scholarly journals Run‐off and sediment storage: The effectiveness of mitigation measures against soil erosion and freshwater pollution

Author(s):  
John Boardman ◽  
Ian David Leigh Foster
2019 ◽  
Vol 11 (2) ◽  
pp. 529-539 ◽  
Author(s):  
Mahmud Mustefa ◽  
Fekadu Fufa ◽  
Wakjira Takala

Abstract Currently, soil erosion is the major environmental problem in the Blue Nile, Hangar watershed in particular. This study aimed to estimate the spatially distributed mean annual soil erosion and map the most vulnerable areas in Hangar watershed using the revised universal soil loss equation. In this model, rainfall erosivity (R-factor), soil erodibility (K-factor), slope steepness and slope length (LS-factor), vegetative cover (C-factor), and conservation practice (P-factor) were considered as the influencing factors. Maps of these factors were generated and integrated in ArcGIS and then the annual average soil erosion rate was determined. The result of the analysis showed that the amount of soil loss from the study area ranges from 1 to 500 tha−1 yr−1 with an average annual soil loss rate of 32 tha−1 yr−1. Considering contour ploughing with terracing as a fully developed watershed management, the resulting soil loss rate was reduced from 32 to 19.2 tha−1 yr−1. Hence, applying contour ploughing with terracing effectively reduces the vulnerability of the watershed by 40%. Based on the spatial vulnerability of the watershed, most critical soil erosion areas were situated in the steepest part of the watershed. The result of the study finding is helpful for stakeholders to take appropriate mitigation measures.


2020 ◽  
Author(s):  
Chengzhong Pan ◽  
Lan Ma

<p>The aim of this study was to investigate how the spatial distribution of grass influenced run-off and erosion from a hillslope with loess and cinnamon soils in the rocky area of Northern China. We set up a trial to test the two soils with different treatments, including bare soil (BS), grass strips on the upper (UGS) and lower (DGS) parts of the slope, grass cover over the entire slope (GS), and a grass carpet on the lower part of the slope (GC), under simulated rainfall conditions. The results showed that the run-off coefficients for the loess and cinnamon soils decreased by between 4% and 20% and by between 2% and 37%, respectively, when covered with grass. Grass spatial distribution had little effect on the run-off, but more effect on erosion than vegetation coverage degree. The most effective location of grass cover for decreasing hillslope erosion was at the foot, and the high efficiency was mainly due to controlling of rill formation and sediment deposition. The soil loss from GS, DGS, and GC on the loess and cinnamon soils was between 77% and 93% less and 55% and 80% less, respectively, compared with the loss from BS. However, the soil characteristics had little effect on soil erosion for well-vegetated slopes. The results highlight the importance of vegetation re-establishment at the foot of hillslope in controlling soil erosion.</p>


2020 ◽  
Vol 17 (1) ◽  
pp. 67
Author(s):  
Oteng Haridjaja

Soil consevation management system is an activity for diminishing sediment enrichment ratio and nutrient leacheds by water run off and soil erosion processes. The research was aimed to study sediment enrichment ratio and nutrient leached by run off and soil erosion on cacao plantations. Arachis pintoi with strips parallel contour and multiple strip cropping of upland rice or soybean (Glycine max) were planted to improve soil physical characterictic on cacao plantation as a main plant. The expriment were conducted with treatments as 10-15% and 40-45% slopes, 5-7 months and 25-27 months cacao ages (as main plants). As sub plots are T1 as a monoculture which to be cleaning under the plant canopy, T2 as a multiple strip cropping of upland rice or soybean, T3 as a combination of T2 and A. Pintoi strip. The results showed that  total N, P2O5, and K2O and organic-C contents in water run off and soil sediments indicated that T3 >T2 >T1 treatment, with the contents of each nutrient: T3 (total N 0.18%; 24.87 mg 100 g-1 P2O5: K2O 15.16 mg 100 g-1), T1 (total N 0.16%, 22.39 mg 100g-1 P2O5, K2O 11.50 mg 100g-1).  The total N, P2O5, K2O and organic-C soil contents < accumulation nutrient contents of total water run off and soil sediment transport. All of treathments have sediment enrichment ratios > 1.


2008 ◽  
Vol 13 (3) ◽  
pp. 253-260 ◽  
Author(s):  
. Sunarti ◽  
Naik Sinukaban ◽  
Bunasor Sanim ◽  
Suria Darma Tarigan

Forest conversion to some land use happened in all watershed, includes Batang Pelepat watershed. The objectives of this research are to know effect of forest conversion to land of rubber (Hevea brasiliensis) and palm oil (Elaeis guinensis Jack) farming on run off and soil erosion and different of erosion rate on agro technology of rubber and palm oil farming in Batang Pelepat watershed. The research was carried out during 3 months, begin October to December 2006. Run off and soil erosion measured plot with gutter in the lower of plot. Experimental design for this research is randomized complete block design, with land use type as treatment and slope class as replication or block. Data analyzed statistically by variance analysis (F-test) and Duncan New Multiple Range Test on confidence 95% (α = 0.05). The results of this research show that area of forest coverage in Batang Pelepat watershed was decreasing. In 1986 this area still 94,50% of watershed area, but in 1994 area of forest only 78,17% and in 2006 forest area 64,20% of watershed area. Forest conversion was carried out to land of rubber and palm oil farming with some actual agro technologies. Land of monoculture rubber I resulted the highest run off and soil erosion more than the other land use type and showed different of run off and soil erosion on land of secondary forest. 


2013 ◽  
Vol 16 (2) ◽  
pp. 161-167
Author(s):  
Siti Masreah Bernas

On some coffee plantations in Lahat Regency South Sumatra, in some places the farmers did not apply agricultural practices, such as tillage, conservation practices, and fertilizers. Many researches have been done to study about effects of organic fertilizer on soil nutrients content and plant growth as well as and the impacts of terrace on soil water content, run-off and erosion. However, there was less research in the highland area. Whereas the possibilityof run off, erosion and nutrient leaching the high land area was high. Thus, it was important to apply terrace and organic coffee pulp in this farm. The aims of this research were to determine the effect of terrace and organic fertilizer on run off and soil erosion, nutrients loss and nutrient content in coffee leaves. Terrace system and organic fertilizer were applied on a one year old coffee plantation in Lahat Regency. Before the treatment applied,coffee pulp as organic fertilizer was decomposed in the chamber for about 2 months. The experiment was conducted in factorial in a Randomized Block Design with two factors. The first factor was coffee pulp compost (0, 3, and 6 Mg ha-1), and the second factor was type of terrace (without, individual, and bund terraces). The size of each plot was 2 m width and 10 m length. Data was analysed by using LSD (Least Significant Different) test. The resultshows that bund terrace reduced runoff and erosion significantly up to 79% (for run off water) and 78% (for eroded soil) compared to without terrace. Organic fertilizer did not affect run off and soil erosion. This may be caused by properties of coffee pulp compost which were fine particulates and the dosages of application were too low to cover soil suface. Bund terrace decreased significantly N, P, K nutrients in soil loss (sediment). The amount of N losswas reduced from 3.37 kg ha-1 per four months (without terrace) to about 0.75 kg ha-1 per four months (bund terrace). Terrace and organic fertilizer did not affect significantly nutrients content in the leaves, but P-content was low without organic fertilizer addition. It is suggested to apply bund terrace and higher organic fertilizer dose on the coffee farm, and further experiments when harvesting the yield (berries) are needed for the second year oldcoffee farm.Keywords: Coffee, compost, erosion, nutrient, pulp, terrace


2019 ◽  
Vol 11 (2) ◽  
pp. 68
Author(s):  
Otieno, J. ◽  
Otieno, A. C. ◽  
Tonui, K. W

Soil erosion is a natural phenomenon, but human activities accelerate it between ten to forty times the natural occurrences. It therefore calls for mitigating measure to curb the effects of erosion since soils form at a slower rate than they are destroyed. A study on land use activities and their effects on soil erosion was conducted in the upland ecosystem in Kenya, Kajulu hills. The study assessed the effectiveness of the mitigation measures adopted by the residents to ease the effects erosion on the hill slopes. A sample size of 295 households out of 1600 households engaged in various mitigating practices was used. The study collected data on the magnitude of soil (kg) lost from the arable lands using collector ditch technique. The data were analyzed using frequency distribution tables and Man U-test. The result showed a double amount (1.198kg/m2) of soil lost on the arable land without mitigation measures as compared to plots under cut off ditches (0,615kg/m2) and vegetative strips (0.904kg/m2) with Man U=7. These findings were above the world wide estimation of soil erosion on arable mountainous regions which range between 1.3-40.kg/m2/year (13-40T/Ha/year) as it was based on one rainy season.


2016 ◽  
Vol 4 (2) ◽  
pp. 407-423 ◽  
Author(s):  
Victoria Naipal ◽  
Christian Reick ◽  
Kristof Van Oost ◽  
Thomas Hoffmann ◽  
Julia Pongratz

Abstract. Currently, the anthropogenic perturbation of the biogeochemical cycles remains unquantified due to the poor representation of lateral fluxes of carbon and nutrients in Earth system models (ESMs). This lateral transport of carbon and nutrients between terrestrial ecosystems is strongly affected by accelerated soil erosion rates. However, the quantification of global soil erosion by rainfall and runoff, and the resulting redistribution is missing. This study aims at developing new tools and methods to estimate global soil erosion and redistribution by presenting and evaluating a new large-scale coarse-resolution sediment budget model that is compatible with ESMs. This model can simulate spatial patterns and long-term trends of soil redistribution in floodplains and on hillslopes, resulting from external forces such as climate and land use change. We applied the model to the Rhine catchment using climate and land cover data from the Max Planck Institute Earth System Model (MPI-ESM) for the last millennium (here AD 850–2005). Validation is done using observed Holocene sediment storage data and observed scaling between sediment storage and catchment area. We find that the model reproduces the spatial distribution of floodplain sediment storage and the scaling behavior for floodplains and hillslopes as found in observations. After analyzing the dependence of the scaling behavior on the main parameters of the model, we argue that the scaling is an emergent feature of the model and mainly dependent on the underlying topography. Furthermore, we find that land use change is the main contributor to the change in sediment storage in the Rhine catchment during the last millennium. Land use change also explains most of the temporal variability in sediment storage in floodplains and on hillslopes.


2020 ◽  
Vol 116 (5/6) ◽  
Author(s):  
Peter G. Ryan ◽  
Lorien Pichegru ◽  
Vonica Perold ◽  
Coleen L. Moloney

In the context of marine anthropogenic debris management, monitoring is essential to assess whether mitigation measures to reduce the amounts of waste plastic entering the environment are being effective. In South Africa, baselines against which changes can be assessed include data from the 1970s to the 1990s on microplastics floating at sea, on macro- and microplastic beach debris, and interactions with biota. However, detecting changes in the abundance of microplastics at sea is complicated by high spatial and temporal heterogeneity in net samples. Beach debris data are easier to gather, but their interpretation is complicated by the dynamic nature of debris fluxes on beaches and the increase in beach cleaning effort over time. Sampling plastic ingested by biota is a powerful approach, because animals that retain ingested plastic for protracted periods integrate plastics over space and time, but there are ethical issues to using biota as bioindicators, particularly for species that require destructive sampling (e.g. turtles, seabirds). Bioindicators could be established among fish and invertebrates, but there are technical challenges with sampling microplastics smaller than 1 mm. Fine-scale debris accumulation on beaches provides an index of macroplastic abundance in coastal waters, and offers a practical way to track changes in the amounts and composition of debris in coastal waters. However, upstream flux measures (i.e. in catchments, rivers and storm-water run-off) provide a more direct assessment of mitigation measures for land-based sources. Similarly, monitoring refuse returned to port by vessels is the best way to ensure compliance with legislation prohibiting the dumping of plastics at sea. Significance: • Monitoring is required to assess whether mitigation measures to reduce waste plastics at sea are making a difference. • Monitoring the leakage of plastic from land-based sources is best addressed on land (e.g. in storm drains and river run-off) before the plastic reaches the sea. • Illegal dumping from ships is best addressed by monitoring the use of port waste reception facilities. • Sampling plastic ingested by biota is a powerful approach, using fish and invertebrates as bioindicators for larger microplastic fragments.


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