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1.
《Quaternary Science Reviews》2007,26(19-21):2631-2643
In order to link the charcoal record from sedimentary archives with the combustion processes that reflect past anthropogenic activity, a novel method based on automated image analysis was developed. It allows a detailed quantification and morphological analysis of the combustion-derived products that were emitted in the area of Lake Lucerne (Central Europe) throughout the last 7200 years.Charcoal-particle distribution reconstructed from the composite sedimentary record shows that the charcoal input is primarily linked to redistribution of detrital μm-size charcoal degradation products from surface runoff into the large lake basin. However, the independent distribution of the coarser charcoal fraction (>38 μm) exhibits four major periods of large-scale fire activity around 5500, 3300, 2400, and 530 cal. BP. These events are synchronous with major anthropogenic changes (lake-dwellings, land-use changes, technological innovations), although it is possible that these major fire episodes could have been indirectly triggered by climatic deterioration and unfavorable environmental conditions. During the late-nineteenth-century, a great increase in slag particles and magnetic spherules of fly-ash occurred due to the steamboat navigation on Lake Lucerne. The successive burning of wood (after AD 1838), coal (after AD 1862), and diesel (after AD 1931) by the steamboat traffic produced specific particle shapes, providing valuable chronological markers for dating the recent sediments and a proxy for fossil fuel combustion.  相似文献   

2.
The relative importance of climate, forest fires and human population size on long‐term boreal forest composition were statistically investigated at regional and local scales in Fennoscandia. We employ pollen data from lakes, reflecting regional vegetation, and small forest hollows, reflecting local vegetation, from Russia, Finland and Sweden to reconstruct the long‐term forest composition. As potential drivers of the Holocene forest dynamics we consider climate, generated from a climate model and oxygen isotope data, past forest fires generated from sedimentary charcoal data and human population size derived from radiocarbon dated archaeological findings. We apply the statistical method of variation partitioning to assess the relative importance of these environmental variables on long‐term boreal forest composition. The results show that climate is the main driver of the changes in Holocene boreal forest composition at the regional scale. However, at the local scale the role of climate is relatively small. In general, the importance of forest fires is low both at regional and local scales. The fact that both climate and forest fires explain relatively small proportions of variation in long‐term boreal vegetation in small forest hollow records demonstrates the complexity of factors affecting stand‐scale forest dynamics. The relative importance of human population size was low in both the prehistorical and the historical time periods. However, this is the first time that this type of data has been used to statistically assess the importance of human population size on boreal vegetation and the spatial representativeness of the data may cause bias to the analysis.  相似文献   

3.
Microscopic charcoal from varved Santa Barbara Basin sediments was used to reconstruct a 560-yr record (A.D. 1425 to 1985) of Santa Ana fires. Comparison of large (>3750 μm2) charcoal with documented fire records in the Santa Barbara Ranger District shows that high accumulations correspond to large fires (>20,000 ha) that occurred during Santa Ana conditions. The charcoal record reconstructed a minimum of 20 large fires in the Santa Barbara region during the study period. The average time between fires shows no distinct change across three different land use periods: the Chumash period, apparently characterized by frequent burning, the Spanish/Early American period with nominal fire control, and the 20th century with active fire suppression. Pollen data support the conclusion that the fire regime has not dramatically changed during the last 500 yr. Comparison of large charcoal particle accumulation rates and precipitation reconstructed from tree rings show a strong relationship between climate and fire history, with large fires consistently occurring at the end of wet periods and the beginning of droughts.  相似文献   

4.
Glaciers show a sensitive and rapid response to climate shifts. Associated changes in ice extent drive variations in the production of rock flour, the suspended product of glacial erosion. These glacigenic sediments may accumulate in downstream lakes, continuously recording glacier history. Consequently, the lacustrine sediment records of such glacier‐fed lakes represent valuable palaeoenvironmental archives that help constrain past climate variability. In this paper, we discuss the multi‐disciplinary methodological toolbox that is applied to fingerprint a glacier signal from such lake sediments. Special emphasis is placed on dating methods, which transform stratigraphical data into climate time series, allowing us to distinguish leads and lags between archives. We also elaborate on techniques that are used to validate sediment‐based glacier signals and resolve their climate signature. Finally, we conclude with a brief outlook on new research avenues such as proxy data–climate model comparisons.  相似文献   

5.
The record of charcoal in lake sediments indicates that fire has always been an important ecological factor in the forest history of northeastern Minnesota. The annually laminated sediments of Lake of the Clouds permit precise dating of the charcoal peaks and record the changes in the influx of various pollen types. A detailed record of the past 1000 yr shows that the average frequency of fire is approximately 60–70 yr, with a range of about 20–100 yr. The amount of charcoal in sediments dating between 1000-500 y.a. is consistently higher than that for the last 500 yr, although the fire frequency for the two periods was not appreciably different. Pollen analysis shows no change or only short-term changes in the percentages of major pollen types following charcoal peaks.  相似文献   

6.
The objective of the present study was to delineate temporal and spatial changes in the coal fire and land use/cover within Bastacolla area of Jharia coal field. Studying this variation helped to decipher interconnection among the dynamics of the coal fire and concomitant changes in land use/cover. The detection of coal fires during a span of 14 years along with transitioning land use/cover was cost-effective and enabled planning for management of coal resources and environment. Landsat series of satellite data of 2002, 2009, 2013, and 2016 were processed for generating land surface temperature profiles vis-a-vis classified land use/cover of the study area. A single cut-off temperature was derived for mapping of coal fires using land surface temperature profile from 2002 to 2016. The satellite images were classified using support vector machines, and for depicting land use/cover change, post-classification change detection was done. Classification accuracy obtained was excellent with kappa coefficient ranging from 0.897 for classified image of 2002 to 0.799 for classified image of 2016. Results revealed that coal fires had shifted to the central west part of the area. Furthermore, pockets of coal fire from northern and eastern part of the study area have diminished. OB dumps and coal quarry/coal dump may be attributed towards the spatial change in coal fire while; OB dumps showed connotation with the highest temperature zones. Ground verifications for temperature profiles and coal fires were carried out using thermal camera which enunciated good agreement with results.  相似文献   

7.
The loess/paleosol sequences of Central Asia are continuous terrestrial records of the Quaternary period and enable detailed comparison with paleoclimatic archives such as marine and ice core records in order to reconstruct regional and global paleoclimatic and paleoecological development during the past 130?000 years. Thermoluminescence (TL) and infrared stimulated luminescence (IRSL) dating methods are applied to the extensively studied loess/paleosol sequence of the section at Darai Kalon/Chashmanigar, Tadjikistan, in order to determine a more accurate chronological framework and climatostratigraphic reconstruction for the last interglacial/glacial cycle. Luminescence dating suggests that the loess above the first pedocomplex from the top, PC1, accumulated during the last glacial period. A high accumulation rate of up to 1.20?m per 1000 years was determined for the last glacial loess, especially for the uppermost 5–8?m. PC1 formed during the last interglacial period (oxygen-isotope stage 5). The loess between PC1 and PC2 is designated to be of penultimate glacial deposition age. Infrared stimulated luminescence and TL age estimates are in agreement to 80?000 years before present (BP), indicating a long-distance transport of the aeolian dust prior to deposition. The upper numerical age-limit range is between 300?000 and 450?000 years. However, reliable dating of the loess older than 130?000 years is not possible due to age scatter between samples and an inadequate increase of paleodose with depth. This high-resolution dating study underlines the importance of the section at Darai Kalon and indicates that it is one of the most continuous loess/paleosol records of the Northern Hemisphere. The chronological results are particularly important for the reconstruction of the human evolution in Central Asia, suggesting much older age estimates than previously obtained for most of the archeological key sites associated with PC5 and PC4 in Tadjikistan.  相似文献   

8.
This paper reviews the application of cosmogenic-nuclide exposure dating to glacier chronology. Exposure dating of glacial landforms has made an outsize impact on this field because the technique filled an obvious need that had already been recognized by glacial geologists. By now, hundreds of studies have used cosmogenic-nuclide exposure dating to date glacial deposits, and in fact it is rare to find a study of glacial geology or glacier chronology, or any paleoclimate synthesis that makes use of such studies, that does not involve exposure dating. These developments have resulted in major contributions to glacier chronology and paleoclimate, in particular i) reconstructing Antarctic ice sheet change, ii) establishing the chronology of late Pleistocene and Holocene glacier change in mountain regions where it was previously unknown; iii) establishing the broad chronological outlines of mountain glaciations prior to the Last Glacial Maximum; and iv) gaining insight into subglacial erosional processes through the observation that many glaciated surfaces preserve cosmogenic-nuclide inventories from long past ice-free periods as well as the present one. An important potential future contribution will be the application of the large data set of exposure-dated glacier chronologies to better understand global and regional climate dynamics during Lateglacial and Holocene millennial-scale climate changes. However, this contribution cannot be realized without significant progress in two areas: i) understanding and accounting for geologic processes that cause apparent exposure ages on glacial landforms to differ from the true age of the landform, and ii) minimizing systematic uncertainties in exposure ages that stem from cosmogenic-nuclide production-rate estimates and scaling schemes. At present there exists an enormous data set of exposure ages on glacial deposits, but these data cannot be used to their full potential in paleoclimate syntheses due to an inadequate understanding of geologic scatter and production-rate uncertainties. The intent of this paper is to highlight this situation and suggest some strategies for realizing this potential.  相似文献   

9.
A 2000-year accumulation of varved sediments from Hell's Kitchen Lake in north-central Wisconsin was analyzed for pollen, charcoal, and seeds. The varves provided an accurate time scale for the study. The pollen record indicates changes on two different time scales. Short-term changes lasting several decades appear to be superimposed on long-term changes lasting several centuries. The short-term changes are related to individual fires, and the long-term changes result from increases or decreases in the frequency of these perturbations. From 2000 to 1150 years ago the average interval between fires was about 100 years, and from 1150 to 120 years ago the interval increased to about 140 years. Evidence from pollen, seeds, and charcoal at Hell's Kitchen Lake suggests that at least two “moist” intervals occurred during the past 2000 years, one between 2000 and 1700 years ago and the other between 600 and 100 years ago. A third but minor “moist” period occurred about 1150 to 850 years ago. A pollen and seed diagram shows that these intervals are characterized by increased percentages of white pine pollen, hemlock pollen, and yellow birch seeds, and by decreased levels of charcoal. The “dry” interval of 1700 to 1150 years ago is characterized by increased percentages of paper birch seeds, oak pollen, and aspen pollen, along with high levels of charcoal. The times of climatic change indicated at Hell's Kitchen Lake are nearly synchronous with those based on studies of tree rings, soils, glacial activity, and other pollen studies from various regions of North America, but the direction of these inferred changes is not always the same. This result suggests that the long-wave pattern of the general circulation has been variable during the past 2000 years.  相似文献   

10.
We examined long-term charcoal records spanning the glacial–interglacial cycles that are evident in two cores collected from Lake Biwa in central Japan. We found that the records of the two cores have a similar long-term variation pattern of charcoal concentrations and abundant large charcoal fragments in postglacial sediments, which indicates that frequent fires occurred near the shores of Lake Biwa during the postglacial period. Analogous natural conditions in the early postglacial period and the early part of the last interglacial period strongly suggest that the frequent fires that occurred only during the postglacial period were anthropogenic. A comparison between the charcoal records of Lake Biwa sediments and the cultural changes and human populations in this district suggests that anthropogenic fires in this district were influenced by the lifestyle and culture of each era rather than by the populations. Humans tended to use more fire at the start of the settlement during the early Neolithic era in this region, in spite of the small population size.  相似文献   

11.
The mechanism of interaction between land use change and landscape pattern is pivotal in research concerning global environmental change. Quantitative evaluation of land use change that has resulted from excessive land development and its impact on landscape pattern are important for sustainable utilization of local land resources. The study area was the Manas River watershed, a typical watershed in an arid area. The present study evaluated the influence of long-term land use change on the landscape pattern; the findings are valuable for economic development and environmental protection. The processes for land use change and changes in landscape pattern were reconstructed and analyzed for data in topographic maps dated 1962 and in remote sensing images taken in 1976, 1989, 1999 and 2008 using mathematical models and landscape metrics. The results indicate significant changes in land use over the past 50 years, with increases in the areas of cultivated land and construction land, and a significant decrease in unused land and woodland areas; grassland and water resources first increased and then tended to decrease over this time. The comprehensive index of land use change is 0.55, indicating an unbalanced, one-way transition in the study area. Landscape fragmentation and diversity increased and landscape dominance decreased; in other words, differences between landscapes decreased. The changes resulted in a significant tendency toward diversity and fragmentation of the landscape. Therefore, large-scale intensive agricultural development can reduce the negative influence of land use change on the landscape pattern.  相似文献   

12.
Land use and land cover change is an important driver of global change (Turner et al., 1993). It is recognized that land use change has important consequences for global and regional climates, the global biogeochemical cycles such as carbon, nitrogen, and water, biodiversity, etc. Nevertheless, there have been relatively few comprehensive studies of global, long-term historical changes in land cover due to land use. In this paper, we review the development of global scale data sets of land use and land cover change. Furthermore, we assess the differences between two recently developed global data sets of historical land cover change due to land use. Based on historical statistical inventories (e.g. census data, tax records, land surveys, historical geography estimates, etc) and applying different spatial analysis techniques, changes in agricultural land cover (croplands, pastures) were reconstructed for the last 300 years. The two data sets indicate that cropland areas expanded from 3–4 million km2 in 1700 to 15–18 million km2 in 1990 (mostly at the expense of forests), while grazing land area expanded from 5 million km2 in 1700 to 31 million km2 in 1990 (mostly at the expense of natural grasslands). The data sets disagree most over Latin America and Oceania, and agree best over North America. Major differences in the two data sets can be explained by the use of a fractional versus Boolean approach, different modelling assumptions, and inventory data sets.  相似文献   

13.
This article provides an overview of the development of soil micromorphological studies of ancient agriculture and the current position of research in this field. The stance adopted by the authors is deliberately combative, and it is hoped that the article will stimulate discussion of the current limitations and potentialities of the technique. The findings of this review may be summarized in three proposals: (1) Soil micromorphology cannot be used at present to identify cultivation in ancient soils. Ambiguous or multiple interpretations of soil micromorphological features are unlikely to be resolved, so that the detection of large scale agricultural features in the field (cultivation marks, lynchets) will remain the most secure and direct guides to the presence of a former cultivated soil. Indirect evidence on inferred land use can be provided from pollen and land snail evidence. (2) Micromorphology should retain a key role in the determination of the impact of agriculture on soils, encompassing issues such as erosion, soil structure, fertility, and biological activity. These can be related to agricultural practice: methods of tillage, manuring, soil conservation, and fallowing. (3) Three areas of micromorphological research can be proposed that address the impact of agriculture on soil: (a) the study of well-sealed, buried agricultural soils which have a clearly understood archaeological context; (b) the study of recent soils with known agricultural histories; (c) the establishment of controlled experiments with ancient agricultural techniques. © 1998 John Wiley & Sons, Inc.  相似文献   

14.
中国历史耕地变化及其对自然环境的影响*   总被引：3，自引：0，他引：3       下载免费PDF全文
农业开发已经直接或间接地影响并正在影响自然环境的许多方面,中国农业开发历史悠久,对自然环境造成的影响广泛而强烈,对认识人类活动导致的全球与区域环境变化具有代表性。文中总结了近年来基于考古和历史文献记录的中国历史耕地变化定量重建和耕地开发环境影响的研究成果。主要结论包括: (1)中国在历史耕地变化重建方面具有独特的优势,主要数据源包括田亩、税赋、人口等与耕地数量相关的数值记录,考古遗址点、聚落、路网、行政建制等与农业活动相关的信息,有关土地开发和农业生产的描述性记录等三大类。 (2)对全国尺度的耕地面积推断始于春秋战国时期,过去1000年以来已重建了省(路)域的垦殖率,过去300年基于历史记录重建的东北、华北等区域垦殖率的分辨率已到县,在重建基础上利用分配模型获得的过去300年格网化垦殖率的分辨率可达10 km×10 km甚至1 km×1 km。相比于当前广泛使用的国际数据集,这些区域定量重建结果更为准确。(3)历史时期中国耕地的3次大规模扩张分别主要出现在西汉、两宋和清中叶,与此相对应,植被破坏和水土流失从北方地区扩展到南方地区,从平原低地扩展到低山丘陵、深山地区;过去300年耕地变化导致了碳排放的增加和可辨识的区域气候变化。未来中国的历史耕地变化重建及其对环境影响研究,应与国际过去土地利用/覆盖研究衔接,研究重点为延长历史耕地重建时限、提高重建单元的空间分辨率和改进耕地格网化分配模型。  相似文献   

15.
Paleoenvironmental reconstructions are important for understanding the influence of long-term climate variability on ecosystems and landscape disturbance dynamics. In this paper we explore the linkages among past climate, vegetation, and fire regimes using a high-resolution pollen and charcoal reconstruction from Morris Pond located on the Markagunt Plateau in southwestern Utah, USA. A regime shift detection algorithm was applied to background charcoal accumulation to define where statistically significant shifts in fire regimes occurred. The early Holocene was characterized by greater amounts of summer precipitation and less winter precipitation than modern. Ample forest fuel and warm summer temperatures allowed for large fires to occur. The middle Holocene was a transitional period between vegetation conditions and fire disturbance. The late Holocene climate is characterized as cool and wet reflecting an increase in snow cover, which reduced opportunities for fire despite increased availability of fuels. Similarities between modern forest fuel availability and those of the early Holocene suggest that warmer summers projected for the 21st century may yield substantial increases in the recurrence and ecological impacts of fire when compared to the fire regime of the last millennium.  相似文献   

16.
中国东海、南海等近海临近琉球海沟、马尼拉海沟等俯冲带,地震频发。过去的海啸研究主要关注历史文献分析、海啸数值模拟等,据此评估中国近岸海啸灾害的历史和风险。历史时期是否引发了海啸,特别是具有特大致灾风险的大海啸记录,目前还不明确。近年来,本课题组通过对海岛、海洋沉积和海岸带及其岛屿的沉积过程、海啸遗迹和历史记录研究,阐述了确定古海啸的系列研究方法。首先通过对南海西沙群岛东岛湖泊沉积序列、大量砗磲和珊瑚块在海岛分布的特征分析,识别出距今千年的一次海啸事件。以此为标志,根据湖泊沉积结构作为识别海岛海啸沉积的特征。同时提出了确定海岛海啸发生时代的样品采集和定年方法,其中包括根据事件沉积层顶部和底部植物残体14C年龄定年和历史文献记录的印证。首次确定在过去1 300年中,南海发生过一次海啸,其发生时间为公元1076年。为了寻找更古老的海啸记录,结合对东海闽浙沿岸过去两千年海洋泥质沉积的分析,发现南海海啸在沉积序列中留下记录,但除此之外沉积记录中并无更强的扰动,因此东海在过去两千年中受到海啸的影响较小。1076年的海啸同时冲击了南海沿岸,通过对广东南澳岛考察发现,岛屿东南海岸保存着距今约1 000年的海啸沉积层,其中夹杂着宋代陶器瓷器残片。对遗迹数量变化的分析显示,岛上的文化受海啸破坏出现了长达500年的文化中断,直至明代中后期设镇之后才逐渐恢复。根据海啸层植物残体、贝壳14C测年、覆盖海啸层的海砂光释光定年以及瓷器碎片的年代鉴定了海啸的发生时代,并据此提出了海岸带古海啸沉积的定年方法。此外,不同环境下海啸沉积的特征也存在较大区别,需要结合地形、沉积物来源以及地球化学特征等多种指标进行识别。有迹象表明海南岛东侧海岸带有海啸破坏的明显证据,需要进行深入的研究。  相似文献   

17.
The microscopic charcoal content of several Quaternary pollen sequences is used to investigate fire history in South Africa both during the Holocene and the Late Pleistocene. Although fluctuations in charcoal composition are recorded, it is difficult to link them directly to either human‐made or natural fires. Strong long‐term variations in microscopic charcoal of Middle and Upper Pleistocene layers are independent of pollen indications of past temperature and moisture conditions. Holocene charcoal sequences from different areas show no correlation, so no phases of regional burning are found. Some fluctuations in charcoal probably are the result of local burning in the various regions. The arrival of Iron Age people some 2000 yr ago apparently did not coincide with widespread wild fires, as these events do not consistently appear in regional microscopic charcoal records. The only exception appears to be the Wonderkrater spring deposit. Relatively open savanna environments, which are implied by pollen analysis at some sites during this period and the generally low microscopic charcoal contents, were either caused by climate change or controlled burning by Iron Age people. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

18.
A key to understanding Late Pleistocene megafaunal extinction dynamics is knowledge of megafaunal ecological response(s) to long-term environmental perturbations. Strategically, that requires targeting fossil deposits that accumulated during glacial and interglacial intervals both before and after human arrival, with subsequent palaeoecological models underpinned by robust and reliable chronologies. Late Pleistocene vertebrate fossil localities from the Darling Downs, eastern Australia, provide stratigraphically-intact, abundant megafaunal sequences, which allows for testing of anthropogenic versus climate change megafauna extinction hypotheses. Each stratigraphic unit at site QML796, Kings Creek Catchment, was previously shown to have had similar sampling potential, and the basal units contain both small-sized taxa (e.g., land snails, frogs, bandicoots, rodents) and megafauna. Importantly, sequential faunal horizons show stepwise decrease in taxonomic diversity with the loss of some, but not all, megafauna in the geographically-small palaeocatchment. The purpose of this paper is to present the results of our intensive, multidisciplinary dating study of the deposits (>40 dates). Dating by means of accelerator mass spectrometry (AMS) 14C (targeting bone, freshwater molluscs, and charcoal) and thermal ionisation mass spectrometry U/Th (targeting teeth and freshwater molluscs) do not agree with each other and, in the case of AMS 14C dating, lack internal consistency. Scanning electron microscopy and rare earth element analyses demonstrate that the dated molluscs are diagenetically altered and contain aragonite cements that incorporated secondary young C, suggesting that such dates should be regarded as minimum ages. AMS 14C dated charcoals provide ages that occur out of stratigraphic order, and cluster in the upper chronological limits of the technique (～40–48 ka). Again, we suggest that such results should be regarded as suspicious and only minimum ages. Subsequent OSL and U/Th (teeth) dating provide complimentary results and demonstrate that the faunal sequences actually span ～120–83 ka, thus occurring beyond the AMS 14C dating window. Importantly, the dates suggest that the local decline in biological diversity was initiated ～75,000 years before the colonisation of humans on the continent. Collectively, the data are most parsimoniously consistent with a pre-human climate change model for local habitat change and megafauna extinction, but not with a nearly simultaneous extinction of megafauna as required by the human-induced blitzkrieg extinction hypothesis. This study demonstrates the problems inherent in dating deposits that lie near the chronological limits of the radiocarbon dating technique, and highlights the need to cross-check previously-dated archaeological and megafauna deposits within the timeframe of earliest human colonisation and latest megafaunal survival.  相似文献   

19.
Forested peatlands are widespread in boreal regions of Canada, and these ecosystems, which are major terrestrial carbon sinks, are undergoing significant transformations linked to climate change, fires and human activities. This study targets millennial‐scale vegetation dynamics and related hydrological variability in forested peatlands of the Clay Belt south of James Bay, eastern Canada, using palaeoecological data. Changes in peatland vegetation communities were reconstructed using plant macrofossil analyses, and variations in water‐table depths were inferred using testate amoeba analyses. High‐resolution analyses of macroscopic charcoal >0.5 mm were used to reconstruct local fire history. Our data showed two successional pathways towards the development of present‐day forested peatlands influenced by autogenic processes such as vertical peat growth and related drying, and allogenic factors such as the occurrence of local fires. The oldest documented peatland initiated in a wet rich fen around 8000 cal. a BP shortly after land emergence and transformed into a drier forested bog rapidly after peat inception that persisted over millennia. In the second site, peat started to accumulate from ~5200 cal. a BP over a mesic coniferous forest that shifted into a wet forested peatland following a fire that partially consumed the organic layer ~4600 cal. a BP. The charcoal records show that fires rarely occurred in these peatlands, but they have favoured the process of forest paludification and influenced successional trajectories over millennia. The macrofossil data suggest that Picea mariana (black spruce) persisted on the peatlands throughout their development, although there were periods of more open canopy due to local fires in some cases. This study brings new understanding on the natural variability of boreal forested peatlands which may help predict their response to future changes in climate, fire regimes and anthropogenic disturbances.  相似文献   

20.
Alluvial and colluvial sediment deposition provide a vital record of environmental change during the Holocene. Firm chronological control on these archives is necessary to enable us to relate sediment dynamics to human activity and climate variability. In the Eastern Mediterranean, such relationships are hard to establish due to the lack of spatially well‐distributed sediment archives with good chronological control. This scarcity is problematic with respect to regional‐scale reconstructions of the temporal variation of sediment dynamics. Here, we present a radiocarbon database (n = 178) of geomorphological activity collected from multiple distinct sediment archives within the territory of Sagalassos in south‐western Turkey. The data were grouped according to their sedimentary facies for analysis using cumulative probability distributions (CPDs) and sedimentation rate (SR) modelling. Two small‐scale colluvial valleys, where chronological information was abundant, were investigated in more detail. Results show that sedimentation chronology differs between individual, nearby cores, as it depends strongly on the local geomorphic situation. A generalizing approach combining multiple core results yields more widely valid conclusions. High sedimentation rates coincided with the initial major anthropogenic disturbance of the landscape and decreased afterwards, probably due to hillslope soil depletion. CPD and SR analysis indicates that in general colluvial sedimentation rates did not change much from 2000 BC onwards. River floodplain sedimentation, in contrast, increased markedly during the first millennium BC and during recent times, and a significant time lag in enhanced sediment deposition between the upper and lower reaches of the river valleys was observed. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

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