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1.
The Xiaohe Cemetery archaeological site(Cal.4–3.5 ka BP)is one of the most important Bronze Age sites in Xinjiang,China.Although the surrounding environment is an extremely arid desert now,abundant archaeological remains indicate that human occupation was common during certain periods in the Holocene.Field investigations and laboratory analyses of a sediment profile near the Xiaohe Cemetery indicate that while the regional environment was arid desert throughout the Holocene there were three episodes of lake formation near the site in the periods 4.8–3.5 ka BP,2.6–2.1 ka BP and 1.2–0.9 ka BP.Geomorphic and hydrological investigations reveal that a lake or lakes formed in a low-lying area when water was derived initially from the Kongque River and then shunted into the Xiaohe River basin.Low amounts of active chemical elements in lacustrine sediment between 4.8–3.5 ka BP indicate abundant and continuous water volume in the lake;the content of active chemical elements increased between 2.6–2.1 ka BP but was still at a relatively low level,suggesting a declining amount of water and diminished inflow.Between 1.2–0.9 ka BP there was a very high content of active elements,suggesting decreased water volume and indicating that the lake was stagnate.In contrast,the general climate condition shows that there had a warm-humid stage at 8–6 ka BP,a cool-humid stage at 6–2.9 ka BP and a warm-dry stage at2.9–0.9 ka BP in this region.The hydrological evolutions around Xiaohe Cemetery did not have one-to-one correspondence with climate changes.Regional comparison indicates that broad-scale climatic conditions played an important role through its influences on the water volume of the Tarim River and Kongque River.But,the formation of the lakes and their level were controlled by geomorphic conditions that influenced how much water volume could be shunted to Xiaohe River from Kongque River.Human occupation of the Xiaohe Cemetery and nearby regions during the Bronze Age and Han-Jin period(202 BC–420 AD)corresponded to the two earlier lake periods,while no human activities existed in the third lake period because of the decreased water volume.  相似文献   

2.
Yangshao culture is the most important mid-Holocene Neolithic culture in the Yellow River catchment,and thus,a study on the impact of human activities on the environment is important.In the current study,the distribution pattern of the cultivated land in late Yangshao culture is reconstructed using GIS tool and site domain analysis(SDA).The results show that the cultivated land during 5.5-5.0 ka BP was mainly distributed in the Weihe River valley,Luohe River valley,northwestern Henan Plain,Fenhe River valley and eastern Gansu region,especially concentrated in the Xi’an-Baoji line of the Weihe River valley.At that time,at least 37,000 km 2 of lands were reclaimed in the middle and lower reaches of the Yellow River,and 132,000 km 2 of lands were affected by agricultural activities.Human activities had become the driving force of land use/land coverage.Charcoal records indicate that the ancestors of Yangshao culture burnt forests for reclamation,leading to the decrease of arbor pollen at 5 ka BP in core areas of the Yangshao culture.The areas that were significantly affected by human activities accounted for 3.2% of the Yangshao culture influenced area,while the moderately affected areas accounted for 20.1% of Yangshao culture influenced area.Meanwhile,92% of the land areas on the edge and outside of the Yangshao culture influenced area were not affected by human activities.The arbor pollen in these areas did not decrease until 4.0 ka BP.  相似文献   

3.
Wu  Li  Sun  Xiaoling  Sun  Wei  Zhu  Cheng  Zhu  Tongxin  Lu  Shuguang  Zhou  Hui  Guo  Qingchun  Guan  Houchun  Xie  Wei  Ke  Rui  Lin  Guiping 《地理学报(英文版)》2020,30(9):1451-1466
Based on archaeological surveys of Neolithic cultural development and GIS spatial analysis,this study reproduced the main characteristics of temporal distribution and settlement selection of the sites from the Neolithic Age in Anhui and identified a relationship between environmental evolution and human activity.The results show that altitude,slope direction,and slope gradient were consistent among the settlements at different stages of the Neolithic Age in Anhui,and the sites were mostly distributed in hilly and plain areas on southeast-or south-facing slopes of low gradients close to rivers.We determined that early Neolithic Age(9.0–7.0 ka BP) sites were scattered in small numbers and likely had little cultural exchange with communities of other provinces.The environmental characteristics of various regions in Anhui indicated that the climate was warm and humid with extensive water distribution.The sites of the mid Neolithic Age(7.0–5.0 ka BP) increased rapidly with wide distribution.They were mainly distributed in the plain area north of the Huaihe River and the southwestern areas of Anhui.In the mid Neolithic Age,the warm and humid climate gradually dried,and our ancestors slowly developed cultural exchanges.The largest number of sites existed during the late Neolithic Age(5.0–4.0 ka BP),and were distributed throughout the province.During this period,the overall climate was relatively dry,but humans could still obtain water and other resources through migration.The relatively benign climate facilitated cultural interaction and exchange,which increased during this time,and the Wanjiang culture matured.We also determined that as early civilization evolved,cultures in different regions responded differently to environmental changes.In humid subtropical regions,especially in low-lying plains and areas beside lakes,rivers,and coastal areas,the relatively dry climate in the late period of the middle Holocene,prefaced by a period of high humidity,was conducive to the development of human culture.The evidence from the Neolithic settlements in Anhui therefore reflects this subtropical man-land relationship between cultural development and environmental conditions.  相似文献   

4.
The temporal-spatial geographic distribution of archaeological sites and its feature between 10.0–2.8 ka BP(ka BP= thousands of years before 0 BP, where "0 BP" is defined as the year AD 1950) were determined, based on GIS spatial analysis in the Poyang Lake Basin. The relationship between geographic distribution of sites of different periods under subsistence existence of ancient civilizations, climate and environmental change was investigated. The results revealed numerous archaeological sites of the Neolithic Age(10.0–3.6 ka BP). The sites were mainly located in the northern part of the Poyang Lake Basin, a hilly and mountainous area with many river terraces suitable for the development of human civilization. The number of archaeological sites rapidly increased during the Shang and Zhou dynasties(3.6–2.8 ka BP) and spread widely on the floodplains of the middle and lower reaches of Ganjiang River and onto the west, south, and southeast beach areas of the Poyang Lake. Holocene records of climate change suggested that it was possible that climate fluctuations had a great impact on human evolution in the study area. Before 3.6 ka BP, westward and northward expansion of Neolithic cultures in the Poyang Lake watershed occurred under the background of climate amelioration(becoming warmer and wetter). The ancient people lived in the hilly areas with high elevation. The simple mode of a fishing and gathering economy was mostly suited to this area in the early Neolithic Age. The scope of human activities was expanded and cultural diversity developed in the late Neolithic Age. However, with population growth and increasing survival pressure in a dry-cold climatic stage after 3.6 ka BP, this simple living mode had to be abandoned, and various forms of economy, the majority being agriculture, were developed on flood plains of the lower reaches of numerous rivers around Poyang Lake. This promoted flourishing of the Bronze culture of South China.  相似文献   

5.
The total precipitation of the highest 1 day, 3 day, 5 day and 7 day precipitation amount （R1 D, R3D, R5D and R7D） in the Yangtze River basin was analyzed with the help of linear trend analysis and continuous wavelet transform method. The research results indicated that： 1） Spatial distribution of RID is similar in comparison with that of R3D, R5D and R7D. The Jialingjiang and Hanjiang river basins are dominated by decreasing trend, which is significant at 〉95% confidence level in Jialingjiang River basin and insignificant at 〉95% confidence level in Hanjiang River basin. The southern part of the Yangtze River basin and the western part of the upper Yangtze River basin are dominated by significant increasing trend of RID extreme precipitation at 〉95% confidence level. 2） As for the R3D, R5D and R7D, the western part of the upper Yangtze River basin is dominated by significant increasing trend at 〉95% confidence level. The eastern part of the upper Yangtze River basin is dominated by decreasing trend, but is insignificant at 〉95% confidence level. The middle and lower Yangtze River basin is dominated by increasing trend, but insignificant at 〉95% confidence level. 3） The frequency and intensity of extreme precipitation events are intensified over time. Precipitation anomalies indicated that the southeastern part, southern part and southwestern part of the Yangtze River basin are dominated by positive extreme precipitation anomalies between 1993-2002 and 1961-1992. The research results of this text indicate that the occurrence probability of flash flood is higher in the western part of the upper Yangtze River basin and the middle and lower Yangtze River basin, esp. in the southwestern and southeastern parts of the Yangtze River basin.  相似文献   

6.
The operation of large-scale reservoirs have modified water and sediment transport processes, resulting in adjustments to the river topography and water levels. The polynomial fitting method was applied to analyze the variation characteristics of water levels under different water discharge values in the Jingjiang reach of the Yangtze River from 1991–2016. The segregation variable method was used to estimate the contributions of the varied riverbed evaluation, the downstream-controlled water level, and the comprehensive roughness on the altered water level at an identical flow. We find that low water levels in the Jingjiang reach of the Yangtze River from 1991–2016 are characterized by a significant downward trend, which has intensified since 2009. Riverbed scouring has been the dominate factor causing the reduced low water level while increased roughness alleviated this reduction. From 1991–2016, there was first a decrease followed by an increase in the high water level. The variation characteristic in terms of the "high flood discharge at a high water level" before 2003 transformed into a "middle flood discharge at a high water level" since 2009. The increased comprehensive roughness was the main reason for the increased high water level, where river scouring alleviated this rise. For navigation conditions and flood control, intensified riverbed scouring of the sandy reaches downstream from dams enhanced the effects that the downstream water level has on the upstream water level. This has led to an insufficient water depth in the reaches below the dams, which should receive immediate attention. The alteredvariation characteristics of the high water level have also increased the flood pressure in the middle reaches of the Yangtze River.  相似文献   

7.
With basic information from 8353 archaeological sites, this study describes a holistic spatial-temporal distribution pattern of archaeological sites of the prehistoric culture sequence from 9.5 ka BP (ka BP = thousands of years before 0 BP, where "0 BP" is defined as the year AD 1950) to 2.3 ka BP in the region that extends from the Yanshan Mountains to the Liaohe River Plain(i.e., the Yan-Liao region) in northern China. Based on spatial statistics analysis – including the spatial density of the sites and Geographic Information System nearest-neighbour analysis, combined with a review of environmental and climatic data – this paper analyses cultural evolution, the spatial-temporal features of the archaeological sites and human activities against the backdrop of climatic and environmental changes in this region. The results reveal that prehistoric cultural evolution in the Yan-Liao region is extensively influenced by climatic and environmental changes. The Xinglongwa, Zhaobaogou and Fuhe cultures, which primarily developed during a habitable period from 8.5 ka BP to 6.0 ka BP with strong summer monsoons, have similar maximum density values, spatial patterns and subsistence strategies dominated by hunting-gathering. Significant changes occurred in the Hongshan and Lower Xiajiadian cultures, with a significant increase in numbers and densities of sites and a slump in average nearest-neighbour ratio when the environment began to deteriorate starting in 6.0 ka BP. Additionally, with the onset of a weak summer monsoon and the predominance of primitive agriculture, sites of these two cultures present a different type of concentric circle-shaped pattern in space. As the environment continuously deteriorated with increasing aridity and the spread of steppe, more sites were distributed towards the south, and primitive agriculture was replaced by livestock husbandry in the Upper Xiajiadian culture. The most densely populated areas of the studied cultures are centralized within a limited area. The Laohahe River and Jiaolaihe River basins formed the core area in which most archaeological sites were distributed during the strong summer monsoon period and the first few thousand years of the weak summer monsoon period.  相似文献   

8.
By using field-survey hydrological data of the related control stations in Dongting Lake and the Yangtze River mainstream in 1951–2010, the evolution characters of water exchange abilities between the two water bodies and their response to the operation of the Three Gorges Reservoir(TGR) from different time scales are analyzed based on their hydraulic relations. The results are shown as follows. Firstly, during July-September, the replenishment ability of Three Outlets to Dongting Lake is stronger, and in January-March, the replenishment ability of Dongting Lake to Yangtze River is stronger. Secondly, there has been an obvious inter-decadal wave on the water exchange coefficient between Dongting Lake and Yangtze River. In 1951–1958 and 1959–1968, the replenishment ability of Three Outlets to Dongting Lake was stronger, but in 2003–2010, the replenishment ability of Dongting Lake to Yangtze River has been strengthened. Thirdly, the spill-division ability of Three Outlets weakens, and the water of Dongting Lake coming from Three Outlets decreases either in typical years or under different dispatching modes of the TGR after the operation of the Three Gorges Reservoir. Furthermore, the water of Dongting Lake coming from Four Rivers takes the dominant position, which obviously enhances the replenishment ability of Dongting Lake to Yangtze River. Fourthly, if the effect of the runoff fluctuation in the basin is not considered, the evolution characters of the exchange capacities and the exchange process between Dongting Lake and Yangtze River in different time scales are generally changed with the variation of the water exchange amount between them, although the factors influencing the water exchange capacities between them is very complex. These show that there is an in-line growth or decline relation between the river-lake water exchange ability and the river-lake water exchange amount.  相似文献   

9.
After the bursting of Huiten Nor in Hoh Xil Region in September, 2011, the topic on whether the water overflowed from the Salt Lake would enter into the Chumaer River and become the northernmost source of the Yangtze River has aroused wide concern from public and academic field. Based on Landsat TM/ETM+/OLI remote sensing images during 2010–2015, SRTM 1 arc-second data, Google Earth elevation data and the observation data from the Wudaoliang meteorological station, the study initially analyzed the variations of the Salt Lake and its overflowing condition and probability. The results showed that the area of the Salt Lake expanded sharply from October 2011 to April 2013, and then it stepped into a stable expansion period. On October 27, 2015, the area of the Salt Lake had arrived at 151.38 km~2, which was about 3.35 times the area of the lake on March 3, 2010. The Salt Lake will overflow when its area reaches the range from 218.90 km~2 to 220.63 km~2. Due to the differences between SRTM DEM and Google Earth elevation data, the water level of the Salt Lake simulated would be 12 m or 9.6 m higher than the current level when the lake overflowed, and its reservoir capacity would increase by 23.71 km~3 or 17.27 km~3, respectively. Meanwhile, the overflowed water of the Salt Lake would run into the Qingshui River basin from its eastern part. Although the Salt Lake does not overflow in the coming decade, with watershed expansion of the Salt Lake and the projected precipitation increase in Hoh Xil region, the probability of water overflow from the Salt Lake and becoming a tributary of the Yangtze River will exist in the long term.  相似文献   

10.
长江口悬沙浓度变化的同步性和差异性(英文)   总被引：1，自引：0，他引：1  
The sediment discharge from the Yangtze River Basin has a stepwise decreasing trend in recent years. The impounding of the Three Gorges Reservoir exacerbated this decreasing trend and affected the change of the suspended sediment concentration(SSC) in the Yangtze River Estuary through the transmission effect. The SSC data of the Yangtze River Estuary during 1959–2012 showed that:(1) The SSC in the South Branch of the Yangtze River in the estuary and in the off-shore sea area displayed decreasing trends and decreased less towards the sea. At the same time, the difference in decreasing magnitude between SSC and sediment discharge became bigger towards the sea.(2) For the North Branch the preferential flow did not change much but the SSC tended to decrease, which was mainly caused by the decrease of SSC in the South Branch and China East Sea.(3) Due to the decreased runoff and the relatively strengthened tide, the peak area of the SSC in the bar shoal section in 2003–2012 moved inward for about 1/6 longitude unit compared with that in 1984–2002, and the inward-moving distance was in the order of flood season > annual average > dry season.(4) In the inlet of the South Passage, the SSC decreased mainly because the increase caused by resuspension and shore-groove exchange was less than the decrease caused by the sharp SSC decrease in the basin and the sea areas. The reverse was true in the middle section, where the SSC showed an increasing trend.(5) In the inlet of the North Passage, under the combined influence of decreased flow split and sediment split ratios, the decreased SSC in the basin and the sea area and decreased amount of resuspension, the SSC displayed a decreasing trend. In the middle section, because the increased amount caused by sediment going over the dyke was markedly more than the decreased amount caused by external environments, the SSC tended to increase. Holistically, the sharp decrease in sediment discharge caused synchronized SSC decreases in the Yangtze River Estuary. But there were still areas, where the SSC displayed increasing trends, indicating synchronicity and difference in the response of SSC to the sharp decrease in sediment discharge from the basin.  相似文献   

11.
Women,Politics, Elections,and Citizenship   总被引：1，自引：1，他引：0  
Abstract

Significantly more women than men are registered voters in the United States, and a higher proportion of women voters actually cast ballots on election day. Yet the 106th Congress (1999-2001) includes only 56 women members, 12% of the total membership of the House and Senate. Likewise, women hold only 22% of the total seats in state legislatures. The purpose of this article is to examine this paradox. It first examines the history of the women's movement in the United States. It then turns to an evaluation of women's progress in gaining elected office. Finally it considers three primary obstacles to women gaining equitable representation: solidarity among women, political culture, and the single-member district system now employed in the United States.  相似文献   

12.
《Urban geography》2013,34(4):470-475
Postmetropolis deepens Edward Soja's engagement with the sociospatial dialectic, one of his major contributions to urban theory. It also represents an uncharacteristic foray into history. The objectives of my contribution are to probe his treatment of time and to extend his sociospatial dialectic into the realm of actor-network theory, thereby further situating the materiality of the city at the theoretical center of social thought.  相似文献   

13.

This study investigates whether women's short commutes should be interpreted as constrained or convenient work trips by examining how race, gender, travel mode, occupation, residential location, workplace location, and Inc.ome affect commuting time. The analysis is restricted to a sample of European American and African American male and female workers residing in Buffalo, New York, and the surrounding county using data drawn from the Public Use Microdata Samples of the 1990 U.S. census. Given the pervasive gender wage gap, women unsurprisingly have more compromised (short commutes to low-Inc.ome jobs) work trips than do men. Multivariate analysis reveals that among those who reverse commute to suburban locations, African American women have the longest work trips.  相似文献   

14.
This study investigates whether women's short commutes should be interpreted as constrained or convenient work trips by examining how race, gender, travel mode, occupation, residential location, workplace location, and Inc.ome affect commuting time. The analysis is restricted to a sample of European American and African American male and female workers residing in Buffalo, New York, and the surrounding county using data drawn from the Public Use Microdata Samples of the 1990 U.S. census. Given the pervasive gender wage gap, women unsurprisingly have more compromised (short commutes to low-Inc.ome jobs) work trips than do men. Multivariate analysis reveals that among those who reverse commute to suburban locations, African American women have the longest work trips.  相似文献   

15.
Chemical weathering and associated soil development trends on glacial forelands are commonly assumed to exhibit increases with time elapsed since glaciation. However, this gross trend is complicated by several other factors including elevation, aspect, and microtopography. This paper demonstrates that on the glacial foreland at Storbreen, Jotunheimen, Norway, chemical weathering and associated soil development trends show significant elevational influences. We sampled soils at shallow depths (0–1, 1–5, and 15–20 cm) at two sites on a moraine dated to 1750 at its elevational extremes of 1155 m (site L) and 1385 m (site H). The two moraine sites also differed developmentally from an adjacent 9000-year-old surface (site T) at an intermediate elevation, 1205 m. Analyses were conducted on the fine-earth fractions. Extractable elemental composition exhibited detectable differences between the same-age soils at different elevations with the lower site L tending to have measured parameters intermediate between the high site H and the older site T. Weathering, as indicated by mineralogy, was more pronounced at the 9000-year-old site T and least evident at the high elevation site H. In addition, elevation under the conditions of the field research may inhibit pedogenesis as indicated by the chemical data. Site H, for example, showed little variation with depth and had in general, less organic matter accumulation, smaller C:N ratio, greater pH, and lesser amounts of the measured extractable elements than the soil at site L. Site T generally had smaller pH and larger levels of the measured elements than the other sites. It was concluded that elevation has a significant control on weathering and pedogenesis that may mask the effects of age in this cold and wet environment.  相似文献   

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18.
ABSTRACT. Wilhelm Richard Wagner fused fantasy based on epic and lore with seamless scores, using landscapes and urban images to forge spatial order on stage. As a footloose composer-conductor, Wagner was considered a globetrotter for his time, and from trans-European tours he drew inspiration for numerous stagings. Nine of his operas have rustic pastoral settings, with actors silhouetted against geological formations, forests, vistas of undulating terrain for pilgrimages, or raging seas, all visually believable scenery. Rienzi and Die Meistersinger von Nürnberg are urban in setting, whereas Die Feen and Das Liebesverbot are set in a castle-like format.  相似文献   

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