Soil Erosion the Natural Movement

Soil Erosion

The natural movement of soil by the action of wind, water, glaciers and air is referred to as soil erosion. The two processes of erosion and deposition always occur simultaneously. When soil is removed from one area it eventually is deposited in another part of the world. It is a natural process and has occurred for thousands of years. Movement of soil is what has created stretches of beaches, deserts and some of the starkest landscapes observed. While it was a natural process, in recent times, actions by humans has increased the rate of soil erosion. And while there is deposition always occurs, it might not be occurring where desired, while erosion occurs in areas where it is least desired.

Globally, soil erosion is a major concern for farmers. It threatens to transform fertile rich soil into arid soil and thereby significantly impact agriculture and the resulting food stock. (Kaiser, 2004) Grass and low shrubs help to hold soil together because they have intricate root systems. In addition, it also breaks the speed of moving water over land.

Cattle-grazing is also viewed as a significant factor that affects soil erosion. When vast stretches of land is subjected to over-grazing, the removal of the grass exacerbates erosion. Growing plants also helps compact the soil making less likely to move. The intensity and period of rainfall also affects the rate of soil erosion. This when coupled with steep slopes and unstable land topography greatly add to the erosion process. (Kumar, Pant, Panda, & Satyal, 2002) it is observed that contour tilling of land on slopes has a better effect in controlling soil erosion on steep mountain slopes. In addition avoiding large agricultural and farming equipment creates more loose soil than manual methods and as such is more damaging to the top soil of a region.

Soil erosion also leaches the nutrients away from the soil. Erosion is also affected by the soil structure, size and composition. While all soil is susceptible to erosion, finer soil with less binding capabilities is more likely to erode faster. (Waswa, Gachene, & Eggers, 2002) Beaches for instance get eroded with every wash of the tide. Wind patterns when combined with wave action also enhance the erosion effect. Recent satellite pictures have also shown Saharan dust, transported by trade winds and crossing the Atlantic Ocean, being deposited on the east coast of the United States, thus changing soil compositions and quality.

Farming practices and the use of local customs of land clearing is often citied as the most critical factor that affects the erosion process. While many of the practices have been carried out for thousands of years the frequency and the scope of the current processes are making the process more dangerous. Due to population explosion, larger areas are being cleared and the soil is being tilled more often than in the past. As the soil gets less fertile often migrant population moves not to clear another section of land, creating a full new cycle of deforestation. Often, the vegetation that is cleared takes to long to regenerate and even if some soil cover does occur it is not the same rate as the initial one.

The industrial world is not completely without its own addition to the soil erosion problem. Excessive construction work offer ample opportunities for soil erosion. Many cities and towns are insisting on better construction practices and imposing fines on those that do not follow the preset guidelines. (DEP, 2008)

There are some less obvious impacts of soil erosion. While the loss of fertile land is a major concern, pollution of the streams and rivers is also a growing concern. Excessive soil erosion is "muddying" up rivers upstream and this soil travels thousands of miles along the course of the river. The muddy water does not allow for transfer of oxygen from the atmosphere into the water and it also blocks out light killing vegetation growth. These rivers cannot support any fish. "The particles act as sandpaper against a fish's gills causing damage and making breathing difficult. Many fish and aquatic insects lay their eggs in gravel beds. The sediments that are deposited in the stream cover up these areas, sometimes even entombing young fish and eggs." (DEP, 2008)

The lack of vegetation also does not act as a sieve to capture the soil. Muddy water also created an environment where the water temperature increases killing any micro organisms that feed at the river bed. Faster movement of water also creates deeper channels and creates wider rivers during storms. (Sotir, 1998) Excessive run off and soil are creating downstream flooding conditions that have been unprecedented when compared to the past. Homes and businesses have been significantly impacted by the new problem as insurance rates and the cost of maintaining a house or business is also on the rise.

Birds and animals that depend on the river's ecosystem are also impacted by the new stream flow and quality of water. Excessive silting of rivers might cause flooding in traditional nesting locations of migratory birds. Often, birds select these locations for life and then lose generations of chicks due to flooding. Contamination in the soil as a result of fertilization upstream also creates toxic levels higher than expected. Wildlife that survives on dependent organisms tends to get affected as well. Phosphorous which is used as a growth aid for land plants also does the same for aquatic plants. Algal blooms in lakes and rivers further deplete the oxygen levels in the water.

The unchecked soil is also creating havoc with ports. Most significant ports are located at or near the mouth of the rivers and the soil often get deposited at these locations. Dredging of ports is often a necessity to maintain the depth of the port to allow larger vessels to enter the port. It is observed that better engineering upstream of dams and reservoirs can help reduce the problems down stream. (ScienceDaily, 2008) Many tests have been undertaken to find out conditions that work the best. Amongst the most significant observations were the compacting of soil and controlling the gradient of the water flow.