bluuebunny/crossref_metadata_2025 huggingface dataset:
Longitudinal Vehicle Dynamics Modeling for AWD/4WD Vehicles to Study Torque Split between Front and Rear Axles
Authors: Sondkar Prashant , Gharpure Swapneel , Schrand Vince , Attibele Pradeep
Published: April 2020

All-wheel Drive (AWD) is a mature technology and most automobile manufacturers offer this feature on their vehicles. Improved traction, enhanced vehicle stability, and better handling are some of the key characteristics of AWD vehicles which are achieved by distributing the appropriate level of torque to the front and rear axles. Accurately capturing the torque split between the two axles is essential for sizing of driveline components like gears, bearings, and shafts. Traditionally, the torque split is considered to be either 50-50%, or solely proportional to the static weight distribution between the two axles. Design decisions are made based on historical test data. In this paper a longitudinal vehicle dynamics model for AWD systems is proposed to understand the influence of various key factors such as dynamic weight transfer, compliance of driveline components, and changing tire radius on the torque split. Comparison with the test data is performed to understand the significance and limitations of the model. While more detailed models have been built and used for various purposes, to the authors’ knowledge, this is the first time a model with this level of fidelity is being used to evaluate driveline component durability.
Semeando saúde: educação ambiental e alimentar em escolas de Itaqui/RS
Authors: Silva Lucas Santos da , Carvalho Paloma De Lourdes Ribeiro , Souza Rafael Rodrigues de , Almeida Lauriane Romeiro de , Godoy Filipe , Ethur Luciana Zago
Published: April 2020

O objetivo do trabalho foi apresentar e discutir os resultados de uma ação de extensão universitária desenvolvida com estudantes do ensino fundamental, em duas escolas do município de Itaqui/RS,buscando instrumentalizar e instigar, de forma lúdica, a importância da educação ambiental e alimentar como meios para melhoria da saúde, da qualidade de vida e para a formação cidadã. A ação foi desenvolvida com alunos do 4° e 5º ano do ensino fundamental (8 a 11 anos), dividida em duas etapas, a primeira focando na educação ambiental e a segunda na educação alimentar. Na primeira etapa foi aplicado um questionário e realizada uma roda de conversa juntamente com atividade prática de semeadura de alface em caixas de ovos contendo substrato para mudas, na segunda etapa foi proposta a construção de uma “horta ilustrativa”, visando promover a educação alimentar. O questionário mostrou que 80% das famílias apresentam preocupação em reciclar embalagens, que algumas famílias cultivam certas verduras em suas residências e que os alunos possuem conhecimento sobre a importância das frutas e verduras para uma alimentação saudável, porém, apenas 50% as consomem diariamente. Com o auxílio da roda de conversa e atividade prática, os alunos semearam alface em caixas de ovos e levaram para suas residências. Com a organização da “horta ilustrativa” pode-se observar que as hortaliças mais conhecidas foram: tomate, cenoura, beterraba e alface. Portanto, a ação foi relevante para discentes/universidade e alunos/escolas, por tratar de educação ambiental e alimentar, além de formar vínculo entre as instituições de ensino.
Saúde bucal na escola: uma experiência extensionista
Authors: Ferreira Izabel Do Rocio Costa , Archegas Lucí Regina Panka , Feger José Elmar , Sousa Gabriela Amanda de
Published: April 2020

A educação em saúde é um dos eixos da Política Nacional de Saúde Bucal. O objetivo deste texto é descrever o Evento de Extensão Universitária Promoção de Saúde Bucal na Escola, realizado em outubro de 2018, que abordou temas como escovação, uso do fio dental e também a utilização de piercing labial e lingual, com discussão crítica e participativa de escolares de 12 a 14 anos de um colégio público estadual de Curitiba. O evento foi realizado no formato de aula expositiva dialogada por acadêmicos do Curso Técnico em Agente Comunitário de Saúde da Universidade Federal do Paraná. No instrumento avaliativo utilizou-se a mensuração de competências desmembradas em conhecimentos, habilidades e atitudes em relação aos temas abordados.  Verificaram-se atitudes positivas dos escolares em termos das competências avaliadas, porém, pouca modificação dos mesmos para discutir assuntos relacionados à saúde, indicando a necessidade de propiciar mais momentos como o aqui relatado.
Conhecendo o cérebro 2018: interdisciplinaridade em um evento de extensão
Authors: Langner Livia Langner , Paduan Natãny Aparecida , Gomes Gabriel Martins , Aguilera Murillo Di Angelis , Sachs Juliane Priscila Diniz , Diniz Bruna Larissa Ramalho , Ekuni Roberta
Published: April 2020

O “Conhecendo o Cérebro” é um evento interdisciplinar, organizado pelo Programa de Extensão Grupo de Estudos em Neurociência, que convida outros projetos da universidade de acordo com a temática proposta para a Semana Nacional de Ciência e Tecnologia. Realizado em outubro de 2018, o mesmo teve como objetivo divulgar Ciência para crianças e adolescentes da Educação Básica da região. Como método, organizou os estandes a partir da temática “Ciência para redução de desigualdades”, contemplando estandes sobre neurociência, equidade de gênero, agronomia, materiais didáticos para cegos no ensino de Biologia e estande de tecnologia. Como resultado, foram mobilizados quatro docentes, 46 alunos de graduação, e um colaborador externo, englobando três cursos de graduação da UENP. Mais de 570 pessoas visitaram o evento e interagiram com os monitores. Conclui-se que o evento atingiu seu objetivo de interagir com a comunidade, divulgando Ciência em um ambiente não-formal de ensino, contribuindo tanto para a formação dos alunos quanto para com a popularização da ciência para a comunidade.
Avaliação da exposição a agrotóxicos: cinco anos de análises toxicológicas
Authors: Santos Claudia Regina dos , Higioka Angela Somavilla , Souza Raquel Cardoso de , Paula Eliza Bianchini de , Coldebella Virginia , Campos Synthia , Neves Mariah Bonelli Rossenq , Fusinato Maryá Nunes , Bauermann Lauren
Published: April 2020

O presente trabalho teve como objetivo apresentar os resultados de 5 anos de análises toxicológicas para as suspeitas de intoxicação aguda por agrotóxicos, e na avaliação da exposição ocupacional dos Agentes de Endemias do estado de SC. Foram realizadas análises para identificação de paraquat em urina e a determinação da atividade das colinesterases, relacionadas à exposição a inibidores da colinesterase. Foram analisados 82,9% dos casos de intoxicação relacionados ao paraquat. Com relação às intoxicações por inibidores da colinesterase, a atividade da butirilcolinesterase foi a mais solicitada para as suspeitas de intoxicações agudas. Para os Agentes de Endemias foram realizadas 2.120 análises para ambas as enzimas. Ainda que o monitoramento tenha tido grande alcance, uma vez as amostras foram provenientes de todo o estado para ambas situações. Ainda a inserção de alunos na atividade reforça a importância na disponibilização da análise à comunidade e na formação de recursos humanos.
Ação extensionista de promoção da saúde de estudantes universitários
Authors: Fonseca Yago Soares , Manganelli Luciane Aparecida Gonçalves , Borges Grasiely Faccin , Alves Calila Oliveira , Barbosa Gabriela De Azevedo , Correia Aline Prates , Mascarenhas Adryane Gomes
Published: April 2020

Objetivo: Relatar a experiência e apresentar os resultados de uma ação de promoção da saúde realizada por estudantes na Universidade Federal do Sul da Bahia. Método: A ação configurou-se como semana de atenção à saúde e foram coletados dados antropométricos e cardiovasculares de acordo com as diretrizes do manual técnico da Vigilância Alimentar e Nutricional a VII Diretriz Brasileira de Hipertensão Arterial e atualização da diretriz de prevenção cardiovascular da Sociedade Brasileira de Cardiologia. Resultados: A ação demonstrou que mais de 60% dos estudantes apresentaram valores adequados para índice de massa corporal, circunferência da cintura e pressão arterial e mais de 40% para relação cintura-quadril, contudo, uma parcela de 10 a 30% apresentou algum parâmetro acima do normal. Conclusões: A ação assumiu o caráter de promoção da saúde e tornou o estudante protagonista. Verificou-se que havia estudantes participantes, com necessidade de atenção à saúde.
A participação da extensão na resolução de caso de criança com Diabetes Mellitus Tipo 1
Authors: Oliveira Marcia De Freitas , Damo Nevoni Goretti , Lopes Caroline , Raitz Isadora Wileman , Pereira Liandra
Published: April 2020

Introdução: Diabetes Mellitus (DM) representa um grupo de doenças caracterizadas por hiperglicemia. Objetivo: foi demonstrar a importância da extensão, da atuação interprossional e multiprofissional para a resolução de um caso clínico dentro de um Projeto de extensão interprofissional na perspectiva de clínica ampliada. Metodologia: foi realizado relato da atuação da extensão universitária em um caso de uma criança de 11 anos de idade com Diabetes mellitus tipo 1 (DMT1) não controlada, apresentando um quadro de hiperplasia gengival, além de fratura incisal no dente 21.  Resultados: O protocolo de atendimento foi preventivo e terapêutico e incluiu: aferição da glicemia capilar, antibioticoterapia profilática, atendimento interprofissional e multiprofissional e controle do quadro de hipoglicemia. O apoio dos familiares foi fundamental para o sucesso do tratamento. Conclusão: Conclui-se que a atuação interprofissional e multiprofissional no planejamento e no desenvolvimento das atividades, favoreceram a interlocução de conhecimentos e experiências para ajudar na resolução das situações vivenciadas, promovendo, assim, melhores condições para o paciente lidar com sua saúde geral e bucal.
Representações de escolares sobre as aulas de educação física: estudo exploratório
Authors: Costa Marcia De Sousa , Mattos Luiz Otavio Neves
Published: April 2020

O presente trabalho teve como objetivo identificar, por intermédio da opinião dos escolares de uma turma de oitavo ano, de uma escola pública estadual do município de Niterói, se/como/por que o componente curricular Educação Física tem deixado, ao longo do tempo, lacunas acerca do seu aprendizado. Trata-se de um estudo exploratório, de natureza descritiva e interpretativa, amparado no referencial teórico das Representações Sociais que fez uso de uma abordagem mista (quantitativa e qualitativa) para interpretar os dados obtidos por intermédio de um questionário semiaberto. Os resultados nos dão indícios de que a ausência da Educação Física nos anos iniciais do Ensino Fundamental pode ter contribuído para o quadro de desinteresse desses escolares, assim como a falta de pluralidade de conteúdos da cultura corporal do movimento.
Improving trust in data and algorithms in the medium of AI
Authors: Vasan Srinivasan Aditya , de Boer Mona
Published: April 2020

Artificial Intelligence (AI) has great potential to solve a wide spectrum of real-world business problems, but the lack of trust from the perspective of potential users, investors, and other stakeholders towards AI is preventing them from adoption. To build and strengthen trust in AI, technology creators should ensure that the data which is acquired, processed and being fed into the algorithm is accurate, reliable, consistent, relevant, bias-free, and complete. Similarly, the algorithm that is selected, trained, and tested should be explainable, interpretable, transparent, bias-free, reliable, and useful. Most importantly, the algorithm and its outcomes should be auditable and properly governed.
What is the value of internal auditing? – A literature review on qualitative and quantitative perspectives
Authors: Eulerich Anna , Eulerich Marc
Published: April 2020

In recent years, research on internal audit has developed significantly. Numerous papers have discussed the importance of internal auditing (IA) as a central pillar of the corporate governance system. Through its activities, IA supports the Audit Committee and the CEO/C-Level. As an independent, objective assurance and advisory function, it is designed to add value through the audit of the internal control system, risk management and the governance processes. Interestingly, research on internal audit unfortunately rarely corresponds to these added value concept defined in the core responsibilities. Therefore, this literature review attempts to highlight the possible perspectives of the added value discussion and to help define future research avenues.
Satellite-based radiative forcing by light-absorbing particles in snow across the Northern Hemisphere
Authors: Cui Jiecan , Shi Tenglong , Zhou Yue , Wu Dongyou , Wang Xin , Pu Wei
Published: April 2020

Abstract. Snow is the most reflective natural surface on Earth and consequently plays an important role in Earth’s climate. Light-absorbing particles (LAPs) deposited on the snow surface can effectively decrease snow albedo, resulting in positive radiative forcing. In this study, we used remote sensing data from NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) and the Snow, Ice, and Aerosol Radiative (SNICAR) model to quantify the reduction in snow albedo due to LAPs, before validating and correcting the data against in situ observations. We then incorporated these corrected albedo reduction data in the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model to estimate Northern Hemisphere radiative forcing in January and February for the period 2003–2018. Our analysis reveals an average corrected reduction in snow albedo of ~0.0246, with instantaneous radiative forcing and daily radiative forcing values of ~5.87 and ~1.69 W m−2, respectively. We also observed significant spatial variations in corrected snow albedo reduction, instantaneous radiative forcing and daily radiative forcing throughout the Northern Hemisphere, with the lowest respective values (~0.0123, ~1.09 W m−2, and ~0.29 W m−2) occurring in the Arctic and the highest (~0.1669, ~36.02 W m−2, and ~10.60 W m−2) in northeastern China. From MODIS retrievals, we determined that the LAP content of snow accounts for 57.6 % and 37.2 % of the spatial variability in Northern Hemisphere albedo reduction and radiative forcing, respectively. We also compared retrieved radiative forcing values with those of earlier studies, including local-scale observations, remote-sensing retrievals, and model-based estimates. Ultimately, estimates of radiative forcing based on satellite-retrieved data are shown to represent true conditions on both regional and global scales.
Eddy covariance flux measurements of gaseous elemental mercury over a grassland
Authors: Osterwalder Stefan , Eugster Werner , Feigenwinter Iris , Jiskra Martin
Published: April 2020

Abstract. Direct measurements of the net ecosystem exchange (NEE)
of gaseous elemental mercury (Hg0) are important to improve our
understanding of global Hg cycling and, ultimately, human and wildlife Hg
exposure. The lack of long-term, ecosystem-scale measurements causes large
uncertainties in Hg0 flux estimates. It currently remains unclear whether
terrestrial ecosystems are net sinks or sources of atmospheric Hg0.
Here, we show a detailed validation of direct Hg0 flux measurements
based on the eddy covariance technique (Eddy Mercury) using a Lumex RA-915 AM mercury monitor. The flux detection limit derived from a zero-flux experiment in
the laboratory was 0.22 ng m−2 h−1 (maximum) with a 50 %
cutoff at 0.074 ng m−2 h−1. We present eddy covariance NEE
measurements of Hg0 over a low-Hg soil
(41–75 ng Hg g−1 in the
topsoil, referring to a depth of 0–10 cm), conducted in summer 2018 at a managed grassland at the
Swiss FluxNet site in Chamau, Switzerland (CH-Cha). The statistical estimate
of the Hg0 flux detection limit under outdoor conditions at the site
was 5.9 ng m−2 h−1 (50 % cutoff). We measured a net summertime
emission over a period of 34 d with a median Hg0 flux of 2.5 ng m−2 h−1 (with a −0.6 to 7.4 ng m−2 h−1 range between the 25th
and 75th percentiles). We observed a distinct diel cycle with higher
median daytime fluxes (8.4 ng m−2 h−1) than nighttime fluxes (1.0 ng m−2 h−1). Drought stress during the measurement campaign in
summer 2018 induced partial stomata closure of vegetation. Partial stomata
closure led to a midday depression in CO2 uptake, which did not recover
during the afternoon. The median CO2 flux was only 24 % of the
median CO2 flux measured during the same period in the previous year
(2017). We suggest that partial stomata closure also dampened Hg0 uptake
by vegetation, resulting in a NEE of Hg0 that was dominated by soil emission.
Finally, we provide suggestions to further improve the precision and handling
of the “Eddy Mercury” system in order to assure its suitability for long-term NEE
measurements of Hg0 over natural background surfaces with low soil Hg
concentrations (< 100 ng g−1). With these improvements, Eddy Mercury has
the potential to be integrated into global networks of micrometeorological
tower sites (FluxNet) and to provide the long-term observations on
terrestrial atmosphere Hg0 exchange necessary to validate regional and
global mercury models.
Integrated System for Atmospheric Boundary Layer Height Estimation (ISABLE) using a Ceilometer and Microwave Radiometer
Authors: Min Jae-Sik , Park Moon-Soo , Chae Jung-Hoon , Kang Minsoo
Published: April 2020

Abstract. Accurate boundary-layer structure and height are critical in analyzing the features of air pollutants as well as the local circulation. Although surface-based remote sensing instruments give high temporal resolution of the boundary-layer structure, there were many uncertainties in determining the accurate atmospheric boundary-layer heights (ABLHs). In this study, an algorithm for an integrated system for ABLH estimation (ISABLE) was developed and applied to the vertical profile data obtained by a ceilometer and microwave radiometer in Seoul City, Korea. A maximum of 19 ABLHs were calculated by the conventional time-variance, gradient, wavelet, and clustering methods using the backscatter coefficient data. Meanwhile, several stable boundary layer heights were extracted by the near-surface inversion and environmental lapse rate methods using potential temperature data. The ISABLE algorithm could find an optimal ABLH from post-processing including k-means clustering and density-based spatial clustering of applications with noise (DBSCAN) techniques. It is found that the ABLH determined by ISABLE exhibited larger correlation coefficients and smaller absolute bias and root mean square errors between the radiosonde-derived ABLHs than those obtained by most conventional methods. Clear skies showed higher daytime ABLH than cloudy skies, and the daily maximum ABLH was recorded in spring due to the stronger radiation. The ABLHs estimated by ISABLE are expected to contribute to the parameterization of vertical diffusion in the atmospheric boundary layer and in understanding the severe smog/haze events that arise from by fumigation during the ABL evolution period.
Semi-equilibrated global sea-level change projections for the next 10 000 years
Authors: Van Breedam Jonas , Goelzer Heiko , Huybrechts Philippe
Published: April 2020

Abstract. The emphasis for informing policy makers on future sea-level rise has been on projections by the end of the 21st century. However, due to the long lifetime of atmospheric CO2, the thermal inertia of the climate system and the slow equilibration of the ice sheets, global sea level will continue to rise on a multi-millennial timescale even when anthropogenic CO2 emissions cease completely during the coming decades to centuries. Here we present global sea-level change projections due to melting of land ice combined with steric sea effects during the next 10 000 years calculated in a fully interactive way with the Earth System Model of Intermediate Complexity LOVECLIMv1.3. The climate forcing is based on the Extended Concentration Pathways defined until 2300 AD with no carbon dioxide emissions thereafter and the inclusion of a methane-emission feedback for the highest forcing scenario, equivalent to a cumulative CO2 release of around 460 to 5800 GtC. After 10 000 years, the sea-level change rate drops below 0.05 m per century and a semi-equilibrated state is reached. The Greenland ice sheet is found to nearly disappear for all forcing scenarios. The Antarctic ice sheet contributes only about 1.6 m to sea level for the lowest forcing scenario with a limited retreat of the grounding line in West Antarctica. For the higher forcing scenarios, the marine basins of the East Antarctic ice sheet also become ice free, resulting in a sea-level rise of up to 27 m. The global mean sea-level change after 10 000 years ranges from 9.2 m to more than 37 m. The projections of multi-millennial semi-equilibrated sea-level rise for a given CO2 forcing are shown to be in good agreement with geological archives.
Percent-level production of 40Ar by an overlooked mode of 40K decay
Authors: Carter Jack , Ickert Ryan B. , Mark Darren F. , Tremblay Marissa M. , Cresswell Alan J. , Sanderson David C. W.
Published: April 2020

Abstract. The decay of 40K to the stable isotopes 40Ca and 40Ar is used as a measure of time for both the K-Ca and K-Ar geochronometers, the latter of which is most generally utilized by the variant 40Ar/39Ar system. The increasing precision of geochronology has forced practitioners to deal with the systematic uncertainties rooted in all radioisotope dating methods. A major component of these systematic uncertainties for the K-Ar and 40Ar/39Ar techniques is imprecisely determined decay constants and an incomplete knowledge of the decay scheme of 40K. Recent studies question whether 40K can decay to 40Ar via an electron capture directly to ground state (ECground), citing the lack of experimental verification as reasoning for its omission. In this study, we (1) provide a theoretical argument in favour of the presence of this decay mode, and (2) evaluate the magnitude of this decay mode by calculating the electron capture to positron ratio (ECground / β+) and after combining it with other estimates, provide a best estimate of 175 ± 65 (2σ). We provide support for this calculation through comparison of the experimentally verified ECground / β+ ratio of 22Na with our calculation using the theory of β decay.When combined with measured values of β+ and β- decay rates, this yields a partial decay constant for 40K direct to ground state 40Ar of 9.6 ± 3.8 × 10−13 a−1 (2σ). We calculate a partial decay constant of 40K to 40Ar of 0.590 ± 0.014 × 10−10 a−1, total decay constant of 5.473 ± 0.107 × 10−10 a−1 (2σ), and conclude that although omission of this decay mode can be significant for K-Ar dating, it is minor for 40Ar/39Ar geochronology and is therefore unlikely to have significantly biased published measurements.
Late Holocene differential subsidence and relative sea level rise in the Tabasco Delta, Mexico
Authors: Nooren Kees , Cohen Kim M. , Nienhuis Jaap H. , Hoek Wim Z.
Published: April 2020

Abstract. Coastal subsidence owing to compaction of Holocene strata and deeper-rooted
components affects large delta plains such as the Tabasco delta in southern
Mexico (Gulf coast). For this system, GNSS3-PPP ground-truthed LiDAR imagery
of high-resolution dated beach-ridge series reveals considerable
differential subsidence on either side of the present Usumacinta-Grijalva
River mouth. Collected field-data allows for quantification of differential
subsidence over several time windows and reconstruction of relative
sea-level rise back to 5000 years ago. Observed differential subsidence of
1–1.5 m is regarded to be syn-sedimentary delta-subsurface compaction of
buried strata in response to the accumulating overburden of the prograding
beach-ridge complex.
Two decades of GPS/GNSS and DInSAR monitoring of Cardona salt mines (NE of Spain) – natural and mining-induced mechanisms and processes
Authors: Rodriguez-Lloveras Xavier , Puig-Polo Carolina , Lantada Nieves , Gili Jose A. , Marturià Jordi
Published: April 2020

Abstract. Cardona area presents surface rising and subsidence
active movements. In 1999 a series of sinkholes appeared due to the
infiltration of Cardener River water into the mine tunnels, damaging surface
infrastructures. Since then, high precision GNSS/GPS was used annually to
position a network of 40 points spread over the area. GNSS/GPS work is
carried out with the Fast-Static (FS) method. Additionally the surface
movements have been monitored with satellite Differential Interferometry
Synthetic Aperture Radar (DInSAR). Results indicate that the movement has a
complex spatial distribution although consistent along time. Some areas show
surface rising during the last two decades, while other areas show
subsidence. The use of the two techniques allowed to determine the most
plausible causes of these movements generated by a set of interwoven natural
and human-induced complex processes.
Depressions caused by localized subsidence in the Netherlands, Belgium and Germany: a link with coal mining?
Authors: Vis Geert-Jan , van Linden Erik , van Balen Ronald , Cohen Kim
Published: April 2020

Abstract. In the coal mining districts of the Netherlands, Belgium and
Germany, we identified 662 previously unidentified depressions at the land
surface using LIDAR data. Their density decreases westwards along with
deepening of the Carboniferous coal layers, while not changing in
dimensions. The timing of their formation based on historical maps and
landowner reports, suggests that they mostly formed during the period
1920–1970, the peak of mining activity. Based on their position, density and
age, we link the formation of depressions to the coal-mining activities in
South Limburg, Germany and Belgium. Our working hypothesis tentatively
explains the origin, mechanism of formation and timing of these local
subsidence features.
InSAR monitoring surface deformation induced by underground mining using Sentinel-1 images
Authors: Zhang Ling , Ge Daqing , Guo Xiaofang , Liu Bin , Li Man , Wang Yan
Published: April 2020

Abstract. Land subsidence can be caused by underground mining
activities. Interferometric Synthetic Aperture Radar (InSAR) has became an
economic, effective and accurate technique for land deformation survey and
monitoring. In mining areas, there may be several factors to overcome for
the succsessful application of InSAR, such as temporal decorrelation and
detectable deformation gradient, that limit the ability of InSAR to
monitoring rapid land subsidence. In this paper, images obtained by the
Sentinel-1 satellite with 6 or 12 d revisiting time are used to improve
the ability to detect a deformation gradient, and reduce the influence of
temporal decorrelation. By combining Small Baseline Subsets (SBAS) and
Interferometric Point Target Analysis (IPTA) methods, using the Nanhu mining
area in Tangshan as an example, the spatial continuous results of land
subsidence in this mining area are obtained with a 70 cm per year maximum
rate, which clearly characterizes the deformation field and its deformation
process. The results show that InSAR is a useful way to monitor land
subsidence in a mining area and provides further data for environment mine
restoration.
Land subsidence monitoring based on PS-InSAR Persistent Scatterers identification with spectral analysis method
Authors: Zhou Di , Yu Jie , Zhu Lin , Wang Yanbing , Zhang Jing , Jiao Shuai , Chen Ren Shu
Published: April 2020

Abstract. Layover occurs as a consequence of the slant range scale
distortion in Synthetic Aperture Radar (SAR) data and it is commonly
observed in the images acquired over urban areas. There may be two or more
Persistent Scatterers (PSs) in one pixel. Moreover, these PSs do not have
amplitude stability and spatial coherence. The threshold method used in the
Persistent Scatterer Interferometric (PSI) SAR technique cannot identify the
PS with two scatterers in urban, the accuracy of urban land subsidence is
reduced. To solve this problem, we used Fast Fourier Transform (FFT) convert
PSs in frequency domain during PS identification process of PSI, by
observing their characteristics in the frequency domain, the layover
scatterers can be identified and separated. The results of simulation
experiment show that by analyzing the peak distribution characteristics of
PSs in the elevation direction under the relatively even space baseline, PSI
with FFT can identify single scatterers and layover scatterers. After
separating the layover scatterers, the reliability of PSs identification are
improved. For the real data experiment, we use 31 Sentinel-1A IW images
covering Beijing from 2014 to 2016 as data sources. The results show that
the proposed method can effectively identify layover scatterers which cannot
be identified by the threshold method in urban, reducing the effect of
layover scatterers, improving the accuracy of urban land subsidence
monitoring.
An InSAR based planning tool for maintaining the Dutch height system
Authors: Alberts Bas , Oyen Anneleen , van Waarden Pieter
Published: April 2020

Abstract. The Dutch height system, called Normaal Amsterdams Peil (NAP), is
realized purely trough leveling between designated benchmarks. In a cycle of
10 years secondary NAP benchmarks, generally located in buildings and civil
engineering structures, are surveyed to provide actual and reliable heights.
However, leveling campaigns are very labor-intensive and take a lot a of
time, resulting in high costs. Furthermore, the planning of secondary
leveling is based on limited prior knowledge. Instead of yearly leveling of
each bench mark within a region, the strategy could be optimized such that
deforming areas are visited more often and stable areas less. Trends
estimated from historical NAP data could be used, but these provide
insufficient information about stability and reliability of published
heights. Therefore we propose to use a nationwide deformation map derived
from InSAR satellite data to optimize the planning of the secondary leveling
campaigns. By using InSAR deformations combined with information of the NAP
benchmarks such as measurement date, type and location, a planning tool has
been developed. The first targeted leveling of NAP benchmarks using this
tool is planned for 2020.
An overview of the land subsidence phenomena occurring in Greece, triggered by the overexploitation of the aquifers for irrigation and mining purposes
Authors: Loupasakis Constantinos
Published: April 2020

Abstract. Land subsidence caused by overexploitation of aquifers
manifests with an increasing frequency in several regions of Greece. The
first signs of land subsidence have been identified since 1965 at the west
side of Thessaloniki (broader Kalochori village region), in the form of a
progressive marine invasion. Since then several areas have been investigated
and proved to be affected mainly by the overexploitation of the aquifers.
The Multidisciplinary nature of the subsidence mechanism combining the
geological, hydrogeological and morphological setting of the areas with the
human activities and the land use data makes their study complicated and
require the intervention of multiple scientific specialties. Furthermore, at
several sites, beside ground truth data, the land subsidence trends and
extends have been also identified via multi-temporal InSAR techniques, such
as PSI and SBAS techniques. Among the sites to be presented in the current
paper is the wider area of Kalochori village in the eastern part of
Thessaloniki plain, the east and west Thessaly plain in central Greece and
the region extending to the west–southwest of the Amyntaio opencast
coalmine in West Macedonia.
Towards unraveling total subsidence of a mega-delta – the potential of new PS InSAR data for the Mekong delta
Authors: Minderhoud Philip S. J. , Hlavacova Ivana , Kolomaznik Jan , Neussner Olaf
Published: April 2020

Abstract. Total subsidence in deltaic areas is the cumulative effect of a
range of driving mechanisms, both natural and anthropogenic. The populous
and low-lying Vietnamese Mekong delta is facing accelerating subsidence
rates and effective mitigation strategies are urgently needed to save-guard
the future sustainability of the delta. This paper gathers results from
existing measurements and estimates of subsidence in the Mekong delta and
presents new, delta-wide datasets of PSI observations of vertical velocity
from 2014–2019. We describe the practical application of this new data in
ongoing projects in Vietnam and outline a planned approach to determine
depth-dependent subsidence rates, using this new dataset in combination with
field surveys and physics-based numerical models, to advance towards
improved quantitation of the contributions of individual subsidence
mechanisms.
Wavelet analysis of land subsidence time-series: Madrid Tertiary aquifer case study
Authors: Tomás Roberto , Pastor José Luis , Béjar-Pizarro Marta , Bonì Roberta , Ezquerro Pablo , Fernández-Merodo José Antonio , Guardiola-Albert Carolina , Herrera Gerardo , Meisina Claudia , Teatini Pietro , Zucca Francesco , Zoccarato Claudia , Franceschini Andrea
Published: April 2020

Abstract. Interpretation of land subsidence time-series to
understand the evolution of the phenomenon and the existing relationships
between triggers and measured displacements is a great challenge. Continuous
wavelet transform (CWT) is a powerful signal processing method mainly
suitable for the analysis of individual nonstationary time-series. CWT
expands time-series into the time-frequency space allowing identification of
localized nonstationary periodicities. Complementarily, Cross Wavelet
Transform (XWT) and Wavelet Coherence (WTC) methods allow the comparison of
two time-series that may be expected to be related in order to identify
regions in the time-frequency domain that exhibit large common cross-power
and wavelet coherence, respectively, and therefore are evocative of
causality. In this work we use CWT, XWT and WTC to analyze piezometric and
InSAR (interferometric synthetic aperture radar) time-series from the
Tertiary aquifer of Madrid (Spain) to illustrate their capabilities for
interpreting land subsidence and piezometric time-series information.
An engineering approach to quantify geomechanical safety factors in UGS programs
Authors: Isotton Giovanni , Teatini Pietro , Stefanelli Raffaele , Ferronato Massimiliano , Janna Carlo , Cerri Matteo , Gukov Timur
Published: April 2020

Abstract. Underground Gas Storage (UGS) has become one of the most
widely used practices to cope with seasonal peaks in energy consumption. The
planning of any new UGS facility, or its upgrading to increase the working
gas volume and reservoir performance, must be supported by an evaluation of
possible induced effects on the environment. From a geomechanical point of
view, storage activity results in a cyclic change in stress and deformation
in the reservoir rock and the surrounding formations. The main environmental
issues to be accounted for when natural fluid pore pressure is planned to be
exceeded are the following: (a) the differential displacements at the land
surface possibly mining the integrity of ground structure; (b) the integrity
of the reservoir and caprock; (c) the possible reactivation of faults, if
the target reservoir is located in a faulted basin; and (d) the vertical
upheaval and land subsidence that can impact on the surface drainage network
in low lying coastal areas. We present an original methodology for
evaluating the geomechanical safety of UGS activities using an approach
derived from what is traditionally applied in the structural design of
buildings. A safety factor, a margin of security against risks, is defined
for each of the geomechanical issues listed above. First, a 3D FE-IE
numerical model is developed to reproduce the stress and displacement due to
the UGS program under evaluation. Then the reservoir pressure is increased
until the “failure” condition is reached allowing to evaluate how far the
project designed condition is from the above limit. The proposed approach is
applied to Romagna, a depleted gas reservoir in Northern Italy converted to
UGS, with the aim of investigating the safety of the project to increase the
reservoir pressure up to 120 % pi, where pi is the original reservoir pressure
before the start of primary production. The 3D geomechanical model has been
developed using recent 3D seismic data, land displacements by InSAR, lab
tests on reservoir and caprock samples, in-situ Modular Formation Dynamic
Tester (MDT) stress tests, and large background information acquired from
other UGS reservoirs located in the same sedimentary basin. The analysis
outcome has revealed that the investigated scenario is safe, with safety
factor larger than 1, in the range from 1.2 to 4. The most critical
condition (the smallest safety factor) has been obtained in relation to the
mechanical integrity of the reservoir formation, under very conservative
conditions (cohesion = 0, friction angle = 30∘).
Modelling subsidence due to Holocene soft-sediment deformation in the Netherlands under dynamic water table conditions
Authors: Kooi Henk , Erkens Gilles
Published: April 2020

Abstract. Local and regional governments in The Netherlands are
increasingly faced with the question how to adjust and optimize groundwater
table conditions in urban areas to minimize ongoing subsidence and its
consequences. To help addressing this question, a model was developed that
includes soft-soil deformation by creep. In this paper, a study is presented
in which the model was used to investigate and intercompare the
effectiveness of measures that (a) prevent anomalous water table drop during
a drought, (b) suppress the seasonal variability of the water table, and (c) involve a permanent rise of the mean water table.
Three-dimensional fully coupled study of groundwater seepage and soil deformation under the action of cyclic pumping and recharge
Authors: Luo Zujiang , Ning Di , Li Zhao , Tian Xiaowei
Published: April 2020

Abstract. This study was undertaken in order to accurately analyze the land subsidence that
is caused by the change in the seepage and stress fields during the pumping and recharge of groundwater. Based on Biot's
consolidation theory and groundwater seepage theory (combined with
theory regarding the nonlinear rheology of soil), the constitutive relationship of soil
was extended to viscoelastic plastic; concurrently, considering the
dynamic changes in hydraulic parameters and soil mechanical parameters, a
three-dimensional fully coupled model of groundwater seepage and soil
deformation was established. Using the groundwater recycling pumping and
recharge test conducted by Land Subsidence Monitoring and Early Warning
Center in Cangzhou City as an example, the site was divided into four
loose porous aquifers. A constantly circulating pumping–recharge flow was simulated numerically, and numerical simulation was carried out
on the third and fourth confined aquifers. The influence of groundwater
seepage on soil deformation was analyzed, and the variation in hydraulic parameters
and soil mechanical parameters were studied under the influence of the abovementioned cyclic pumping and recharge. The results show that soil
deformation lags behind the change in the groundwater level, and that permanent residual deformation of soil is
produced by water level fluctuations during groundwater
pumping–recharge cycles. The effective porosity, the
permeability coefficient and the Poisson ratio are positively correlated
with the water level fluctuation in groundwater pumping–recharge cycles,
whereas the modulus of deformation is negatively correlated with the water
level fluctuation in groundwater during this process. All parameters
change, and this change is permanent. The simulated results are in good agreement with the measured values.
Integrated impact assessment of adaptive management strategies in a Dutch peatland polder
Authors: van Hardeveld Henk , de Jong Harm , Knepflé Maxim , de Lange Thijs , Schot Paul , Spanjers Bas , Teurlincx Sven
Published: April 2020

Abstract. To achieve a more sustainable management of the subsiding
Dutch peatlands, adaptations such as progressively higher surface water
levels, pressurized field drains and a transition from dairy farming to
paludiculture are considered. However, a clear understanding of
implementation pathways for adaptive management strategies is lacking.
Therefore, we used the RE:PEAT tool to elucidate the short-term and
long-term impacts during 2025–2100 of two adaptive management strategies in
Polder Zegveld and how to fairly distribute the costs and benefits of these
strategies among the stakeholder groups. The strategies resulted in marked
differences in soil subsidence and temporal trends in societal costs and
benefits that affected stakeholders unequally. The adaptations were shown to
reduce soil subsidence and enhance the sustainability of peatland
management. We explored several options for a collective implementation of
the adaptative management strategies. In addition, we discuss several ideas
to further capitalize on the potential of the RE:PEAT tool to support
peatland management. Currently, we are developing additional features that
enable high spatio-temporal resolution simulations of the integrated
dynamics of the surface water system, the shallow groundwater system,
rainfall-runoff processes and solute transport. In combination with the
PCDitch model, this will also enable detailed ecological assessments. This
will pave the way for implementation pathways for adaptive management
strategies that will contribute to a more sustainable peatland management.
Factors that condition physical vulnerability to ground fracturing in Mexico City
Authors: Carreon-Freyre Dora , Gutierrez-Calderon Raul I. , Cerca Mariano , Alcantara-Duran Carlos F.
Published: April 2020

Abstract. In spite of subsidence being a well-studied geological phenomenon in Mexico City, its effects and risks for urban infrastructure and inhabitants have been neglected. Damage in the short, medium and long term implies maintenance and important mitigation costs. There are not systematic studies that address methodologies for the estimation of physical vulnerability of the geological media to fracture. In this work, factors conditioning the deformation and susceptibility to fracturing are analyzed using a deterministic approach. The identified physical variables were mapped, measured and integrated into a database that allowed for an adequate correlation of the parameters that condition fractures spatial distribution. A methodology for estimating a vulnerability index to fracturing (VIF) useful for decision making is proposed in this work.
Hydraulic behavior of subsidence-induced surface discontinuities in the hydrogeology of the Aguascalientes valley
Authors: Guerrero-Martínez Lilia , Hernández-Marín Martín , Muñoz-Zavala Ángel Eduardo
Published: April 2020

Abstract. The impact of faults and fissures (discontinuities) on the groundwater flow
has become important in several parts of the world because the
heterogeneous and anisotropic distribution of permeability in fault zones is
difficult to characterize. Based on this, we propose an analysis of patterns
of parameters measured in groundwater, under the premise that the observed
anomalies can be indicators of the hydraulic behavior of the flow in the
direction perpendicular to the fault plane. In this context, if the
discontinuities are sealed, they behave as hydraulic barriers, causing
variation in the continuity of the parameters across the fault plane.
Conversely, when faults are a conduit, they appear to have a small or null
variation in the distribution of the parameter measurements. The impact of
discontinuities in groundwater flow in a zone with a large number of faults
and fissures such as that of the Aguascalientes valley is being studied
using a graphical-correlation analysis with the revision of 230 wells,
through the measurement of parameters such as temperature and static levels
across discontinuities, in order to determine the hydraulic behavior of the
faults. This investigation considered values over 4 ∘C for
geothermal variations and 10 m for hydraulic-head changes to define
fault behavior. Results show three zones through mapping analysis, where the fault
presents barrier behavior and where the hanging block represents high
values; these anomalies are much higher than the average across the valley
and indicate the propensity for the fault to restrict horizontal flow. In
conclusion, the Oriente fault presents complex behavior of a barrier–conduct system
along the fault. This analysis gives a robust way to describe fault behavior
without referring to elaborate and invasive hydrological investigations.
Greenhouse gas emissions and surface water management
Authors: Motelica-Wagenaar Anne Marieke , Beemster Jos
Published: April 2020

Abstract. Soil subsidence is one of the major issues in the
management area of the water authority Amstel, Gooi and Vecht, including
emissions of greenhouse gases. This paper describes four different methods
to calculate these emissions in agricultural peat meadows, based on (1) the
mean lowest groundwater level, (2) the mean groundwater level, (3) the
subsidence rates and (4) general numbers. The emissions were calculated in
two polders (about 2600 ha peat meadow), these were comparable for all
methods, ranging from 42 up to 50 kton CO2-eq yr−1 (based on data of
2015), which is about 14.5 up to 19 t CO2-eq ha−1 yr−1. Besides, the
greenhouse gas emissions were compared for different policy scenario's in
one polder subunit (283 ha): (1) standard policy (lowering surface water
level at the same rate as soil subsidence taking place), (2) passive
rewetting (surface water level fixation), (3) subsurface irrigation by
submerged drains, and (4) a maximum surface water level decrease of 6 mm yr−1.
Comparing the four policy scenario's in one polder subunit, greenhouse gas
emissions were lowest in case of subsurface irrigation, decreasing
greenhouse gas emissions by about 35 %–50 % in this polder compared to
standard policy, meaning a decrease of about 5.5–9.3 t CO2-eq ha−1 yr−1.
This represents a value of about 550–930 EUR ha−1 yr−1 (at a price of EUR 100 per ton CO2-eq). The scenario passive rewetting leads to a decrease of about
12 %–21 %, or 2–3 t CO2-eq ha−1 yr−1 compared to standard policy. The
estimation of the decrease in GHG emissions depends on the assumptions made.
In this study it was assumed that subsurface irrigation halves soil
subsidence. The water board will use the described procedures to estimate
greenhouse gas emissions in the future to support water level management in
areas with peat soils.
Using InSAR settlement data in a levee strengthening project for building settlement risk assessment
Authors: van Buuren Rob R. , Haasnoot Jacco K. , de Koning Michel , Weijland Marco , van Zanten Hans J. W.
Published: April 2020

Abstract. For the levee strengthening project Krachtige IJsseldijken Krimpenerwaard (KIJK) a study has been done
to examine all buildings along 10 km of levee. These buildings are an
important factor in the design stage, because of its sensitivity to
deformations due to the natural compaction of the soft deposits (creep) and
the potential effects of the levee strengthening. This paper covers the
quantification of building settlement due to natural subsidence using InSAR.
Research is performed in the city archives to establish the characteristics
of the buildings, such as the foundation type. Although the city archive is
well organised, it is not complete. The building data density is
substantially improved using InSAR information. This enhanced data set is a
key factor in establishing an consistent assessment of the risk of damage
for the different levee strengthening alternatives.