A tiny and low-cost ground-based Fabry-Perot interferometer (FPI) was designed using a filter behind etalon and Galilean telescope system for the thermospheric wind observation with OI 630.0 nm nightglow emissions (~250 km). Based on the instrument, experiments were carried out at Langfang (39.40° N, 116.65° E) site for a rough comparison and Kelan (38.71° N, 111.58° E) site for a detailed validation. Wind results of Langfang experiment are well consistent with measurements of two other FPIs deployed at Xinglong (40.40° N, 117.59° E) and Kelan which are retrieved by the American National Center for Atmospheric Research (A-NCAR). In Kelan experiment, the averaged wind deviation between our FPI and A-NCAR FPI is 11.8 m/s. The averaged deviation of wind measurement error between them is 2.9 m/s. The comparisons suggest good agreement. Then, the analysis of influencing factors was made. The center determination offset has an exponential relation with wind deviation, while the radius calculation offset is linear with wind deviation.
{"title":"A Tiny Fabry-Perot Interferometer with Postpositional Filter for Measurement of the Thermospheric Wind","authors":"Houmao Wang, Y. Wang, Jian-Xi Fu","doi":"10.1515/acgeo-2016-0089","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0089","url":null,"abstract":"A tiny and low-cost ground-based Fabry-Perot interferometer (FPI) was designed using a filter behind etalon and Galilean telescope system for the thermospheric wind observation with OI 630.0 nm nightglow emissions (~250 km). Based on the instrument, experiments were carried out at Langfang (39.40° N, 116.65° E) site for a rough comparison and Kelan (38.71° N, 111.58° E) site for a detailed validation. Wind results of Langfang experiment are well consistent with measurements of two other FPIs deployed at Xinglong (40.40° N, 117.59° E) and Kelan which are retrieved by the American National Center for Atmospheric Research (A-NCAR). In Kelan experiment, the averaged wind deviation between our FPI and A-NCAR FPI is 11.8 m/s. The averaged deviation of wind measurement error between them is 2.9 m/s. The comparisons suggest good agreement. Then, the analysis of influencing factors was made. The center determination offset has an exponential relation with wind deviation, while the radius calculation offset is linear with wind deviation.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"2748-2760"},"PeriodicalIF":2.3,"publicationDate":"2016-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0089","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67091724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper describes certain aspects of the F region storm morphology based on vertical incidence measurements at single ionosonde station Chilton (51°.60′N, 358°.70′E). The topics discussed include requirements for better understanding of the ionospheric F region morphology and its forecasting under geomagnetically quiet and disturbed conditions. A few common storms during the years of low (1996 and 1997) and high (2000 and 2001) solar activity are considered as well as the Short-Term Ionospheric Forecasting (STIF) method by using two representative examples. The merits are stressed of near-real-time use of data to provide more accurate specification of the geomagnetically disturbed ionosphere and forecast its structure few hours in advance.
{"title":"Mid-Latitude Single Station F region Storm Morphology and Forecast","authors":"L. Cander","doi":"10.1515/acgeo-2016-0007","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0007","url":null,"abstract":"This paper describes certain aspects of the F region storm morphology based on vertical incidence measurements at single ionosonde station Chilton (51°.60′N, 358°.70′E). The topics discussed include requirements for better understanding of the ionospheric F region morphology and its forecasting under geomagnetically quiet and disturbed conditions. A few common storms during the years of low (1996 and 1997) and high (2000 and 2001) solar activity are considered as well as the Short-Term Ionospheric Forecasting (STIF) method by using two representative examples. The merits are stressed of near-real-time use of data to provide more accurate specification of the geomagnetically disturbed ionosphere and forecast its structure few hours in advance.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"541-566"},"PeriodicalIF":2.3,"publicationDate":"2016-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0007","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67087594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Located between eastern segments of the Atlas and Tell-Rif oro-genic belts, the “Dome zone” of northern Tunisia is characterized by the juxtaposition of various structures that mainly controlled the long geody-namic history of this part of the south-Tethyan Margin. To better understand the organization and deep extension of these structures, gravity data from the Teboursouk key area are proposed. These data include the plotting of Bouguer anomaly map and related parameters such as vertical and horizontal gradients, upward continuation and Euler solution. Compared to geological and structural maps available, they allow the identification of new deep structures and greater precision regarding the characteristics and organization of known ones; consequently, an updated structural pattern is proposed.
{"title":"Gravity Data from the Teboursouk Area (“Diapirs Zone”, Northern Tunisia): Characterization of Deep Structures and Updated Tectonic Pattern","authors":"F. Hachani, H. Balti, A. Kadri, M. Gasmi","doi":"10.1515/acgeo-2015-0072","DOIUrl":"https://doi.org/10.1515/acgeo-2015-0072","url":null,"abstract":"Located between eastern segments of the Atlas and Tell-Rif oro-genic belts, the “Dome zone” of northern Tunisia is characterized by the juxtaposition of various structures that mainly controlled the long geody-namic history of this part of the south-Tethyan Margin. To better understand the organization and deep extension of these structures, gravity data from the Teboursouk key area are proposed. These data include the plotting of Bouguer anomaly map and related parameters such as vertical and horizontal gradients, upward continuation and Euler solution. Compared to geological and structural maps available, they allow the identification of new deep structures and greater precision regarding the characteristics and organization of known ones; consequently, an updated structural pattern is proposed.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"379-397"},"PeriodicalIF":2.3,"publicationDate":"2016-11-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2015-0072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67087504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
One of the most challenging problems in the estimation of seismic hazard is the ability to quantify seismic activity. Empirical models based on the available earthquake catalogue are often used to obtain activity of source regions. The major limitation with this approach is the lack of sufficient data near a specified source. The non-availability of data poses difficulties in obtaining distribution of earthquakes with large return periods. Such events recur over geological time scales during which tectonic processes, including mantle convection, formation of faults and new plate boundaries, are likely to take place. The availability of geometries of plate boundaries, plate driving forces, lithospheric stress field and GPS measurements has provided numerous insights on the mechanics of tectonic plates. In this article, a 2D finite element model of Indo-Australian plate is developed with the focus of representing seismic activity in India. The effect of large scale geological features including sedimentary basins, fold belts and cratons on the stress field in India is explored in this study. In order to address long term behaviour, the orientation of stress field and tectonic faults of the present Indo- Australian plate are compared with a reconstructed stress field from the early Miocene (20 Ma).
{"title":"Intra Plate Stresses Using Finite Element Modelling","authors":"S. Jayalakshmi, S. Raghukanth","doi":"10.1515/acgeo-2016-0050","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0050","url":null,"abstract":"One of the most challenging problems in the estimation of seismic hazard is the ability to quantify seismic activity. Empirical models based on the available earthquake catalogue are often used to obtain activity of source regions. The major limitation with this approach is the lack of sufficient data near a specified source. The non-availability of data poses difficulties in obtaining distribution of earthquakes with large return periods. Such events recur over geological time scales during which tectonic processes, including mantle convection, formation of faults and new plate boundaries, are likely to take place. The availability of geometries of plate boundaries, plate driving forces, lithospheric stress field and GPS measurements has provided numerous insights on the mechanics of tectonic plates. In this article, a 2D finite element model of Indo-Australian plate is developed with the focus of representing seismic activity in India. The effect of large scale geological features including sedimentary basins, fold belts and cratons on the stress field in India is explored in this study. In order to address long term behaviour, the orientation of stress field and tectonic faults of the present Indo- Australian plate are compared with a reconstructed stress field from the early Miocene (20 Ma).","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1370-1390"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0050","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67089809","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Karviná region is well known as an area with an intensive mining induced seismicity. The local geological pattern, especially subsurface sedimentary layers, belongs to one of the most important factors that influence the amplification of seismic effect on the surface. In order to investigate the amplification effect, there are used methods of spectral ratio that enable to analyse records of vibrations. In the present study, two methods, signed as SSR (standard spectral ratio) and HVSR (horizontal to vertical spectral ratio), were used for the site effect evaluation. The analysis was performed in the populated Doubrava locality where high seismic loading on the surface due to mining induced seismicity is documented.
{"title":"Study of Site Effect at Seismic Station Located in Undermined Area of Karviná Region (Czech Republic)","authors":"M. Lednická, Z. Kaláb","doi":"10.1515/acgeo-2016-0053","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0053","url":null,"abstract":"The Karviná region is well known as an area with an intensive mining induced seismicity. The local geological pattern, especially subsurface sedimentary layers, belongs to one of the most important factors that influence the amplification of seismic effect on the surface. In order to investigate the amplification effect, there are used methods of spectral ratio that enable to analyse records of vibrations. In the present study, two methods, signed as SSR (standard spectral ratio) and HVSR (horizontal to vertical spectral ratio), were used for the site effect evaluation. The analysis was performed in the populated Doubrava locality where high seismic loading on the surface due to mining induced seismicity is documented.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1715-1730"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0053","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67089834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Time-frequency peak filtering (TFPF) is an effective tool for the removal of random noise and can be used to process seismic data with a low signal- to-noise ratio. A crucial aspect of this algorithm is the choice of window length (WL) of the time-frequency distribution. Whereas a fixed WL cannot simultaneously preserve signal and attenuate noise, timevarying WLs can achieve this goal. We propose a new method, L-DVV (delay vector variance), which successfully processes non-stationary signals by using the surrogate to measure the non-linearity of a time series. This method is sensitive to random noise and can accurately recover seismic signal masked by noise. Since the linearity criterion also meets the unbiased estimation criterion of the TFPF algorithm, the L-DVV method can be used for time-varying WL TFPF processing. Analysis of synthetic and real seismic data shows that the time-varying WL TFPF algorithm is effective at removing noise and recovering seismic signal.
{"title":"Removal of Random Noise in Seismic Data by Time-varying Window-length Time-frequency Peak Filtering","authors":"Pengjun Yu, Yue Li, Hongbo Lin, N. Wu","doi":"10.1515/acgeo-2016-0059","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0059","url":null,"abstract":"Time-frequency peak filtering (TFPF) is an effective tool for the removal of random noise and can be used to process seismic data with a low signal- to-noise ratio. A crucial aspect of this algorithm is the choice of window length (WL) of the time-frequency distribution. Whereas a fixed WL cannot simultaneously preserve signal and attenuate noise, timevarying WLs can achieve this goal. We propose a new method, L-DVV (delay vector variance), which successfully processes non-stationary signals by using the surrogate to measure the non-linearity of a time series. This method is sensitive to random noise and can accurately recover seismic signal masked by noise. Since the linearity criterion also meets the unbiased estimation criterion of the TFPF algorithm, the L-DVV method can be used for time-varying WL TFPF processing. Analysis of synthetic and real seismic data shows that the time-varying WL TFPF algorithm is effective at removing noise and recovering seismic signal.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1703-1714"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0059","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67090507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Magnetic properties of deposits around the shipwrecks (“Munin” and “Abille”) in the Gulf of Gdańsk were investigated. Values of magnetic susceptibility (χ) are relatively low; however, they reveal significant differences between investigated sites. The values of χ around “Abille” wreck were 5-8×10-8 m3/kg. Around “Munin” wreck results were more diversified reaching value of χ between 3.07×10-8m3/kg and 12.92×10-8 m3/kg. The spatial variability of χ coincided with near-bottom water currents distribution in the Gulf of Gdańsk. Magnetic minerals were identified by thermomagnetic analysis. Around “Abille” wreck we have found magnetite with small amount of maghemite or hematite. The “Munin” sediments include only one magnetic phase; in several samples it is magnetite, in the others — maghemite. Day—Dunlop plot shows that “Abille” set is shifted towards lower magnetization ratio and higher coercivity ratio. The correlation between the distribution of χ and hydrodynamic condition around shipwrecks allows to determine the direction of contaminant transport.
{"title":"Magnetometry as a Tool to Estimate the Pollution of Marine Environment Around Small Shipwrecks (Gulf of Gdańsk) — Preliminary Results","authors":"Magdalena Gwizdała, M. Jeleńska, Leszek Łęczyński","doi":"10.1515/acgeo-2016-0056","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0056","url":null,"abstract":"Magnetic properties of deposits around the shipwrecks (“Munin” and “Abille”) in the Gulf of Gdańsk were investigated. Values of magnetic susceptibility (χ) are relatively low; however, they reveal significant differences between investigated sites. The values of χ around “Abille” wreck were 5-8×10-8 m3/kg. Around “Munin” wreck results were more diversified reaching value of χ between 3.07×10-8m3/kg and 12.92×10-8 m3/kg. The spatial variability of χ coincided with near-bottom water currents distribution in the Gulf of Gdańsk. Magnetic minerals were identified by thermomagnetic analysis. Around “Abille” wreck we have found magnetite with small amount of maghemite or hematite. The “Munin” sediments include only one magnetic phase; in several samples it is magnetite, in the others — maghemite. Day—Dunlop plot shows that “Abille” set is shifted towards lower magnetization ratio and higher coercivity ratio. The correlation between the distribution of χ and hydrodynamic condition around shipwrecks allows to determine the direction of contaminant transport.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1691-1702"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0056","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67089965","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An integrated Visual Basic Application interface is described that allows for sensitivity analysis, calibration and routing of hydraulichydrological models. The routine consists in the combination of three freeware tools performing hydrological modelling, hydraulic modelling and calibration. With such an approach, calibration is made possible even if information about sewers geometrical features is incomplete. Model parameters involve storage coefficient, time of concentration, runoff coefficient, initial abstraction and Manning coefficient; literature formulas are considered and manipulated to obtain novel expressions and variation ranges. A sensitivity analysis with a local method is performed to obtain information about collinearity among parameters and a ranking of influence. The least important parameters are given a fixed value, and for the remaining ones calibration is performed by means of a genetic algorithm implemented in GANetXL. Single-event calibration is performed with a selection of six rainfall events, which are chosen so to avoid non-uniform rainfall distribution; results are then successfully validated with a sequence of four events.
{"title":"Sensitivity Analysis and Calibration of a Rainfall-Runoff Model with the Combined Use of EPA-SWMM and Genetic Algorithm","authors":"G. Giudice, R. Padulano","doi":"10.1515/acgeo-2016-0062","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0062","url":null,"abstract":"An integrated Visual Basic Application interface is described that allows for sensitivity analysis, calibration and routing of hydraulichydrological models. The routine consists in the combination of three freeware tools performing hydrological modelling, hydraulic modelling and calibration. With such an approach, calibration is made possible even if information about sewers geometrical features is incomplete. Model parameters involve storage coefficient, time of concentration, runoff coefficient, initial abstraction and Manning coefficient; literature formulas are considered and manipulated to obtain novel expressions and variation ranges. A sensitivity analysis with a local method is performed to obtain information about collinearity among parameters and a ranking of influence. The least important parameters are given a fixed value, and for the remaining ones calibration is performed by means of a genetic algorithm implemented in GANetXL. Single-event calibration is performed with a selection of six rainfall events, which are chosen so to avoid non-uniform rainfall distribution; results are then successfully validated with a sequence of four events.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1755-1778"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0062","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67090303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hou-Wen Huang, P. Fan, Jie Li, Mingyang Wang, Xiaoli Rong
Rock is a typical inhomogeneous material with a large number of flaws in different scales; the stress field of the rock in its elastic state consists of two parts: the elastic stress, which distributes uniformly in the entire region; and an additional stress, which only exists around the flaws. Theoretical expressions of the additional stress and local stress are derived based on the Maxwell model. Core disking which takes place under the condition that the axial stress is rapidly reduced while the confining pressure is kept unchanged is explained with a new method. Unloading duration’s effect on core disking is analyzed. A new criterion for core disking is presented based on attributing the core disking to the result of the exceedance of local tensile stress over the tensile strength. Based on our theoretical analysis and the conclusions from published resources, core disking is most likely to occur if the maximum principal stress is more than five to six times the tensile strength.
{"title":"A Theoretical Explanation for Rock Core Disking in Triaxial Unloading Test by Considering Local Tensile Stress","authors":"Hou-Wen Huang, P. Fan, Jie Li, Mingyang Wang, Xiaoli Rong","doi":"10.1515/acgeo-2016-0068","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0068","url":null,"abstract":"Rock is a typical inhomogeneous material with a large number of flaws in different scales; the stress field of the rock in its elastic state consists of two parts: the elastic stress, which distributes uniformly in the entire region; and an additional stress, which only exists around the flaws. Theoretical expressions of the additional stress and local stress are derived based on the Maxwell model. Core disking which takes place under the condition that the axial stress is rapidly reduced while the confining pressure is kept unchanged is explained with a new method. Unloading duration’s effect on core disking is analyzed. A new criterion for core disking is presented based on attributing the core disking to the result of the exceedance of local tensile stress over the tensile strength. Based on our theoretical analysis and the conclusions from published resources, core disking is most likely to occur if the maximum principal stress is more than five to six times the tensile strength.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1430-1445"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0068","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67090874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Droughts are natural phenomena affecting the environment and human activities. There are various drought definitions and quantitative indices; among them is the Standardised Precipitation Index (SPI). In the drought investigations, historical events are poorly characterised and little data are available. To decipher past drought appearances in the southeastern Alps with a focus on Slovenia, precipitation data from HISTALP data repository were taken to identify extreme drought events (SPI ≤ -2.00) from the second half of the 19th century to the present day. Several long-term extreme drought crises were identified in the region (between the years 1888 and 1896; after World War I, during and after World War II). After 1968, drought patterns detected with SPI changed: shorter, extreme droughts with different time patterns appeared. SPI indices of different time spans showed correlated structures in space and between each other, indicating structured relations.
{"title":"Extreme Historical Droughts in the South-Eastern Alps — Analyses Based on Standardised Precipitation Index","authors":"M. Brenčič","doi":"10.1515/acgeo-2016-0017","DOIUrl":"https://doi.org/10.1515/acgeo-2016-0017","url":null,"abstract":"Droughts are natural phenomena affecting the environment and human activities. There are various drought definitions and quantitative indices; among them is the Standardised Precipitation Index (SPI). In the drought investigations, historical events are poorly characterised and little data are available. To decipher past drought appearances in the southeastern Alps with a focus on Slovenia, precipitation data from HISTALP data repository were taken to identify extreme drought events (SPI ≤ -2.00) from the second half of the 19th century to the present day. Several long-term extreme drought crises were identified in the region (between the years 1888 and 1896; after World War I, during and after World War II). After 1968, drought patterns detected with SPI changed: shorter, extreme droughts with different time patterns appeared. SPI indices of different time spans showed correlated structures in space and between each other, indicating structured relations.","PeriodicalId":50898,"journal":{"name":"Acta Geophysica","volume":"64 1","pages":"1731-1754"},"PeriodicalIF":2.3,"publicationDate":"2016-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1515/acgeo-2016-0017","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67087823","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：