PROJECT 3 : SOIL EROSION ANALYSIS
Initial observation showed that Kampung X area is experiencing a severe erosion problem. As a researcher, I have been tasked by the Department of Agriculture, Malaysia, to undertake the soil erosion rate studies from 1990 to 2010. After undertaking a desk study, I decided to use Revised Universal Soil Loss Equation (RUSLE). RUSLE is an erosion prediction and conservation planning tool to estimate soil loss on specific slopes in specific fields. The RUSLE predicts soil loss for a given site as a product of five major factors (Equation 1), whose values at a particular location can be expressed numerically.
The soil loss is calculated as follows:
- A = R × K × LS × C × P
- where A is annual soil loss (tons/ha/yr),
- R is rainfall erosivity factor,
- K is soil erodibility factor,
- LS is slope length and steepness factor,
- C is cropping and management factor, and
- P is conservation supporting practices factor
- R is the rainfall-runoff erosivity factor or index that index measures the erosion force of specific rainfall. The relationship between rainfall erosivity index and mean annual precipitation for the Peninsular Malaysia can be represented by following regression equation R = P/2 , where P is in mm of annual total rainfall. After analysing the 15 years’ rainfall data, P is found to be 2200 mm, and R is calculated as 1100.
- The soil erodibility factor (K) represents the average long-term soil and soil-profile response to the erosive power associated with rainfall and runoff. K is also the mean annual soil loss per unit of R for a standard condition of bare soil.
- P reflects the impact of support practices on the average annual erosion rate. It indicates the fractional amount of erosion that occurs when any special practices are used compared with what would occur without them.
- C is the cover management factor used to reflect the effect of cropping and management practices on erosion rates. C is often used to compare the relative impacts of management options on conservation plans
- The potential erosion values are divided into seven classes, from class 1 of very low erosion potential to class 7 of exceptional erosion potential
The maps retrieved from QGIS are based on the data above and the erosion class is displayed in legend of each map. Below are the maps of soil erosion in Kampung X from year 1990, 2000 and 2010:
The soil erosion percentage and area was calculated by retrieving the Unique Value Report of these maps from QGIS. The data shown below in table:
Soil erosion percentage and area of Kampung X in year 1990
Soil erosion percentage and area of Kampung X in year 2000
Soil erosion percentage and area of Kampung X in year 2010
The graph below shows the soil erosion changes from year 1990 until 2010 in Kampung X :
By using the data provided, I have able to study the soil erosion activities from 1990 to 2010 in Kampung X from analysis retrieved using QGIS. There are huge importance of soil erosion analysis in city planning and several ways on how soil erosion can be controlled
Soil erosion analysis plays a crucial role in city planning due to its significant impacts on the environment, infrastructure, and human well-being. Soil erosion can lead to the loss of fertile topsoil, reduced soil quality, and degradation of ecosystems. By conducting soil erosion analysis, city planners can identify areas prone to erosion and take measures to protect sensitive habitats, preserve biodiversity, and maintain ecological balance. Soil erosion can pose risks to infrastructure such as roads, bridges, and buildings. Through erosion analysis, city planners can identify areas with high erosion potential and design appropriate infrastructure measures to mitigate erosion impacts, ensuring the long-term stability and durability of infrastructure projects. Soil erosion contributes to sedimentation in water bodies, affecting water quality and causing drainage issues. By analyzing soil erosion patterns, city planners can implement stormwater management strategies such as erosion control structures, retention ponds, and vegetative buffers to reduce sedimentation and improve water management. Erosion can lead to increased surface runoff, which exacerbates flood risks. Understanding soil erosion patterns allows city planners to identify vulnerable areas and implement erosion control measures, such as terracing, contour farming, and green infrastructure, to minimize runoff and decrease the likelihood of flooding. Soil erosion analysis provides valuable information for land use planning decisions. By identifying areas prone to erosion, planners can allocate suitable land uses, such as preserving forests or implementing agricultural practices that reduce erosion risks, ensuring sustainable and responsible land management.
To control soil erosion, various techniques and practices can be employed. One of them is, Planting trees, shrubs, grasses, and groundcover helps stabilize the soil, reduce erosion, and enhance water infiltration. City planners can incorporate vegetation buffers, green spaces, and conservation areas into urban planning to minimize erosion risks. Implementing erosion control structures, such as retaining walls, gabions, riprap, and terraces, can intercept runoff, slow down water flow, and prevent soil erosion on slopes and vulnerable areas. Promoting sustainable agricultural practices, including contour plowing, crop rotation, cover cropping, and terracing, reduces soil erosion in agricultural areas and minimizes the use of harmful chemicals that can contribute to erosion. Integrating storm water management techniques such as permeable pavements, bio-retention basins, and green roofs into urban design can effectively manage runoff and reduce erosion risks. Raising awareness among the public, landowners, and developers about the importance of soil erosion and the use of erosion control measures fosters a culture of responsible land management and encourages sustainable practices.
By conducting soil erosion analysis and implementing appropriate erosion control measures, city planners can protect the environment, minimize infrastructure risks, enhance water management, and promote sustainable urban development.
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