Soil Erosion and Sedimentation Control Using Biological Methods
Abdul Rahman Mahmud1*
1 Environment Institute of Malaysia
*Corresponding Author: [email protected]
Accepted: 15 October 2021 | Published: 1 November 2021
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Abstract: Soil erosion and sedimentation are one of the important challenges in the implementation of development projects. One of the problems faced by project proponents to implement soil erosion and sedimentation control is the financial aspect. To overcome this problem, alternatives for the use of biological resources and biomass can be used. This study aims to identify biological resources that can be used for soil erosion and sedimentation control. This study uses a systematic literature review method related to aspects of soil erosion control. This study found that resources in the project site, such as topsoil reuse, vegetation, and ground cover plants such as creepers and legumes, can effectively reduce soil erosion and sedimentation. By using biomass resources at project site it will further reduce the cost in soil erosion control.
Keywords: soil erosion, sedimentation, best management practices, BMPs, biological method, mulching, creepers, topsoil
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1. Introduction
Soil erosion is defined as detachment soil particles and the transportation of eroded soil particles due to erosive agents action, namely wind and water (Igwe, P.U., Nwezi, C.C., Echendu, J.E., Chukwunyere, I.C., Okonkwo 2017; Schoonover and Crim 2015). Uncontrolled earthworks will bring significant implications to the river's pollution. It occurs through the process of siltation and sedimentation. Sedimentation is defined as the process of settling eroded soil particles to the river bed. The water quality parameter for soil erosion and sedimentation is suspended solids (Akademi Sains Malaysia 2017). The increase in suspended solids in an area is usually due to earthworks and site clearing activities. Nowadays, project proponents are faced with the issue of how to implement erosion control effectively. One of the problems they face is due to cost constraints. The cost of erosion control is considered high by the project proponent causes are very serious erosion problems to occur continuously.
2. Methodology
This study using the literature review method in identifying potential soil erosion approach by using biological method. The study was conducted by looking at past and recent studies related to soil erosion and sedimentation especially on bioengineering and biological solution. The study began by examining the vegetative selection factors for soil erosion and sedimentation control.
Next, the study explores the applicability of biological materials at the project site for soil erosion and sedimentation.
3. Literature Review
A study on the Pahang River basin pointed out that about 30% of the sediment load in the river came from the plantations, even though they only occupy about 8% (240,000 hectares) of the total basin area (29,300 sq.km). The Pahang River, the largest in Peninsular Malaysia, was estimated to carry down 4.5 million sediment tonnes a year to the sea (Akademi Sains Malaysia 2017). While quarrying, housing and logging activities are categorized as activities that also contribute to high soil erosion rate. Studies show that soil erosion and sedimentation from construction activities are at high level if there is no mitigation measures being implemented (Abdul Rahman Mahmud, Zaini Sakawi, and Khairul Nizam Abdul Maulud 2019). The Department of Agriculture Malaysia classifies soil erosion into few level of risk (Jabatan Pertanian Malaysia 2020). It can guide the project proponents carry out earthworks effectively to reduce the soil erosion risk. Soil erosion by water can be influenced by five main factors (Agereh et al. 2019). The first is the rainfall factor.
Raindrop hitting the soil surface will break up the soil into small particles (Morgan 2005). With the kinetic energy in the rainfall, it will transport the particles untill it deposited. Rainfall strength is measured in units of kinetic energy.
The second factor of soil erosion is soil type (Adiaha et al. 2019; Kusumandari 2014; Yiferu, Taddese, and Mebrate 2018). The soil has its strength. The large spaces between the soil particles will cause soil erosion to occur rapidly (Hossain and Salam 2019; Morgan 2005; Řeháček et al.
2017). Soils from the sand type have large gap that make it easy for water to infiltrate, while soils with silt and clay type are quite difficult to be infiltrate by water because they have very small particle spaces. The third factor is due to topographic factors (Jeloudar, Sepanlou, and Emadi 2018). Areas with higher slope lengths will have a higher potential for soil erosion. It is due to the formation of higher velocity of runoff water (Agereh et al. 2019; Yesuph and Dagnew 2019). The fourth factor of soil erosion is a cover crop, which acting to protect soil surface. Plants that has capabilities and strength roots will better withstand and prevent erosion from occurring. The fifth factor is due to land practice factors (Highlands, Tamfuh, and Chotangui 2020). That is the extent to which the soil can be control from erosion occurring. The best land practice ensures that runoff can be reduced by roughing the soil surface or installing a physical control structure in the construction site (Jeloudar et al. 2018)
4. Finding & Discussion
4.1 Factor in selection of vegetation for cover crop in erosion control
There are five main factors for plant selection to ensure effective soil erosion and sedimentation control. The first factor that needs to be considered is the rate of plant growth. Plants that are planted must have the characteristics to grow quickly in the soil surface. Vigorous and fast earthworks will open up a wide area that exposure to the rainfall. Fast-growing plants are needed for erosion control to cover the surface from erosion quickly. The second is the aspect of soil surface suitability (Ranjitham, Prabhakaran, and Dhanusuya 2020). Certain species have spesific properties of soil surfaces suitability and types of nutrients that could hence the stem. The third is a selection from the aspect of plant species. Plants of invasive species are less suitable (Li et al.
2008; USDA 2006). It can dominate ecosystems quickly. The fourth is a less maintenance factor.
That's means that the plant can stand on its own by building its nutrient system naturally. The fifth
is the strength factor. Plants with strong roots and stems are needed to prevent soil erosion from occurring.
4.2 Biomass as erosion control at construction sites
Based on the literature review we have conducted, showing that biomass material and residues resulting from site clearing activities (refer to Figure 1) can be use for effective soil erosion control.
Such materials can be used for erosion control measures. In this case, the cost of erosion control can be reduced and subsequently, soil erosion control can be done effectively.
Figure 1.0: The use of biomass and residue in erosion control
4.2.1 Reuse Topsoil
The construction process usually involves three main stages, namely the site clearence, building construction and operation (Abdul Rahman Mahmud et al. 2019). Earthwork activity at the site clearing stage is a very important activity. Large-scale site clearing will impact the environment—
especially a serious problem to soil erosion and sedimentation (soil erosion from erthworks).
Therefore, to carry out development activities and site site clearing. The main thing that needs to be done is the planning aspect.The project proponent shall carry out site clearing activities in stages. Implementing earthworks in stages can reduce the impact on soil erosion and sedimentation problems (Morgan 2005).
Figure 2.0: Mixture of topsoil and mulches
For soil erosion and sedimentation control, the project proponent must take the initiative by not removing the topsoil and plants found in the during earthworks stages. Topsoil is very important to be reused for erosion control. Topsoil contains good nutrient that could supply to plant growth.
Topsoil can be reused for planting plants for erosion control. Through observation on the implementation of EIA projects in the field, it was found that the project proponents themselves do not understand the benefits of topsoil. Among often problems identified, the earthworks contractors remove topsoil and not properly storing it for erosion control (Ummunah UP and Nwogu NC 2015). The project proponent usually uses hydromulching techniques for replanting plants at the project site, that would inccur more cost for erosion control.
4.2.2 Biomass
Biomass is one of the materials found on the project site. How can biomass be used for erosion control? Erosion control can be implemented by converting biomass to mulches. Trees brunches, wood and leaves can be shredded to form mulches. Areas of soil that have been exposed to erosion factors need to be protected. After the earthworks are done, the soil surface is infertile because it does not have sufficient nutrients in assisting plant growth. Therefore mulching can be made by using biomass such as waste wood, leaves and other biomass (Igwe, P.U., Nwezi, C.C., Echendu, J.E., Chukwunyere, I.C., Okonkwo 2017; Stolte et al. 2016).
Figure 3.0: Mulching for erosion control
Biomass that has been mulched can be placed on the surface of the eroded soil. The decomposition process will occur naturally (Laban, Metternicht, and Davies 2018). Mulching will play a role in supplying nutrients to the soil through the process of biodegradation. The content of carbon, nitrogen, phosphorus, and potassium in mulching allows fertile soil (Asian Development Bank 2017).. Mulching also plays a role in holding back the rainwater that falls, and rainwater will be absorbed into the soil. It will increase the fertility of the soil to be cultivated. Lalljee (2013) found that mulch can reduce by 90% of soil erosion from occurring. This mulching process can reduce the cost of soil erosion control among project proponents effectively at the project site. Mulching can also be used on sloping areas. It is combined with this binder to strengthen the mulch structure (USDA 2006). In the context of Malaysia's construction activities, mulching is widely used for road projects, where mulching is used in sloping areas to protect the slope from erosion.
4.2.3 Use of creepers plant and vetiver grass
One of the important methods used in the implementation of soil erosion control is the vegetative cover. Two commonly used types of plants are vegetative that have a strong root structure and creeping. Therefore, there are two species of crops used: vetiver grass and creeping plants (Truong and Loch 2004). For vetiver grass, it has a long root structure. Allows it to grip the ground firmly.
Vetiver grass from the species Crysopogon Zizanodes has been widely applied to stabilize slopes.
This method is known as the bioengineering method. Vetiver grass can grow quickly and is less maintenance. Vetiver grass also has the advantage of absorbing heavy metal suitable for phytoremediation to treat contaminated soil areas. In Malaysia's context, vetiver grass has been widely used in riverbank and slope maintenance. The use of creeping plants is very suitable for flat areas such as oil palm and rubber plantations (Mulinge et al. 2017). Creeping legume species are well suited for surface protection crops. This species has an advantage because it supplies nutrients to the soil, and seeds can grow independently, which could accelerate the plant's growth.
Figure 4.0: Vetiver Grass for slope erosion control
5. Conclusion
Based on the study stated, soil erosion and sedimentation are important aspects that need to be taken into account in implementing development. Issues related to increased costs for erosion control can be overcome if the project proponent has a basic knowledge of using biologically based materials or biomass used in the project site.
References
Abdul Rahman Mahmud, Zaini Sakawi, and Khairul Nizam Abdul Maulud. 2019. “Analisa Laporan EIA Dalam Aspek Kajian Hakisan Tanah Dan Sedimentasi Bagi Projek Perumahan.” Jurnal Kejuruteraan 31(2). doi: 10.17576/jkukm-2019-31(2)-23.
Adiaha, M. S., E. E. Oku, V. O. Chude, G. I. C. Nwaka, and B. Ukem. 2019. “Predicting Soil Erosion with Estimation of Saturated Hydraulic Conductivity from Soil Porosity : A Strategy for Meeting the SDG Goal Two and Six.” 136(September):194–225.
Agereh, Sareh Rajabi, Farshad Kiani, Kazem Khavazi, Hassan Rouhipour, and Farhad Khormali Id. 2019. “An Environmentally Friendly Soil Improvement Technology for Sand and Dust Storms Control.” 6(1):63–71. doi: 10.15171/EHEM.2019.07.
Akademi Sains Malaysia. 2017. Ersoion & Sedimentation.
Asian Development Bank. 2017. Sustainable Land Management in Asia: Introducing the
Landscape Approach.
Highlands, Bamenda, Primus Azinwi Tamfuh, and Asafor Henry Chotangui. 2020. “Land Characteristics and Agricultural Suitability Status along a Toposequence in Santa ,.” 1–
9. doi: 10.24966/AES-8780/100022.
Hossain, Mehjabin, and Tareq Bin Salam. 2019. “Changes in Soil Physico-Chemical Properties and Fertility Status of Long-Term Cultivated Soils in Southwestern Bangladesh.”
23:31–41.
Igwe, P.U., Nwezi, C.C., Echendu, J.E., Chukwunyere, I.C., Okonkwo, N. .. 2017. “Adaptations to Soil Erosion : A Review.” (12):1126–34.
Jabatan Pertanian Malaysia. 2020. Garis Panduan Pembangunan Pertanian Di Tanah Bercerun.
Vol. 3.
Jeloudar, F. Taleshian, M. Ghajar Sepanlou, and S. M. Emadi. 2018. “Impact of Land Use Change on Soil Erodibility.” 4(1):59–70. doi: 10.22034/gjesm.2018.04.01.006.
Karuku, George Njomo. 2018. “L UPINE PUBLISHERS Soil and Water Conservation Measures and Challenges in Kenya ; a Review.” 2(5):259–79. doi:
10.32474/CIACR.2018.02.000148.
Kusumandari, Ambar. 2014. “Soil Erodibility of Several Types of Green Open Space Areas in Yogyakarta City , Indonesia.” Procedia Environmental Sciences 20:732–36. doi:
10.1016/j.proenv.2014.03.087.
Laban, Peter, Graciela Metternicht, and Jonathan Davies. 2018. Soil Biodiversity and Soil Organic Carbon : Keeping Drylands Alive.
Lalljee, Bhanooduth. 2013. “Mulching as a Mitigation Agricultural Technology against Land Degradation in the Wake of Climate Change.” International Soil and Water Conservation Research 1(3):68–74. doi: 10.1016/S2095-6339(15)30032-0.
Li, Ming-Han, James R. Schutt, Jett McFalls, Eric K. Bardenhagen, Chan Yong Sung, and Lee Wheelock. 2008. “Successional Establishment, Mowing Response, and Erosion Control Characteristics of Roadside Vegetation in Texas.” 7(2):106p.
Morgan, R. P. .. 2005. Soil Erosion & Conservation. Third.
Mulinge, J., H. Saha, L. Mounde, and L. Wasilwa. 2017. “Effect of Legume Cover Crops on Soil Moisture and Orange Root Distribution.” International Journal of Plant & Soil Science 16(4):1–11. doi: 10.9734/ijpss/2017/32934.
Ranjitham, M., R. Arun Prabhakaran, and J. Dhanusuya. 2020. “REAEARCH ON METHODS OF CONTROLLING SOIL EROSION.” 3965–72.
Řeháček, David, Tomáš Khel, Josef Kučera, Jan Vopravil, and Martin Petera. 2017. “Effect of Windbreaks on Wind Speed Reduction and Soil Protection against Wind Erosion.”
2017(2):1–8. doi: 10.17221/45/2016-SWR.
Resource, Oahu, Development Council, and Pacific Islands Area. 2012. “Vetiver Grass Installation Guide.” (November):1–15.
Schoonover, Jon E., and Jackie F. Crim. 2015. “An Introduction to Soil Concepts and the Role of Soils in Watershed Management.”
Stolte, Jannes, Mehreteab Tesfai, and Jacob Keizer. 2016. Soil Threats in Europe.
Susanti, Yuari, S. Syafrudin, and Muhammad Helmi. 2019. “Soil Erosion Modelling at Watershed Level in Indonesia : A Review 3 Soil Erosion Modelling at Watershed Skale in Indonesia.” 8(201 9).
Truong, P. N. V., and R. Loch. 2004. “Vetiver System for Erosion and Sediment Control.”
Proceeding of 13th International Soil Conservation Organisation Conference (247):1–
6.
Ummunah UP, and Nwogu NC. 2015. “Mechanical & Aerospace Engineering Mechanical &
Aerospace Engineering.” in international Conference and Exhibition on Mechanical &
Aerospace Engineering.
USDA. 2006. “Erosion Control Treatment Selection Guide.”
Yesuph, Asnake Yimam, and Amare Bantider Dagnew. 2019. “Soil Erosion Mapping and Severity Analysis Based on RUSLE Model and Local Perception in the Beshillo Catchment of the Blue Nile Basin ,.” Environmental Systems Research 1–21. doi: 10.1186/s40068- 019-0145-1.
Yiferu, Yishak, Girma Taddese, and Tesfaye Mebrate. 2018. “Influence of Soil Erosion and Conservation Practices on Soil Physical Properties in Ginaberet , Ethiopia.” 2(6):288–
97. doi: 10.15406/freij.2018.02.00062.
