scholarly journals Review: Design norms for soil and water conservation structures in the sugar industry of South Africa

Water SA ◽  
2019 ◽  
Vol 45 (1 January) ◽  
Author(s):  
Daniel Otim ◽  
Jeff Smithers ◽  
Aidan Senzanje ◽  
Rianto Van Antwerpen
Keyword(s):  
South Africa ◽  
South African ◽  
Water Conservation ◽  
Soil Conservation ◽  
Soil Loss ◽  
Sugar Industry ◽  
Empirical Models ◽  
Soil And Water Conservation ◽  
The South ◽  
Soil And Water

This paper contains a critical review of the norms employed in the design of soil and water conservation structures in the South African sugar industry and highlights research needs in order to update them. Sugarcane in South Africa is grown on wide-ranging soils, sometimes in non-ideal climates and on steep topographies where soils are vulnerable to erosion. A consequence of unsustainable soil loss is reduction in field production capacity. Sugarcane fields are protected against erosion through, inter alia, the use of engineered waterways, contour banks and spill-over roads. The South African Sugarcane Research Institute (SASRI), previously known as the South African Sugar Experiment Station (SASEX), developed a nomograph to easily compute the maximum width of field panels based on soil type, tillage method, replant method, surface structures to control runoff, surface cover and slope. This was followed by guidelines and norms for the design of soil and water conservation structures. However, the nomograph was developed based on an acceptable soil loss of 20 t·ha−1·yr−1, yet soil formation rates in South Africa range between 0.25 and 0.38 t·ha−1·yr−1. Comparisons between design norms in the National Soil Conservation Manual and norms used in the sugar industry clearly show discrepancies that need to be investigated. The design of soil conservation structures includes the design of both contour bank spacing and hydraulic capacity. The sustainable soil loss method is recommended in the design of contour spacing and it determines contour spacing based on evaluation of site-specific sheet and rill erosion potential of the planned contour spacing while the hydraulic design employs Manning’s equation. Considering that increases in both design rainfall and design floods are anticipated in South Africa, it is necessary to incorporate these projections in the design of soil and water conservation structures. Many soil loss models exist, of which empirical models are the most robust and provide stable performances. The majority of empirical models are lumped models which estimate average annual soil loss. The Modified Universal Soil Loss Equation (MUSLE) estimates event-based erosion and, given that the majority of soil erosion occurs during a few extreme events annually, the design norms should be updated using the MUSLE.

scholarly journals Effects of water and soil conservation works on runoff and sediment variation in the areas with high and coarse sediment yield of the middle Yellow River

2018 ◽  
Vol 38 ◽  
pp. 01033
Author(s):  
Wei Ying Sun ◽  
Pan Zhang ◽  
Li Li ◽  
Jiang Nan Chen
Keyword(s):  
Sediment Yield ◽  
Water Conservation ◽  
Human Activities ◽  
Soil Conservation ◽  
Yellow River ◽  
Soil And Water Conservation ◽  
Contribution Rate ◽  
Rainfall Variation ◽  
Runoff Reduction ◽  
Soil And Water

The areas with high and coarse sediment yield of the middle Yellow River is well known for its severe erosion, high sediment yields. Since 1982 when the 8 key soil and water conservation harnessing regions has been built, the ecological environment has been gradually improved and the amount of sediment and runoff entering the Yellow River has been reduced continuously. Some researchers considered that it was owing to the water and soil conservation works (WSCW), while others believed that it was caused by the rainfall variation, but this has not been quantified for the effect respectively. This paper deals with the effects of WSCW on runoff and sediment variation. The study has been carried out in the Sanchuanhe River watershed, where was listed as one of the 8 key soil and water conservation harnessing regions. The results show that the contribution rate of human activities was 80.2% after 1st harnessing stage (1970-1979), 43.0% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 98.4%, and was 44.8% after 4th harnessing stage (1997-2006). With regard to the influence on runoff reduction in the watershed, the contribution rate of human activities was 62.5% compared with the natural factors after 1st harnessing stage (1970-1979), 28.4% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 69.6%, and was 37.0% after 4th harnessing stage (1997-2006). The results revealed that human activities exerted the largest effects on the sediment reduction and explained 66.6% of the variation in the specific sediment yield. This study suggests that a combination of human activities and rainfall variation effectively reduces runoff and sediment delivery of the Loess Plateau. Generally The runoff reduction and contribution of rainfall variation to runoff reduction in this area were as large as human activities. After many years' harnessing the great benefit have been obtained in water and soil loss control in this watershed.

Evaluation of Four Kinds of Water and Soil Conservation Measures on Highway Side Slope

2013 ◽  
Vol 726-731 ◽  
pp. 3843-3846
Author(s):  
Shu Li Wang ◽  
Jian Ping Zhou ◽  
Zhen Yang
Keyword(s):  
Water Conservation ◽  
Soil Conservation ◽  
Soil And Water Conservation ◽  
Water Holding Capacity ◽  
Side Slope ◽  
Network Measure ◽  
Conservation Measures ◽  
Hollow Brick ◽  
Water Holding ◽  
Soil And Water

Four kinds of protective measures and three contrast measures were chosen on Harbin-Suifenhe highway to analyze the effects of different types of soil and water conservation measure on highway side slope soil. The results showed that Soil and water conservation measures of highway side slope increased water holding capacity and soil conservation capacity significantly. The saturated water holding capacity, capillary water holding capacity and field water holding capacity of E, PP grid measure were 1.79 times,1.60 times and 1.62 times respectively of that in contrast 1 measure. E, PP grid measure, resin network measure and spread planting measures reduced runoff 58.5%, 59.3% and 50.8% compared with contrast measures. Consider of landscape and cost factors, spread planting measures was recommended to use on the smaller slope degree of highway side, E, PP grid measure, resin network measure were recommended to be used on the steep slope of highway side, hex hollow brick measure was not recommended.

scholarly journals Advances in soil conservation research: challenges for the future

2014 ◽  
Vol 4 ◽  
Author(s):  
Ildefons Pla
Keyword(s):  
Environmental Protection ◽  
Water Conservation ◽  
Soil Conservation ◽  
Soil Degradation ◽  
Crop Production ◽  
C Sequestration ◽  
Soil And Water Conservation ◽  
Water Degradation ◽  
Empirical Approaches ◽  
Soil And Water

Increased human influences on soils frequently result in widespread land and soil degradation. The processes of soil and water degradation are closely linked, as unfavourable changes in the hydrological processes affect soil water regimes. In the last 15-20 years there has been increased interest in human-induced climate change, associated with increased atmospheric concentrations of greenhouse gases. Most of the present and future problems of land and soil degradation, water supply and natural disasters are mainly attributed to these climate changes. At the same time, and probably related to it, there has been a change in the focus of research on soil and water conservation. From the late 1960s there was an increasing interest in stimulating studies related to soil and water conservation. This was a great change from the previous emphasis on more static studies of the characteristics of the soil resource, mainly for soil classification and mapping, and for land evaluation related to agricultural and other uses. This situation was due to the increasing evidence of the global problems of land, soil and water degradation, and their effects on food production and the environment. Particular attention was paid to the processes of soil and water degradation in relation to their use and management for agricultural purposes. These efforts led to the development of models and evaluation systems mainly using empirical approaches. Later studies demonstrated the limitations of the generalized universal use of these empirical approaches. Concurrently there was an increase in related organizations, conventions, congresses and conferences associated with the renewed interest on soil and water conservation. A global assessment of human-induced soil degradation (GLASOD) demonstrated the paucity, difficult accessibility and poor quality of basic information. This information, however, is essential for adequate planning and effective application of practices to prevent soil and water degradation. The most recent conventions and programs at international and regional levels are generally based on re-interpretations, and a different processing method or representation of old information using “new” terminology. In other cases, new information has been mostly generated through indirect or remote sensing deductions, usually without adequate ground-truthing. The decreasing public or private support for more integrated interdisciplinary studies and the compulsion to quickly publish papers has resulted in a very specialized and isolated consideration of different aspects related to the degradation of soil functions. This frequently results in over-simplifications, failures and even contradictions in the proposed strategies to control soil degradation. Currently we have reached quasi-stagnation in soil conservation research and a new series of soil conservation terms (soil quality, desertification, tillage erosion) and clichés (“C sequestration”, “no-tillage”) have been introduced. These are derived from different interests, but generally they are very empirical approaches without a strong scientific basis. However, they attract increased attention from organizations setting policies and providing funds for research in soil and water conservation, and as a consequence many research activities in the last 20 years have been concentrated in such topics. Regretfully, these approaches have very limited accuracy and are insufficient for developing adequate policies for land use and management. Climate, soil and socio-economic conditions differ greatly from one location to another and are changing continuously. There cannot therefore be simple universal prescriptions regarding practices of sustainable soil management for crop production and environmental protection or for mitigation of the greenhouse effect by “C sequestration” in soils. The adequate selection of those sustainable practices must be based on research with a broader vision of soil conservation, where all the system components and their interactions are considered and understood with a far-sighted approach, to ensure that short term gains in one aspect or location do not induce long-term losses in other aspects or elsewhere. Research needs to be directed to better the understanding of the processes and reactions in soils related to chemical recycling and water balance over a range of spatial and temporal scales, with the common objective of improving crop production and environmental protection. Lasting solutions will only be found if adequately trained researchers in soil science and hydrology, who recognize the complexity of the problems, develop appropriate strategies.

scholarly journals Soil Erosion and Crop Productivity Loss in Palghar and Thane Districts of Maharashtra

Agropedology ◽  
2019 ◽  
Vol 28 (2) ◽  
Author(s):  
S. V. Shejale ◽  
◽  
S. B. Nandgude ◽  
S. S. Salunkhe ◽  
M. A. Phadtare ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
Soil Loss ◽  
Productivity Loss ◽  
Research Work ◽  
Crop Productivity ◽  
Soil And Water Conservation ◽  
Conservation Practice ◽  
Conservation Measures ◽  
Soil And Water

Present research work was carried out on soil erosion and crop productivity loss in Palghar and Thane districts. The study also describes tolerable soil loss and relationship between top-soil loss and yield loss. The estimated average annual soil loss was 40.45 t ha-1yr-1 before adoption of the soil and water conservation measures (by USLE method) and estimated average tolerable soil loss was 9.36 t ha-1 yr-1, for Palghar district. Similarly, for Thane district the estimated average annual soil loss and tolerable soil loss were found to be 35.89 t ha-1 yr-1 and 9.61 t ha-1 yr-1, respectively for Thane district. The estimated average conservation practice factor (P) factors were obtained as 0.32 for Palghar district and 0.30 for Thane district to bring the soil loss below the tolerable limit. After adoption of soil and water conservation measures, the estimated soil loss were 9.02 t ha-1 yr-1 and 9.38 t ha-1 yr-1 for Palghar and Thane districts, respectively.

scholarly journals Effects of land use, slope gradient, and soil and water conservation structures on runoff and soil loss in semi-arid Northern Ethiopia

2013 ◽  
Vol 34 (3) ◽  
pp. 236-259 ◽  
Author(s):  
Gebeyehu Taye ◽  
Jean Poesen ◽  
Bas Van Wesemael ◽  
Matthias Vanmaercke ◽  
Daniel Teka ◽  
...  
Keyword(s):  
Land Use ◽  
Water Conservation ◽  
Soil Loss ◽  
Soil And Water Conservation ◽  
Northern Ethiopia ◽  
Slope Gradient ◽  
Runoff And Soil Loss ◽  
Effects Of Land Use ◽  
Semi Arid ◽  
Soil And Water

Application of a RUSLE-based soil erosion modelling on Mauritius Island

Soil Research ◽  
2012 ◽  
Vol 50 (8) ◽  
pp. 645 ◽  
Author(s):  
Rody Nigel ◽  
Soonil D. D. V. Rughooputh
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
Soil Loss ◽  
Regional Scale ◽  
Soil And Water Conservation ◽  
Geographical Information ◽  
Environmental Damage ◽  
Total Soil ◽  
Mauritius Island ◽  
Soil And Water

Soil erosion by water is one of the most important natural resources management problems in the world. The damages it causes on-site are soil loss, breakdown of soil structure, and decline in organic matter content, nutrient content, fertility, and infiltration rate. Lands with the highest erosion risk on Mauritius Island are crop cultivations (sugarcane, tea, vegetables) on erosion-susceptible terrain (slopes >20% coupled with highly erodible soils). The locations of such lands on Mauritius were mapped during previous, qualitatively based regional-scale erosion studies. In order to propose soil conservation strategies, there is a need to apply a more quantitative approach to supplement the previous, qualitatively based studies. This paper reports an application of the Revised Universal Soil Loss Equation (RUSLE) within a geographical information system in order to estimate soil loss on the island, and particularly for the high-erosion areas. Results show that total soil loss on the island is estimated at 298 259 t year–1, with soil loss from high-erosion areas summing 84 780 t year–1 (28% of total soil loss). If all of the high-erosion areas were afforested, their soil loss would be reduced to 10 264 t year–1, i.e. a reduction of 88% for the high-erosion areas and a reduction of 25% for the island. This study thus calls for soil and water conservation programs directed to these erosion-prone areas before the land degradation and environmental damage they are causing become irreversible. The methodological approach used in this work to quantitatively estimate soil loss from erosion-prone areas can be adopted in other countries as the basis for a nationwide erosion assessment in order to better inform environmental policy needs for soil and water conservation.

scholarly journals The effect of natural infrastructure on water erosion mitigation in the Andes

2021 ◽  
Author(s):  
Veerle Vanacker ◽  
Armando Molina ◽  
Miluska Rosas-Barturen ◽  
Vivien Bonnesoeur ◽  
Francisco Román-Dañobeytia ◽  
...  
Keyword(s):  
Soil Erosion ◽  
Water Conservation ◽  
Soil Loss ◽  
Southern Oscillation ◽  
Soil And Water Conservation ◽  
The Andes ◽  
Conservation Measures ◽  
Erosion Mitigation ◽  
Soil And Water ◽  
Loss Rates

Abstract. Soil erosion by water is affecting natural and anthropogenic environments through its impacts on water quality and availability, loss of soil nutrients, flood risk, sedimentation in rivers and streams, and damage to civil infrastructure. Sustainable management aims to avoid, reduce and reverse soil erosion and can provide multiple benefits for the environment, population, and livelihoods. We conducted a systematic review of 121 case studies from the Andes to answer the following questions: (1) Which erosion indicators allow us to assess the effectiveness of natural infrastructure? (2) What is the overall impact of working with natural infrastructure on on-site and off-site erosion mitigation? and (3) Which locations and types of studies are needed to fill critical gaps in knowledge and research? Three major categories of natural infrastructure were considered: protective vegetation, soil and water conservation measures, and adaptation measures that regulate the flow and transport of water. From the suite of physical, chemical and biological indicators commonly used in soil erosion research, two indicators were particularly relevant: soil organic carbon (SOC) of topsoil, and soil loss rates at the plot scale. In areas with protective vegetation and/or soil and water conservation measures, the SOC of topsoil is –on average– 1.3 to 2.8 times higher than in areas under traditional agriculture. Soil loss rates in areas with natural infrastructure were reported to be 38 % to 54 % lower than rates measured in untreated croplands. Further research is needed to evaluate whether the reported effectiveness holds during extreme events related to, for example, El Niño–Southern Oscillation.

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