scholarly journals Investigation of Soil Erosion from Bare Steep Slopes of the Humid Tropic Philippines

2005 ◽  
Vol 9 (5) ◽  
pp. 1-30 ◽  
Author(s):  
A. L. Presbitero ◽  
C. W. Rose ◽  
B. Yu ◽  
C. A. A. Ciesiolka ◽  
K. J. Coughlan ◽  
...  

Abstract At the Visayas State College of Agriculture (ViSCA) on the island of Leyte in the Philippines, hydrologic and soil-loss measurements were recorded for 32 erosion events over 3 yr on three 12-m-long bare soil plots with slopes of approximately 50%, 60%, and 70%. Measurements included rainfall and runoff rates at 1-min intervals, total soil lost per event from the plot, rill details when observed after an erosion event, and soil settling-velocity characteristics. Storm events are characterized by high rainfall rates but quite low rates of runoff, because of the consistently high infiltration rate of the stable clay soil (an Oxic Dystropept). Both observation and modeling indicated that overland flow is commonly so shallow that much of the soil surface is likely to be unsubmerged. For the 70% slope plot, half the events recorded mean sediment concentrations from 100 to 570 kg m−3. A somewhat constant hydrologic lag between rainfall and runoff is used to estimate a Manning’s roughness coefficient n of about 0.1 m−1/3 s, a value used to estimate velocity of overland flow. Possible effects of shallow flows and high sediment concentrations on existing erosion theory are investigated theoretically but are found to have only minor effects for the ViSCA dataset. A soil erodibility parameter β was evaluated for the data whenever rilling was recorded following an erosion event. The values of β indicate that, except for events with higher stream powers, other erosion processes in addition to overland flow could have contributed to soil loss from erosion plots in a significant number of events.

2021 ◽  
Vol 11 (15) ◽  
pp. 6763
Author(s):  
Mongi Ben Zaied ◽  
Seifeddine Jomaa ◽  
Mohamed Ouessar

Soil erosion remains one of the principal environmental problems in arid regions. This study aims to assess and quantify the variability of soil erosion in the Koutine catchment using the RUSLE (Revised Universal Soil Loss Equation) model. The Koutine catchment is located in an arid area in southeastern Tunisia and is characterized by an annual mean precipitation of less than 200 mm. The model was used to examine the influence of topography, extreme rainstorm intensity and soil texture on soil loss. The data used for model validation were obtained from field measurements by monitoring deposited sediment in settlement basins of 25 cisterns (a traditional water harvesting and storage technique) over 4 years, from 2015 to 2018. Results showed that slope is the most controlling factor of soil loss. The average annual soil loss in monitoring sites varies between 0.01 and 12.5 t/ha/y. The storm events inducing the largest soil losses occurred in the upstream part of the Koutine catchment with a maximum value of 7.3 t/ha per event. Soil erosion is highly affected by initial and preceding soil conditions. The RUSLE model reasonably reproduced (R2 = 0.81) the spatiotemporal variability of measured soil losses in the study catchment during the observation period. This study revealed the importance of using the cisterns in the data-scarce dry areas as a substitute for the classic soil erosion monitoring fields. Besides, combining modeling of outputs and field measurements could improve our physical understanding of soil erosion processes and their controlling factors in an arid catchment. The study results are beneficial for decision-makers to evaluate the existing soil conservation and water management plans, which can be further adjusted using appropriate soil erosion mitigation options based on scientific evidence.


2021 ◽  
Author(s):  
Ivan Dugan ◽  
Leon Josip Telak ◽  
Iva Hrelja ◽  
Ivica Kisić ◽  
Igor Bogunović

<p><strong>Straw mulch impact on soil properties and initial soil erosion processes in the maize field</strong></p><p>Ivan Dugan*, Leon Josip Telak, Iva Hrelja, Ivica Kisic, Igor Bogunovic</p><p>University of Zagreb, Faculty of Agriculture, Department of General Agronomy, Zagreb, Croatia</p><p>(*correspondence to Ivan Dugan: [email protected])</p><p>Soil erosion by water is the most important cause of land degradation. Previous studies reveal high soil loss in conventionally managed croplands, with recorded soil losses high as 30 t ha<sup>-1</sup> under wide row cover crop like maize (Kisic et al., 2017; Bogunovic et al., 2018). Therefore, it is necessary to test environmentally-friendly soil conservation practices to mitigate soil erosion. This research aims to define the impacts of mulch and bare soil on soil water erosion in the maize (Zea mays L.) field in Blagorodovac, Croatia (45°33’N; 17°01’E; 132 m a.s.l.). For this research, two treatments on conventionally tilled silty clay loam Stagnosols were established, one was straw mulch (2 t ha<sup>-1</sup>), while other was bare soil. For purpose of research, ten rainfall simulations and ten sampling points were conducted per each treatment. Simulations were carried out with a rainfall simulator, simulating a rainfall at an intensity of 58 mm h<sup>-1</sup>, for 30 min, over 0.785 m<sup>2</sup> plots, to determine runoff and sediment loss. Soil core samples and undisturbed samples were taken in the close vicinity of each plot. The results showed that straw mulch mitigated water runoff (by 192%), sediment loss (by 288%), and sediment concentration (by 560%) in addition to bare treatment. The bare treatment showed a 55% lower infiltration rate. Ponding time was higher (p < 0.05) on mulched plots (102 sec), compared to bare (35 sec), despite the fact that bulk density, water-stable aggregates, water holding capacity, and mean weight diameter did not show any difference (p > 0.05) between treatments. The study results indicate that straw mulch mitigates soil water erosion, because it immediately reduces runoff, and enhances infiltration. On the other side, soil water erosion on bare soil under simulated rainstorms could be high as 5.07 t ha<sup>-1</sup>, when extrapolated, reached as high as 5.07 t ha<sup>-1 </sup>in this study. The conventional tillage, without residue cover, was proven as unsustainable agro-technical practice in the study area.</p><p><strong>Key words: straw mulch, </strong>rainfall simulation, soil water erosion</p><p><strong>Acknowledgment</strong></p><p>This work was supported by Croatian Science Foundation through the project "Soil erosion and degradation in Croatia" (UIP-2017-05-7834) (SEDCRO).</p><p><strong>Literature</strong></p><p>Bogunovic, I., Pereira, P., Kisic, I., Sajko, K., Sraka, M. (2018). Tillage management impacts on soil compaction, erosion and crop yield in Stagnosols (Croatia). Catena, 160, 376-384.</p><p>Kisic, I., Bogunovic, I., Birkás, M., Jurisic, A., Spalevic, V. (2017). The role of tillage and crops on a soil loss of an arable Stagnic Luvisol. Archives of Agronomy and Soil Science, 63(3), 403-413.</p>


Soil Research ◽  
1992 ◽  
Vol 30 (4) ◽  
pp. 465 ◽  
Author(s):  
DJ Chittleborough ◽  
KRJ Smettem ◽  
E Cotsaris ◽  
FW Leaney

The pathways of dissolved organic carbon (DOC) through a podzolic soil (Xeralf) with strong texture contrast are described. During winter, most of the DOC passes through macropores in the profile and flows laterally through the B horizons. During summer the presence of dry, hydrophobic organic matter on the soil surface and the A1 horizon causes DOC to flow overland. DOC concentrations vary seasonally. Highest concentrations are measured during summer overland flow. For all horizons, the longer the dry period the greater the DOC concentration in the subsequent flow. During storm events there is a marked flushing effect in the B horizons but in the A horizon and the surface, DOC concentrations tend to rise. There was a marked decrease in DOC concentration in flow from the B3 compared to the upper horizons. This may be due to adsorption by fine clays lining the macropores.


Soil Research ◽  
1988 ◽  
Vol 26 (4) ◽  
pp. 661 ◽  
Author(s):  
RJ Loch ◽  
TE Donnollan

A field study by using simulated rain and run-on water was carried out to determine the effects of different amounts of wheat stubble mulch (ranging from 0.1 to 3 t ha-1) and increasing discharge on erosion. Rain-flow erosion decreased with increasing amounts of stubble. Concentrations of bed-load sediment carried by rain-flow decreased with increasing plot discharge. As discharges increased, overland flow probably became too deep for drop impact to effectively disturb the soil surface and entrain sediment. Only plots carrying 0.1 t ha-1 stubble showed definite scour by overland flow. However, sediment concentrations produced by scour were well below those measured in rill flow on bare soil at this site, showing that even very small rates of stubble mulch can, in some situations, significantly reduce erosion. Discharges at which rilling develops fully must be much larger than those at which scour by overland flow is initiated. Future work will need to consider discharges much larger than those used in this study.


2013 ◽  
Vol 4 (2) ◽  
pp. 1-6
Author(s):  
Fizzahutiah Taha ◽  
Shenbaga R. Kaniraj

Soil erosion is one of the problems of environmental concern. Natural causes such as rainfall and human development activities are the two main factors that can cause soil erosion. In order to control soil erosion, especially in urban areas, the bare soil surface needs to be covered by plants as much as possible. Re-vegetation, the best permanent erosion control measure, might take time to be complete. Therefore, some suitable temporary measures should be applied to minimize the amount of soil loss. Topographical features and climate are among the factors that determine the amount of soil erosion. In order to control the rate of erosion, it is important to estimate the amount of soil loss. Universal Soil Loss Equation (USLE) is one of the approaches to estimate the rate of soil loss. In this study, the topographical features of a site prone to erosion within University Malaysia Sarawak (UNIMAS), were investigated by field survey. Laboratory experiments were carried out on soil samples collected from the site. Theparameters for use in USLE were evaluated. The soil loss at the site in 2011 was estimated as 52.85 t ha-1 and the soil erosion risk atthe site was categorized as moderately high. 


2020 ◽  
Vol 12 (4) ◽  
pp. 1597 ◽  
Author(s):  
Birhanu Kebede ◽  
Atsushi Tsunekawa ◽  
Nigussie Haregeweyn ◽  
Amrakh I. Mamedov ◽  
Mitsuru Tsubo ◽  
...  

The use of anionic polyacrylamide (PAM) as a soil conditioner could help prevent soil loss by water. In this study, we determined the effective granular PAM rate that best reduces runoff and soil loss from Oxisols. Furthermore, the effectiveness of the selected PAM rate was tested by applying it in a mixture with gypsum (G) or lime (L). The study was conducted in two phases: (i) Dry PAM rates of 0 (C), 20 kg ha−1 (P20), 40 kg ha−1 (P40), and 60 kg ha−1 (P60) were applied onto soil surface and run for six consecutive rainfall storms of 70 mm h−1 intensity for 1 h duration, and the effective PAM rate was selected; and (ii) G (4 t ha−1) or L (2 t ha−1) were applied alone or mixed with the selected PAM rate. The P20 was found to be effective in reducing runoff in the beginning while P40 and P60 were more effective starting from the third storm through the end of the consecutive storms, but with no statistically significant difference between P40 and P60. Hence, P40 was selected as the most suitable rate for the given test soil and rainfall pattern. On the other hand, the mixed application of P40 with G or L increased infiltration rate (IR) in the first two storms through improving soil solution viscosity. However, effectiveness of the mixtures had diminished by various degrees as rain progressed, as compared to P40 alone, which could be attributed to the rate and properties of G and L. In conclusion, the variation in effectiveness of PAM rates in reducing runoff with storm duration could indicate that the effective rates shall be selected based on the climatic region in that lower rates for the short rains or higher rates for elongated rains. Moreover, combined application of PAM with L could offer a good option to both fairly reduce soil erosion and improve land productivity especially in acidic soils like Oxisols, which requires further field verification.


2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Gebreyesus Brhane Tesfahunegn ◽  
Lulseged Tamene ◽  
Paul L. G. Vlek

Even though scientific information on spatial distribution of hydrophysical parameters is critical for understanding erosion processes and designing suitable technologies, little is known in Geographical Information System (GIS) application in developing spatial hydrophysical data inputs and their application in Morgan-Morgan-Finney (MMF) erosion model. This study was aimed to derive spatial distribution of hydrophysical parameters and apply them in the Morgan-Morgan-Finney (MMF) model for estimating soil erosion in the Mai-Negus catchment, northern Ethiopia. Major data input for the model include climate, topography, land use, and soil data. This study demonstrated using MMF model that the rate of soil detachment varied from <20 t ha−1y−1to >170 t ha−1y−1, whereas the soil transport capacity of overland flow (TC) ranged from 5 t ha−1y−1to >42 t ha−1y−1. The average soil loss estimated by TC using MMF model at catchment level was 26 t ha−1y−1. In most parts of the catchment (>80%), the model predicted soil loss rates higher than the maximum tolerable rate (18 t ha−1y−1) estimated for Ethiopia. Hence, introducing appropriate interventions based on the erosion severity predicted by MMF model in the catchment is crucial for sustainable natural resources management.


2010 ◽  
Vol 53 (1) ◽  
pp. 179-184 ◽  
Author(s):  
Avacir Casanova Andrello ◽  
Carlos Roberto Appoloni

The aim of this study was to examine the beryllium-7 behavior in the soil. Natural variability of beryllium-7 concentration was calculated to be about 23% (relative standard deviation), and the depth distribution could be approximated by an exponential decay in bare soil, with an average penetration depth in the soil about 1 cm. The nuclide was not found below 2 cm depth, which confirmed its utilization to infer the erosion processes as a tracer of soil surface. The maximum beryllium-7 concentration in the analyzed period was about 40 Bq.kg-1.


Soil Research ◽  
2008 ◽  
Vol 46 (3) ◽  
pp. 191 ◽  
Author(s):  
Meni Ben-Hur ◽  
Marcos Lado

Soil surface sealing is one of the main causes for low infiltration rate (IR) and high runoff and soil loss under raindrop impact conditions in arid and semiarid regions. Many studies have focused on the effects of soil properties on seal formation under fast wetting conditions. However, in the field, soils can be exposed to different wetting conditions, before an intense rainfall event, which can affect the role of the soil properties on seal formation. The present paper reviews the effects of different initial wetting conditions and their interactions with soil properties on seal formation, IR, runoff, and soil loss in smectitic soils. Fast wetting of soil causes aggregate slaking, which enhances seal formation, runoff, and soil loss under rainfall, mainly in soils with > 40% clay content. An increase in clay content of the soil increases aggregate strength, but at the same time increases the slaking forces. Hence, in soils with low clay content (<40%) and low aggregate stability, raindrop impact alone was sufficient to break down the aggregates and to develop a seal. In contrast, in soils with > 40% clay content and high aggregate stability, slaking plays an important role in aggregate breakdown and seal formation. An increase of raindrop kinetic energy, from 8 to 15.9 kJ/m3, decreased the effect of the slaking forces on seal formation and runoff. It was suggested that the effects of raindrop kinetic energy and of the slaking forces on aggregate disintegration and seal formation are complementary. An increase in soil exchangeable sodium percentage (ESP), from 0.9 to 20.4%, decreased the effect of slaking forces on seal formation and runoff production under rainfall with 15.9 kJ/m3 kinetic energy. Probably, increasing the ESP increased the soil dispersivity, and therefore diminished the effect of the slaking forces on aggregate disintegration and seal formation. Aging (the time since wetting) of soil increased the stability of soil structure, decreased the seal formation, maintained high IR, and diminished soil loss amounts. These effects of soil aging depend on both the prewetting rate of the soil and soil texture.


2000 ◽  
Vol 42 (9) ◽  
pp. 179-186 ◽  
Author(s):  
H. Vanden Bossche ◽  
J. M. Audic ◽  
A. Huyard ◽  
C. Gascuel-Odoux ◽  
F. Trolard ◽  
...  

Sewage sludge is used as fertilizer, owing to its nutrient contents. But little is known about the consequences of sludge disposal on erosion intensity and P losses from soil to runoff. This paper reports on a study of three simulated storm events (40 mm h-1 during 30 min), performed on a field supplied with liquid sludge (23 g L-1 of dry solid). The sludge phosphorus content was 26.5 g kg-1 of dry solid. The runoff and erosion intensity as well as the P losses were monitored during the experiment. The distribution of phosphorus on the soil surface, was investigated after the last simulation. Sludge disposal reduced the total amount of runoff water collected during the experiment from 290 m3 ha−1 to 134 m33 ha−1. It also decreased the quantity of sediment exported from 1200 kg ha−1 to 500 kg ha−1 and the total phosphorus loss from 2.7 kg ha-1 P to 1.4 kg ha−1 P. But, it increased the average concentration of dissolved phosphorus in the overland flow from 0.15 mg L−1 P to 0.57 mg L−1 P. The distribution pattern of P and organic matter, on the soil surface, after the simulations, showed a heterogeneity induced by the runoff processes. This effect is increased by sludge disposal.


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