Seminar 3: Rivers and Lakes & Climate PDF

1.3. Rivers and. Lakes\ \ There is a fairly wide network of rivers in the British Isles. Though generally short in length, they are [navigable] but in their lower [reaches], especially during high [tides]. The mild [maritime climate] keeps them free of ice throughout the year. Their direction and ch...

1.3. Rivers and. Lakes\ \ There is a fairly wide network of rivers in the British Isles. Though generally short in length, they are [navigable] but in their lower [reaches], especially during high [tides]. The mild [maritime climate] keeps them free of ice throughout the year. Their direction and character are determined by the position of the mountains. Most of the rivers flow in the eastward direction since the west coast is [mountainous].\ \  British rivers form deep [estuaries], and strong tides penetrate into them, thus preventing the formation of deltas. Many of the rivers are joined together by canals. This system of rivers and canals provides a good [means] of cheap inland water transport.\ \ The largest river in Great Britain is *the Severn *(350 km) which follows from central Wales and [flows into] the Bristol Channel. *The Thames*(332 km) and *the Trent *(274 km) flow into the North Sea. Among other important rivers, which [flow eastwards] to the North Sea are the Tees and Tyne in England, and the rivers Tweed, Forth, Dee and Spey in Scotland. These are the rivers flowing into the Irish Sea: the Mersey and Eden of England, and the Clyde on which Glasgow stands. The longest river in the British Isles is the river* Shannon *(384 km) flowing from north to south in the Republic of Ireland.\           Owing to the fact that British lakes are rather small and remote, with no [outlets], they afford limited economic possibilities. The largest lake in Great Britain and the biggest inland loch in Scotland is *Loch Lomond,* covering a surface of 70 sq. km, but the largest fresh water lake of the whole British Isles is *Lough Neagh *(381 sq. km) in Northern Ireland. The sixteen major long and narrow lakes among steep slopes of the mountains in north-west England form the celebrated Lake District which is a tourist attraction. The deepest lake is Wastewater, the largest lake is Windermere.            1.4. Climate and Weather\ \ Weather is not the same as climate. The weather of the British Isles is greatly [variable]. No wonder the British never get tired of discussing the weather. The climate of a place or region, on the other hand, represents the average weather conditions over a long period of time.\ \ The geographical position of the British Isles within latitudes 50° to 61° N is a basic factor in [determining] the main characteristics of the climate. Britain\'s climate is dominated by the influence of the sea. It is much milder than that in any other country in the same [latitudes]. The marine influences warm the land in winter and cool it in summer. This [moderating effect of the sea] is in fact the cause of the relatively small seasonal contrasts experienced in Britain.\ \ The prevailing winds in the British Isles are [westerlies]. They are extremely [moist], as a result of their long [passage] over the warm waters of the North Atlantic.\ \ North and north-west winds often bring heavy falls of snow to north Britain during late October and November, but they are usually [short-lived]. Continental winds from the east sometimes reach the British Isles in summer as a warm and dry air stream, but they are more frequently experienced in winter when they cross the North Sea and bring cold, continental-type weather to the eastern and inland districts of Great Britain.\ \ [Relief] is the most important factor controlling the distribution of temperatures and [precipitation] in Britain. The actual temperatures experienced in the hilly and mountainous parts are considerably lower than those in the lowlands. The average [annual rainfall] in Britain is about 1,100 mm. The mountainous areas of the west and north have far more rainfall than the lowlands of the south and east. The western Scottish Highlands, the Lake District, Welsh Uplands and parts of Devon and Cornwall in the south-west receive more than 2,000 mm of rainfall each year.\ \ In contrast, the eastern lowlands are much drier. Much of eastern and south-eastern England (including London) receive less than 700 mm each year, and snow falls on only 15 to 18 days of the year on average.\ \ Rainfall is fairly well distributed throughout the year, although March to June are the driest months and October to January are the wettest.\ \ In Ireland the climate situation is a bit different, for here the rain-bearing winds have not been [deprived of] their moisture, and much of the Irish plain receives up to 1,200 mm of rainfall [per year], usually in the form of steady and [prolonged] [drizzle]. Snow, on the other hand, is rare owing to the [warming effects] of the Gulf Stream.\ \ Because of the Gulf Stream and predominantly maritime air masses that reach the British Isles from the west, the range in temperature throughout the year is never very great. The annual mean temperature in England and Wales is about +10 °C, in Scotland and Northern Ireland about +9 °C. July and August are the warmest months of the year, and January and February the coldest.\ \ The [distribution] of sunshine shows a general [decrease] from south to north --- the south has much longer periods of sunshine than the north.\ \ 1.5. Vegetation and Landscape\ \ The landscape is rich and varied, sometimes showing marked contrasts within short distances, particularly on the coasts. Most of the land is agricultural of which over one third is arable, and the rest being [pasture] and [grazing]. [Woodlands] cover about 8 per cent of the country. Today only a few scattered areas of extensive woodland remain, such as the New Forest in Hampshire and Sherwood Forest in Nottinghamshire.\ \ The present vegetation of Great Britain owes much of its character to the influence of man. Only in the remote parts of Ireland and the Scottish Highlands [remnants] of the natural vegetation still exist. The original natural vegetation consists of forest, [fen] and [marsh] in the wet [lowlands], and [shrub], [heath] and [moorland] on the [uplands].\ \ In the mountainous regions of Great Britain the vegetation is represented by [coniferous] and mixed forests with the predominance of [pine, oak and birch]. The greatest [density] of woodland occurs in the north and east of Scotland, in some parts of southeast England and on the Welsh border. The most common trees are oak, [beech, ash and elm]. In the north and on higher ground in the west these are replaced by birch pine, [fir and spruce].\ \ Midland Britain appears to be well wooded because of the [numerous hedges] and isolated trees. Hedges are a [typical feature] of countryside landscape in England.\ \ Generally, the flora of Great Britain is [impoverished] compared to that of continental Europe. Great Britain\'s flora comprises 3354 [vascular plant] species in total, of which 2297 are native and 1057 have been introduced into the island. The island has a wide variety of [trees], including [native species] of [birch], [beech], [ash], [hawthorn], [elm], [oak], [yew], [pine], [cherry] and [apple]. Other trees have been naturalised, introduced especially from other parts of Europe (particularly Norway) and North America. Introduced trees include several varieties of pine, [chestnut], [maple], [spruce], [sycamore] and [fir], as well as [cherry plum] and [pear trees]. The tallest species are the [Douglas firs]; two specimens have been recorded measuring 65 meters. The [Fortingall Yew] in [Perthshire] is the oldest tree in Europe.\ \ There are at least 1500 different species of [wildflower] in Britain, Some 107 species are particularly rare or vulnerable and are protected by the [Wildlife and Countryside Act 1981]. It is illegal to uproot any wildflowers without the landowner\'s permission. Various wildflowers represent specific counties. These include [red poppies], [bluebells], [daisies], [daffodils],[rosemary], [gorse], [iris], [ivy], [mint], [orchids], [brambles], [thistles], [buttercups],[primrose], [thyme], [tulips], [violets], [cowslip], [heather] and many more. There are also many species of [algae], [lichens], [fungi] and [mosses] across the island.\ \ 1.6. Animal Life\ \ Animal [diversity] is modest, as a result of factors including the island\'s small land area, the relatively recent age of the habitats developed since the last [Ice Age] and the island\'s physical separation from [continental Europe], and the effects of seasonal variability. Great Britain has also gone through [industrialisation] and increasing [urbanisation], which have contributed towards the overall loss of species. Studies from 2006 suggested that 100 species have become extinct in the UK during the 20th century including the wolf, the bear, the boar, the deer ‑­\ \ and the Irish elk. However, some species, such as the [brown rat], [red fox], and introduced [grey squirrel], are well adapted to urban areas.\ \ [Rodents] make up 40% of the total number of [mammal species in Great Britain]. These include [squirrels], [mice], [voles], [rats] and the recently reintroduced [European beaver]. There is also an abundance of [rabbits],[hares], [hedgehogs], [shrews], [moles] and several species of [bat]. Carnivorous mammals include the [badger], [weasel], [stoat] and elusive [wildcat]. There are foxes in most rural areas, and otters are found along many rivers and streams.\ \ Various species of [seal], [whale] and [dolphin] are found on or around British shores and coastlines. The largest land-based wild animals today are [deer]. The [red deer] is the largest species, with [roe deer] and [fallow deer]also prominent; the latter was introduced by the [Normans]. Habitat loss has affected many species. [Extinct large mammals] include the [brown bear],[grey wolf] and [wild boar]; the latter has had a limited reintroduction in recent times.\ \ There is a wealth of [birdlife in Britain], 583 species in total, of which 258 breed on the island or remain during winter. Because of its mild winters for its latitude, Great Britain hosts important numbers of many wintering species, particularly [ducks], [geese] and [swans]. Other well known bird species include the [golden eagle], [grey heron], [kingfisher], [pigeon], [sparrow], [pheasant], [partridge], and various species of [crow], [finch], [gull], [auk], [grouse], [owl] and [falcon].\ \ There are a lot of song-birds. Blackbirds, sparrows and starlings are probably most common. There are mane sea birds, which nest round the coasts and often fly for inland in search of food or shelter in rough weather.\ \ There are six species of [reptile] on the island; three [snakes] and three[lizards] including the legless [slow worm]. One snake, the [adder], is venomous but rarely deadly. [Amphibians] present are [frogs], [toads] and [newts].