The paper presents the study of the vegetation recovery after the descent of the lahar during the eruption of the Sarychev Peak volcano(Matua Isl.,Middle Kuriles) in 2009.The works were carried out in 2017.It was foun...The paper presents the study of the vegetation recovery after the descent of the lahar during the eruption of the Sarychev Peak volcano(Matua Isl.,Middle Kuriles) in 2009.The works were carried out in 2017.It was found that during the secondary succession,plant communities,typical of the altitudinal zonation of the volcanic structure vegetation,are formed on lahar sediments in the following manner: the upper sections of the slope are occupied by sparse meadow and shrub vegetation,the middle are presented by shrub belt with a developed canopy,and the lower are representative of shrub large-grass belt.At the same time,the ordination analysis of the vegetation cover of the lahar valley by the detrended correspondence analysis(DCA) revealed the dispersion of the counting areas along the altitudinal gradient.This is opposite to that characteristic for both,the background communities on the slopes of the studied volcanic structure,and for communities in dynamical equilibrium of a typical altitude profile.Besides,directly correlating indicators of α-diversity of communities indicate the presence of open young communities at the stage of a complex grouping.Since the species Duschekia fruticosa which is an identifier in buried sites,forms communities in a state of dynamic equilibrium,with individuals of 40–50 years old,and at the time of the work,formed a canopy with individuals of 7–8 years old,a complete recovery of the communities of the lahar valley is possible in no less than 40 years.The acquired data on the recovery of vegetation on lahar contribute to the study of succession processes in the sites located in the zone of active volcanism.In addition,in this work,for the first time,the rates of restoration of the vegetation cover following its destruction as a result of burial by lahar products,are estimated.The specific features of this process are also considered.Employing the broad range of mathematical methods for quantitative analysis of indicators of young communities inhabiting the substrate makes it possible to identify patterns of vegetation formed during succession processes.The specifics of this organization are taken into account in this analysis.展开更多
Energy cone is a unique but characteristic slope that describes the extent of deposits left around a volcano by various fiowage phenomena, usually regarded as the boundary of pyroclastic and the source region of lahar...Energy cone is a unique but characteristic slope that describes the extent of deposits left around a volcano by various fiowage phenomena, usually regarded as the boundary of pyroclastic and the source region of lahar. The energy cone value is determined as 0.07 by the energy-Hne model com- bined with the parameters of plume height and gradient, and the energy cone spread extent is defined by the numerical simulation method LAHARZ to simulate with this value based on the 1 ： 50 000 digi-tal elevation model of Tianchi （天池） Volcano, and the source region profiles in the north and south slope can prove the correctness of this threshold. This energy cone threshold and extent can be used as the reference of pyroelastic flow and lahar simulation.展开更多
This study undertook a comprehensive sedimentological and grain-size analysis of two previously uncharacterized volcanoclastic deposits exposed in the northwestern sector of Chihuahua City, Mexico. The primary objecti...This study undertook a comprehensive sedimentological and grain-size analysis of two previously uncharacterized volcanoclastic deposits exposed in the northwestern sector of Chihuahua City, Mexico. The primary objective was to propose a systematic genetic classification for these deposits, employing traditional sedimentological techniques and an advanced computerized granulometric analysis technique based on orthogonal images to discern their grain size distribution. Through these studies, evidence was sought to classify them genetically, presenting arguments to define them either as a lahar or a volcanic debris avalanche. Results were critically compared against existing literature data pertaining to lahars and debris avalanches, yielding moderate success. The analysis identified one of the deposits as a non-eruptive or post-eruptive lahar. This identification was substantiated by the delineation of distinct overbank and transition facies within the deposit, providing compelling evidence for its genetic classification.展开更多
Due to specific environmental conditions, headwater catchments located on volcanic slopes and valleys are characterized by distinctive hydrology and sediment transport patterns. However, lack of sufficient monitoring ...Due to specific environmental conditions, headwater catchments located on volcanic slopes and valleys are characterized by distinctive hydrology and sediment transport patterns. However, lack of sufficient monitoring causes that the governing processes and patterns in these areas are rarely well understood. In this study, spatiotemporal water discharge and sediment transport from upstream sources was investigated in one of the numerous headwater catchments located in the lahar valleys of the Kamchatka Peninsula Sukhaya Elizovskaya River near Avachinskii and Koryakskii volcanoes. Three different subcatchments and corresponding channel types （wandering rivers within lahar valleys, mountain rivers within volcanic slopes and rivers within submountain terrains） were identified in the studied area. Our measure- ments from different periods of observations between years 2012-2014 showed that the studied catchment was characterized by extreme diurnal fluctuation of water discharges and sediment loads that were influenced by snowmelt patterns and high infiltration rates of the easily erodible lahar deposits. The highest recorded sediment loads were up to 9-104 mg/L which was related to an increase of two orders of magnitude within a one day of observations. Additionally, to get a quantitative estimate of the spatial distribution of the eroded material in the volcanic substrates we applied an empirical soil erosion and sediment yield model - modified universal soil loss equation （MUSLE）. The modeling results showed that even if the applications of the universal erosion model to different non-agricultural areas （e.g., volcanic catchments） can lead to irrelevant results, the MUSLE model delivered might be acceptable for non-lahar areas of the studied volcanic catchment. Overall the results of our studyincrease our understanding of the hydrology and asso- ciated sediment transport for prediction of risk manage- ment within headwater volcanic catchments.展开更多
基金supported by the Russian Geographical Society (research grant 09/2017-Р,2017)Far Eastern Branch of the Russian Academy of Sciences (17-I-1-036 э,2017)。
文摘The paper presents the study of the vegetation recovery after the descent of the lahar during the eruption of the Sarychev Peak volcano(Matua Isl.,Middle Kuriles) in 2009.The works were carried out in 2017.It was found that during the secondary succession,plant communities,typical of the altitudinal zonation of the volcanic structure vegetation,are formed on lahar sediments in the following manner: the upper sections of the slope are occupied by sparse meadow and shrub vegetation,the middle are presented by shrub belt with a developed canopy,and the lower are representative of shrub large-grass belt.At the same time,the ordination analysis of the vegetation cover of the lahar valley by the detrended correspondence analysis(DCA) revealed the dispersion of the counting areas along the altitudinal gradient.This is opposite to that characteristic for both,the background communities on the slopes of the studied volcanic structure,and for communities in dynamical equilibrium of a typical altitude profile.Besides,directly correlating indicators of α-diversity of communities indicate the presence of open young communities at the stage of a complex grouping.Since the species Duschekia fruticosa which is an identifier in buried sites,forms communities in a state of dynamic equilibrium,with individuals of 40–50 years old,and at the time of the work,formed a canopy with individuals of 7–8 years old,a complete recovery of the communities of the lahar valley is possible in no less than 40 years.The acquired data on the recovery of vegetation on lahar contribute to the study of succession processes in the sites located in the zone of active volcanism.In addition,in this work,for the first time,the rates of restoration of the vegetation cover following its destruction as a result of burial by lahar products,are estimated.The specific features of this process are also considered.Employing the broad range of mathematical methods for quantitative analysis of indicators of young communities inhabiting the substrate makes it possible to identify patterns of vegetation formed during succession processes.The specifics of this organization are taken into account in this analysis.
基金supported by the Natural Science Foundation of China (No. 40972209)the Special Projects of the Fundamental Scientific Research of the Institute of Geology, China Earthquake Administration (No. IGCEA1103)
文摘Energy cone is a unique but characteristic slope that describes the extent of deposits left around a volcano by various fiowage phenomena, usually regarded as the boundary of pyroclastic and the source region of lahar. The energy cone value is determined as 0.07 by the energy-Hne model com- bined with the parameters of plume height and gradient, and the energy cone spread extent is defined by the numerical simulation method LAHARZ to simulate with this value based on the 1 ： 50 000 digi-tal elevation model of Tianchi （天池） Volcano, and the source region profiles in the north and south slope can prove the correctness of this threshold. This energy cone threshold and extent can be used as the reference of pyroelastic flow and lahar simulation.
文摘This study undertook a comprehensive sedimentological and grain-size analysis of two previously uncharacterized volcanoclastic deposits exposed in the northwestern sector of Chihuahua City, Mexico. The primary objective was to propose a systematic genetic classification for these deposits, employing traditional sedimentological techniques and an advanced computerized granulometric analysis technique based on orthogonal images to discern their grain size distribution. Through these studies, evidence was sought to classify them genetically, presenting arguments to define them either as a lahar or a volcanic debris avalanche. Results were critically compared against existing literature data pertaining to lahars and debris avalanches, yielding moderate success. The analysis identified one of the deposits as a non-eruptive or post-eruptive lahar. This identification was substantiated by the delineation of distinct overbank and transition facies within the deposit, providing compelling evidence for its genetic classification.
文摘Due to specific environmental conditions, headwater catchments located on volcanic slopes and valleys are characterized by distinctive hydrology and sediment transport patterns. However, lack of sufficient monitoring causes that the governing processes and patterns in these areas are rarely well understood. In this study, spatiotemporal water discharge and sediment transport from upstream sources was investigated in one of the numerous headwater catchments located in the lahar valleys of the Kamchatka Peninsula Sukhaya Elizovskaya River near Avachinskii and Koryakskii volcanoes. Three different subcatchments and corresponding channel types （wandering rivers within lahar valleys, mountain rivers within volcanic slopes and rivers within submountain terrains） were identified in the studied area. Our measure- ments from different periods of observations between years 2012-2014 showed that the studied catchment was characterized by extreme diurnal fluctuation of water discharges and sediment loads that were influenced by snowmelt patterns and high infiltration rates of the easily erodible lahar deposits. The highest recorded sediment loads were up to 9-104 mg/L which was related to an increase of two orders of magnitude within a one day of observations. Additionally, to get a quantitative estimate of the spatial distribution of the eroded material in the volcanic substrates we applied an empirical soil erosion and sediment yield model - modified universal soil loss equation （MUSLE）. The modeling results showed that even if the applications of the universal erosion model to different non-agricultural areas （e.g., volcanic catchments） can lead to irrelevant results, the MUSLE model delivered might be acceptable for non-lahar areas of the studied volcanic catchment. Overall the results of our studyincrease our understanding of the hydrology and asso- ciated sediment transport for prediction of risk manage- ment within headwater volcanic catchments.
