Columbia

The Columbia begins its 1,243-mile (2,000 km) journey in the southern Rocky Mountain Trench in British Columbia (BC). Columbia Lake – 2,690 feet (820 m) above sea level – and the adjoining Columbia Wetlands form the river's headwaters. The trench is a broad, deep, and long glacial valley between the Canadian Rockies and the Columbia Mountains in BC. For its first 200 miles (320 km), the Columbia flows northwest along the trench through Windermere Lake and the town of Invermere, a region known in British Columbia as the Columbia Valley, then northwest to Golden and into Kinbasket Lake. Rounding the northern end of the Selkirk Mountains, the river turns sharply south through a region known as the Big Bend Country, passing through Revelstoke Lake and the Arrow Lakes. Revelstoke, the Big Bend, and the Columbia Valley combined are referred to in BC parlance as the Columbia Country. Below the Arrow Lakes, the Columbia passes the cities of Castlegar, located at the Columbia's confluence with the Kootenay River, and Trail, two major population centers of the West Kootenay region. The Pend Oreille River joins the Columbia about 2 miles (3 km) north of the U.S.–Canada border.^[10]

Course of the Columbia River

The Columbia enters eastern Washington flowing south and turning to the west at the Spokane River confluence. It marks the southern and eastern borders of the Colville Indian Reservation and the western border of the Spokane Indian Reservation.^[11] The river turns south after the Okanogan River confluence, then southeasterly near the confluence with the Wenatchee River in central Washington. This C‑shaped segment of the river is also known as the "Big Bend". During the Missoula Floods 10,000 to 15,000 years ago, much of the floodwater took a more direct route south, forming the ancient river bed known as the Grand Coulee. After the floods, the river found its present course, and the Grand Coulee was left dry. The construction of the Grand Coulee Dam in the mid-20th century impounded the river, forming Lake Roosevelt, from which water was pumped into the dry coulee, forming the reservoir of Banks Lake.^[12]
The river flows past The Gorge Amphitheatre, a prominent concert venue in the Northwest, then through Priest Rapids Dam, and then through the Hanford Nuclear Reservation. Entirely within the reservation is Hanford Reach, the only U.S. stretch of the river that is completely free-flowing, unimpeded by dams and not a tidal estuary. The Snake River and Yakima River join the Columbia in the Tri‑Cities population center. The Columbia makes a sharp bend to the west at the Washington–Oregon border. The river defines that border for the final 309 miles (497 km) of its journey.^[13]

The Columbia River Gorge, facing east toward Beacon Rock

The Deschutes River joins the Columbia near The Dalles. Between The Dalles and Portland, the river cuts through the Cascade Range, forming the dramatic Columbia River Gorge. No other river except for the Klamath completely breaches the Cascades—the other rivers that flow through the range also originate in or very near the mountains. The headwaters and upper course of the Pit River flows through much of the Cascades; in contrast the Columbia cuts through the range nearly a thousand miles from its source in the Rocky Mountains. The gorge is known for its strong and steady winds, scenic beauty, and its role as an important transportation link.^[14] The river continues west, bending sharply to the north-northwest near Portland and Vancouver, Washington, at the Willamette River confluence. Here the river slows considerably, dropping sediment that might otherwise form a river delta. Near Longview, Washington and the Cowlitz River confluence, the river turns west again. The Columbia empties into the Pacific Ocean just west of Astoria, Oregon, over the Columbia Bar, a shifting sandbar that makes the river's mouth one of the most hazardous stretches of water to navigate in the world.^[15] Because of the danger and the many shipwrecks near the mouth, it acquired a reputation as the "Graveyard of Ships".^[16]
The Columbia drains an area of about 258,000 square miles (670,000 km²).^[6] Its drainage basin covers nearly all of Idaho, large portions of British Columbia, Oregon, and Washington, and small portions of Montana, Wyoming, Utah, and Nevada; the total area is similar to the size of France. Roughly 745 miles (1,200 km) of the river's length and 85 percent of its drainage basin are in the U.S.^[17] The Columbia is the twelfth-longest river and has the sixth-largest drainage basin in the United States.^[6] In Canada, where the Columbia flows for 498 miles (801 km) and drains 39,700 square miles (103,000 km²), the river ranks 23rd in length,^[18] and its basin ranks 13th in size.^[19] The Columbia shares its name with nearby places, such as British Columbia, as well as with landforms and bodies of water.

Cox's Bazar the longest unbrolken beach

(Bangladesh) Miles of golden sands, towering cliffs, surfing waves, rare conch shells, colorful pagodas, Buddhist temples and tribes, delightful sea-food--this is Cox's Bazar, the tourist capital of Bangladesh. Having the world's longest (120 kilometers.) beach sloping gently down to the blue waters of the Bay of Bengal, Cox's Bazar is one of the most attractive tourist sport in the country. There are also a few very old wooden Buddhist temples at Ramu, a few kilometers from Cox's Bazar, well worth visiting.Located at a distance of 152 km. south of Chittagong, the leading seaport of Bangladesh, Cox's Bazar is connected both by air and road from Dhaka and Chittagong.A drive to Teknaf, which is the southernmost tip of the mainland of Bangladesh, is a memorable journey. A day trip to either Moheshkhali or Sonadia, the deltaic islands nestled among the gentle waves of the Bay of Bengal, will also be really interesting.Other attractions for visitors are conch shell market, tribal handicraft, salt and prawn cultivation.Besides, the longest sea-beach, Cox's Bazar and its adjoin areas have a lot of things to see and places deserve visit by the tourists.Himchari: It is about 32 km. South of Cox's Bazar along the beach, a nice place for picnic and shooting. The famous "Broken Hills" and waterfalls here are rare sights.Inani: It is about 32 km. South of Cox's Bazar and just on the beach, with the sea to the west and a background of steep hills to the east. Inani casts a magic spell on those who step into that dreamland. It is only half an hour's drive from Cox's Bazar and an ideal place for Sea-bathing and picnic.Maheskhali: An island off the coast of Cox's Bazar. It has an area of 268 square kilometers. Through the centre of the island and along the eastern coast line rises a range of low hills, 300 feet high; but the coast to the west and north is a lowlying treat, fringed by mangrove jungle. In the hills on the coast is built the shrine of Adinath, dedicated to siva. By its side on the same hill is Buddhist Pagoda.Ramu: This is a typical Buddhist village, about 16 km. from Cox's Bazar, on the main road to Chittagong. There are monasteries, khyangs and pagodas containing images of Buddha in gold, bronze and other metals inilaid with precious stones.One of the most interesting of these temples is on the bank of the Baghkhali river. It houses not only interesting relics and Burmes handicrafts but also a large bronze statue of Buddha measuring thirteen feet high and rests on a six feet high pedestal. The wood carving of this khyang is very delicate and refined.The village has a charm of its own. Weavers ply there trade in open workshops and craftsmen make handmade cigars in their pagoda like houses.Sonadia Island: It is about seven kilometer of Cox's Bazar and about nine square kilometer in area. The western side of the island is sandy and different kinds of shells are found on the beach. Off the northern part of the island, there are beds of window pane oysters. During winter, fisherman set up temporary camps on the island and dry their catches of sea fish.St. Martins Island: This small coral island about 10km (6mi) south-west of the southern tip of the mainland is a tropical cliché, with beaches fringed with coconut palms and bountiful marine life. There''s nothing more strenuous to do here than soak up the rays, but it''s a clean and peaceful place without even a mosquito to disrupt your serenity. It''s possible to walk around the island in a day because it measures only 8 sq km (3 sq mi), shrinking to about 5 sq km (2 sq mi) during high tide. Most of island''s 5500 inhabitants live primarily from fishing, and between October and April fisher people from neighbouring areas bring their catch to the island''s temporary wholesale market. A ferry leaves Teknaf for St Martin every day and takes around 3 hours.Getting to St. Martin''s is a three-step program. First you''ll need to fly or bus it down to Cox''s Bazar, and then catch a bus to Teknaf, which is right on the very tip of Bangladesh, sandwiched up against Myanmar. From Teknar, ferries run daily to St. Martin Island. The total distance from Dhaka to the island is 510km (316mi).The Aggameda Khyang, Cox's Bazar: Equally elaborate in plan, elevation and decoration is the Aggameda Khyang near the entrance to the Cox's Bazar town which nestles at the foot of a hill under heavy cover of a stand of large trees. The main sanctuary-cum-monastery is carried on a series of round timber columns, which apart from accommodating the prayer chamber and an assembly hall, also is the repository of a large of small bronze Buddha images-mostly of Burmese origin-- and some old manuscripts. Beyond the main khyang to the south there is an elevated wooden pavilion and a smaller brick temple with a timber and corrugated metal root. Apart from bearing an inscription in Burmese over its entrance the temple contains some large stucco and bronze Buddha images.Teknaf: Southernmost tip of Bangladesh, Teknaf situated on the Naaf river and just at the end of the hilly regions of the district. Mayanmar is on the opposite bank of Naaf river. Wild animals and birds are available but the most interesting thing is a journey on the river. Wide sandy beach in the backdrop of high hills with green forests is an enchanting scene never to be forgotten.The Cox's Bazar Holiday Complex of Bangladesh Parjatan Corporation, the National Tourism Organization is an ideal tourist resort having a number of facilities for the visitors.

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Danube-morava confluence

Black and white waters differ in their planktonic fauna and flora. Tables 2 and 3 compare the number of planktonic animals caught in black and white water localities only a few meters apart. The black water was not as extreme an example as the Rio Negro system. However, it can be seen that the black water held greater numbers of rotifers but fewer crustaceans and mites. These crustaceans are important foods for larval fish. The zones where the two waters mix are attractive to ostracods and young fish. These mixing zones tend to have many animals. The abundance is shown in Table 3, which compares animals in 10 litres of water.[4]

Blackwater river

A blackwater river is a river with a deep, slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water that is darkly stained, resembling tea or coffee. Most major blackwater rivers are in the Amazon River system and the Southern United States. The term is used in fluvial studies, geology, geography, ecology, and biology. Not all dark rivers are blackwater in that technical sense. Some rivers in temperate regions, which drain or flow through areas of dark black loam, are simply black due to the color of the soil; these rivers are black mud rivers. There are also black mud estuaries. Blackwater rivers are lower in nutrients than whitewater rivers and have ionic concentrations higher than rainwater.[1][2] The unique conditions lead to flora and fauna that differs from that in whitewater. Where blackwater and whitewater combines is attractive to a diverse group of organisms. Black and white waters differ significantly in their ionic composition, as shown in Table 1. Black waters are more acidic, resulting in an aluminium concentration greater than that of the more neutral white waters. The major difference is the concentrations of sodium, magnesium, calcium and potassium; these are very low in black waters. This has ecological implications. Some animals need more calcium than is available in blackwaters, so for example, snails, which need much calcium to build shells, are not abundant in blackwaters. The lack of dissolved ions in black waters results in a low conductivity, similar to that of rainwater. Black and white waters differ in their planktonic fauna and flora. Tables 2 and 3 compare the number of planktonic animals caught in black and white water localities only a few meters apart. The black water was not as extreme an example as the Rio Negro system. However, it can be seen that the black water held greater numbers of rotifers but fewer crustaceans and mites. These crustaceans are important foods for larval fish. The zones where the two waters mix are attractive to ostracods and young fish. These mixing zones tend to have many animals. The abundance is shown in Table 3, which compares animals in 10 litres of water.[4]