SUMMARY / RELATED TOPICS

Soil erosion

Soil erosion is the displacement of the upper layer of soil, it is one form of soil degradation. This natural process is caused by the dynamic activity of erosive agents, that is, ice, air, plants and humans. In accordance with these agents, erosion is sometimes divided into water erosion, glacial erosion, snow erosion, wind erosion, zoogenic erosion and anthropogenic erosion. Soil erosion may be a slow process that continues unnoticed, or it may occur at an alarming rate causing a serious loss of topsoil; the loss of soil from farmland may be reflected in reduced crop production potential, lower surface water quality and damaged drainage networks. Human activities have increased by 10 -- 50 times the rate. Excessive erosion causes both "on-site" and "off-site" problems. On-site impacts include decreases in agricultural productivity and ecological collapse, both because of loss of the nutrient-rich upper soil layers. In some cases, the eventual end result is desertification. Off-site effects include sedimentation of waterways and eutrophication of water bodies, as well as sediment-related damage to roads and houses.

Water and wind erosion are the two primary causes of land degradation. Intensive agriculture, roads, anthropogenic climate change and urban sprawl are amongst the most significant human activities in regard to their effect on stimulating erosion. However, there are many prevention and remediation practices that can curtail or limit erosion of vulnerable soils. Rainfall, the surface runoff which may result from rainfall, produces four main types of soil erosion: splash erosion, sheet erosion, rill erosion, gully erosion. Splash erosion is seen as the first and least severe stage in the soil erosion process, followed by sheet erosion rill erosion and gully erosion. In splash erosion, the impact of a falling raindrop creates a small crater in the soil, ejecting soil particles; the distance these soil particles travel can be as much as 0.6 m vertically and 1.5 m horizontally on level ground. If the soil is saturated, or if the rainfall rate is greater than the rate at which water can infiltrate into the soil, surface runoff occurs.

If the runoff has sufficient flow energy, it will transport loosened soil particles down the slope. Sheet erosion is the transport of loosened soil particles by overland flow. Rill erosion refers to the development of small, ephemeral concentrated flow paths which function as both sediment source and sediment delivery systems for erosion on hillslopes. Where water erosion rates on disturbed upland areas are greatest, rills are active. Flow depths in rills are of the order of a few centimeters or less and along-channel slopes may be quite steep; this means that rills exhibit hydraulic physics different from water flowing through the deeper, wider channels of streams and rivers. Gully erosion occurs when runoff water accumulates and flows in narrow channels during or after heavy rains or melting snow, removing soil to a considerable depth. Valley or stream erosion occurs with continued water flow along a linear feature; the erosion is both downward, deepening the valley, headward, extending the valley into the hillside, creating head cuts and steep banks.

In the earliest stage of stream erosion, the erosive activity is dominantly vertical, the valleys have a typical V cross-section and the stream gradient is steep. When some base level is reached, the erosive activity switches to lateral erosion, which widens the valley floor and creates a narrow floodplain; the stream gradient becomes nearly flat, lateral deposition of sediments becomes important as the stream meanders across the valley floor. In all stages of stream erosion, by far the most erosion occurs during times of flood, when more and faster-moving water is available to carry a larger sediment load. In such processes, it is not the water alone that erodes: suspended abrasive particles and boulders can act erosively as they traverse a surface, in a process known as traction. Bank erosion is the wearing away of the banks of a river; this is distinguished from changes on the bed of the watercourse, referred to as scour. Erosion and changes in the form of river banks may be measured by inserting metal rods into the bank and marking the position of the bank surface along the rods at different times.

Thermal erosion is the result of weakening permafrost due to moving water. It can occur both at the coast. Rapid river channel migration observed in the Lena River of Siberia is due to thermal erosion, as these portions of the banks are composed of permafrost-cemented non-cohesive materials. Much of this erosion occurs. Thermal erosion affects the Arctic coast, where wave action and near-shore temperatures combine to undercut permafrost bluffs along the shoreline and cause them to fail. Annual erosion rates along a 100-kilometre segment of the Beaufort Sea shoreline averaged 5.6 metres per year from 1955 to 2002. At high flows, kolks, or vortices are formed by large volumes of rushing water. Kolks cause extreme local erosion, plucking bedrock and creating pothole-type geographical features called Rock-cut basins. Examples can be seen in the flood regions result from glacial Lake Missoula, which created the channeled scablands in the Columbia Basin region of east

ASIA Publishers

ASIA Publishers is a Seoul-based book publisher best known for producing multi-volume series of translated Korean literature in bilingual format at novella length and featuring a short biography of the author, a background of the social and historical setting of the work, a brief collection of Korean critical response to the works. ASIA Publishers was started in 2006, by publisher Kim Jae-Boom, publishing its first collection/magazine ASIA,which is a quarterly magazine of Asian literature; the magazine collects and publishes short stories, recent issues in Asia and book reviews. In 2012 ASIA Publishers began publishing series of Korean fiction in both English and Korea in a 5 collection to be 7 collections series intended to cover all of "early modern" Korean fiction; these volumes, titled the “Bi-lingual Edition Modern Korean Literature” were sub-grouped by theme, with collection #1, for instance, focusing on Partition and Division, Industrialization, Women in Korean Society. The authors were a broad range and well known including, Kyoung-sook Shin, Park Wan-so, Kim Won-il, Hwang Sok-yong.

In fact, the publication of these works was considered significant enough to be noted on the Cheong Wa-Dae website. ASIA Publishers is printing a "K-Fiction Series", intended to appeal to a younger audience; this series includes authors Park Min-gyu and Son Bo-mi, who represent the cutting edge of contemporary Korean fiction. The current book titles include: Dinner with Buffet. ASIA Magazine "Bi-lingual Edition Modern Korean Literature" Series "K-Fiction" Series A Fine Balance by Rohinton Mistry Such a Long Journey by Rohinton Mistry Family matters by Rohinton Mistry Ramayana Mahabarata Shahnameh VOL. 1 NO. 1 VOL. 1 NO. 2 VOL. 1 NO. 3 VOL. 2 NO. 1 VOL. 2 NO. 2 VOL. 2 NO. 3 VOL. 2 NO. 4 VOL. 3 NO. 1 VOL. 3 NO. 2 VOL. 3 NO. 3 VOL. 3 NO. 4 VOL. 4 NO. 1 VOL. 4 NO. 2 Indian Special VOL. 4 NO. 3 Vietnamese Special VOL. 4 NO. 4 Philippine Special VOL. 5 NO. 1 Mongolian Special VOL. 5 NO. 2 Palestine Special VOL. 5 NO. 3 Indonesian Special VOL. 5 NO. 4 Turkish Special VOL. 6 NO. 1 Special Focus on Asians reflecting on Asia and its future VOL. 6 NO. 2 Special Focus on Arab writers discuss ‘Jasmine Revolution’ VOL. 6 NO. 3 Special Focus on The contemporary Chinese literature landscape through writers VOL. 6 NO. 4 Special Focus on Story heritages of Asia VOL. 7 NO. 1 Special Focus on Hanoi VOL. 7 NO. 2 Special Focus on Shanghai VOL. 7 NO. 3 Special Focus on Sapporo VOL. 7 NO. 4 Special Focus on Delhi VOL. 8 NO. 1 Special Focus on Seoul VOL. 8 NO. 2 Special Focus on Istanbul VOL. 8 NO. 3 Special Focus on Taipei VOL. 8 NO. 4 Special Focus on Asian cities and writers VOL. 9 NO. 1 Special Focus on Vladivostok VOL. 9 NO. 2 Special Focus on Bangkok VOL. 9 NO. 3 Special Focus on Incheon VOL. 9 NO. 4 Special Focus on Hong Kong VOL. 10 NO. 1 Special Focus on Siem Reap

Pescador Island

Pescador Island is an island located in the Tañon Strait, a few kilometres from the western coast of the island of Cebu in the Philippines. It is part of the municipality of Moalboal; the island derives its name from the Philippines' Spanish colonial heritage and the abundance of fish living on the surrounding coral reef, the many fishermen that fish them. The rich marine life attracts recreational divers from the many dive operations in nearby Panagsama; the underwater composition of the Pescador island reef is a sandy slope covered with soft coral from 5–10 metres, followed by a wall covered with hard corals dropping down to about 40 metres. On the west side of the island, an open-top underwater cave nicknamed'the Cathedral' can be found. Most recreational dive tours start at the island's south end, let the divers drift with the current either along the east or the west side of the island. Visibility conditions vary, but the current in the Tañon Strait pushes in clear water that allows visibility up to 40 metres.

The island itself has a lighthouse and access steps on east sides. The warm waters of the Philippines harbour a rich marine life, with over 2,500 species of fish, many of these are found around Pescador island, contributing to the island being so popular with recreational divers. A rather more unusual part of the Pescador island biodiversity is the large school of sardines that have made the relative sanctuary of the reef its home. After an earthquake in February 2012, the school left the island, affecting the population of larger predatory fish. However, in May 2013 the school so did the bigger fish. Sightings of sharks have been reported; as Pescador Island is a marine park, dive shops are required to pay a fee for each diver they bring to the island. Proceeds from entrance fees are managed by the Municipality of Moalboal and Moalboal Dive Center Association towards the finance of a number of conservation programs in the municipality; these programs include patrols and enforcement to abolish destructive fishing, village improvement programs and disposal of plastic and other wastes entering the local waters, marine conservation education of village children and adults, reef and mangrove rehabilitation.

Geographic data related to Pescador Island at OpenStreetMap