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1.
整理《中国近五百年旱涝分布图集》及其"续编""再续编"中1471-2000年间浙江金华与安徽屯溪两个站点的旱涝指数,将其作为反映钱塘江年径流量波动的指标,根据1950-2000年实测的钱塘江径流大小与海宁盐官站潮差和涌潮大小的相关关系,推断出五百余年来钱塘江涌潮强度变迁趋势。经检验,钱塘江流域旱涝指数特征与史料所载涌潮异常年份相符,且指数序列与同时期海宁盐官历年最大潮差值序列之间的相关系数具有较强相关性。将现代实测盐官历年最大潮差与旱涝指数拟合,得到函数关系式为y=-7.2x2+40.3x+580.1(其中x为旱涝指数,y为盐官年最大潮差)。又根据盐官潮差与涌潮高度间函数关系推出了明中期以后盐官历年涌潮最大强度,并绘制了1471-2001年间的钱塘江涌潮强弱变化曲线图。  相似文献   

2.
River basin management activities are often carried out in the context of real or perceived environmental change. Views of environmental change provided by the oral tradition are compared with histories of change reconstructed from the historical documentary record for the Nogoa River, Queensland, and the Avon River, Victoria. Quite different perspectives on the nature and causes of river channel change are provided by the two types of sources. River basin managers appear to have generally adopted the views provided by the more easily accessible oral tradition, leading to management strategies that are not necessarily justifiable in the light of the documentary history.  相似文献   

3.
《Political Geography》2006,25(4):361-382
Countries that share rivers have a higher risk of military disputes, even when controlling for a range of standard variables from studies of interstate conflict. A study incorporating the length of the land boundary showed that the shared river variable is not just a proxy for a higher degree of interaction opportunity. A weakness of earlier work is that the existing shared rivers data do not distinguish properly between dyads where the rivers run mainly across the boundary and dyads where the shared river runs along the boundary. Dyads with rivers running across the boundary would be expected to give rise to resource scarcity-related conflict, while in dyads where the river forms the boundary conflict may arise because river boundaries are fluid and fuzzy. Using a new dataset on shared water basins and two measures of water scarcity, we test for the relevance of these two scenarios. Shared basins do predict an increased propensity for conflict in a multivariate analysis. However, we find little support for the fuzzy boundary scenario. Support for a scarcity theory of water conflict is somewhat ambiguous. Neither the number of river crossings nor the share of the basin upstream is significant. Dry countries have more conflict, but less so when the basin is large. Drought has no influence. The size of the basin, however, is significantly associated with conflict. Modernization theory receives some support in that development interacted with basin size predicts less conflict, and we find some evidence here for an environmental Kuznets curve. The importance of basin size suggests a possible ‘resource curse’ effect for water resources.  相似文献   

4.
This study is the result of surveys and excavations carried out in a selected area of the middle basin of the Tagus river (Southern Meseta, Iberian Peninsula). The analysis of palaeoecological data, material assemblages, settlement patterns, domestic structures, funerary evidence and socio-economic context in the regional archaeological record from the Neolithic (5000 BC) to the beginning of the Iron Age (500 BC) allows us to identify several long-term historic processes; particularly, two habitational, demographic and socio-economic cycles, which contradict the traditional idea that the prehistory of inner Iberia presents almost no apparent change during these four millennia.  相似文献   

5.
This paper examines the links between Cold War geopolitics and economic development to explain the relatively rapid proliferation of the concept of river basin development throughout so-called “developing areas” of Asia, the Middle East, Africa and Latin America during the latter half of the twentieth century. The research focuses on the United States Bureau of Reclamation, the most significant water resource development agency of the US government, and its engagement in what it termed “foreign activities” beginning in the aftermath of World War II. Grounded in recent work on technopolitics, the constructed scales of water resource development, and histories of the “global” Cold War, this research examines the advancement of water resource development in the Litani River basin in Lebanon—as guided by staff of the US Bureau of Reclamation—during the period from 1950 to 1970. The Bureau operated as a geopolitical agent attempting to implement a universalized model of river basin development, but encountered continuous difficulties in the form of political and biophysical contingencies. The Bureau’s efforts, centred on the basin as the most appropriate unit of development, were consistently undercut by scale-making projects related to global and regional geopolitical concerns. The research concludes that understandings of the technopolitics of development interventions would benefit from a closer engagement with recent discussions regarding the construction of spatial scale within political geography and related fields. River basin development and its material transformation of multiple locales remains one of the largely neglected, but vitally important, legacies of Cold War geopolitics.  相似文献   

6.
A holistic landscape approach to cultural resource analysis of a set of archaeological sites in the central Penobscot Valley led to inferences regarding the Holocene physical and biological environmental context. Targeted environmental studies include (1) examination of forest and wetland changes through time and (2) lake-level studies as a key to paleohydrology. These studies were combined with broad-scale geomorphic investigations and detailed stratigraphic analyses, and studies of archaeological sites and their artifact assemblages. Together, these studies provide a picture of dramatic changes to the physical and vegetational landscape. These included reestablishment of a major river following deglaciation, evolution of extensive lakes to uplands and peatlands, and a shifting mosaic of open and closed forest composed of a variety of hardwood and softwood species. Inferences based on buried soils exposed in archaeological excavations supported climatic interpretations based on vegetation and paleohydrology. As a result, this work allowed evaluation of (1) site formation and preservation processes and (2) occupational patterns. Site formation and preservation of Early Holocene sites can be linked to sedimentation by hydraulic damming upstream of rapids at the mouths of tributary streams. Shifting human land use reflected by changes in occupation patterns appears to correspond to changes in forest composition as well as wetland and stream evolution through time.  相似文献   

7.
In the fall of 2001, staff of the Florida Bureau of Archaeological Research were led by river divers to an underwater site in the Apalachicola River containing a large concentration of prehistoric and historic artifacts lying on the riverbed. Subsequent inspection of the submerged river bank and scoured limestone river channel revealed a myriad of objects, which included iron fasteners, metal tools and implements, broken glass bottles, stone projectile points, scattered bricks and stone blocks, and other materials. Discovery of two large fragments of a wooden watercraft, a bayonet, a copper arrowhead, and flintlock gun barrels initially prompted researchers to hypothesize that the site might represent the remains of a U.S. Army boat that was attacked in 1817 by Seminole Indians while en route upriver. The episode, which caused the deaths of more than 30 soldiers and several women who were aboard the boat, led to the First Seminole War and the U.S. Army invasion of Florida. To investigate this hypothesis, a systematic survey of the riverbed was undertaken in the spring of 2002 to record underwater features and recover additional diagnostic artifacts. These activities employed side-scan sonar as well as diver visual investigations. This paper presents a case study of the value and broader significance of aggregate data where interpretation was underpinned by artefactual, historical and environmental analysis.  相似文献   

8.
We consider the history of woodland clearing in central western New South Wales, Australia, which has led to the present highly cleared and fragmented landscape. A combined approach is used examining available historical land‐use data and using regression analysis to relate the pattern of cleared and wooded areas in the recent landscape to environmental variables, taking into account the contagious nature of clearing. We also ask whether it would be possible to apply a simple simulation modelling approach to reconstruct a credible historical sequence of clearing in the study area. The historical data indicate that annual clearing rates have varied substantially in the study area and selective tree removal (ringbarking and thinning) has been common. These findings make it unlikely that a simple simulation approach would replicate the spatial and temporal sequence of woodland loss. Our regression results show that clearing patterns can be related to environmental variables, particularly annual rainfall and estimated pre‐European vegetation type, but that patterns are dominated by contagion.  相似文献   

9.
结合相关文献资料对柘皋河流域商周时期遗址野外考察,辅以高分辨率遥感资料等对流域内遗迹形态要素、平面特征、微地貌形态等分析,经钻孔获取遗迹点垂直剖面资料分析,采集相关含碳土样进行测年分析,从形状、位置、面积、微地貌、内部结构特征、土质特征、与古水系关系等指标来分析柘皋河流域商周晚期遗址点形态特征,探究遗址点形态特征的形成原因。  相似文献   

10.
An understanding of the nature and magnitude of hydrological, physical habitat and physico‐chemical effects resulting from surface‐water diversions in river systems is essential for effective management of water resources. For most coastal‐draining rivers in New South Wales, however, there are few data available on irrigation diversions, their hydrological impacts and environmental effects. This paper therefore presents an analysis of mean daily surface‐water diversions for pasture irrigation from approximately three years of metered data and the resultant effects on daily flows and aquatic habitats in the Bega‐Bemboka River. The period of analysis of the hydrological effects of irrigation diversions is extended to the full length of record (approximately five years) for gauging stations most affected by irrigation diversions, using Maintenance of Variance Extension Type 1 (MOVE.1) modelling techniques. The annual mean, median and peak daily rates of water diversion by metered surface‐water licences used to irrigate 925 ha of dairy pasture are 10.5 Ml d?1, 7.3 Ml d?1 and 41.5 Ml d?1, respectively. Diversion effects on flow duration statistics are such that the measured 90th and 95th daily flow duration percentiles at the gauging station most affected by upstream irrigation diversions are equivalent to the 97th and 99th flow duration percentiles, respectively, under MOVE.1 modelled natural flow conditions. While diversions for irrigation over the three‐year data period account for only 6.6% of total flow volumes, diversions as a proportion of daily surface‐water inflows increase exponentially under decreasing flow rates. Median and maximum daily diversion rates attain 91% and 118%, respectively, of total surface‐water inflows to the diversion‐affected reach when upstream inflows range from 15 to 20 Ml d?1. This exponentially‐increasing relationship between daily diversion rates and declining surface‐water inflows suggests that ‘rule of thumb’ guidelines on sustainable diversion limits based on mean or median annual percentage diversion volumes need to be applied cautiously to river systems with no or limited capacity to manipulate flows to meet downstream consumptive demands.  相似文献   

11.
《水经注》是我国古代以水道为纲记载地理信息的著名典籍,对于研究早期水道情况和政区变迁有着极为重要的意义。本文以《水经注》卷六《涑水篇》作为研究对象,在前人既有研究的基础之上,利用相关文献和考古资料对其进行全面考释,主要涉及文本校勘、史源探求以及对水道、城邑分布的复原,并以古今对照的形式绘制出地图,将研究的结果直观呈现出来。  相似文献   

12.
To assess the geomorphological importance of waterfall recession in volcanic bedrock, we examined recession rates of six waterfalls in the lower reaches of Kaminokawa river basin on the Osumi Peninsula in southern Kyushu. The examination was performed with an empirical equation that uses a dimensionless parameter obtained by dimensional analysis of relevant measured factors, including erosive force, size of waterfall, and bedrock resistance. Welded Ata ignimbrite, formed at approximately 110 ka, may have played an initiating role to maintain such waterfalls because it resists weathering more than other local rocks. Estimated recession rates for the six waterfalls range from 0.2 to 3.0 cm/y, which compare with estimated rates for waterfalls in another region characterised by welded ignimbrite. Comparison of equation‐derived recession rates of waterfalls with actual recession distances from confluences supports the idea that an original waterfall will subsequently split into two distinct waterfalls when it recesses past an upstream junction of two channels. Our findings revealed that all six waterfalls likely would have been at almost the same point lower in the watershed in the past, marking the general site of the original waterfall. Moreover, the ancestral original waterfall is highly likely to have started from a point between the caldera rim and present river mouth. There, a knickpoint was likely caused by the river dropping into an inner part of the caldera, possibly just after the eruption of the Ata ignimbrite. The waterfall erodes upstream away from the caldera basin, and this happens to be to the east.  相似文献   

13.
In many coastal catchments of south eastern New South Wales, Australia, changes in river morphology are a response to human impact superimposed on spatial and temporal patterns of variability in precipitation and discharge. Understanding, and preferably quantifying, spatial and temporal patterns of hydrologic variability are essential to understanding natural changes, and to separate these from artificial changes in river systems. Prediction and management of water resources are also dependent upon this understanding. We assess the variability in precipitation and discharge using the wavelet transform which projects the time series of data into a three dimensional surface of frequency, amplitude and time. The analysis reveals that changes across time often reflect changes in individual seasons and may be linked to changes in particular seasonal atmospheric circulation systems. Strong perturbations in the analysis of one catchment are consistent with documented, geomorphically‐effective, flooding sequences. The characteristics of the series in the transformed data reveal interesting differences at certain times and scales which may be a reflection of changes in larger scale atmospheric processes.  相似文献   

14.
Landform conservation is the main task of geomorphology in the 21st Century. Since landforms provide the templates for the development of wildlife habitats, landform change is likely to cause habitat loss, inducing a reduction of biodiversity. From the viewpoint of ‘geomorphic species’, specific landforms such as natural rivers, tidal flats and coral reefs are endangered species in the Japanese islands. To avoid the further destruction of natural rivers, environmentally appropriate flood control plans are necessary. The analysis of the Chitose Diversion Channel project in Hokkaido, Japan, revealed that (1) the construction of this diversion channel has caused not only environmental problems but also serious social conflicts relating to habitats within and beyond the drainage basin; (2) excavation of a deep channel changed the groundwater supply which previously supported a natural river system, and (3) selection of a very high discharge value as the target of flood control was the main reason for planning this project. From a landform conservation perspective, the method adopted in Japan is unsuitable because it does not incorporate the scientific procedure necessary for selecting the ‘best’ peak discharge corresponding to the target rainfall with a certain recurrence period. An alternative flood control plan, combining the selection of a lower peak discharge, construction of retention pools and the restoration of meandering river channels is proposed to avoid the further destruction of natural rivers.  相似文献   

15.
The basin of the Zanjón Rojo and Blanco is located in the northeast of the Central Plateau of Santa Cruz province (Argentina). Each sector of the basin has specific characteristics which represent different microenvironments. We have studied two different archeological contexts in the period from the Final Pleistocene to Late Holocene in each of these sectors. In this paper, we analyze the effects of different taphonomic processes and agents on the zooarcheological assemblages in order to evaluate the role played by those that can redeposit or move bones pre- and post-depositionally during site formation in this sector of Patagonia. The bone specimens that were analyzed come from two stratigraphic contexts with wide sequences of human occupation; one is AEP-1 at Piedra Museo and the other is Cueva Maripe at La Primavera, located in the lower and upper sectors of the basin, respectively. The comparison between both sites was based on different modification patterns identified on bone surfaces for the different phases of settlement in Patagonia. The results showed complex and different taphonomic histories in both sites, and while the main processes involved in bone movement were roots and rodents, both had little significance in comparison with others, such as manganese and carbonate.  相似文献   

16.
历史时期疏勒河水系变迁及相关问题研究   总被引:2,自引:0,他引:2  
疏勒河是河西走廊西部的重要河流,关于历史时期其水系的演变问题,前辈学者已从不同角度予以关注,但在方法与详尽程度方面仍有较大改进空间。本文在充分发掘地方文献的基础上,充分利用游记、考古材料,并结合自然科学相关研究成果,就历史时期各阶段疏勒河流域水系分布状况与演变过程进行了全面讨论,订正了一些广为流传的明显错误,并就其中涉及到的部分古代地名问题提出了自己的看法。  相似文献   

17.
The Blue Mountains region of New South Wales, including the World Heritage listed Blue Mountains National Park, is arguably one of Australia's most highly valued and iconic wilderness areas. Common to this region are upland swamps (formally ‘temperate highland peat swamps on sandstone’), which play a vital hydrological role at the headwaters of the river catchments, as well as providing the habitat for an array of flora and fauna species. This paper involves an interdisciplinary examination into the need and potential for adaptive management in the Blue Mountains. It uses geomorphic (physical) knowledge of swamp condition and social data about the volunteers who rehabilitate them. Research involved using the River Styles river condition framework across 47 swamps and questionnaires and interviews with local rehabilitation volunteers. It is proposed that there is a need and a potential to combine geomorphic understanding with further engagement of community volunteers in order to enable an interdisciplinary approach to adaptive management. Such an approach could result in the effective environmental management of upland swamps in the Blue Mountains.  相似文献   

18.
This article proposes to understand the environmental impacts of a gold mining exploration in the Cerrado biome or Brazilian Savanna at the end of the nineteenth century in Mid-Western, Brazil. Firstly, the Cerrado biome is described according to perceptions about the ecological characteristics, ecological researches conducted, and mainly according to the ecosystem of the Pireneus mountains our area of research. Secondly, the historical mining impacts of nineteenth century are presented through reflections on the mining techniques of gold exploration, and through the environmental consequences of metal concentration in the area. Finally, the eco-archaeological study of the soil samples from the Almas river area in Mid-Western Brazil is demonstrated, as well as, the interpretation about the emergency of historical pollution patterns.  相似文献   

19.
The 137Cs (caesium‐137) method was used to investigate medium‐term rates of sediment deposition on the floodplain of the Labasa River, on Vanua Levu island in northern Fiji. The Labasa basin is commercially important for sugarcane farming, which provides much revenue and sustains the economy in the greater Labasa area. Alluvium was sampled at three riverbank sites in vertical increments of 30 mm. Measured net vertical accretion rates, based on analysis of depth‐profiles of 137Cs activity, ranged from 10 mm yr?1 at a low‐lying site near a tributary confluence with the main river, to 60 mm yr?1 on a levée that was elevated slightly above the adjacent floodplain. These rates of accretion are high, but in general agreement with rates recorded using similar methods in other tropical Pacific island river systems. Soil erosion under sugarcane on hilly parts of the lower Labasa basin is an important factor in rapid floodplain development. Observations made during Cyclone Ami, which traversed Vanua Levu island in early 2003, illustrate the major contribution of severe storm events to floodplain sediment supply, by triggering numerous landslides on catchment slopes and in‐channel debris floods, and by generating large‐magnitude overbank floods.  相似文献   

20.
The dramatic growth of dietary isotope studies in archaeological literature attests to the significant potential this technique has for shedding light on past societies. Human diet reflects complex, inter-linked factors such as status, cultural preferences or environmental constraints on food production. In this study dietary isotope analysis is used to examine the human skeletal remains from Ban Non Wat, northeast Thailand. The study aims to use isotopic data to give insight into patterns of migration and subsistence strategy during prehistory. Ban Non Wat is the most comprehensively excavated site in the Upper Mun River Valley (UMRV), and understanding of prehistoric society in this area is crucial to answering questions of how social complexity arose in the region. Carbon isotope analysis has highlighted migrant individuals invisible to strontium isotope analysis and shown links between unusual burial practice and differences in diet. Results also indicate that diet changed substantially through time, with more reliance on rice in the Bronze Age, correlated with an increase in social differentiation. There is a move away from reliance on rice agriculture in the Iron Age, a time when oxygen isotopes show that environmental conditions were becoming drier, possibly resulting in rice agriculture becoming less viable.  相似文献   

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