East Of Britain Research Articles

Collaborative monitoring of wind turbine performance based on probabilistic power curve comparison

A wind farm is usually equipped with multiple wind turbines of the same type. These wind turbines often work under same complex conditions. Accurate performance degradation monitoring is crucial for ensuring the reliable operation of wind farms and reducing maintenance costs. Motivated by this, this article develops a new wind turbine performance degradation monitoring scheme, which is based on pairwise comparison of the probability power curves of different wind turbines in a wind farm. Firstly, covariate matching is used to eliminate the inherent differences in meteorological variables of different turbines within the same data segment. Next, two probabilistic wind power curves, the quantile power curve and density power curve, model the functional relationship between the meteorological variables and wind power output. Then, deviation vectors are generated by calculating the deviation of probabilistic power curves between each pair of wind turbines. Finally, a directional Hotelling T2 control chart is proposed to monitor the deviation vectors. We apply the new method on the real data of a wind farm in East Britain. Results show that the proposed monitoring technique can monitor wind turbine performance degradation more precisely and comprehensively than the existing approaches.

On the earliest Acheulean in Britain: first dates and in-situ artefacts from the MIS 15 site of Fordwich (Kent, UK).

Northern Europe experienced cycles of hominin habitation and absence during the Middle Pleistocene. Fluvial gravel terrace sites in the east of Britain and north of France provide a majority of the data contributing to this understanding, mostly through the presence or absence of stone-tool artefacts. To date, however, relatively few sites have been radiometrically dated, and many have not been excavated in modern times, leading to an over-reliance on selectively sampled and poorly dated lithic assemblages. This includes Fordwich (Kent, UK), where over 330 bifaces were discovered through industrial quarrying in the 1920s. Here, we present the first excavation and dating of artefacts discovered in situ at Fordwich, alongside their technological analysis and relationship to those previously recovered. The site is demonstrated to retain deposits of Lower Palaeolithic artefacts, with 251 flakes, scrapers and cores identified to date. Infrared-radiofluorescence (IR-RF) dating of feldspar reveals 112 artefacts to have come from levels dating to at least 570 ± 36 to 513 ± 30 thousand years ago (ka) and are most plausibly assigned to an MIS 14 deposition, with artefacts produced during MIS 15 (approx. 560–620 ka). Indeed, these IR-RF samples provide minimum ages for artefacts. Combined with evidence from exposures linked to the original quarrying activities, a similar MIS 15 age is suggested for the more than 330 handaxe artefacts discovered in the 1920s. The remaining excavated artefacts come from levels dated to between 347 ± 22 and 385 ± 21 ka (MIS 10 or 11), with this later age interpreted to reflect post-MIS 14 deposition by substrate gullying and solifluction. These data demonstrate Fordwich to be one of the earliest Palaeolithic sites in northwestern Europe, and to retain the only large Acheulean handaxe assemblage directly dated to pre-MIS 13. Thus, Fordwich is determined to be a crucial piece of the pre-Anglian Palaeolithic puzzle in northern Europe.

Diagnosing links between atmospheric moisture and extreme daily precipitation over the UK

ABSTRACTAtmospheric moisture characteristics associated with the heaviest 1% of daily rainfall events affecting regions of the British Isles are analysed over the period 1997–2008. A blended satellite/rain‐gauge data set (GPCP‐1DD) and regionally averaged daily rain‐gauge observations (HadUKP) are combined with the ERA Interim reanalysis. These are compared with simulations from the HadGEM2‐A climate model which applied observed sea surface temperature and realistic radiative forcings. Median extreme daily rainfall across the identified events and locations is larger for GPCP (32 mm day−1) than HadUKP and the simulations (∼25 mm day−1). The heaviest observed and simulated daily rainfall events are associated with increased specific humidity and horizontal transport of moisture (median 850 hPa specific humidity of ∼6 g kg−1 and vapour transport of ∼150 g kg− 1m s− 1 for both observed and simulated events). Extreme daily rainfall events are less common during spring and summer across much of the British Isles, but in the south east region, they contribute up to 60% of the total number of distinct extreme daily rainfall events during these months. Compared to winter events, the summer events over south east Britain are associated with a greater magnitude and more southerly location of moisture maxima and less spatially extensive regions of enhanced moisture transport. This contrasting dependence of extreme daily rainfall on moisture characteristics implies a range of driving mechanisms that depend upon location and season. Higher spatial and temporal resolution data are required to explore these processes further, which is vital in assessing future projected changes in rainfall and associated flooding.

New Tourism Archives: The records of the East African Professional Hunters’ Association

The newly released records of the East African Professional Hunters’ Association (EAPHA), held at the University of Florida, contain a wide variety of documentary source material for scholars interested in hunting, tourism, conservation, wildlife management, land use issues and the history of colonialism and white settlement in East Africa. Despite a parochial and somewhat misleading name, the EAPHA served as the leading professional association for those involved in East Africa's safari tourism industry, including safari companies, outfitters, travel and tourism agencies, hotels and lodges, rail and airline corporations, and the professional guides for whom the Association was created. From its foundation in 1934 to its dissolution in 1977, the Association strived to promote the safari business for its members, to ensure a high quality of experience for visiting tourists, and to conserve the wildlife upon which the industry depended. In pursuing these objectives, the EAPHA left behind numerous reports, committee minutes, correspondence, press clippings, publicity statements, and a variety of other documents that shed light on an important phase of tourism development in Britain's East African territories of Kenya, Tanganyika and Uganda.

Using citizen science to investigate the role of productivity in House Sparrow Passer domesticus population trends

Capsule Seasonal variation in garden House Sparrow numbers provides a tool to examine overall annual productivity, measuring the combined success of multiple breeding attempts and post-fledging survival.Aims To develop a metric to use British Trust for Ornithology (BTO) Garden BirdWatch (GBW) data to measure annual productivity in House Sparrows across regions and habitats exhibiting contrasting population trends.Methods We examine variation in annual productivity by quantifying the height of the seasonal peak of garden House Sparrows relative to pre-breeding numbers. We use BTO Nest Record Scheme (NRS) data to explore the demographic drivers of variation in this metric and relate differences to BTO/Joint Nature Conservation Committee/Royal Society for Protection of Birds Breeding Bird Survey regional population trends.Results GBW annual productivity was similar between rural and urban gardens but was lower in the south and the east of Britain (1.32 fledglings per adult), where populations are declining, than in the north and west where populations are stable (1.37 fledglings per adult). Analysis of NRS data showed similar regional variation in clutch and broods sizes.Conclusion The intensity of effort required to measure breeding success directly through nest monitoring has limited the scale of data collection but these results suggest that Garden BirdWatch (GBW) data can provide a measure of annual productivity across multiple sites. Regional variation in annual productivity (primarily driven by reduced clutch sizes) mirrors population trends, suggesting that reduced breeding success may be influencing House Sparrow population recovery.

Estimating the profitability of the British east coast main line

Successful railway franchising requires both bidders and tendering authority to have a good understanding of the underlying economics of that part of the railway. However, an earlier franchise contract for Britain's east coast main line franchise was terminated early by the government in 2006, while a more recent franchisee has recently passed the franchise back to the government, having suffered unduly during the recession of 2008–2009. Both bidders made very significant (and, it would appear, unsustainable) promises to government in terms of paying a premium to operate the services concerned, but such premia inevitably derive from the competitive situation of franchising. This paper sets out some indicative analysis of train operator profitability in Britain which provides some guidance as to the appropriate level of premium for this – and other – franchises, with some more general conclusions.

Infection of Arum Maculatum by the rust Puccinia sessilis at Carmel NNR, South Wales

rum maculatum is probably one of the most familiar plants of our native flora. It adorns our hedgerows and base-rich woodlands in spring and summer, the characteristic fruits lasting well into the autumn. Its common name is Lordsand-Ladies, although Prime (1960) records over a hundred English names for this plant throughout Britain, together with detailed information on its folklore, variation and ecology. It is very common throughout England and Wales, and according to Prime is frost sensitive. As a consequence its frequency declines northwards and it is local in Scotland (www.bsbimaps.org.uk/atlas/main.php). It is an extremely variable plant with differences recorded between individuals and between populations. Prime records differences in the floral structure, leaf shape, venation and pigmentation, but the most striking visible difference is the presence in some plants of dark purple-black markings on the leaves (hence the specific epithet “maculatum”, which means “spotted”) whilst other plants are unspotted. The purple-spotted plants are very conspicuous (Fig. 1) and the dark blotches are usually irregular in shape and vary in size from small dots of a few millimetres to a few centimetres in diameter. This pigmentation is confined to the central layers of the leaf and was once thought to be the result of a virus infection but is now known to be due to anthocyanin production. Local and national floras have not generally formally distinguished these forms, though Sell & Murrell (1996), while not accepting the varieties as part of the formal description of taxa, do give varietal names for plants with spots (var. maculatum) and those without (var. immaculatum) in their discussion. Prime carried out a comprehensive study across Britain in the 1950s and he showed in general that spotted plants became less common towards the north and east of Britain. Puccinia sessilis is a rust fungus. Many rusts have life cycles which involve the production of up to five different spore stages and the participation of two different host plants. P. sessilis exhibits this type of life cycle. Two spore stages are produced on Arum and the other three spore stages are produced on the alternate host Phalaris arundinacea (Reed Canary-grass). Arum is infected by the rust in the early spring and this results in the formation of discrete orangeyellow pustules on the upper surface of the leaf (Fig. 2). Within these pustules minute spherical bodies called pycnia are produced which are the first spore stage of the rust. After about 10–14 days these develop into the next spore stage, which is produced on the underside of the leaf. These structures (called aecia) look like little coronets (Fig. 3) and produce aeciospores, which in turn infect another plant from a different family (the alternate host), which in this case is Phalaris arundinacea. Infection of Phalaris occurs during the summer months, and two different spore types are subsequently produced. The first of these (urediniospores) are produced continuously during the summer and are responsible for spreading the disease throughout the stand of Phalaris. During late summer/autumn yet another type of spore (teliospore) is produced which is the overwintering stage of the rust. The following spring these teliospores themselves germinate to produce the final spore stage in the life cycle (the basidiospore), and it is this spore stage that reinfects Arum in the spring thus completing the life cycle of the rust (Wilson & Henderson 1966). For the rust to survive, therefore, both host plants must be present to allow cross infection to take place to enable the rust to complete its life cycle.

Revised estimate of numbers of wintering Red-throated Divers Gavia stellata in Great Britain

Capsule An estimated 17 000 Red-throated Divers winter around Great Britain. Aim To produce an up-to-date assessment of the numbers of Red-throated Divers wintering around Great Britain. Methods A revised Great Britain (GB) wintering population estimate for Red-throated Divers was compiled using data primarily from systematic line transect surveys by aircraft over marine nearshore areas conducted during 2001–06, supplemented with county bird records and Wetland Bird Survey (WeBS) counts, both from 1995 to 2005. Population estimates for each survey area around GB were calculated as the mean of either annual means (aerial surveys) or annual maxima (WeBS, county bird records) of all data collected within January and February of each year. These were summed to give a revised GB wintering population estimate. Results A total of 17116 (13198–21034, 95% confidence interval) Red-throated Divers were estimated to winter around GB. Distribution was uneven. By far the greatest numbers were found off southeast and east Britain (59.3% of the total was between Flamborough Head, Yorkshire, and Dungeness, Kent), with large concentrations off the English south coast (10.9%), north Wales and Liverpool Bay (9.8%), and eastern Scotland (6.1%). Conclusion This is a minimum plausible population estimate and the true population size may be larger. The new 1% of population threshold for statutory conservation work is 170 birds.

Legacies of Slavery in North-West Uganda: The Story of the ‘one-Elevens’

AbstractThis article outlines the history of a people known as ‘Nubi’ or ‘Nubians’, northern Ugandan Muslims who were closely associated with Idi Amin's rule, and a group to which he himself belonged. They were supposed to be the descendants of former slave soldiers from southern Sudan, who in the late 1880s at the time of the Mahdi's Islamic uprising came into what is now Uganda under the command of a German officer named Emin Pasha. In reality, the identity became an elective one, open to Muslim males from the northern Uganda/southern Sudan borderlands, as well as descendants of the original soldiers. These soldiers, taken on by Frederick Lugard of the Imperial British East Africa Company, formed the core of the forces used to carve out much of Britain's East African Empire. From the days of Emin Pasha to those of Idi Amin, some Nubi men were identified by a marking of three vertical lines on the face – the ‘One-Elevens’. Although since Amin's overthrow many Muslims from the north of the country prefer to identify themselves as members of local Ugandan ethnic groups rather than as ‘Nubis’, aspects of Nubi identity live on among Ugandan rebel groups, as well as in cyberspace.

Legacies of Slavery in North-West Uganda: The Story of the 'One-Elevens'

This article outlines the history of a people known as ‘Nubi’ or ‘Nubians’, northern Ugandan Muslims who were closely associated with Idi Amin's rule, and a group to which he himself belonged. They were supposed to be the descendants of former slave soldiers from southern Sudan, who in the late 1880s at the time of the Mahdi's Islamic uprising came into what is now Uganda under the command of a German officer named Emin Pasha. In reality, the identity became an elective one, open to Muslim males from the northern Uganda/southern Sudan borderlands, as well as descendants of the original soldiers. These soldiers, taken on by Frederick Lugard of the Imperial British East Africa Company, formed the core of the forces used to carve out much of Britain's East African Empire. From the days of Emin Pasha to those of Idi Amin, some Nubi men were identified by a marking of three vertical lines on the face – the ‘One-Elevens’. Although since Amin's overthrow many Muslims from the north of the country prefer to identify themselves as members of local Ugandan ethnic groups rather than as ‘Nubis’, aspects of Nubi identity live on among Ugandan rebel groups, as well as in cyberspace.

Timing and duration of moult in three populations of Purple Sandpipers Calidris maritima with different moult/migration patterns

Timing and duration of primary moult in three populations of Purple Sandpipers Calidris maritima were described and discussed in relation to the birds’ need to complete moult before the onset of winter, when resources are required for survival. We predicted that moult would be completed earlier by birds wintering at higher latitudes. The south Norwegian breeding population, which moults and winters along the coast of east Britain (54–57°N) had a mean starting date of 21 July for primary moult (16 July for females and 24 July for males), a mean duration of 61 days, and completed on 20 September. Resident Icelandic (64–65°N) birds had a mean starting date of 22 July for primary moult (17 July for females and 25 July for males), a mean duration of 51 days, and completed on 11 September. Birds moulting in north Norway (70°N) arrived in north Norway in suspended primary moult or without having started moult, and completed it there. They had a mean completion date of 2 November for primary moult (31 October for females and 3 November for males). Starting date and duration could not be estimated because some suspended moult for an undetermined period, but it was thought that they started in late August. It is likely that most originated from Russia. The onset of moult appears to be set by the end of breeding and there is little overlap in these two events. The earlier start of moult by females in all three populations may be because they abandon the males when the chicks hatch, leaving the males to attend the chicks. Although the duration of primary moult followed the expected trend, being fastest in north Norway and slowest in Britain, the onset of moult was so late in north Norway that they had an unexpectedly late completion date, despite their rapid moult. The late completion of primary moult in north Norway suggests that wintering in the far north may not pose the energetic constraints on Purple Sandpipers that had previously been supposed.

Spatial trends in the sighting dates of British butterflies.

A strong relationship between appearance dates and temperature has been demonstrated over two decades for most British butterflies. Given this relationship over time, this paper tests whether comparable spatial trends in timing are also apparent. A major survey of British butterflies is used to calculate mean sighting dates of adults across the country, and these are compared with geographic patterns in temperature. With the use of regression techniques, we calculated latitudinal (south-north) and longitudinal (east-west) gradients in sighting date and temperature. The majority of butterflies appear later in the east of Britain where temperatures are lower during summer, but not the rest of the year. Most butterflies are also seen later in the cooler north of the country, by upto 3-4 days/100 km. However, no geographical relationship between temperature and timing of appearance was detected for over a third of the species analysed, suggesting their populations may be adapted to their local climates. We suggest possible mechanisms for this and discuss the implications of such adaptation for the ability of butterfly species to respond to rapid climate warming.

Fluvial deposition on periodically emergent shelves in the Quaternary: example records from the shelf around Britain

This paper explores the record of fluvial sedimentation on continental shelves during the Quaternary, in areas that are shallow seas in the present day. During episodes of higher global ice volume than the present, which account for a large proportion of Quaternary time, large parts of the shelf were dry land, drained by rivers. The latter included extensions of still-existing rivers as well as complete systems that are now lost beneath Holocene interglacial seas. In areas where extensive epi-continental seas have formed during interglacials, there is considerable potential for large areas of submerged fluvial sediments to survive on the shelf, providing evidence of former river courses and for the evolution of these rivers during the late Cenozoic. Examples of now-submerged fluvial systems from the shelf to the south and east of Britain are examined. Submerged terraces of the extended River Thames have been mapped beneath the southern North Sea in the area offshore from the Thames estuary. Further offshore, however, all evidence of former sub-aerial drainage during the last glacial has been removed by erosion and it is uncertain whether the Thames and Rhine, which would have joined in this area, flowed northwards to the North Sea or southwards to the English Channel, although the latter is regarded as more likely. The Rhine–Thames is just one example of the very large system that would have existed only during low stands, their concentrated freshwater output having a potentially significant effect on ocean systems.

The impact of aerial reconnaissance in Devon (Great Britain)

While some of the earliest regular aerial reconnaissance for archaeology was carried out in the south and east of Britain, work in west has been of more recent date. The emphasis has chiefly been upon the well preserved archaeology of the western uplands such as Dartmoor and Bodmin Moor, where aerial photography has played a very important role in the mapping of the upstanding monuments. The archaeological understanding of the South West England and Wales has been dominated by the archaeology of these uplands, which were long believed to have been preferentially occupied in the prehistoric period. Since the 1950s, however, reconnaissance by Professeur St Joseph and David Wilson from Cambridge, has indicated that these areas can also be productive of cropmarks, and the last ten years have seen the development of regional flying programmes examining these areas through more intensive survey. Climate, soil and cropping conditions in the west are all substantially less favourable to cropmark production than in the east, and locally based flying represents the most efficient and effective way to exploit the narrower windows of opportunity. Results over the last fifteen years have transformed our perception of the later prehistoric and Romano-British settlement of the lowlands of South West England and Wales, the nature of the Roman Conquest and the changing relationship between highland and lowland areas.

From subjects to citizens: British ‘East African Asians’

In the 25 years since their expulsion the Uganda Asian refugees, in concert with earlier arrivals from East Africa, have made remarkable economic and cultural progress to become one of Britain's wealthiest minority ethnic communities with a strong cultural presence. The majority of the refugees and migrants are Gujaratis, a people with whom the British have shared a joint history spanning four centuries and three continents. In this article, I trace this joint history in Gujarat and East and Central Africa, laying emphasis upon the social consequences of the military imperialisms that, for some seven centuries, rendered Gujaratis subjects of foreign powers. It is argued that, as political subjects, certain Gujarati groups were able to prosper economically whilst retaining their cultural traditions. This historically evolved socio‐economic pattern finds expression in the Gujarati ‘merchant ideology’. It is suggested that in contemporary Britain East African Asians are no longer political subjects but, for the first time, prosperous and successful citizens of the country in which they live. This transition from subjects to citizens may have disruptive repercussions upon their culture, challenges which are most likely to be met by the rising generations.

Population Trends of Common British Butterflies at Monitored Sites

1. In recent decades, many of the common and widespread butterflies in Britain which do not already occupy the whole of the country have expanded in range. 2. Populations of the species which have expanded in range, monitored for varying periods during 1974-92 have, overall, shown significantly more increases than declines in abundance, as have the species with ranges which already occupy most of Britain. 3. Nearly all of the common species have increased in abundance more in the east of Britain than in the west. 4. Although the reasons for recent range expansions and increases in abundance of common butterflies are not known, it seems likely that changes in weather have played a role. 5. It is argued that the geographical differences in population trends suggest that a factor (or factors) with a similar eastern bias is also implicated in the changes in abundance and perhaps of range. Some possible factors are discussed briefly

Visions of Power: Imagery and Symbols in Late Iron Age Britain

This article is a speculative essay about one aspect of authority and power in the late Iron Age. Excellent narratives exist which discuss the political context of the rise of the polities of Verica and Cunobelin in the South East of Britain, but over the last few decades the place of druids in this story has been neglected. However druids did exist, and they need to be worked into our narratives of the past. What follows leads to a discussion of their nature and function in society, and of their decline in importance during the large-scale social changes which took place in the generations immediately preceding the Roman conquest. The article uses a mixture of ethnographic, historical, numismatic, and archaeological evidence.

Trees and their response to wind: mid Flandrian strong winds, Severn Estuary and inner Bristol Channel, southwest Britain

The response of contemporary trees to strong winds (gale force and greater) is repeatable and well defined, as shown by field studies in south east Britain after the October 1987 and January 1990 events, combined with awide-ranging literature survey. It involves the general processes of windprune, windsnap, windtilt and windthrow. Windprune depends on a range of physical and physiological mechanisms and leads to the loss of axial symmetry by a tree, especially where open-grown at an exposed site. Windsnap, windtilt and windthrow see the fall of a tree, as the result of either the breaking of the trunk or partial to full uprooting. Damage of this sort in a forest or woodland ranges from single trees, to scattered groups (swathes), to general devastation. In the main, perfectly healthy trees in youth or early maturity are affected by windsnap, windtilt and windthrow during strong wind events. Their fall-direction is readily established using the position of the rootball or snapped end of the trunk, the alignment of a broken trunk and stump, the taper of the trunk, the position on the trunk of relatively crowded branches (tree crown), and the position of the typically upward acute angle between branch and trunk. Contemporary trees overthrown by wind fall in a direction close to the wind. The variance of fall-directions in a sample due to a single wind event is observed to increase with the size of the woodland area from which the sample is drawn, but appears to become constant for sample areas in excess of 102- 103ha. Because this constant variance is relatively small, the mean fall-direction becomes, in contemporary woodlands and forests, a trustworthy indicator of the general direction of the strong wind which felled the trees. Rooted peats of mid Flandrian age (ca. 6000-2500 conventional radiocarbon years) which include prostrate trees are widely present among the post-glacial estuarine silts exposed along the shores of the Severn Estuary and the inner Bristol Channel. The trees when overthrown appear in the main to have been perfectly healthy and in youth to early maturity. Oak and alder are the predominant species, and their fall-directions, as judged from the criteria listed from contemporary forests and woodlands, and measured at 18 horizons distributed over 14 sites, are highly coherent both locally and over the area as a whole. Using a model in which the variance of fall-directions observed for a single event is combined with a probability density for event mean directions, it appears that the trees fossilized in the peats were felled by strong winds which blew chiefly toward a range of directions from N.N.W . clockwise to S.S.E. A westerly zonal air-flow is indicated but, compared to the contemns than now, with a greater emphasis on both southerly and westerly to northwesterly blows.

The future of lucerne in British agriculture: an economic assessment

AbstractWith its potential for high yields and high animal output, lucerne appears to be an underexploited crop in British agriculture. In this paper an attempt is made to assess the prospects for expansion of the area of lucerne in Britain from an economic viewpoint, concentrating on lucerne as a conservation crop. Under good management lucerne is shown to have lower production costs than grass and its inclusion in the diet of dairy cows, but not beef cattle, could significantly lower winter feed costs. However, under apparently similar growing conditions, lucerne yields on different farms vary significantly, ranging from 9 to 13 t dry matter ha−1 a−1. At the lower yields, the economic attraction of growing and feeding lucerne in place of grass is small. Moreover, since potential lucerne production is concentrated in the south and east of Britain, lucerne competes with other arable crops. For lucerne to offer a gross margin per unit area comparable with these, the price for conserved lucerne would have to be set at a level at which dairy farmers would derive little economic advantage from feeding it. Thus, although lucerne is a forage crop with some potential, at present it is likely to offer economic possibilities only where producers can combine high yields with on‐farm utilization of the crop.

The effect of the wreck of seabirds in February 1983 on auk populations on the Isle of May (Fife)

The wreck of 30,000 auks in east Britain in early 1983 has been described as a disaster and catastrophe. Work on the Isle of May indicates that it had no significant effect on the numbers or breeding of auks there.