China
Africa
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Agricultural Adaptation to Climate Change
Published in Brenda Groskinsky, Climate Actions, 2022
Richard M. Cruse, Enheng Wang, Chunmei Wang, Fernando García-Préchac, Panos Panagos, Baoyuan Liu, Emily Heaton, Dennis Todey
The construction of terraces and check dams is primarily responsible for the sediment load reduction of the Yellow River (Wang et al. 2016). This practice also improves food security through creating fertile flat agricultural land (Shi et al. 2020) in the Loess Plateau region. By 2018, 3.36 million ha of terraces had been built in the Loess Plateau region (Gao et al. 2020). Terraces increase rainfall infiltration and reduce surface runoff and soil loss, thus increasing crop yield and ultimately productivity. Check dam use in the Loess Plateau region began at least 400 years ago. In the past century, the two most important periods for check dam construction were 1968–1976 and 2004–2008. Prior to 2015, 56,422 check dams above the Tongguan station were constructed (Liu, X., Gao, Y., Ma, S., & Dong, G. 2018). Check dams, temporary structures designed across drainage channels, are effective measures for stopping coarse sediment transport to the Yellow River and was reported to be the dominant approach for sediment control in sub-catchments of this region (Da-Chuan et al. 2008). The agricultural landscape has been changed from sloping cropland to terraced and check dam–dominated farmland in many areas of the Loess Plateau region.
Soil Erosion and Its Control
Published in Sandeep Samantaray, Abinash Sahoo, Dillip K. Ghose, Watershed Management and Applications of AI, 2021
Sandeep Samantaray, Abinash Sahoo, Dillip K. Ghose
The terrace is an earthen embankment, built across slope, for controlling runoff and minimize soil erosion. Terrace acts as an intercept to slope of land distributing surface of land slope into strips. Length of run of the runoff is reduced in limited widths of strips. It has been established that soil loss is proportional to square root of the slope length, i.e. by limiting run length, there is reduction of soil erosion. Soil eroded by raindrop splash and runoff scour streams down the slope and gets blocked up by terraces. Scour of soil surface due to runoff water is started by runoff at a velocity above critical value, achieved during a flow on a long length of sloping run. By restricting the run length, runoff velocity remains less than critical value and hence there is prevention of soil erosion due to scour. Terraces are classified into two major types: broad-base terraces and bench terraces.
Erosion by Water: Assessment and Control
Published in Brian D. Fath, Sven E. Jørgensen, Megan Cole, Managing Soils and Terrestrial Systems, 2020
José Miguel Reichert, Nadia Bernardi Bonumá, Gustavo Enrique Merten, Jean Paolo Gomes Minella
Terraces are mechanical structures constructed across a slope and consist of a channel and an earth or stone bank to intercept surface runoff, allow it to infiltrate and evaporate, or divert the excess to a stable outlet at a nonerosive velocity. Depending upon their function or type of construction, terraces are classified as retention or absorption, diversion or graded, and bench terraces. Retention or absorption terraces are used when water is to be stored on the hillside of slopes less than 4.5°, having level channels able to accumulate runoff volume generated by a 10 years return period rainfall (Figure 8). Diversion or graded terraces aim at intercepting runoff and conducting it to a proper outlet through a channel of a slight grade, usually 1:250 (Figure 9) on slopes less than 7°. Bench terraces are used on steep slopes, up to 30°, alternating a series of shelves (cuts) and raises (fills) (Figure 10). Research data from several authors[10] indicate effectiveness in soil loss control of bench terraces up to 93%. Terraces must be properly designed to avoid even greater soil erosion damage[44] and should be planned considering the whole farm, a group of neighboring farms, or even a small hydrographic catchment,[45] to ensure optimization of land use.
GIS and remote sensing-based assessment of soil erosion risk using RUSLE model in South-Kivu province, eastern, Democratic Republic of Congo
Published in Geomatics, Natural Hazards and Risk, 2021
Luc Cimusa Kulimushi, Pandurang Choudhari, Leonard K. Mubalama, Gedeon T. Banswe
GIS and remote sensing-based RUSLE model have demonstrated to be a suitable approach for soil mapping and estimation of soil erosion, especially in the poor data context. The valuable outcomes from this study kept policymakers and managers aware of the reliably predicted erosion phenomena within the province, it can help to manage land and water resources by adopting terraces to reduce the slope length hence minimize soil erosion below the current rate. Finally, future research could contribute to link soil erosion to the socio-economic problem.
Rapid mapping application of vegetated terraces based on high resolution airborne LiDAR
Published in Geomatics, Natural Hazards and Risk, 2018
Danilo Godone, Daniele Giordan, Marco Baldo
In fact, land cover is a key factor in terrace stability assessment; e.g. in the study area olive orchards class also include an ‘abandoned’ subclass. The documented presence of abandoned sectors points out several issues. Undetected terraces may suffer lack of maintenance, especially if located in abandoned areas (Stanchi et al. 2012; Tarolli et al. 2014). Damaged and/or unstable terraces could be trigger factors for slope instabilities (Shrestha et al. 2004).
The drivers for the collapse of Lake Haramaya and proposed integrated rehabilitation strategies
Published in International Journal of River Basin Management, 2023
Sitotaw Haile Erena, R. Uttama Reddy, Awol Akmel Yesuf
Structurally, stone terraces and walls can control the problem in areas where stones are available. In areas where there is no stone, soil bund can replace terracing. Terrace helps to bring sloping land into different level strips to enable the cultivation of various crops in these landscapes.