bluuebunny/crossref_metadata_2025 huggingface dataset:
Preliminary results of land subsidence monitoring in the Ca Mau Province
Authors: Karlsrud Kjell , Tunbridge Lloyd , Quoc Khanh Nguyen , Quoc Dinh Nguyen
Published: April 2020

Abstract. A previous study of the Ca Mau province in Vietnam (Karlsrud et al., 2017a) suggested that ongoing groundwater pumping, which by 2012 had caused a drawdown of the water level in aquifers of up to 20 m, caused subsidence of the order 2–4 cm yr−1, and could have reached over 40 cm already. Earlier InSAR studies also suggested ongoing subsidence rates of that order. If the groundwater pumping continues, the total subsidence could reach well over 1 m within the next few decades. The predicted climate driven sea level rise, to be of the order of 60 cm by 2100, will further add to the severe effect of the subsidence. As most of the Ca Mau province lies only 0.5 to 1.5 m a.s.l. (above sea level), the consequences would rapidly become very serious for the livelihood of people in the region. Increased saltwater intrusion into canals and tributaries in the province, and beginning salination of some of the aquifers from which groundwater is pumped, is already observed. In 2017, for the first time, a physical system for subsidence monitoring was installed at three selected locations in the Ca Mau province. At each
location a deep benchmark to a depth of 100 m was installed, each with 3 piezometers at depths ranging from 15 to 60 m. An InSAR corner reflector was also installed at each site. The paper presents data collected from these new monitoring stations up
until the middle 2019. When including estimated subsidence stemming from the soil levels deeper than 100 m, the total present rate of subsidence at the three new monitoring stations range from 17 to 44 mm yr−1. New and previous data show an almost linear decrease in water level within the aquifers from which groundwater is pumped. The data show some seasonal variations in subsidence rates, which is also reflected in variations in pore pressures in the sediments. Such variations are probably related to seasonal variations in levels of groundwater pumping. It is feared that many of the other provinces south of Ho Chi Minh city, face similar subsidence problems. The monitoring program should be extended to verify that. Measures to reduce groundwater and subsidence are urgently needed.
Spatial–temporal characterization of land subsidence induced by large area distribution of recent dredger fill
Authors: Lin Jinxin , Wang Hanmei , Yang Tianliang , Huang Xinlei
Published: April 2020

Abstract. Large-scale land subsidence often occurs after
large-scale land formation caused by dredger fill, which affects the sustainable
development of the region. In order to prevent and control land subsidence
in the area with dredger fill, the characteristics of land subsidence and
its main influencing factors need to be studied. A typical region was
examined using geological survey data, land-level monitoring and comparative
analysis, to provide insight regarding the variability of dredger-fill
characteristics and impacts on land subsidence. The geological survey
results provided the information about burial distribution characteristics
of dredger fill and its underlying soil layers. The land-level monitoring
results were analyzed to characterize the spatial–temporal distribution of
land subsidence. The comparative analysis of land subsidence with the
formation time, soil properties, thicknesses of dredger fill and the lower
soft soil layer provided information about the different impacts. The
monitoring results show that the land subsidence of dredger fill areas was
substantially larger than that of adjacent areas. The later the filling was
formed, the thicker the filling is, and the more clay-rich the soil property and
the thicker the soft soil layer is, the larger the land subsidence is.
Finally, the future trend of land subsidence in the study area are given and
some suggestions on the prevention and control of land subsidence are also given.
InSAR Detection of Localized Subsidence Induced by Sinkhole Activity in Suburban West-Central Florida
Authors: Oliver-Cabrera Talib , Wdowinski Shimon , Kruse Sarah , Robinson Tonian
Published: April 2020

Abstract. Sinkhole activity in west-central Florida is a major
hazard for people and property. Increasing frequency of sinkhole collapse is
often related to an accelerated use of groundwater and land resources. In
this work, we use radar interferometry acquired over a selected region in
Hernando County in west-central Florida to observe small localized
deformation possibly caused by sinkhole activity. The data used for the
study consist of acquisitions from one TerraSAR-X frame covering a time span
of approximately 1.7 years with spatial resolution of 0.25 by 0.60 m. We
applied the Persistent Scatterer Interferometry (PSI) technique using the
Stanford Method for Persistent Scatterers (StaMPS). Results reveal several
areas of localized subsidence at rates ranging from −3.7 to −4.9 mm yr−1.
Ground truthing and background verification of the subsiding locations
confirmed the relationship of the subsidence with sinkhole presence.
Land subsidence and associated ground fracturing: study cases in central Mexico with ALOS-2 PALSAR-2 ScanSAR Interferometry
Authors: Strozzi Tazio , Carreon-Freyre Dora , Wegmüller Urs
Published: April 2020

Abstract. Land subsidence affects highly developed urban areas in
central Mexico, where inhabitants rely on groundwater for about 60 % of
water supply and most of the cities are located in volcanic valleys filled
with fine and coarse grained sediments. Compaction associated to groundwater
depletion in areas with subsoil contacts sediments-rock have caused
differential subsidence, ground fracturing and eventually the reactivation
of pre-existing faults, depending on the local geological setting. Remote
sensing monitoring methods of land deformation have proved to be useful
tools to assess this geological hazard for urban planning. We used L-band
ScanSAR data from the ALOS-2 PALSAR-2 mission to produce a regional land
subsidence map over an area of about 350 km × 350 km over central Mexico.
Our results indicate with a remarkable spatial coverage widespread land
subsidence over the major cities, which is ranging from more than 30 cm yr−1
in Mexico City to 5–10 cm yr−1 in other locations.
Permafrost seasonal surface changes revealed from Sentinel-1 InSAR time-series, Yamal peninsula
Authors: Teshebaeva Kanayim , van Huissteden Ko J. , Puzanov Alexander V. , Balykin Dmitry N. , Sinitsky Anton I. , Kovalevskaya Nelley
Published: April 2020

Abstract. Widespread thawing of permafrost in the northern Eurasian
continent causes severe problems for infrastructure and global climate. We
test the potential of Sentinel-1 SAR imagery to enhance detection of
permafrost surface changes in the Siberian lowlands of the northern Eurasian
continent at the Yamal peninsula site. We used InSAR time-series technique
to detect seasonal surface movements related to permafrost active layer
changes. The satellite InSAR time-series analysis has detected continuous
movements, subsidence in three zones, which have occurred during the time
period from 2017 to 2018. Observed subsidence zones show up to 180 mm yr−1
rates of seasonal active layers changes. These seasonal ground displacement
patterns align well with lithology and linked to anthropogenic impact on the
permafrost surface changes in the area. The results show that Sentinel-1
mission is of great importance for the longer-term monitoring of active
layer thickening in permafrost regions. The combined analyses of the
obtained InSAR time series with additional field observations may support
regular process monitoring as part of a global warming risk assessment.
Monitoring shallow subsidence in cultivated peatlands
Authors: van Asselen Sanneke , Erkens Gilles , de Graaf Francis
Published: April 2020

Abstract. Accurate monitoring of shallow subsidence in cultivated
peatlands is a great challenge. Peat compaction by loading and peat
oxidation by groundwater level lowering are two important processes
contributing to shallow subsidence in cultivated peatlands, causing an
overall increase in soil wetness over time and hence a lower soil-bearing
capacity and agricultural production. Peat oxidation also causes emission of
CO2 and other greenhouse gasses. Rigorous monitoring techniques are
urgently needed to spatially and temporally map the amount and rate of
subsidence and to monitor effects of measures to reduce subsidence and its
negative impacts on livestock farming and agriculture. Monitoring shallow
subsidence in peatlands is particularly challenging, because subsidence is a
slow and spatially complex process, with average rates in the order of mm yr−1 but with higher rates possibly occurring on shorter timescales.
The desired monitoring system must be able to capture this temporal and
spatial variability, and preferably the contribution of different processes
to total subsidence. The system needs to be applicable (technically- and
financially-speaking) at regional scales, without severely impacting daily
farming activities. To help design and test a subsidence monitoring system
for cultivated peatland areas, four methods to measure subsidence are
applied and assessed in a cultivated peatland in Overijssel (NL), namely
spirit levelling, extensometery, LiDAR, and InSAR. In this paper, we focus on
the levelling and extensometery methods and measurements. Subsidence was
measured since October 2018 at eight livestock farms once every three months
by levelling. In the same period, extensometers have measured vertical
movement of (sub)surface levels hourly at two livestock farms. In addition,
phreatic groundwater levels are continuously monitored. Preliminary results
show vertical movements (up and down) in the order of centimeters on the
timescale of weeks. These movements seem to be related to groundwater level
fluctuations, but also evapotranspiration is expected to contribute to
additional subsidence during the summer period. Because long term net
subsidence is a slow process, additional data collection is needed to assess
the different methods and the temporal and spatial fluctuations in
subsidence on longer timescales. This is vital information to design the
optimal method for monitoring subsidence in cultivated peatlands on large
spatial scales, and to help in selecting effective measures to reduce
subsidence and greenhouse gas emission in peatlands.
General Survey of Large-scale Land Subsidence by GACOS-Corrected InSAR Stacking: Case Study in North China Plain
Authors: Xiao Ruya , Yu Chen , Li Zhenhong , Song Chuang , He Xiufeng
Published: April 2020

Abstract. Satellite-based InSAR (Interferometric Synthetic Aperture
Radar) provides an effective way to measure large-scale land surface
motions. Currently, the atmospheric phase delay is one of the most critical
issues in InSAR deformation monitoring. Generic Atmospheric Correction
Online Service (GACOS) is a free, globally available and easy-to-implement
tool to generate high-resolution zenith total delay maps, which could be
used for InSAR atmospheric delay correction. The mean velocity could then be
estimated by stacking multiple GACOS-corrected interferograms. We applied
the proposed GACOS-corrected InSAR stacking method in the North China Plain
and analysed its performance. Within the 549 interferograms, more than
85 % gained positive correction performances. The correlation between the
phase-dZTD indicator and the performance reached 0.89, demonstrating a
significant relationship. Deformation maps revealed by InSAR stacking with
and without GACOS corrections showed that GACOS could mainly remove the
topography-related and long wavelength signals.
Ground motion areas detection (GMA-D): an innovative approach to identify ground deformation areas using the SAR-based displacement time series
Authors: Bonì Roberta , Meisina Claudia , Poggio Linda , Fontana Alessandro , Tessari Giulia , Riccardi Paolo , Floris Mario
Published: April 2020

Abstract. In this work, an innovative methodology to generate the
automatic ground motion areas mapping is presented. The methodology is based
on the analysis of the Synthetic Aperture Radar (SAR)-based displacement
time series. The procedure includes two modules developed using the
ModelBuilder tool (ArcGis). These modules allow to identify the ground
motion areas (GMA) using only one dataset and the persistent GMA (PGMA)
considering the different monitored periods and datasets. These areas
represent clusters of targets characterized by the same displacement time
series trend. The procedure was tested using different sensors such as
ERS-1/2, ENVISAT, COSMO-SkyMed and Sentinel-1 covering the periods,
1992–2000, 2003–2010, 2012–2016 and 2014–2017, respectively, over an area of
about 500 km2 in the Venetian-Friulian coastal Plain (NE Italy). The
resulting mapping allows to detect priority areas where to address further
in situ investigations such as to verify the presence of localized buried
landforms.
Analysis of land subsidence changes on the Beijing Plain from 2004 to 2015
Authors: Guo Lin , Gong Huili , Li Xiaojuan , Zhu Lin , Lv Wei , Lyu Mingyuan
Published: April 2020

Abstract. Land subsidence, as a surface response to the
development, utilization and evolution of underground space, has become a
global and multidisciplinary complex geological environment problem. Since
the 1960s, land subsidence has been developing rapidly in
the Beijing Plain area. Against the backdrop of the integration of Beijing,
Tianjin and Hebei in addition to “southern water” (South-to-North Water Diversion
Project, SNWDP) entering Beijing, the systematic study of the evolution
mechanism of land subsidence is of great significance for the sustainable development of the
regional economy. Firstly, this study used ENVISAT ASAR and RADARSAT-2 data
to obtain surface deformation information for the Beijing Plain area from
2004 to 2015 and then verified the results. Secondly, the study area was divided
into units using a 960 m×960 m grid, and the ground settlement rate of each
grid unit from 2004 to 2015 was obtained. Finally, the Mann–Kendall test was
performed on the grid to obtain the mutation information for each grid unit.
Combined with hydrogeology and basic geological conditions, we have attempted to
analyze the causes of the mutations in the grid. The results show that 2347
grid cells were mutated in a single year, with most of these distributed
across the Yongding River alluvial fan and the middle and lower parts of
the Chaobai River alluvial fan. A total of 1128 grid cells were
mutated in multiple years, with the majority of these cells mainly distributed across the
upper-middle area of the alluvial fan, near the emergency water source and
at the edge of the groundwater funnel. This study aims to provide favorable
technical support and a scientific basis for urban construction in Beijing.
Identification of the ground movements caused by mining-induced seismicity with the satellite interferometry
Authors: Hejmanowski Ryszard , Witkowski Wojciech T. , Guzy Artur , Malinowska Agnieszka
Published: April 2020

Abstract. The assessment of the impact of mining-induced seismicity on the natural environment and infrastructure is often limited to the analysis of terrain surface vibrations. However, similar seismic phenomena, like earthquakes, may also imply dislocations and deformations of the rock mass. Such ground movements may occur in areas which are not directly under the influence of the mining. The study of the displacement field caused by mining-induced seismicity is usually carried out with the use of geodetic methods. Classical geodetic measurements provide discrete information about observed ground movements. As a result, they generally do not provide spatially and temporally relevant estimates of the total range and values of ground movements for specific periods of interest. Moreover, mining-induced seismicity causes a severe threat to buildings. That is why, regarding the
complexity of the mechanism of occurrence of mining-induced seismicity and
their impact on ground movements, this problem remains a substantial research issue. The presented research aimed to analyse the ground movements caused by mining-induced seismicity. The ground displacements were established based on data from Sentinel-1 satellites applying differential interferometric synthetic aperture radar (DInSAR). The results of the investigation in the copper mining area of the Lower Silesia region of Poland revealed that the observed subsidence caused by mining-induced
seismicity usually has a shape of a regular ellipse. The radius of these ground movements does not exceed approximately 2–3 km from the
mining-induced tremor's epicenter, and the total subsidence reaches ca. 10–20 cm. More than 50 % of the total subsidence is observed on the
surface within a few days after the mining tremor occurrence. Furthermore,
the deformations of the surface occur when the energy of mining-induced tremor reaches values of the order of 105 J or higher. The presented
research can contribute to better identification and evaluation of the
mechanism of the rock mass deformation process caused by mining-induced
seismicity. In addition, the use of satellite radar interferometry improves
the quality of monitoring of these dynamic phenomena significantly. The data
retrieved using this method allow for quasi-continuous monitoring of the
local subsidence bowls caused by mining-induced seismicity.
Characterizing marshland compressibility by an in-situ loading test: design and set-up of an experiment in the Venice Lagoon
Authors: Teatini Pietro , Da Lio Cristina , Tosi Luigi , Bergamasco Alessandro , Pasqual Stefano , Simonini Paolo , Girardi Veronica , Zorzan Paolo , Zoccarato Claudia , Ferronato Massimiliano , Roner Marcella , Marani Marco , D'Alpaos Andrea , Cola Simonetta , Zambon Giuseppe
Published: April 2020

Abstract. The fate of coastal marshlands in the near future will strongly depend on their capability to maintain their elevation above a rising mean sea level. Together with the deposition of inorganic sediments during high tides, organic soil production by halophytic vegetation, and organic matter decomposition, land subsidence due to natural soil compression is a major factor controlling the actual elevation of salt-marsh platforms. Due to their high porosity and compressibility, the marsh sedimentary body undergoes large compression because of the load of overlying more recent deposits. The characterization of the geotechnical properties of these deposits is therefore of paramount importance to quantify consolidation versus accretion and relative sea level rise. However, undisturbed sampling of this loose material is extremely challenging and lab tests on in-situ collected samples are not properly representative of in-situ conditions due to the scale effects in highly heterogeneous silty soils such as those of the Venice lagoon. To overcome this limitation, an in-situ loading test was carried out in the Lazzaretto Nuovo salt-marsh in the Venice Lagoon, Italy. The load is obtained by a number of plastic tanks that are filled with seawater, reaching a cumulative load of 40 kN applied on a 2.5×1.8 m2 surface. Specific instrumentations were deployed before positioning the tanks to measure soil vertical displacement at various depths below the load (0, 10, and 50 cm) and distances (0, 40, and 80 cm) from the load centre. Moreover, six pressure transducers were used to record overpressure dissipation over time. The collected datasets will be interpreted through a 3-D flow-deformation model that, once calibrated, provides reliable estimates of the compressibility values for each monitored depth interval.
Multi‐scale simulation of rock compaction through breakage models with microstructure evolution
Authors: Buscarnera Giuseppe , Chen Yanni , Lizárraga José , Zhang Ruiguo
Published: April 2020

Abstract. Regional subsidence due to fluid depletion includes the interaction among multiple physical processes. Specifically, rock compaction is governed by coupled hydro-mechanical feedbacks involving fluid flow, effective stress change and pore collapse. Although poroelastic models are often used to explain the delay between depletion and subsidence, recent evidence indicates that inelastic effects could alter the rock microstructure, thus exacerbating coupling effects. Here, a constitutive law built within the framework of Breakage Mechanics is proposed to account for the inherent connection between rock microstructure, hydraulic conductivity, and pore compaction. Furthermore, it is embedded into a 1-D hydromechanical coupled finite element analysis (FEA) to explore the effects of micro-structure rearrangement on the development of reservoir compaction. Numerical examples with the proposed model are compared with simulations under constant hydraulic conductivity to illustrate the model capability to capture the non-linear processes of reservoir compaction induced by fluid depletion.
Use of displacement as a proxy for dike safety
Authors: Jamalinia Elahe , Vardon Phil , Steele-Dunne Susan
Published: April 2020

Abstract. Climatic conditions and vegetation cover influence water flux in a slope which affect the pore water pressure and self weight, hence its stability. High evapotranspiration and low precipitation rates during summer cause dry soil with low soil moisture (SM) that leads to soil shrinkage, which leads to
cracking and reduced shear strength, which consequently decreases the stability of slopes. Soil re-wetting increases slope weight and exerts an additional driving force on the slope.
Using Earth observation (EO) data facilitates frequent, large-scale monitoring to identify the vulnerable areas along the slopes to avoid instability.
Here we study the displacement of a vegetated dike subject to SM variations under varying climatic conditions.
Results show that the SM and magnitude of total displacement at a desired location are highly positively correlated without time lag.
This proof-of-concept study shows that near surface displacement due to interaction with the atmosphere has a strong relation with the water availability in the slope and therefore the Factor of Safety (FoS).
Infiltration of surface water through subsidence failure assessment applying electric prospecting, case Aguascalientes Valley, Mexico
Authors: Acuña-Lara Fernando , Pacheco-Martinez Jesús , Luna-Villavicencio Hugo , Hernández-Marín Martín , González-Cervantes Norma
Published: April 2020

Abstract. Land subsidence is an anthropogenic hazard triggered by different causes, one of them is groundwater overexploitation over aquifer systems composed for granular compressible sedimentary fill. One of the effects of this phenomenon is the generation and reactivation of ground failures, becoming risk points for aquifer pollution through the fast infiltration of contaminated water. A system of failures and fractures has developed in the Aguascalientes valley since 1980's when groundwater overexploitation became intensive. Currently, the entire valley present regional subsidence and several ground failures have developed; many of them crossing surficial water flows and sewage pipes, thus, inducing filtering of domestic wastewater to the subsoil and increasing the environmental hazard for the aquifer system. In this work, we present the results of a study to assess the surficial water infiltrations through a subsidence related ground failure crossing a small stream, which carries domestic wastewater. Additionally, we investigate the acquisition method of Electrical Resistivity Tomography (ERT) and the electrode placement more suitable to detect the flow of contaminated water through the studied ground failure. To find out the potential leakage, we use electric geophysical methods, applying Schlumberger, Wenner and dipole-dipole arrangements with electrode separations from 2.5 to 10 m in order to explore a depth from 9 to 30 m. The obtained results showed that the Schlumberger configuration appears to be more helpful to detect changes in the stratigraphy toward depth, while dipole-dipole and Wenner are more suitable to detect lateral variations such as the vertical wastewater leakage in the first 6 to 8 m depth. Resulted resistivity models showed that in the first 10 m depth, the contaminant flow follow with a vertical path through the ground failure, then, the it becomes horizontal, flowing through the more permeable soil strata. Therefore, for the studied sites, the filtration of domestic wastewater through ground failure does not represent an immediate hazard to the aquifer system. Nevertheless, ground failures crossing damaged wastewater pipes or contaminated surficial water flows in Aguascalientes Valley, could induce the infiltration of polluted water to the near surface strata, favoring a potential aquifer pollution in a long term.
Parameter estimation of a multiple aquifer-aquitard system from a single extensometer record: Las Vegas, Nevada, USA
Authors: Burbey Thomas J.
Published: April 2020

Abstract. The purpose of this investigation is to develop a
semi-analytical procedure for quantifying aquifer and aquitard properties
from a single extensometer record in lieu of the time-consuming development
of more complex numerical models to quantify and constrain these parameter
values. Despite a limited 12-year record and the fact that water levels both decline and increase on an annual basis, estimates of both aquifer and
aquitard parameters have been reasonably estimated at the Lorenzi
extensometer site in Las Vegas Valley, Nevada when compared to the estimates
developed numerically. The key factors that allow for accurate estimates of
elastic and inelastic skeletal specific storage and hydraulic conductivity
of the aquitards and elastic specific storage and hydraulic conductivity of
the intervening aquifers is the presence of pumping cycles at multiple
frequencies, and measured heads at all the aquifer units covered in the
extensometer record and the inherent assumption that the aquitards have
identical hydrologic characteristics and are homogeneous and isotropic. This latter assumption is also a usual limitation in numerical modelling of these settings because of the complex temporal head relationships occurring within the aquitards that are rarely, if ever, measured.
A shallow compaction model for Holocene Mississippi Delta sediments
Authors: Zoccarato Claudia , Törnqvist Torbjörn E. , Teatini Pietro , Bridgeman Jonathan G.
Published: April 2020

Abstract. The extensive loss of land elevation and the consequent exposure to flood hazards are seriously threatening the long-term survival of the Mississippi Delta. Shallow compaction of the top soil is one of the major components contributing to the relative sea level rise. In the last decades, more subsidence measurements have become available and recent studies demonstrate that compaction of Holocene strata is dominant. Here we propose a novel application aimed at modeling the present-day shallow compaction due to consolidation processes in the top soil. Soil compaction is properly computed and accounts for the large soil grain motion and the delayed dissipation of pore-water overpressure. The grain motion is described by means of a Lagrangian approach with an adaptive mesh where the grid nodes follows the accretion/compaction processes. Model calibration is
obtained from stratigraphic and geochrology information collected at the Myrtle Grove Subsidence Superstation, where a nearly 40 m-deep sediment core that penetrates the entire Holocene succession allows testing model results over long (millennial) timescales.
Model validation with available observations from rod surface-elevation table – marker horizon (RSET-MH) data enables the model to predict future scenarios.
Land Subsidence risk maps and InSAR based angular distortion structural vulnerability assessment: an example in Mexico City
Authors: Fernández-Torres Enrique , Cabral-Cano Enrique , Solano-Rojas Dario , Havazli Emre , Salazar-Tlaczani Luis
Published: April 2020

Abstract. Land subsidence is a phenomenon present in several cities
in central Mexico, and results from a combination of groundwater resources'
overexploitation and the local stratigraphic nature. Furthermore, subsidence
occurs inhomogeneously in space, producing differential vertical
displacements, which affect both the natural media, as well as human-built
structures. Subsidence associated structural-vulnerability assessments
usually rely on direct field measurements to determine parameters such as
angular distortion. However, the large areas in which land subsidence occurs
(city-scale) in Mexico City hinders a direct quantification of differential
displacements for all buildings and structures present in it. A Sentinel-1
based subsidence analysis shows that the highest velocities are located on
the eastern sector of the city. This velocity map was used as the basis for
a population density weighted land subsidence correlation analysis. Our Land
Subsidence Risk assessment indicates that 15.43 % of the population of
Mexico City live in intermediate, high and very-high risk zones which
corresponds to 1 358 873 inhabitants. Therefore, a significant percentage of
Mexico City's population is vulnerable to suffering damage in their housing
structures due to land subsidence. Furthermore, the lower income inhabitants
share a proportionally greater economic cost due to land subsidence and
associated shallow faulting. The structural vulnerability analysis of the
civil structures in the city was performed using angular distortion maps
derived from the subsidence velocity gradient between October 2014–October
2017 period. These maps indicate that within this time window,
∼12 % of the total urbanized area in Mexico City had
already exceeded a 0.002 radian angular distortion threshold; above which
damage in civil structures is more likely to occur. In fact, more than 1 million people have already suffered damages in their houses due to the
differential ground subsidence and the resulting structural angular
distortion. With these results, we can evaluate correspondence between
angular distortion map and critical infrastructure of the city, as a result,
we found that between 0 % and 12.84 % of these buildings have undergone
over 0.002 radian angular distortion.
Coastal Lowlands' Inundation Risk Assessment with High-resolution TanDEM-X DEM in Qingdao Coastal Plains, China
Authors: Li Peng , Li Miao , Li Zhenhong , Wang Houjie
Published: April 2020

Abstract. Global warming plays a principal role on the continuous increasing
sea-level rise, which exposes coastal regions worldwide to flooding threat.
However, the challenge is that the regional impact of SLR flooding can be
variable, especially when considering multiple effects of land subsidence,
long-term general sea-level rise and extreme weather conditions like storm
surge. In this paper, we build module with high-resolution InSAR-derived
precision DEMs with resolution of 4 m, long-term SLR trend and episodic
signals of climate change to calculate the relative sea level in AD 2100 on
various scenarios over the Jiaozhou Bay, one typical region of the biggest
peninsula in China and an important economic centre adjoining to the Yellow
Sea. The potential of TanDEM-X DEM for coastal vulnerability mapping in the
Qingdao coastal area were evaluated in order to investigate the effect of
the accuracy and resolution of coastal topography on the reliability and
usefulness of elevation-based sea-level rise assessments. The results reveal
that coastal lowland areas over the JiaozhouBay are extremely vulnerable in
the following years within 21st century with use of high-accuracy TanDEM-X
DEM data, which would be an advantage for further elevation-based dynamic
assessments of coastal inundation events considering storm surges, abnormal
high tides, and extreme precipitation events. which would be vital for
locally coastal protection and decision-making.
The potential impact of measures taken by water authorities on greenhouse gas emissions
Authors: Motelica-Wagenaar Anne Marieke , Pelsma Tim A. H. M. , Moria Laura , Kosten Sarian
Published: April 2020

Abstract. Water authorities responsible for water quantity and water quality management may strongly influence the magnitude of greenhouse gas emissions from the surface waters and the adjacent peat areas within their territories. Climate smart water management (reducing influx of organic matter and improving water quality) is therefore a potentially strong mitigation tool. We hypothesize that climate smart water management has a stronger mitigation potential than reducing emissions from the operational management of a Water Authority. Based on literature data on greenhouse gas emissions from ditches and agricultural peatlands, we present a case study of a Dutch Water Authority – Amstel, Gooi and Vecht (operated by Waternet). We estimate that greenhouse gas emissions from the 195 km2 large peat area within its territory are 470 kt CO2-eq per
year. An additional 231 kt CO2-eq yr−1 is emitted from the water bodies within the 102 km2 large water area territory. Both emissions are considerably higher than the estimated climate footprint of the operational management of the water board (∼62 kt CO2-eq per year in 2017). While Waternet strives to have a net zero emission of greenhouse gases related to its operational management by 2020, we postulate that measures (to be taken before 2030) such as the prevention of organic matter and nutrients entering surface waters, the removal of organic carbon from ditches and higher groundwater levels in agricultural peatlands, may reduce greenhouse gas emissions in ditches and agricultural peat meadows with 26 and 27 kt CO2-eq per year, respectively. Measures that are taken to reduce greenhouse gas emissions in water bodies are expected to have a positive impact on water quality as well.
Reconstruction of earth fissures 3-D from videos
Authors: Riquelme Adrián , Tomás Roberto , Cano Miguel , Pastor José Luis , Gootee Brian , Cook Joseph P.
Published: April 2020

Abstract. Earth fissures are pervasive cracks that develop on
valley floors as a consequence of land subsidence associated with extensive
groundwater withdrawal. To capture geometrical, geological and geotechnical
information of ground fissures is of paramount importance for their
characterization. Recent advances in remote sensing techniques and the
accessibility to remotely piloted aircraft systems (RPAS) as well as the
evolution of onboard digital cameras enable the capture of digital photos
and videos. Using digital photos along with the Structure from Motion (SfM)
technique and following certain strategies, we can reconstruct a 3-D model of
the earth fissures under study. This technique requires digital photos, but
when a digital video is available, we can convert it into a set of frames
and equally apply the procedure. Besides, the extraction of frames from a
video assures a key condition for the SfM technique: the overlap between
photos. The resulting 3-D model should be scaled and oriented using a rigid
transformation matrix or even better including ground control points (GCP)
into the captured photos or frames. The latter enables the geo-referencing
of the point cloud and the correction of linear and non-linear deformations.
In this work, the proposed methodology is illustrated through the
application of SfM technique to a high-resolution video downloaded from
YouTube (i.e. https://youtu.be/9xdAnftBKvY, last access: 20 February 2020). The video shows a mile-long
earth fissure that appeared sometime between March 2014 and December 2014
near the Tator Hills (Arizona, USA) over Quaternary sediments. The Arizona
Geological Survey captured these videos using an RPAS. The frames of the
video were downloaded and extracted using a simple Matlab code. Then, we
sub-sampled the frames and processed them using the software Agisoft
Metashape Professional. Finally, we got metric data from Google Earth and
generated a 3-D model. The quality of the 3-D model strongly depends on the
quality of the photos and the GCP. However, this study shows the potential
of this technique, instrumentation and data available on Internet for the
development of 3-D point clouds and 3-D models for the detailed analysis of
earth fissures.
Remotely triggered subsidence acceleration in Mexico City induced by the September 2017 Mw 7.1 Puebla and the Mw 8.2 Tehuantepec September 2017 earthquakes
Authors: Solano-Rojas Dario , Cabral-Cano Enrique , Fernández-Torres Enrique , Havazli Emre , Wdowinski Shimon , Salazar-Tlaczani Luis
Published: April 2020

Abstract. Mexico City, a large megacity with over 21 million inhabitants, is
exposed to several hazards, including land subsidence, earthquakes, and
flooding. Hazard assessments for each hazard type is typically treated
separately and usually do not include considerations for any relations among the hazards. Our data makes it plausible for an earthquake triggering case that temporarily accelerated the subsidence rate in the metropolitan area as a result of the Mw 8.2 Tehuantepec and the Mw 7.1 Puebla, September 2017
earthquakes that affected Mexico City. Furthermore, the triggering effect
induced rapid slip along previously developed shallow faults associated with
subsidence. These results indicate that any future scenario of land
subsidence should consider a potential triggering effect by large
earthquakes. Similarly, earthquake hazard assessments should also consider
potential impact on shallow faulting and fracturing associated with land
subsidence.
Vulnerability of Venice's coastland to relative sea-level rise
Authors: Tosi Luigi , Da Lio Cristina , Donnici Sandra , Strozzi Tazio , Teatini Pietro
Published: April 2020

Abstract. Relative sea-level rise (RSLR), i.e. sea-level rise due
to climate changes combined with land subsidence, is one of the processes
that is most severely threatening the coastal systems around the world. The
Venice coastland forms the major low-lying area in Italy and encompasses a
variety of environments, such as farmlands, estuaries, deltas, lagoons and
urbanized areas. Valuable ecosystems, historical heritages and economic
activities are located in this area. Since most of the territory lies at a
ground elevation below or slightly above the mean sea-level, also a few
mm yr−1 of land subsidence can seriously impacts on the Venice coastal system.
In this study, we present an analysis of the vulnerability to RSLR
considering an uneven land subsidence distribution, with an application on
the Venice coastland. The analysis is delineated at the regional scale by an
index-based model and a proper coupling of various thematic layers, such as
high spatial resolution land subsidence data retrieved by satellite SAR
interferometry, ongoing and projected sea-level rise trends, and
morpho-physiographic setting of the coastland.
Land subsidence characteristics and disaster prevention in the Tongzhou area, Beijing
Authors: Yong Luo , Long Zhao , Lin Zhu , Fang Tian , Kunchao Lei , Aihua Sun
Published: April 2020

Abstract. Accurately assessing the impact of groundwater exploitation on
land subsidence can provide scientific support for decision-makers. This
article establishes a groundwater–subsidence model in a typical area using the land subsidence characteristics of Tongzhou, China, and subsequently classifies a land subsidence early warning zone based on the land subsidence rate.
Results show that land subsidence occurred throughout the whole Tongzhou District.
The land subsidence that developed to the west of Liuzhuang, Tongzhou city and Taihu was the most serious The maximum annual subsidence rate reached 120 mm a−1 under the
current groundwater extraction conditions, and the early warning level for land
subsidence reached its highest level. If the pumping of groundwater was reduced by 50 % in the
second and the fourth aquifers and by
60 % in the third aquifer, the land subsidence early warning level would be largely reduced and would
meet the requirements for land subsidence control.
Investigating the effectiveness of drain infiltration to minimize peat oxidation in agricultural fields in Flevoland, the Netherlands
Authors: Hoogland Frouke , Roelandse Arjen S. , de La Loma González Beatriz , Waterloo Maarten J. , Mooij Perry W. , Verhagen Sabine A. , Velstra Jouke
Published: April 2020

Abstract. In the Province of Flevoland, the Netherlands, land
subsidence poses a problem to agriculture and water management. The peat
layers in the soil are susceptible to compression and oxidation causing
further subsidence. Applying subirrigation through the tile drain system to
maintain saturation of the peat may be a measure to slow down subsidence. A
study was therefore carried out at two sites, Nagele and Zeewolde, to assess
the impact of subirrigation in the peat on the seasonal variation in soil
moisture content, and corresponding redox conditions. Bacterial community
analysis was carried out to verify the hydrochemical observations.
Subirrigation proved to be an efficient measure to maintain a high water
level in the peat soil as long as the permeability in the upper part of the
peat was sufficient to allow transmission of water into the inter-drain area
and when the peat layer extended enough below the minimum regional water
level to prevent drainage to the sand layer underneath. The peat showed dual
porosity and water levels could well be maintained by subirrigation at the
Nagele site. At the Zeewolde site, the variability in the thin peat layer
allowed drainage to occur in the sand layer, preventing subirrigation to
maintain high water levels. However, at both sites the peat layer remained
close to saturation throughout the summer, which may be caused by the
fine-grained mineral layer isolating the peat from water extraction via
evapotranspiration. Nitrate concentrations of up to 100 mg L−1 were observed
were high (>50 mg L−1) in the oxic mineral top layer but
were low in the peat (0.3 mg L−1) at both Nagele and Zeewolde sites.
Sulphate concentrations also showed a decrease with depth in the peat at
Nagele, indicating a transition from sub-oxic above 1.5 m depth to anoxic
conditions at 3.5 m depth. The hydrochemical observations in the soil
moisture in the peat at Nagele confirmed that conditions were sub-oxic in
the upper part of the peat (0.7 m below soil surface) to anoxic at greater
depth (3.5 m). Soil microbe analyses showed few nitrification bacteria in
the peat, whereas communities specialised in denitrification and
ammonification were present, as well as sulphate reducing bacteria and
methanogenic species. This confirmed the sub-oxic to anoxic conditions in
the peat deduced from the hydrochemical observations. At Zeewolde,
conditions remained sub-oxic throughout the profile.
Cost-benefit analysis of urban subsidence mitigation strategies in Gouda, the Netherlands
Authors: Kok Sien , Hommes-Slag Saskia
Published: April 2020

Abstract. This paper presents the approach and outcomes of an exploratory
cost-benefit analysis of subsidence mitigation strategies in the inner city
of Gouda, the Netherlands. Results indicate that especially the strategy
focusing on reducing damage, rather than a strategy aiming to halt
subsidence altogether, might have a positive economic rationale.
Detection of sinkhole occurrence, experiences from South Africa
Authors: Ferentinou Maria , Witkowski Wojciech , Hejmanowski Ryszard , Grobler Hennie , Malinowska Agnieszka
Published: April 2020

Abstract. Sinkholes are alarming and dangerous events, they have a worldwide
occurrence, and are imposing a potential risk to urban communities and the
widely developed built environment. Losses due to catastrophic sinkhole
collapse, foundation, pavement and structural repairs, occur more often, due
to the increased pressure to develop even on sinkhole prone land, and the
aging of existing water supply infrastructure in the majority of cities.
Remote sensing earth observation methods have proved to be valuable tools
during the last two decades in long-term sinkhole hazard assessment.
Satellite air borne and ground earth observation methods have primarily
facilitated the wide detection of continuous displacement on the earth's
crust. National sinkholes catalogues are necessary for town planers decision
makers, and government authorities. In many instances the ground collapse is
the result of water ingress from old poorly maintained leaking pipelines, or
extensive dewatering activities. In the current study a comprehensive review
of the current literature is presented in order to show experiences from
South Africa and present recent mapping using PSInSAR methodology in
Centurion South Africa.
Application of seismic prospecting to determine the width of influence of surface faults associated to land subsidence – a case of study in the Aguascalientes Valley, México
Authors: Luna-Villavicencio Hugo , Pacheco-Martínez Jesús , Acuña-Lara Fernando , Hernández-Marín Martín , González-Cervantes Norma
Published: April 2020

Abstract. Aguascalientes valley, located in the central part of
México, is affected for a land subsidence process triggered by
groundwater withdrawal since the 1980's. Currently, the
occurrence and the reactivation of surface faults and earth fissures due to
differential subsidence, is the main concern for government bureaus dealing
with urban planning, because of the damages that these terrain
discontinuities are able to cause in constructions and infrastructure. The
deformation and rupture process produces an active linear discontinuity with
a variable width of influence, where the constructions and infrastructure
are prone to get damage. Therefore, the determination of this width of
influence is critical for urban planning and hazard determination. In this work, the results of a geophysical seismic survey carried out in six
surface discontinuities located in the subsidence area of the Aguascalientes
Valley, are presented and discussed. The study included acquisition of
seismic tomography profiles measured perpendicularly to the discontinuities,
in order to obtain the P-wave velocity sections. The resulted P-wave
velocity models show a low-velocity anomaly within the fracture trace with
widths from 50 to 100 m. This anomaly is interpreted as a mechanically
disturbed zone due to the activity of the surface fault, this is, due to the
presence of fracturing caused to the adjacent material by the differential
subsidence. The results suggest that the material in the disturbed zone, is
experiencing a increase in secondary porosity, caused by the deformation and
rupture process, and the subsequent generation of small fissures and voids. The results of this study have practical implications because the
methodology allows defining the influence zone of an active discontinuity,
and therefore, to establish a restricted width along the surface
discontinuity. The definition of this restraint zone is a first step to
produce a subsidence hazard zoning including not only the discontinuity
trace but its width of influence.
Detection of subsidence in the Ebro Delta plain using DInSAR: analysis of the measurements and the factors that control the phenomenon
Authors: Rodriguez-Lloveras Xavier , Vilà Miquel , Mora Oscar , Pérez Fernando , Pi Roser , Marturià Jordi
Published: April 2020

Abstract. The Ebro Delta is a highly vulnerable Mediterranean
coastal ecosystems located on the northern Mediterranean coast of Spain.
Determining its subsidence rate and sources is a key issue for the present
and future management of this area. Differential Interferometry Synthetic
Aperture Radar (DInSAR) compared with the contribution to subsidence of the
compaction of delta's sediments and the lithosphere's deformation, indicated
a general Ebro Delta subsidence ranging from <1 to ∼ 2.3 mm yr−1. Subsidence is determined to be mainly driven by natural
sediment compaction (∼ 76 %), with areas strongly influenced
by local processes associated to their sedimentary distribution and
composition, or external factors such as sea level rise.