Fine particulate matter (PM2.5) is a major source of air pollution and exerts serious impacts on human health. The 3D urban landscape patterns can significantly affect the diffusion and emissions of PM2.5. However, studies on the relationships between 3D urban landscape patterns and PM2.5 pollution across different seasons remain understudied. With the ground-level air pollutants estimated by the remote sensing and fine-scale building information, this study applied the multiscale geographically weighted regression model to explore such relationships. Wuhan, the largest metropolis in Central China, was selected as the study area for the application of our methodology. The results showed that the direction, degree, and scale of the effect of 3D urban landscape patterns on PM2.5 pollution varied across seasons. For building height, the standard deviation of building height had a significant positive correlation with PM2.5 all year round. For building density, the building count density showed a significant positive correlation with PM2.5 in general, with the bandwidth in winter and autumn smaller than in spring and summer. The building plan area fraction exerted both positive and negative influences on PM2.5, dependent on season and location. The bandwidth of it gradually increased from spring to winter, with the effect changing from local to regional scale. For building volume, the floor area ratio showed a significant negative correlation with PM2.5 in winter and autumn, and a localized effect was found, especially in winter. The findings of this study provide practical implications for urban planning and policy making to mitigate PM2.5 pollution in the rapidly urbanizing regions.
{"title":"Exploring the relationships between 3D urban landscape patterns and PM2.5 pollution using the multiscale geographic weighted regression model","authors":"Haoyan Duan, Qian Cao, Lunche Wang, Xihui Gu, Khosro Ashrafi","doi":"10.1177/03091333241241458","DOIUrl":"https://doi.org/10.1177/03091333241241458","url":null,"abstract":"Fine particulate matter (PM<jats:sub>2.5</jats:sub>) is a major source of air pollution and exerts serious impacts on human health. The 3D urban landscape patterns can significantly affect the diffusion and emissions of PM<jats:sub>2.5</jats:sub>. However, studies on the relationships between 3D urban landscape patterns and PM<jats:sub>2.5</jats:sub> pollution across different seasons remain understudied. With the ground-level air pollutants estimated by the remote sensing and fine-scale building information, this study applied the multiscale geographically weighted regression model to explore such relationships. Wuhan, the largest metropolis in Central China, was selected as the study area for the application of our methodology. The results showed that the direction, degree, and scale of the effect of 3D urban landscape patterns on PM<jats:sub>2.5</jats:sub> pollution varied across seasons. For building height, the standard deviation of building height had a significant positive correlation with PM<jats:sub>2.5</jats:sub> all year round. For building density, the building count density showed a significant positive correlation with PM<jats:sub>2.5</jats:sub> in general, with the bandwidth in winter and autumn smaller than in spring and summer. The building plan area fraction exerted both positive and negative influences on PM<jats:sub>2.5</jats:sub>, dependent on season and location. The bandwidth of it gradually increased from spring to winter, with the effect changing from local to regional scale. For building volume, the floor area ratio showed a significant negative correlation with PM<jats:sub>2.5</jats:sub> in winter and autumn, and a localized effect was found, especially in winter. The findings of this study provide practical implications for urban planning and policy making to mitigate PM<jats:sub>2.5</jats:sub> pollution in the rapidly urbanizing regions.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"237 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140302115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-02-23DOI: 10.1177/03091333241236394
Zixuan Chen, Qiong Li, Pushuang Li, Jiantao Zhou, Yating Su, Weiming Liu, Yuanlong Luo, Chen Wen, Xuechao Xu, Shengli Yang
A consensus has not yet been reached on effects of climate change and driving mechanisms between the Tibetan Plateau (TP) and adjacent monsoonal areas during the Marine Isotope Stage 3 (MIS 3). Loess–paleosol sequences from the TP provide valuable information about the MIS 3 environmental history. Detailed color index and a diffuse reflectance spectral (DRS) analysis of Zhouqu (ZQ) loess from the Western Qinling Mountains were conducted to investigate climate change on the eastern margin of the TP during the MIS 3. Our results show that the variations in color index and iron oxide content in ZQ loess are mainly caused by the pedogenesis and climate conditions. The lightness (L*) value and hematite (Hm) content were used to reconstruct the precipitation history and temperature changes, respectively. The reconstructed records revealed that climate change during the MIS 3 was characterized by high frequency and large amplitude, with millennial-scale changes superimposed on orbital-scale changes. Warm–humid climate occurred in the late MIS 3, while the early climate of MIS 3 was relatively cold–dry. The Indian summer monsoon (ISM) and temperature variations during the MIS 3 mainly occurred due to obliquity and precession. The North Atlantic cooling led to the southward movement of the Intertropical Convergence Zone, and the downstream cooling of the atmosphere by the westerly jet could result in events on a millennial-scale in the eastern margin of the TP. The interhemispheric forcing may play an important role in driving the strong summer monsoon in the late MIS 3.
关于青藏高原（TP）和邻近季风区在海洋同位素第三阶段（MIS 3）期间气候变化的影响和驱动机制尚未达成共识。青藏高原的黄土-页岩沉积序列提供了有关 MIS 3 环境历史的宝贵信息。我们对西秦岭舟曲黄土进行了详细的颜色指数和漫反射光谱分析，以研究MIS 3期间TP东缘的气候变化。结果表明，舟曲黄土颜色指数和氧化铁含量的变化主要是由成土机制和气候条件引起的。利用光度（L*）值和赤铁矿（Hm）含量分别重建了降水历史和温度变化。重建的记录显示，MIS 3 期间的气候变化具有高频率、大振幅的特点，千年尺度的变化叠加在轨道尺度的变化之上。MIS 3晚期气候温暖湿润，而MIS 3早期气候相对寒冷干燥。印度夏季季风（ISM）和温度的变化主要发生在 MIS 3 期间，是由偏斜和前向引起的。北大西洋的冷却导致热带辐合带南移，西风喷流对大气的下游冷却可能导致热带辐合带东缘发生千年尺度的事件。在 MIS 3 晚期，半球间强迫可能在推动夏季季风强劲方面发挥了重要作用。
{"title":"High-resolution climate change during the Marine Isotope Stage 3 revealed by Zhouqu loess in the eastern margin of the Tibetan Plateau","authors":"Zixuan Chen, Qiong Li, Pushuang Li, Jiantao Zhou, Yating Su, Weiming Liu, Yuanlong Luo, Chen Wen, Xuechao Xu, Shengli Yang","doi":"10.1177/03091333241236394","DOIUrl":"https://doi.org/10.1177/03091333241236394","url":null,"abstract":"A consensus has not yet been reached on effects of climate change and driving mechanisms between the Tibetan Plateau (TP) and adjacent monsoonal areas during the Marine Isotope Stage 3 (MIS 3). Loess–paleosol sequences from the TP provide valuable information about the MIS 3 environmental history. Detailed color index and a diffuse reflectance spectral (DRS) analysis of Zhouqu (ZQ) loess from the Western Qinling Mountains were conducted to investigate climate change on the eastern margin of the TP during the MIS 3. Our results show that the variations in color index and iron oxide content in ZQ loess are mainly caused by the pedogenesis and climate conditions. The lightness (L*) value and hematite (Hm) content were used to reconstruct the precipitation history and temperature changes, respectively. The reconstructed records revealed that climate change during the MIS 3 was characterized by high frequency and large amplitude, with millennial-scale changes superimposed on orbital-scale changes. Warm–humid climate occurred in the late MIS 3, while the early climate of MIS 3 was relatively cold–dry. The Indian summer monsoon (ISM) and temperature variations during the MIS 3 mainly occurred due to obliquity and precession. The North Atlantic cooling led to the southward movement of the Intertropical Convergence Zone, and the downstream cooling of the atmosphere by the westerly jet could result in events on a millennial-scale in the eastern margin of the TP. The interhemispheric forcing may play an important role in driving the strong summer monsoon in the late MIS 3.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"15 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951418","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-02-22DOI: 10.1177/03091333241235158
Joseph R McAuliffe, Norbert Jürgens, Felicitas Gunter, Antje Burke
Circular depressions are concave, shallow depressions found on planar landscape surfaces in the southern Namib Desert. They occur on gravelly substrates with nearly level to very slightly inclined surfaces. The depressions range from 6 to 10 m in diameter with centers typically depressed 10–20 cm below the level of the surrounding terrain. Locations of individual circular depressions were mapped at one site using ground-based measurements and at three additional sites using Google Earth imagery. At all sites, circular depressions are highly overdispersed with densities ranging from approximately 10–20/ha and corresponding nearest neighbor distances of 17–24 m. Large fragments of weathered calcrete and stones occur on soil surfaces surrounding circular depressions, but not within the depressions. Circular depressions at one site contained active burrow systems of Brants’ whistling rat ( Paratomys brantsii). Bioturbation by these rodents contributes to the non-cohesive nature of the sandy substrate, which promotes aeolian deflation and formation of the depressions. Excavations of the burrow systems by the honey badger ( Mellivora capensis) in search of rodent prey can transfer large stones and calcrete fragments from the subsurface to the surface and subsequently move those materials about the surface. Even if such sequential, horizontal displacements are in random directions, such movements can eventually yield a central, clast-free area surrounded by a peripheral zone where the clasts accumulate once they have been displaced beyond the margin of the area to which the predator is drawn in search of rodent prey. A conceptual model consisting of a two-dimensional random walk of large clasts about the surface until they are displaced from the focal “arena” of rodent occupation provides a novel explanation for origin of a spatially organized pattern that is initiated through the random displacement of those materials. Comparable microtopographic patterning associated with bioturbation in other arid and semi-arid environments may have similar origins.
{"title":"Occurrence and formation of clast-free circular depressions in the southern Namib Desert, Tsau ǁKhaeb (Sperrgebiet) National Park, Namibia","authors":"Joseph R McAuliffe, Norbert Jürgens, Felicitas Gunter, Antje Burke","doi":"10.1177/03091333241235158","DOIUrl":"https://doi.org/10.1177/03091333241235158","url":null,"abstract":"Circular depressions are concave, shallow depressions found on planar landscape surfaces in the southern Namib Desert. They occur on gravelly substrates with nearly level to very slightly inclined surfaces. The depressions range from 6 to 10 m in diameter with centers typically depressed 10–20 cm below the level of the surrounding terrain. Locations of individual circular depressions were mapped at one site using ground-based measurements and at three additional sites using Google Earth imagery. At all sites, circular depressions are highly overdispersed with densities ranging from approximately 10–20/ha and corresponding nearest neighbor distances of 17–24 m. Large fragments of weathered calcrete and stones occur on soil surfaces surrounding circular depressions, but not within the depressions. Circular depressions at one site contained active burrow systems of Brants’ whistling rat ( Paratomys brantsii). Bioturbation by these rodents contributes to the non-cohesive nature of the sandy substrate, which promotes aeolian deflation and formation of the depressions. Excavations of the burrow systems by the honey badger ( Mellivora capensis) in search of rodent prey can transfer large stones and calcrete fragments from the subsurface to the surface and subsequently move those materials about the surface. Even if such sequential, horizontal displacements are in random directions, such movements can eventually yield a central, clast-free area surrounded by a peripheral zone where the clasts accumulate once they have been displaced beyond the margin of the area to which the predator is drawn in search of rodent prey. A conceptual model consisting of a two-dimensional random walk of large clasts about the surface until they are displaced from the focal “arena” of rodent occupation provides a novel explanation for origin of a spatially organized pattern that is initiated through the random displacement of those materials. Comparable microtopographic patterning associated with bioturbation in other arid and semi-arid environments may have similar origins.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"5 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-02-16DOI: 10.1177/03091333241229919
Nazimul Islam, Torsten Vennemann, Ulf Büntgen, Paolo Cherubini, Stuart N Lane
Recent developments in tree-ring research offer great potential for reconstructing past climate changes; determining the frequencies of natural hazards; and assessing the availability of freshwater resources over timescales that extend well into the pre-instrumental period. Here, we review the state of dendrochronological research in the Himalaya and outline future directions for tree-ring-based hydrological reconstructions in a region that has a pressing societal need to understand the causes and consequences of past, present and future changes in the hydrological cycle. We used ‘tree ring’ and ‘Himalaya’ as keywords to identify scholarly articles from the Web of Science that were published between 1994 and 2022. The resulting 173 publications were separated by their spatial coverage into the western, central and eastern Himalaya, as well as their scientific purpose (e.g. reconstructing growth-climate relationships, temperature, precipitation, streamflow, floods, droughts, etc.). Our analysis shows that dendrochronological research in the Himalaya primarily focused on understanding growth-climate relationships using annual tree-ring widths measurements obtained for coniferous species, and their application in climate reconstructions. Reconstructions of hydrological processes such as streamflows, and extremes such as glacial and landslide lake outburst floods, have received less attention. Recent advances in dendrochronology, including blue intensity (BI), quantitative wood anatomy (QWA), and tree-ring stable isotopes (TRSI) should be combined to improve the resolution and accuracy of hydrological reconstructions in all parts of the Himalaya. Such studies may allow us to better understand the effects of climate change and the Himalayan water resources for its lowland surroundings. They may also facilitate decision-making processes for mitigating the impacts of climate change on natural hazards, and for better managing water resources in the region.
树环研究的最新发展为重建过去的气候变化、确定自然灾害发生的频率以及评估淡水资源的可用性提供了巨大的潜力，其时间尺度远远超过了前仪器时期。在此，我们回顾了喜马拉雅地区的树木年代学研究现状，并概述了该地区基于树环的水文重建的未来方向，因为该地区的社会迫切需要了解过去、现在和未来水文循环变化的原因和后果。我们使用 "树环 "和 "喜马拉雅 "作为关键词，从 Web of Science 中查找 1994 年至 2022 年间发表的学术文章。根据其空间覆盖范围（喜马拉雅西部、中部和东部）及其科学目的（如重建生长与气候的关系、温度、降水、溪流、洪水、干旱等），我们将这 173 篇文章进行了分类。我们的分析表明，喜马拉雅地区的树木年代学研究主要集中在利用针叶树种的年轮宽度测量来了解生长与气候的关系，以及在气候重建中的应用。对溪流等水文过程以及冰川和滑坡湖溃决洪水等极端事件的重建则较少关注。应结合树木年代学的最新进展，包括蓝强度（BI）、定量木材解剖（QWA）和树环稳定同位素（TRSI），提高喜马拉雅山所有地区水文重建的分辨率和准确性。这些研究可以让我们更好地了解气候变化的影响以及喜马拉雅山水资源对其周围低地的影响。这些研究还可以促进决策进程，减轻气候变化对自然灾害的影响，更好地管理该地区的水资源。
{"title":"Tree-ring hydrological research in the Himalaya: State of the art and future directions","authors":"Nazimul Islam, Torsten Vennemann, Ulf Büntgen, Paolo Cherubini, Stuart N Lane","doi":"10.1177/03091333241229919","DOIUrl":"https://doi.org/10.1177/03091333241229919","url":null,"abstract":"Recent developments in tree-ring research offer great potential for reconstructing past climate changes; determining the frequencies of natural hazards; and assessing the availability of freshwater resources over timescales that extend well into the pre-instrumental period. Here, we review the state of dendrochronological research in the Himalaya and outline future directions for tree-ring-based hydrological reconstructions in a region that has a pressing societal need to understand the causes and consequences of past, present and future changes in the hydrological cycle. We used ‘tree ring’ and ‘Himalaya’ as keywords to identify scholarly articles from the Web of Science that were published between 1994 and 2022. The resulting 173 publications were separated by their spatial coverage into the western, central and eastern Himalaya, as well as their scientific purpose (e.g. reconstructing growth-climate relationships, temperature, precipitation, streamflow, floods, droughts, etc.). Our analysis shows that dendrochronological research in the Himalaya primarily focused on understanding growth-climate relationships using annual tree-ring widths measurements obtained for coniferous species, and their application in climate reconstructions. Reconstructions of hydrological processes such as streamflows, and extremes such as glacial and landslide lake outburst floods, have received less attention. Recent advances in dendrochronology, including blue intensity (BI), quantitative wood anatomy (QWA), and tree-ring stable isotopes (TRSI) should be combined to improve the resolution and accuracy of hydrological reconstructions in all parts of the Himalaya. Such studies may allow us to better understand the effects of climate change and the Himalayan water resources for its lowland surroundings. They may also facilitate decision-making processes for mitigating the impacts of climate change on natural hazards, and for better managing water resources in the region.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"48 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2024-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951416","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-10-25DOI: 10.1177/03091333231208612
Charlotte Wiman, Tessa Harden, Zhixiong Shen, B. Brandon Curry, Joeri B Reinders, R. Edward Beighley, Samuel E Muñoz
Slackwater deposits representing past flood events provide a robust means to extend systematic gage records further back in time, place historic floods in a longer-term context, and reduce uncertainties in flood hazard analysis. The identification and application of slackwater deposits in riverine paleoflood hydrology has traditionally been limited to arid bedrock-controlled environments and periglacial environments. In this study, we utilize methods developed in humid alluvial settings and apply them to slackwater deposits, one of the first studies to do so. This novel approach uses sediment texture and geochemistry to distinguish slackwater deposits from in situ material in a temperate alluvial setting. We identify multiple slackwater deposits in two rock shelters situated on bluffs adjacent to the lower Ohio River. Flood age estimates are based on optically stimulated luminescence (OSL) dating, and discharge estimates are based on a 1D HEC-RAS model. The uppermost slackwater deposit at both sites corresponds to the AD 1937 historic flood of record (∼31,400 m 3 /s), while another slackwater deposit identified only at the lower elevation site corresponds to a paleoflood that occurred around AD 1650 with a discharge of ∼23,900 m 3 /s. Our findings imply that the AD 1937 flood represents the largest magnitude flood on the lower Ohio River in at least the last 400 years. Inclusion of the paleoflood into a flood frequency analysis for the Ohio River at Louisville reduces uncertainties in large flood quantiles by ∼50%.
{"title":"Large floods on the lower Ohio River inferred from slackwater deposits","authors":"Charlotte Wiman, Tessa Harden, Zhixiong Shen, B. Brandon Curry, Joeri B Reinders, R. Edward Beighley, Samuel E Muñoz","doi":"10.1177/03091333231208612","DOIUrl":"https://doi.org/10.1177/03091333231208612","url":null,"abstract":"Slackwater deposits representing past flood events provide a robust means to extend systematic gage records further back in time, place historic floods in a longer-term context, and reduce uncertainties in flood hazard analysis. The identification and application of slackwater deposits in riverine paleoflood hydrology has traditionally been limited to arid bedrock-controlled environments and periglacial environments. In this study, we utilize methods developed in humid alluvial settings and apply them to slackwater deposits, one of the first studies to do so. This novel approach uses sediment texture and geochemistry to distinguish slackwater deposits from in situ material in a temperate alluvial setting. We identify multiple slackwater deposits in two rock shelters situated on bluffs adjacent to the lower Ohio River. Flood age estimates are based on optically stimulated luminescence (OSL) dating, and discharge estimates are based on a 1D HEC-RAS model. The uppermost slackwater deposit at both sites corresponds to the AD 1937 historic flood of record (∼31,400 m 3 /s), while another slackwater deposit identified only at the lower elevation site corresponds to a paleoflood that occurred around AD 1650 with a discharge of ∼23,900 m 3 /s. Our findings imply that the AD 1937 flood represents the largest magnitude flood on the lower Ohio River in at least the last 400 years. Inclusion of the paleoflood into a flood frequency analysis for the Ohio River at Louisville reduces uncertainties in large flood quantiles by ∼50%.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"44 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135169036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-10-23DOI: 10.1177/03091333231209157
Velagapalli Chiranjeevi, Kamal Singh, D Kishan
This paper analyzes the stabilizing effect of stone dust, granite dust, marble dust, and calcium lignosulphonate on construction materials and natural soils during road construction. The ultimate aim was to enhance the soil’s engineering properties such that the pavement constructed could correctly withstand the load applied. To achieve this, every stabilizer was amalgamated with the soil at various percentages between 5 and 50%. Measurements were made of Atterberg limit tests, moisture content, and specific gravity. The research demonstrated that a diminution in optimal moisture content was seen, with an elevation in maximum dry density and California bearing ratio (CBR). Enhancements in the unconfined compressive strength were also identified. The outcomes determined that the untreated soil’s CBR was 2.27% and in the case of soil with 45% additives, the CBR attained was 5.05%. When the soil was mixed with 50% additives, performance of 30.21%, 17.42%, and 12.82% was exhibited for (a) liquid limit, (b) plastic limit, and (c) plasticity index. Moreover, via the addition of presented stabilizers, the soil’s mechanical properties were elevated appreciably.
{"title":"Soil stabilization by integrating dust particles with calcium lignosulphanate","authors":"Velagapalli Chiranjeevi, Kamal Singh, D Kishan","doi":"10.1177/03091333231209157","DOIUrl":"https://doi.org/10.1177/03091333231209157","url":null,"abstract":"This paper analyzes the stabilizing effect of stone dust, granite dust, marble dust, and calcium lignosulphonate on construction materials and natural soils during road construction. The ultimate aim was to enhance the soil’s engineering properties such that the pavement constructed could correctly withstand the load applied. To achieve this, every stabilizer was amalgamated with the soil at various percentages between 5 and 50%. Measurements were made of Atterberg limit tests, moisture content, and specific gravity. The research demonstrated that a diminution in optimal moisture content was seen, with an elevation in maximum dry density and California bearing ratio (CBR). Enhancements in the unconfined compressive strength were also identified. The outcomes determined that the untreated soil’s CBR was 2.27% and in the case of soil with 45% additives, the CBR attained was 5.05%. When the soil was mixed with 50% additives, performance of 30.21%, 17.42%, and 12.82% was exhibited for (a) liquid limit, (b) plastic limit, and (c) plasticity index. Moreover, via the addition of presented stabilizers, the soil’s mechanical properties were elevated appreciably.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"74 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135412780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-10-14DOI: 10.1177/03091333231206314
Sadao Takaoka
Landslides have received significant attention as an important natural disturbance that maintains biodiversity, but most previous studies have focused on the early stages of succession during years or decades in sites or small watersheds. The present study aimed to determine what regional drivers influence long-term ecological succession in large, ancient landslide scarps across a mountainous region in Japan. A landscape-level analysis of 993 landslide scarps using GIS revealed that climatic factors, especially snowfall, are important regional drivers of vegetation development on landslide head scarps in the region. While vegetation has developed on ancient landslide scarps, not all of them have returned to their pre-landslide vegetation state even though hundreds or thousands of years may have passed. The relationship between the number of vegetation types and maximum snow depth shows that where the maximum snow depth is less than 100 cm, more than 50% of the landslide scarps are covered by one type of vegetation, and the percentage of scarps covered by one type of vegetation decreases with increasing snow cover. The deeper the snow, the more vegetation types tend to develop on the landslide scarps. Since forest vegetation cannot develop due to heavy snow, meadows, grasslands, and shrublands are found on the scarps. It is concluded that the combined effects of both landslide-caused disturbances and climatic factors are creating regional diversity in vegetation types.
{"title":"A landscape-level study on vegetation richness of ancient landslide areas","authors":"Sadao Takaoka","doi":"10.1177/03091333231206314","DOIUrl":"https://doi.org/10.1177/03091333231206314","url":null,"abstract":"Landslides have received significant attention as an important natural disturbance that maintains biodiversity, but most previous studies have focused on the early stages of succession during years or decades in sites or small watersheds. The present study aimed to determine what regional drivers influence long-term ecological succession in large, ancient landslide scarps across a mountainous region in Japan. A landscape-level analysis of 993 landslide scarps using GIS revealed that climatic factors, especially snowfall, are important regional drivers of vegetation development on landslide head scarps in the region. While vegetation has developed on ancient landslide scarps, not all of them have returned to their pre-landslide vegetation state even though hundreds or thousands of years may have passed. The relationship between the number of vegetation types and maximum snow depth shows that where the maximum snow depth is less than 100 cm, more than 50% of the landslide scarps are covered by one type of vegetation, and the percentage of scarps covered by one type of vegetation decreases with increasing snow cover. The deeper the snow, the more vegetation types tend to develop on the landslide scarps. Since forest vegetation cannot develop due to heavy snow, meadows, grasslands, and shrublands are found on the scarps. It is concluded that the combined effects of both landslide-caused disturbances and climatic factors are creating regional diversity in vegetation types.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135801424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-10-03DOI: 10.1177/03091333231180805
Zhenqin Shi, Jingeng Huo, Wenbo Zhu, Ran Ma, Hua Xue, Zechen Wang
The overcapacity and overdevelopment of cities have led to various environmental hazards and resource depletion, making it crucial to evaluate the suitability of urban development. This research field provides scientific evidence and policy recommendations to improve land use quality and distribution. However, contemporary studies solely focus on construction land versus non-construction land competition, ignoring potential constraints from agriculture and ecology on parcel development. Using the land use situation of Zhengzhou City, this study comprehensively evaluated urban development suitability through hierarchical analysis, Delphi method, and eight-direction analysis. A multi-attribute overlay was applied with spatial restrictions from ecological protection and agricultural production, combined with urban expansion and development conditions. The results indicated that: (1) Ecological protection was critical for sustainable urban development, and areas like the Yellow River coast, northwest wetland, and southwest woodland were significant for ecological protection. High suitability areas for agricultural production were primarily located within the existing cultivated land. (2) Regarding urban expansion, the southeast of the city center was identified as the most suitable area, mainly covered by dryland. (3) Overall, the unsuitable, basically unsuitable, medium, suitable, and highly suitable areas for urban development covered 244, 921, 3024, 2224, and 944 km 2 , respectively. (4) The southeast-northwest direction showed prominent spatial characteristics for urban development suitability, while intensive development mode dominated the east-west direction of the city center. These findings provide significant guidance for land development and utilization, optimizing the spatial pattern, and formulating policies in Zhengzhou. Nevertheless, the weight calculation process presents a subjective factor that needs to be addressed in future research. More objective weight calculation results are necessary to achieve a more scientifically rigorous evaluation of urban development suitability.
{"title":"Comprehensive evaluation of urban development suitability based on constraints and development factors: A case study of the central urban area of Zhengzhou, China","authors":"Zhenqin Shi, Jingeng Huo, Wenbo Zhu, Ran Ma, Hua Xue, Zechen Wang","doi":"10.1177/03091333231180805","DOIUrl":"https://doi.org/10.1177/03091333231180805","url":null,"abstract":"The overcapacity and overdevelopment of cities have led to various environmental hazards and resource depletion, making it crucial to evaluate the suitability of urban development. This research field provides scientific evidence and policy recommendations to improve land use quality and distribution. However, contemporary studies solely focus on construction land versus non-construction land competition, ignoring potential constraints from agriculture and ecology on parcel development. Using the land use situation of Zhengzhou City, this study comprehensively evaluated urban development suitability through hierarchical analysis, Delphi method, and eight-direction analysis. A multi-attribute overlay was applied with spatial restrictions from ecological protection and agricultural production, combined with urban expansion and development conditions. The results indicated that: (1) Ecological protection was critical for sustainable urban development, and areas like the Yellow River coast, northwest wetland, and southwest woodland were significant for ecological protection. High suitability areas for agricultural production were primarily located within the existing cultivated land. (2) Regarding urban expansion, the southeast of the city center was identified as the most suitable area, mainly covered by dryland. (3) Overall, the unsuitable, basically unsuitable, medium, suitable, and highly suitable areas for urban development covered 244, 921, 3024, 2224, and 944 km 2 , respectively. (4) The southeast-northwest direction showed prominent spatial characteristics for urban development suitability, while intensive development mode dominated the east-west direction of the city center. These findings provide significant guidance for land development and utilization, optimizing the spatial pattern, and formulating policies in Zhengzhou. Nevertheless, the weight calculation process presents a subjective factor that needs to be addressed in future research. More objective weight calculation results are necessary to achieve a more scientifically rigorous evaluation of urban development suitability.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"120 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135695627","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vegetation carbon sequestration in alpine areas of West China, such as the Qilian Mountains on the northeastern Tibetan Plateau, has been subject to long-term human intervention under a warming climate since the launch of the western development strategy (WDS) in 2000. However, the human impacts on vegetation carbon sequestration capacity during this period remain unclear. In this study, the magnitude and direction of human impacts on vegetation carbon sequestration capacity (defined as net primary production, NPP) were assessed by the deviation of remote-sensing–estimated actual NPP data from the simulated potential NPP. The potential value was derived from natural system coupling under the assumption that human activities ceased during the assessment period. The impacts of natural forces and historic human activities were then effectively exfoliated in our final assessment using a process-based IBISi model. The results indicate that the total actual vegetation carbon sequestration capacity in the Qilian Mountains has reduced compared with its potential value since the WDS launched. This reduction was mainly attributed to grazing in the grasslands. However, deforestation, mineral resource exploitation, and the construction of hydropower facilities have also caused a reduction in vegetation carbon sequestration capacity at the local scales. In contrast, forestry protections and afforestation, and agricultural activities associated with reclamation, cultivation, irrigation, and fertilization, have resulted in local increases in the vegetation carbon sequestration capacity in the corresponding forest lands, shrublands, and croplands. These findings highlight the importance of ecological protections for vegetation carbon sequestration and were expected to provide evidence to verify the improvement of ecological management and the increasing of carbon sinks in West China.
{"title":"Human impacts on vegetation carbon sequestration capacity in the Qilian Mountains, northeastern Tibetan Plateau since 2000","authors":"Biao Zeng, Fuguang Zhang, Ying Cao, Yanqi Shen, Zhenhua Meng","doi":"10.1177/03091333231201025","DOIUrl":"https://doi.org/10.1177/03091333231201025","url":null,"abstract":"Vegetation carbon sequestration in alpine areas of West China, such as the Qilian Mountains on the northeastern Tibetan Plateau, has been subject to long-term human intervention under a warming climate since the launch of the western development strategy (WDS) in 2000. However, the human impacts on vegetation carbon sequestration capacity during this period remain unclear. In this study, the magnitude and direction of human impacts on vegetation carbon sequestration capacity (defined as net primary production, NPP) were assessed by the deviation of remote-sensing–estimated actual NPP data from the simulated potential NPP. The potential value was derived from natural system coupling under the assumption that human activities ceased during the assessment period. The impacts of natural forces and historic human activities were then effectively exfoliated in our final assessment using a process-based IBISi model. The results indicate that the total actual vegetation carbon sequestration capacity in the Qilian Mountains has reduced compared with its potential value since the WDS launched. This reduction was mainly attributed to grazing in the grasslands. However, deforestation, mineral resource exploitation, and the construction of hydropower facilities have also caused a reduction in vegetation carbon sequestration capacity at the local scales. In contrast, forestry protections and afforestation, and agricultural activities associated with reclamation, cultivation, irrigation, and fertilization, have resulted in local increases in the vegetation carbon sequestration capacity in the corresponding forest lands, shrublands, and croplands. These findings highlight the importance of ecological protections for vegetation carbon sequestration and were expected to provide evidence to verify the improvement of ecological management and the increasing of carbon sinks in West China.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"26 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89175285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2023-08-24DOI: 10.1177/03091333231197168
Sunmei Jin, G. Hou, Youcheng Chen, Hong Qiao, Bin Han, C. E, Zhuoma Lancuo, Jingyi Gao, Zhuoma Wende
The occupation process and survival strategies of prehistoric humans on the Tibetan Plateau are important scientific questions for understanding human adaptation to extreme high-altitude environments. Here, we report a newly discovered microlithic site at Daiqu (DQ) in the Tongtian River basin of the central-eastern plateau. We collected 239 lithic artifacts from the DQ site for typological analysis. OSL and AMS14C dating samples were collected from the human active layer. Lipid residues from hearth sediments were analyzed, and we simulated and assessed environmental extremity and route accessibility for the site. Dating results suggest that the stable sedimentary layers began to form around 10.96 ± 0.56 ka BP at the DQ site. Human activity at DQ as early as 9271 ± 143 cal a BP, making it the earliest reported Holocene site with accurate stratigraphic dating on the plateau hinterland to date. Hearths and lithic artifacts indicate that the DQ site was a frequently used seasonal hunting camp, where quality lithic raw material was obtained and microliths processed. Prehistoric humans occupying the site relied on non-ruminant terrestrial animals as food resources. The DQ site is ideally situated to serve as a transit station for hunter-gatherers as they migrated between high and low elevations. Ameliorating Holocene climate promoted prehistoric human exploration of more environmentally extreme areas.
史前人类在青藏高原的占领过程和生存策略是了解人类适应极端高海拔环境的重要科学问题。本文报道了在中东部高原通天河流域代渠(DQ)新发现的一处微石器遗址。我们从DQ遗址收集了239件石器文物进行类型学分析。OSL和AMS14C定年样品采集自人类活动层。分析了炉膛沉积物中的脂质残留物，并模拟和评估了该地点的环境极限和路线可达性。测年结果表明，DQ遗址的稳定沉积层在10.96±0.56 ka BP左右开始形成。DQ的人类活动最早可达9271±143 cal a BP，是迄今为止在高原腹地有准确地层测年记录的最早的全新世遗址。壁炉和石器文物表明，DQ遗址是一个经常被使用的季节性狩猎营地，在那里获得了优质的石器原料，并加工了微石器。居住在这里的史前人类以非反刍陆生动物为食物来源。DQ遗址的地理位置非常理想，可以作为狩猎采集者在高海拔和低海拔之间迁徙的中转站。全新世气候的改善促进了史前人类对环境极端地区的探索。
{"title":"Prehistoric human occupation and adaptation on the hinterland of the Tibetan Plateau in the Early Holocene","authors":"Sunmei Jin, G. Hou, Youcheng Chen, Hong Qiao, Bin Han, C. E, Zhuoma Lancuo, Jingyi Gao, Zhuoma Wende","doi":"10.1177/03091333231197168","DOIUrl":"https://doi.org/10.1177/03091333231197168","url":null,"abstract":"The occupation process and survival strategies of prehistoric humans on the Tibetan Plateau are important scientific questions for understanding human adaptation to extreme high-altitude environments. Here, we report a newly discovered microlithic site at Daiqu (DQ) in the Tongtian River basin of the central-eastern plateau. We collected 239 lithic artifacts from the DQ site for typological analysis. OSL and AMS14C dating samples were collected from the human active layer. Lipid residues from hearth sediments were analyzed, and we simulated and assessed environmental extremity and route accessibility for the site. Dating results suggest that the stable sedimentary layers began to form around 10.96 ± 0.56 ka BP at the DQ site. Human activity at DQ as early as 9271 ± 143 cal a BP, making it the earliest reported Holocene site with accurate stratigraphic dating on the plateau hinterland to date. Hearths and lithic artifacts indicate that the DQ site was a frequently used seasonal hunting camp, where quality lithic raw material was obtained and microliths processed. Prehistoric humans occupying the site relied on non-ruminant terrestrial animals as food resources. The DQ site is ideally situated to serve as a transit station for hunter-gatherers as they migrated between high and low elevations. Ameliorating Holocene climate promoted prehistoric human exploration of more environmentally extreme areas.","PeriodicalId":49659,"journal":{"name":"Progress in Physical Geography-Earth and Environment","volume":"1 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85835611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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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