What is Soil Erosion?
Soil erosion is when soil moves (like a slope) to a different place. It can be a short distance or kilometers carried by rivers. Soil erosion is occurring by winds, rains, floods, glaciers, rivers, and earthquakes. Soil erosion is a natural occurring process which affects all landforms. The soil that is moved goes down the flattered land in which it may block roads and damage houses. It enters the streams and rivers in which it harms wildlife and makes water dirty and goes out to the sea. In agriculture, soil erosion is wearing away of a field's topsoil by natural physical forces of water and the wind or farming activities such as tillage. Erosion involves three distinct actions, soil detachment, movement, and deposition.
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Rill erosion is when on sloping land, the water that runs off may gather in small V-shaped rolls. Gully erosion occurs on spread subsoils. These are mostly deep and create a lot of sediment, which often feeds into rivers. Mass-movement erosions when gravity combines with heavy rain or earthquakes and the whole slopes can slump, slip or slide. Slips are one of the main forms of erosion in the North Island. They are a direct result of the change from forest to pasture. Slips occur when the soil (topsoil and subsoil) on slopes becomes saturated.Slips are common, where the underlying rock is mudstone or siltstone. In the South Island, soil slips are widespread throughout the hill country (Gisborne, Taihape, Wanganui, Taranaki and King Country), but mostly north of Christchurch. Streambank erosion is common throughout New Zealand, especially in rivers and watercourses with periodic flooding. I chose this topic because it is one of the main crisis in NZ. It will affect our future if we don’t take action now. New Zealand loses 200 - 300 million tonnes of soil every year in the ocean. The rate of of soil erosion is New Zealand is about ten times faster than the rest of the world. If we don’t start taking action, then our crops, plants and trees will start dying, New Zealand will be
Yes this feature is the result of erosion and depositional processes however, it is not associated with the current water course. This feature may be the result of a Gilbert type delta that once occupied this area. Gilbert type deltas have three main components; topsets, foresets and bottomsets. Topsets are fluvial sediments (primarily sandur deposits) that were deposited on the subaerial delta surface. Erosive events occurring on the upper forslope can result in downslope channels and chutes. These features are then eroded by either strong currents or by debris flow resulting in these channels and chutes to become filled. Foresets are a combination of sand and gravel facies. The are deposited by gravitational processes on the delta foreslope and the grains tend to become finer and more angular downslope. Bottomsets consist of fine grained silts and clay and are deposited at the foot of the delta front.
is being eroded by the sea so that cliffs, up to 20 metres high rise
As can be seen from the photo( Image 1), looking downstream, there were steep sections of bank where it appeared the erosive forces of the river when high have cause part of the bank to fall away leaving steep about 1m high drops on the bank with exposed rocky soil visible. The phenomenon also illustrate that it is an alluvial landforms, which will find erosional feature from fluvial
Longshore drift influences the deposition and erosion of sediments. Waves erode the coast and transport the eroded material along the coastline. Over a period of time, the material will be deposited on a beach or form a larger feature such as a spit. Groynes are structures built at equal intervals along the coastline. Their purpose is to restrict longshore drift, preventing coastal erosion.
Erosion is when the elements such as wind, water, and ice remove pieces of land. (“What is Coastal Erosion?”) Coastal Erosion takes place when destructive waves wear parts of the coast away. Four ways in which this takes place are corrasion/abrasion, hydraulic action, attrition, and corrosion/solution. (“Internet Geography”) Corrasion/abrasion is when materials are hurled at the base of cliffs through waves. Hydraulic action is when waves hit the base of a cliff and air is compacted, when the wave leaves air is rushed out and often this causes the material to break. Attrition is when the waves cause rocks and pebbles to smash into each other and eventually break into pieces. Finally, Corrosion/solution is when certain types of cliff erode from the result of acids in the sea. (“Internet Geography”) Coastal Erosion is the natural process of taking land away permanently from one place to put it somewhere else. (“What is Coastal Erosion?”) Eroding coastlines are an abundant and important topic because it can change people’s surroundings in a negative way. I would like to address the questions surrounding Coastal Erosion.
There are many different ways that erosion is being caused. Some natural but most un-natural or man-made. The
Although, against all the evidence proving bananas are the problem, some farmers are still in denial. These farmers refuse to acknowledge the damage they are causing and, in turn, refuse to make any effort to stop it. Fortunately, denial has been fading out in recent years as more banana growers implement new methods of minimising their sediment
Coastal erosion is a diverse issue with many different causes. However, it is basically defined as a situation that for some reason or another causes the amount of coastline in a given area to decrease. The causes behind coastal erosion are varied. They are often the result of manmade problems, such as pollution (Williams). However, the erosion of some coastlines is a natural process that occurs without human interaction (Internet Geography).
Engineers, scientists, and/or volunteers place brush, roots, trees and other plants to cover banks. This helps to stop erosion by reversing loose soil. Hard structures like rock or cement are sometimes used too. Some pros is that there is a high chance of success and there is a recovery of streamside habitat. The recovery of streamside habitat occurs because animals use plants as shade and hiding places from predators, the plants affect dissolved oxygen levels, and because herbivores may eat/live in the plants (hollows of trees, fungi and roots). Some cons of this natural solution is loss of existing vegetation and results take time.
The rivers and creeks along the wet tropics in far North Queensland are followed by massive amounts of banana farms. These farms run across 1500 kilometres of the Queensland coastline. During heavy rainfall, which is plentiful in the area, sediment and nutrients run off into the rivers and eventually end up in the Great Barrier Reef. One of the biggest threats to the Reef is Johnstone River, as it is one of the closest rivers to the Reef, and the farms along its coast are producing the highest yields. Banana farms are used very intensely and combined with the plentiful floods in the area, sediment runoff from the farms is at an all-time
Soil erosion began with the dawn of agriculture, when people abandoned their hunter-gatherer lifestyles and began using the land for intensive agriculture, thus removing the protective vegetation cover and growing food crops on disturbed soil surfaces. For many civilizations, it is believed that surface wash erosion, that can occur unnoticed until it is too late, was a main contributing factor for their demise. Soil erosion and other degradative processes have destroyed, over the millennia, as much arable land as is now cultivated.
The issue that I will be outlining is land erosion. I have chosen this issue because it is a big problem in Australia and in the world as it effects many industries, especially agriculture. Soil degradation is the decline in soil quality caused by its improper use, usually for agricultural, pastural, industrial or urban purposes.
...e affecting the reef. Nevertheless, there are practices being put in place to increase the reefs future resilience. Overall, it would seem that farming practices operating so close to the coast need to be closely monitored as to minimize the amounts of herbicides, pesticides and sediment that flow onto the reef, which also have an impact on the crown of thorn starfish. On the other hand, the reefs long term problem is climate change. Although, this is not just a local problem that affects the reef, but a global threat. However, industries operating off the reef have been taking actions to reduce their carbon footprint. Even though a lot is being done for the resilience of the reef, there is still a lot needed to be done to guarantee the reef future. So in the hope our children don’t have to learn about the Great Barrier reef in text books, and through television.
Along the coast where there are alternating patterns of hard and soft rock, headlands and bays may form as a result of hydraulic action. The harder more resistant rock erodes away slower, forming a headland that juts out into the ocean. When the softer rock between headlands erodes away and at a faster rate, it creates a curved inlet, or bay.
Slope stability is the potential of soil covered slopes to withstand and undergo movement. Stability is determined by the balance of shear stress and shear strength. A previously stable slope may be initially affected by preparatory factors, making the slope conditionally unstable. Triggering factors of a slope failure can be climatic events can then make a slope actively unstable, leading to mass movements. Mass movements can be caused by increase in shear stress, such as loading, lateral pressure, and transient forces. Alternatively, shear strength may be decreased by weathering, changes in pore water pressure, and organic material.