by a decline of ground-water level in aquifers beneath the area, subsidence caused by oil and gas withdrawal can be examined by searching for local increases of subsidence at oil and gas fields crossed by leveling lines. Twenty nine field are crossed by lines with repeated leveling surveys. Subsidence profiles across these fields indicate local increases of subsidence at six fields--Alco-Mag, Chocolate Bayou, Goose Creek, Hastings, Mykawa, and South Houston. Although ground-water withdrawal is undoubtedly the most important factor contributing to the local subsidence at each field, oil and gas withdrawal may be partly responsible for the local increases. Except for Chocolate Bayou, the volume of petroleum production at each field was sufficient to account for the increase. The volume of petroleum production, however, in general is not a reliable index for predicting the local increase because land within many fields with significant production did not show local increases of subsidence. With the exception of the 1-m subsidence caused by petroleum withdrawal at Goose Creek (1917-1925), local increases of subsidence were less than 0.3 m. End_of_Record - Last_Page 301-------

Land Subsidence International Symposium held in Venice

The Third International Symposium on Land Subsidence was held March 18–25, 1984, in Venice, Italy. Sponsors were the Ground‐Water Commission of the International Association of Hydrological Sciences (IAHS), the United Nations Educational, Scientific, and Cultural Organization (UNESCO), the Italian National Research Council (CNR), the Italian Regions of Veneto and Emilia‐Romagna, the Italian Municipalities of Venice, Ravenna, and Modena, the Venice Province, and the European Research Office. Cosponsors included the International Association of Hydrogeologists (IAH), the International Society for Soil Mechanics and Foundation Engineering (ISSMFE), and the Association of Geoscientists for International Development (AGID).Organized within the framework of UNESCO's International Hydrological Program, the symposium brought together over 200 international interdisciplinary specialists in the problems of land subsidence due to fluid and mineral withdrawal. Because man's continuing heavy development of groundwater, gas, oil, and minerals is changing the natural regime and thus causing more and more subsiding areas in the world, there had been sufficient new land subsidence occurrence, problems, research, and remedial measures since the 1976 Second International Symposium held in Anaheim, California, to develop a most interesting program of nearly 100 papers from about 30 countries. The program consisted of papers covering case histories of fluid and mineral withdrawal, engineering theory and analysis, karst “sink‐hole”‐type subsidence, subsidence due to dewatering of organic deposits or due to application of water (hydrocompaction), instrumentation, legal, socioeconomic, and environmental effects of land subsidence, and remedial works.

International Survey on Land Subsidence

The International Association of Hydrological Sciences (IAHS) is conducting a detailed survey on land subsidence occurrence, research, and remedial activities throughout the world. The questionnaire requests information on location, causes, amounts, and rates of subsidence; problems and costs resulting from the subsidence and remedial measures taken; research completed or active; and list of publications describing the area or research.Plans call for IAHS to publish all responses received from this survey. In addition, the information will be summarized in a state of the art paper at the Second International Symposium on Land Subsidence, to be held in Anaheim, California, December 10–17, 1976.

Mathematical simulation of the subsidence of Venice: 1. Theory

A review of land subsidence theory and an outline of the justification for our choice of a model to simulate the subsidence at Venice are provided. The review is essentially a search for a mathematical model that can be used to link realistically the occurrence of land subsidence to the groundwater withdrawals that are its cause. The Biot system of equations for three‐dimensional consolidation offers the best approach at the theoretical level, but the large number of required parameters precludes application of the approach in practice. Approaches based on the independent solution of the diffusion equation provide a practical alternative, as long as the conditions underlying the development of the equation are recognized, and, if necessary, monitored. At Venice, we have chosen a two‐step procedure to analyze the subsidence in the complex aquifer‐aquitard system that exists there. First, the regional hydraulic head drawdowns are calculated in a two‐dimensional vertical cross section in radial coordinates, using an idealized 10‐layer representation of the geology. The computations are carried out with a model based on the diffusion equation and solved with a numerical finite element technique. The calculated head values in the aquifers are then used as time dependent boundary conditions in a set of one‐dimensional vertical consolidation models solved with a finite difference technkme and applied to a more refined representation of each aquitard. This approach appears to offer the best trade off between theoretical elegance, data availability, and computer limitation. Its main disadvantage lies in the limitations imposed by the requirements of radial symmetry.