Pub Date : 2022-08-08DOI: 10.1080/02723646.2022.2108206
J. E. Sáenz-Ceja, M. Mendoza
ABSTRACT Mean fire interval (MFI) is the average time between successive fires, influenced by environmental factors such as latitude, elevation, and vegetation type. This study evaluated the relationship between MFI and latitude in conifer forests of western North America. First, we obtained pre-fire-disruption MFI data from dendrochronology-based fire history studies in western Canada, the United States, and Mexico montane ranges. Then, we used generalized additive models (GAMs) to evaluate the relationship between MFI and latitude, considering elevation and conifer forest type as covariables. In addition, we mapped the spatial mean fire intervals (SMFIs) through inverse distance weighting (IDW). MFI increased significantly at higher latitudes, influenced by elevation and conifer forest type (R2 = 0.7). Furthermore, we found longer MFI in high elevations of the Madrean Archipelago, the Rocky Mountains, and the Alaska Range. Fire frequency also decreased in the boreal, Douglas-fir, and subalpine forests, with MFI longer than 20 yr. Moreover, the shortest SMFIs were found in the Mexican sierras and the Madrean Archipelago, with fire intervals between 4.1 and 5.6 yr. Our results showed a latitudinal gradient of MFI in conifer forests of western North America, which provides valuable information for fire management and the restoration of natural fire regimes.
{"title":"Latitudinal gradient of fire return interval in conifer forests of western North America","authors":"J. E. Sáenz-Ceja, M. Mendoza","doi":"10.1080/02723646.2022.2108206","DOIUrl":"https://doi.org/10.1080/02723646.2022.2108206","url":null,"abstract":"ABSTRACT Mean fire interval (MFI) is the average time between successive fires, influenced by environmental factors such as latitude, elevation, and vegetation type. This study evaluated the relationship between MFI and latitude in conifer forests of western North America. First, we obtained pre-fire-disruption MFI data from dendrochronology-based fire history studies in western Canada, the United States, and Mexico montane ranges. Then, we used generalized additive models (GAMs) to evaluate the relationship between MFI and latitude, considering elevation and conifer forest type as covariables. In addition, we mapped the spatial mean fire intervals (SMFIs) through inverse distance weighting (IDW). MFI increased significantly at higher latitudes, influenced by elevation and conifer forest type (R2 = 0.7). Furthermore, we found longer MFI in high elevations of the Madrean Archipelago, the Rocky Mountains, and the Alaska Range. Fire frequency also decreased in the boreal, Douglas-fir, and subalpine forests, with MFI longer than 20 yr. Moreover, the shortest SMFIs were found in the Mexican sierras and the Madrean Archipelago, with fire intervals between 4.1 and 5.6 yr. Our results showed a latitudinal gradient of MFI in conifer forests of western North America, which provides valuable information for fire management and the restoration of natural fire regimes.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"1 1","pages":""},"PeriodicalIF":1.6,"publicationDate":"2022-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48777464","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}
Pub Date : 2022-07-10DOI: 10.1080/02723646.2022.2091312
M. Türkeş, V. Dede, O. Dengiz, H. Senol, S. Serin
ABSTRACT The aim of the study is to reveal geomorphological characteristics and evolution of the periglacial landforms occurred on the summit of the Kaz Dağı (in Turkish) characterised with a specific mountain environment developed under the dry summer subtropical Mediterranean climate. To reach this aim, morphoclimatic processes-characteristics and soil development of the Kaz Dağı district have been evaluated. Kaz Dağı (1774 m a.s.l.), which had been called as the Mount Ida in Greek Mythology, forms a physical geographic border between Çanakkale and Balıkesir provinces. Periglacial landforms consisting of the non-sorted circles including mud circles and stony earth circles, non-sorted steps and cryoturbation terraces and block currents, are found in subalpine vegetation zone at upper boundary of Mount Ida. According to morphogenetic process analysis, on the summit of the Kaz Dağı, the dominant processes are freezing + freezing-thawing in the December-March period, freezing-thawing + weathering in the November and April months, and weat-hering in which frost is not effective in the April-November period. As for pedological processes and mineralogical characteristics of soils formed under the same climatic conditions but on different parent materials of various periglacial landforms, taxonomy of these soils was classified at the Entisol ordo described as young soils.
{"title":"Periglacial landforms and soil formation on summit of the Mount lda (Kaz Dağı), Biga Peninsula-Turkey","authors":"M. Türkeş, V. Dede, O. Dengiz, H. Senol, S. Serin","doi":"10.1080/02723646.2022.2091312","DOIUrl":"https://doi.org/10.1080/02723646.2022.2091312","url":null,"abstract":"ABSTRACT The aim of the study is to reveal geomorphological characteristics and evolution of the periglacial landforms occurred on the summit of the Kaz Dağı (in Turkish) characterised with a specific mountain environment developed under the dry summer subtropical Mediterranean climate. To reach this aim, morphoclimatic processes-characteristics and soil development of the Kaz Dağı district have been evaluated. Kaz Dağı (1774 m a.s.l.), which had been called as the Mount Ida in Greek Mythology, forms a physical geographic border between Çanakkale and Balıkesir provinces. Periglacial landforms consisting of the non-sorted circles including mud circles and stony earth circles, non-sorted steps and cryoturbation terraces and block currents, are found in subalpine vegetation zone at upper boundary of Mount Ida. According to morphogenetic process analysis, on the summit of the Kaz Dağı, the dominant processes are freezing + freezing-thawing in the December-March period, freezing-thawing + weathering in the November and April months, and weat-hering in which frost is not effective in the April-November period. As for pedological processes and mineralogical characteristics of soils formed under the same climatic conditions but on different parent materials of various periglacial landforms, taxonomy of these soils was classified at the Entisol ordo described as young soils.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"531 - 580"},"PeriodicalIF":1.6,"publicationDate":"2022-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43137418","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}
Pub Date : 2022-06-24DOI: 10.1080/02723646.2022.2090656
R. Mittal, S. Said, M. Beg
ABSTRACT The current study explores the planform morphological changes that have occurred in the upper segment of the Yamuna River by using Landsat images from 1979 to 2019. The river segment was divided into 18 sections at equal spacing, viz., S1 to S18, and the centerline and bank line shifting, channel width, alterations in meander geometry and braiding characteristics in terms of sinuosity index (SI) and braiding index (BI) were evaluated. The results indicate a maximum centerline shifting eastward at section S-5 and westward at S17 during 1999, with respect to the base year of 1979. The average eastward and westward centerline shifting remained insignificant. The average west bank shifting ranged from 0.407 km to 0.892 km east and 0.440 km to 0.418 km west, indicating relatively higher west bank shifting towards east. The average east bank shifting ranged from 0.335 km to 0.505 km east and 0.344 km to 0.896 km west, indicating a narrowing of the bank width throughout the segment length. During the assessment period, the river segment exhibited sinuous characteristics and non-braided behavior. The outcomes of this study could be useful in predicting future trends in river shifting and developing sustainable land use planning strategies along floodplains.
{"title":"Assessment of Changes in Planform Morphology of the Upper Yamuna River Segment, India, Using Remote Sensing and GIS","authors":"R. Mittal, S. Said, M. Beg","doi":"10.1080/02723646.2022.2090656","DOIUrl":"https://doi.org/10.1080/02723646.2022.2090656","url":null,"abstract":"ABSTRACT The current study explores the planform morphological changes that have occurred in the upper segment of the Yamuna River by using Landsat images from 1979 to 2019. The river segment was divided into 18 sections at equal spacing, viz., S1 to S18, and the centerline and bank line shifting, channel width, alterations in meander geometry and braiding characteristics in terms of sinuosity index (SI) and braiding index (BI) were evaluated. The results indicate a maximum centerline shifting eastward at section S-5 and westward at S17 during 1999, with respect to the base year of 1979. The average eastward and westward centerline shifting remained insignificant. The average west bank shifting ranged from 0.407 km to 0.892 km east and 0.440 km to 0.418 km west, indicating relatively higher west bank shifting towards east. The average east bank shifting ranged from 0.335 km to 0.505 km east and 0.344 km to 0.896 km west, indicating a narrowing of the bank width throughout the segment length. During the assessment period, the river segment exhibited sinuous characteristics and non-braided behavior. The outcomes of this study could be useful in predicting future trends in river shifting and developing sustainable land use planning strategies along floodplains.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"446 - 477"},"PeriodicalIF":1.6,"publicationDate":"2022-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48342418","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}
Pub Date : 2022-06-15DOI: 10.1080/02723646.2022.2089446
L. Salemi, Robson Willians da Costa Silva, Rafael Pires Fernandes, Tatiana Morgan Bertelli de Andrade, P. Camargo, L. Martinelli, J. M. de Moraes
ABSTRACT A number of riparian ecosystem functions such as reducing chemicals are associated with high soil moisture conditions. Finding easy-to-measure riparian features that indicate soil moisture regime in riparian ecosystem may of use in environmental management. In this study, we answered the following question: can streambank height, on which these riparian zones are, indicate soil moisture regime? By measuring soil matric potential (0.15–0.9 m depth) and water table depth on a weekly basis at three forested riparian zones on different bank heights (low, moderate and high) and under a similar soil type, we demonstrate that riparian zones on high-to-moderate streambank height (h ≥ 1 m) generally have lower water table compared to riparian zones on low streambanks (h ≤ 0.3 m). This difference on water table depth led to significant differences in soil matric potential as water table depth lowers. However, in order to predict soil moisture regime more accurately, streambank height must be associated with a detailed field description of local factors such as soil type which can help in explaining deviations from the expected pattern of soil moisture as shown in moderate and high.
{"title":"Can streambank height indicate soil moisture regime of riparian zones? A case study in deep soils of a first-order watershed in Southeast Brazil","authors":"L. Salemi, Robson Willians da Costa Silva, Rafael Pires Fernandes, Tatiana Morgan Bertelli de Andrade, P. Camargo, L. Martinelli, J. M. de Moraes","doi":"10.1080/02723646.2022.2089446","DOIUrl":"https://doi.org/10.1080/02723646.2022.2089446","url":null,"abstract":"ABSTRACT A number of riparian ecosystem functions such as reducing chemicals are associated with high soil moisture conditions. Finding easy-to-measure riparian features that indicate soil moisture regime in riparian ecosystem may of use in environmental management. In this study, we answered the following question: can streambank height, on which these riparian zones are, indicate soil moisture regime? By measuring soil matric potential (0.15–0.9 m depth) and water table depth on a weekly basis at three forested riparian zones on different bank heights (low, moderate and high) and under a similar soil type, we demonstrate that riparian zones on high-to-moderate streambank height (h ≥ 1 m) generally have lower water table compared to riparian zones on low streambanks (h ≤ 0.3 m). This difference on water table depth led to significant differences in soil matric potential as water table depth lowers. However, in order to predict soil moisture regime more accurately, streambank height must be associated with a detailed field description of local factors such as soil type which can help in explaining deviations from the expected pattern of soil moisture as shown in moderate and high.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"433 - 445"},"PeriodicalIF":1.6,"publicationDate":"2022-06-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47539983","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}
Pub Date : 2022-06-10DOI: 10.1080/02723646.2022.2080798
Michael Vinicius de Sordi, A. Salgado, Claudia Mendes Cordeiro, António Alberto Teixeira Gomes, Luiz Fernando de Paula Barros, Antônio Pereira Magalhães Júnior
ABSTRACT Passive margins typically present escarpments that separate high relief coastal draining catchments from lower-relief inland ones. Widespread drainage reorganization processes in these areas commonly lead to drainage divide retreat inland. This study examines how unfavorable natural factors—long distance from the regional base level, dry climate, and resistant basement lithology—interfere in the processes of inland advance of coastal catchments. Therefore, morphological evidence of drainage reorganization was identified within the northern Serra do Espinhaço Mountain range, and Gilbert’s metrics and χ values were calculated. Thisrange forms a significant drainage divide along South America's passive margin, located hundreds of kilometers inland. It is also characterized by erosion-resistant quartzites substratum and currently experiences a semiarid climate. Our results demonstrate that while the northern Serra do Espinhaço is not a typical passive margin escarpment, it behaves like one since this mountain range acts as a divider between rivers that drain directly into the Atlantic and rivers draining westwards towards the continent's interior. This significant drainage divide retreats inland, driven by ocean draining rivers headward erosion through captures despite adverse geographical location and geological conditions. Divide retreat is ongoing along South America's passive margin, and this process has not yet reached equilibrium.
摘要被动边缘通常存在将高起伏海岸排水集水区与低起伏内陆排水集水区分隔开来的悬崖。这些地区广泛的排水重组过程通常会导致排水鸿沟向内陆退缩。本研究考察了不利的自然因素——距离区域基准面较远、气候干燥和基底岩性具有抵抗力——如何干扰沿海集水区向内陆推进的过程。因此，在Serra do Espinhaço山脉北部发现了排水重组的形态学证据，并计算了Gilbert度量和χ值。这个山脉沿着南美洲内陆数百公里的被动边缘形成了一个重要的排水分水岭。它还具有耐侵蚀石英岩底层的特点，目前处于半干旱气候。我们的研究结果表明，虽然Serra do Espinhaço北部不是一个典型的被动边缘悬崖，但它的行为就像一个悬崖，因为这个山脉是直接流入大西洋的河流和向西流入大陆内陆的河流之间的分隔带。尽管地理位置和地质条件不利，但由于海洋排水河流通过捕获造成的源头侵蚀，这一巨大的排水鸿沟向内陆退缩。分歧正在南美洲的被动边缘消退，这一过程尚未达到平衡。
{"title":"Drainage network evolution and divide retreat along a passive margin: the permanence of disequilibrium under unfavorable natural conditions in eastern south america","authors":"Michael Vinicius de Sordi, A. Salgado, Claudia Mendes Cordeiro, António Alberto Teixeira Gomes, Luiz Fernando de Paula Barros, Antônio Pereira Magalhães Júnior","doi":"10.1080/02723646.2022.2080798","DOIUrl":"https://doi.org/10.1080/02723646.2022.2080798","url":null,"abstract":"ABSTRACT Passive margins typically present escarpments that separate high relief coastal draining catchments from lower-relief inland ones. Widespread drainage reorganization processes in these areas commonly lead to drainage divide retreat inland. This study examines how unfavorable natural factors—long distance from the regional base level, dry climate, and resistant basement lithology—interfere in the processes of inland advance of coastal catchments. Therefore, morphological evidence of drainage reorganization was identified within the northern Serra do Espinhaço Mountain range, and Gilbert’s metrics and χ values were calculated. Thisrange forms a significant drainage divide along South America's passive margin, located hundreds of kilometers inland. It is also characterized by erosion-resistant quartzites substratum and currently experiences a semiarid climate. Our results demonstrate that while the northern Serra do Espinhaço is not a typical passive margin escarpment, it behaves like one since this mountain range acts as a divider between rivers that drain directly into the Atlantic and rivers draining westwards towards the continent's interior. This significant drainage divide retreats inland, driven by ocean draining rivers headward erosion through captures despite adverse geographical location and geological conditions. Divide retreat is ongoing along South America's passive margin, and this process has not yet reached equilibrium.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"405 - 432"},"PeriodicalIF":1.6,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44718978","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}
Pub Date : 2022-04-21DOI: 10.1080/02723646.2022.2068405
Supriya Ghosh, Prasanta Mandal, B. Bera
ABSTRACT Confluence of river channels plays a significant role in channel avulsion, flood plain evolution and dynamics of the fluvial system. The principal objectives of the present study are (i) to analyze the direction and degree of confluence shifting through the recent past (1955–2020) by applying geospatial techniques and (ii) to find out the probable causes of confluence dynamics of the Raidak river system within quaternary geological sites of a Himalayan foreland basin in West Bengal, India, applying fluvio-geomorphological and sedimentary bank facies. Modified Normalized Difference Water Index method is also used. The result shows that the Raidak-Sankosh confluence (RSC) shifted by 9.94 km of the total distance between 1955 and 2020, whereas Raidak-I-Torsa confluence (RTC) has shifted 4.29 km overall distance during the same period. Both confluences were shifted toward the south and south-east directions. Total erosion and accretion area at the proximity of RSC and RTC has been registered as 40.1 sq km and 47.57 sq km and 39.67 sq km and 37.99 sq km, respectively, for the 65-year period. The key factors of confluence dynamics are regular flood events and channel avulsion, non-cohesive bank materials and huge channel bed sedimentation with multiple bars.
{"title":"Geospatial and fluvio-geomorphological investigation of confluence dynamics of river Raidak within Himalayan foreland basin, India","authors":"Supriya Ghosh, Prasanta Mandal, B. Bera","doi":"10.1080/02723646.2022.2068405","DOIUrl":"https://doi.org/10.1080/02723646.2022.2068405","url":null,"abstract":"ABSTRACT Confluence of river channels plays a significant role in channel avulsion, flood plain evolution and dynamics of the fluvial system. The principal objectives of the present study are (i) to analyze the direction and degree of confluence shifting through the recent past (1955–2020) by applying geospatial techniques and (ii) to find out the probable causes of confluence dynamics of the Raidak river system within quaternary geological sites of a Himalayan foreland basin in West Bengal, India, applying fluvio-geomorphological and sedimentary bank facies. Modified Normalized Difference Water Index method is also used. The result shows that the Raidak-Sankosh confluence (RSC) shifted by 9.94 km of the total distance between 1955 and 2020, whereas Raidak-I-Torsa confluence (RTC) has shifted 4.29 km overall distance during the same period. Both confluences were shifted toward the south and south-east directions. Total erosion and accretion area at the proximity of RSC and RTC has been registered as 40.1 sq km and 47.57 sq km and 39.67 sq km and 37.99 sq km, respectively, for the 65-year period. The key factors of confluence dynamics are regular flood events and channel avulsion, non-cohesive bank materials and huge channel bed sedimentation with multiple bars.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"207 - 241"},"PeriodicalIF":1.6,"publicationDate":"2022-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45614674","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}
Pub Date : 2022-04-19DOI: 10.1080/02723646.2022.2064065
W. Imsong, G. T. Thong, Shubhra Sharma
ABSTRACT The Belt of Schuppen (BoS) of Nagaland is a NE-SW trending linear zone lying adjacent to the Brahmaputra Valley of Assam in Northeast India. Geomorphic, stratigraphic and chronologic data from the Dzüdza and Chathe river valleys that cut across the BoS have been studied to understand the influence of climate on landform evolution in parts of the BoS. Fluvial landforms in the Dzüdza and Chathe river valleys evolved in four major phases bracketed between 22–17 ka (Phase IV), 13–9.0 ka (Phase III), 7–5 ka (Phase II) and 3.5–1.5 ka (Phase I), indicating multi-centennial to millennial changes in monsoon intensity. Climatically, Phase-III was dominated by valley aggradation initiated by onset of the Indian Summer Monsoon (ISM) and persisted intermittently till the early Holocene-strengthened ISM. The other phases of aggradation are attributed to transient or weak ISM. The present study suggests that fluvial aggradation was associated with enhanced precipitation and sediment supply in the BoS valley, whereas the transient and weak ISM is manifested in episodic pulses of alluvial ingression from the tributaries to the trunk valleys; along with post depositional tectonic modifications of the landforms.
{"title":"Causes of pulsating evolution of fluvial landforms since the marine isotopic stage-2 in the belt of Schuppen, Nagaland, NE India","authors":"W. Imsong, G. T. Thong, Shubhra Sharma","doi":"10.1080/02723646.2022.2064065","DOIUrl":"https://doi.org/10.1080/02723646.2022.2064065","url":null,"abstract":"ABSTRACT The Belt of Schuppen (BoS) of Nagaland is a NE-SW trending linear zone lying adjacent to the Brahmaputra Valley of Assam in Northeast India. Geomorphic, stratigraphic and chronologic data from the Dzüdza and Chathe river valleys that cut across the BoS have been studied to understand the influence of climate on landform evolution in parts of the BoS. Fluvial landforms in the Dzüdza and Chathe river valleys evolved in four major phases bracketed between 22–17 ka (Phase IV), 13–9.0 ka (Phase III), 7–5 ka (Phase II) and 3.5–1.5 ka (Phase I), indicating multi-centennial to millennial changes in monsoon intensity. Climatically, Phase-III was dominated by valley aggradation initiated by onset of the Indian Summer Monsoon (ISM) and persisted intermittently till the early Holocene-strengthened ISM. The other phases of aggradation are attributed to transient or weak ISM. The present study suggests that fluvial aggradation was associated with enhanced precipitation and sediment supply in the BoS valley, whereas the transient and weak ISM is manifested in episodic pulses of alluvial ingression from the tributaries to the trunk valleys; along with post depositional tectonic modifications of the landforms.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"381 - 404"},"PeriodicalIF":1.6,"publicationDate":"2022-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46386444","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}
Pub Date : 2022-02-18DOI: 10.1080/02723646.2022.2042916
N. Teale, D. A. Robinson
ABSTRACT This paper examines precipitation associated with large-scale patterns of water vapor transport in the eastern United States. Daily 4 km gridded precipitation from PRISM (1981–2017) is sorted into a subset according to previously defined patterns of water vapor transport supplying the moisture on each day. These subsets are then analyzed to characterize the precipitation associated with each water vapor transport pattern. While each moisture transport pattern is associated with at least occasional precipitation, with seasonal variations, the highest precipitation averages are issued from near-coastal and coastal moisture transport patterns. Moisture transport patterns emanating from the Gulf of Mexico are associated with highest average precipitation inland. Each pattern has a spatially distinct contribution to annual and seasonal precipitation totals. The water vapor transport patterns of moderate intensity and moderate associated precipitation contribute the most to average annual precipitation. Most moisture transport patterns are associated with statistically significant increases in areas of very heavy precipitation (x ≥ 50 mm). By identifying which atmospheric moisture transport patterns are responsible for increasing areas of very heavy precipitation, and by characterizing the precipitation totals and contribution associated with each, this paper demonstrates the utility of examining precipitation variability through moisture transport patterns.
{"title":"Eastern US precipitation investigated through patterns of moisture transport","authors":"N. Teale, D. A. Robinson","doi":"10.1080/02723646.2022.2042916","DOIUrl":"https://doi.org/10.1080/02723646.2022.2042916","url":null,"abstract":"ABSTRACT This paper examines precipitation associated with large-scale patterns of water vapor transport in the eastern United States. Daily 4 km gridded precipitation from PRISM (1981–2017) is sorted into a subset according to previously defined patterns of water vapor transport supplying the moisture on each day. These subsets are then analyzed to characterize the precipitation associated with each water vapor transport pattern. While each moisture transport pattern is associated with at least occasional precipitation, with seasonal variations, the highest precipitation averages are issued from near-coastal and coastal moisture transport patterns. Moisture transport patterns emanating from the Gulf of Mexico are associated with highest average precipitation inland. Each pattern has a spatially distinct contribution to annual and seasonal precipitation totals. The water vapor transport patterns of moderate intensity and moderate associated precipitation contribute the most to average annual precipitation. Most moisture transport patterns are associated with statistically significant increases in areas of very heavy precipitation (x ≥ 50 mm). By identifying which atmospheric moisture transport patterns are responsible for increasing areas of very heavy precipitation, and by characterizing the precipitation totals and contribution associated with each, this paper demonstrates the utility of examining precipitation variability through moisture transport patterns.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"43 1","pages":"589 - 613"},"PeriodicalIF":1.6,"publicationDate":"2022-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48711860","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}
Pub Date : 2022-02-16DOI: 10.1080/02723646.2022.2032922
M. Özdemir, Hülya Kaymak, Enes Ertan Kulaksız
ABSTRACT In this study, the weathering forms on the andesite of volcanic Mount Ağın (1807 m) located within the borders of Afyonkarahisar province in the Central Western Anatolia part of the Aegean Region were investigated. The climatic characteristics of the study area, chemical and mineralogical-petrographic properties of the andesites, porosity, diaclase systems, and biogenic erosion cause formation of characteristic shape generations on the andesites. In the field, andesites have been weathered by mechanical effects based on salt crystallization, freeze-thaw, shrinkage-expansion, and by the chemical effects of waterbased on hydrolysis-hydration-oxidation. The weathering product formed as a result of differential weathering has been subsequently moved by erosion, and the unweathered parts came to the surface to form distinctive forms in the topography. Weathering forms seen on the andesites have been investigated in detail for the first time in Turkey. The aim of this study is to reveal the close relationship between erosional forms of “andesite topography” and the factors playing a significant role in the formation of these weathering features. According to field observations and laboratory analyses, the original weathering forms on the mass have been explored and classified, and consequently revealed their formation mechanism and morphometric properties.
{"title":"Weathering geomorphology of Mount Ağın Andesites located in cool humid environment in Afyonkarahisar/Turkey","authors":"M. Özdemir, Hülya Kaymak, Enes Ertan Kulaksız","doi":"10.1080/02723646.2022.2032922","DOIUrl":"https://doi.org/10.1080/02723646.2022.2032922","url":null,"abstract":"ABSTRACT In this study, the weathering forms on the andesite of volcanic Mount Ağın (1807 m) located within the borders of Afyonkarahisar province in the Central Western Anatolia part of the Aegean Region were investigated. The climatic characteristics of the study area, chemical and mineralogical-petrographic properties of the andesites, porosity, diaclase systems, and biogenic erosion cause formation of characteristic shape generations on the andesites. In the field, andesites have been weathered by mechanical effects based on salt crystallization, freeze-thaw, shrinkage-expansion, and by the chemical effects of waterbased on hydrolysis-hydration-oxidation. The weathering product formed as a result of differential weathering has been subsequently moved by erosion, and the unweathered parts came to the surface to form distinctive forms in the topography. Weathering forms seen on the andesites have been investigated in detail for the first time in Turkey. The aim of this study is to reveal the close relationship between erosional forms of “andesite topography” and the factors playing a significant role in the formation of these weathering features. According to field observations and laboratory analyses, the original weathering forms on the mass have been explored and classified, and consequently revealed their formation mechanism and morphometric properties.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"44 1","pages":"330 - 361"},"PeriodicalIF":1.6,"publicationDate":"2022-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46037785","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}
Pub Date : 2022-02-14DOI: 10.1080/02723646.2022.2035891
M. Moreno, M. Sugg, Camila Moreno, Dr. Johnathan Sugg, Dr. Baker L. Perry, J. Runkle, R. Leeper
ABSTRACT Droughts are a natural, recurrent climate extreme that can inflict long-lasting devastation on natural ecosystems and socio-economic sectors. Unlike other natural hazards, drought onset is insidious and often affects a greater spatial extent over a prolonged temporal scale. In the United States the evolution of drought and its impacts are typically region-specific and intensified precipitation variability may obscure how drought may manifest. In this study, we examine the spatiotemporal trends of drought using self-organizing maps (SOM), competitive learning subset of artificial neural networks (ANN), requiring unsupervised training of inputs. We introduced monthly Palmer Drought Severity Index (PDSI) values to the SOM to identify existing clusters of wetting and drying patterns from 1895 to 2016. After training, we created cartographic visualizations of the SOM output and conducted a subsequent time-series analysis to link with the geographic patterns of drought. Over the last 40 years, precipitation intensified in the Northeast, Midwest, and upper Great Plains across several nodes. Across the majority of SOM patterns, we identified no significant changes of drying or wetting patterns over the last century for the greater part of the CONUS.
{"title":"Examining spatiotemporal trends of drought in the conterminous United States using self-organizing maps","authors":"M. Moreno, M. Sugg, Camila Moreno, Dr. Johnathan Sugg, Dr. Baker L. Perry, J. Runkle, R. Leeper","doi":"10.1080/02723646.2022.2035891","DOIUrl":"https://doi.org/10.1080/02723646.2022.2035891","url":null,"abstract":"ABSTRACT Droughts are a natural, recurrent climate extreme that can inflict long-lasting devastation on natural ecosystems and socio-economic sectors. Unlike other natural hazards, drought onset is insidious and often affects a greater spatial extent over a prolonged temporal scale. In the United States the evolution of drought and its impacts are typically region-specific and intensified precipitation variability may obscure how drought may manifest. In this study, we examine the spatiotemporal trends of drought using self-organizing maps (SOM), competitive learning subset of artificial neural networks (ANN), requiring unsupervised training of inputs. We introduced monthly Palmer Drought Severity Index (PDSI) values to the SOM to identify existing clusters of wetting and drying patterns from 1895 to 2016. After training, we created cartographic visualizations of the SOM output and conducted a subsequent time-series analysis to link with the geographic patterns of drought. Over the last 40 years, precipitation intensified in the Northeast, Midwest, and upper Great Plains across several nodes. Across the majority of SOM patterns, we identified no significant changes of drying or wetting patterns over the last century for the greater part of the CONUS.","PeriodicalId":54618,"journal":{"name":"Physical Geography","volume":"43 1","pages":"680 - 699"},"PeriodicalIF":1.6,"publicationDate":"2022-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47650436","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}
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