Using digital photogrammetry to monitor soil erosion under conditions of simulated rainfall and wind

Soil Research ◽  
2010 ◽  
Vol 48 (1) ◽  
pp. 36 ◽  
Author(s):  
S. Moritani ◽  
T. Yamamoto ◽  
H. Andry ◽  
M. Inoue ◽  
T. Kaneuchi

We investigated a method to measure sheet erosion by characterising the soil erosion of an upland field in a dryland environment. Digital photogrammetry was used to measure the erosion rates of soil surfaces packed to different densities under simulated rainfall or wind conditions. The photogrammetry system consisted of 2 digital cameras, a rainfall simulator, a wind tunnel, and a computer program for 3-dimensional algorithm analysis. First, we assessed the accuracy of our method by comparing conventionally measured data to photogrammetric data under conditions of either no rainfall or no wind application. Two statistical parameters were used to evaluate the soil surface evolution: the mean absolute error (MAE) and the mean relative error (MRE). Their values were 0.21 mm and 15.8%, respectively. We then assessed the precision of our system under simulated rainfall conditions using 3 different dry bulk densities for the packed saturated soil surface. At densities of 0.91, 0.98, and 1.09 g/cm3, the MAE (MRE) values were 2.21 mm (392.5%), 1.07 mm (126.4%), and 0.59 mm (57.6%), respectively. It was possible to monitor and evaluate both the amount of eroded soil and the erosion mechanism in a specific area. Moreover, this system could be applied to measuring wind erosion with an MAE accuracy as high as 0.21 mm. The digital elevation models (DEMs) allowed for detailed analyses of soil surface evolution, and it was also possible to monitor sheet erosion with high spatial and temporal resolutions.

2011 ◽  
Vol 91 (2) ◽  
pp. 279-290 ◽  
Author(s):  
Zisheng Xing ◽  
Lien Chow ◽  
Herb W. Rees ◽  
Fanrui Meng ◽  
John Monteith ◽  
...  

Xing, Z., Chow, L., Rees, H. W., Meng, F., Monteith, J. and Stevens, L. 2011. A comparison of effects of one-pass and conventional potato hilling on water runoff and soil erosion under simulated rainfall. Can. J. Soil Sci. 91: 279–290. Hilling plays an important role in potato production, but is found to be inducing soil loss. An artificial rainfall simulation system was used to evaluate the differences between one-pass hilling (OPH, hilling performed when planting, or shortly after planting) and conventional hilling (CH, hilling performed approximately 35–45 d after planting) as well as their combination with a cover crop (ryegrass; _R) on runoff and soil loss. A three-replicate randomized block experimental design with constant rainfall intensity (120 mm h−1) was used in this study. No significant differences in runoff were found between different hilling methods. The soil losses, however, showed significant differences both among treatments, among canopy cover classes, and among their interaction terms (all P<0.001). The mean soil loss for CH was significantly higher than that for OPH, by 40%, and the mean soil loss for CH_R was higher than that for OPH_R by 57%. On average, the CH treatments (CH and CH_R) induced greater soil loss than the OPH treatments (OPH and OPH_R) by 47%. Further, the effects can vary with different canopy cover percentages. The OPH treatments (OPH and OPH_R) induced more soil loss than CH treatments (CH and CH_R), by 4.4 to 12.8%, in the <30% canopy cover group, while soil loss in the CH treatments was greater than that in OPH treatments for both the 30–70% and >70% canopy cover groups by 21–94%. Irrespective of treatment, soil loss before canopy forming was 2.4 to 8.9 times higher than the soil loss for the partial to full canopy period. With a cover crop, the CH and OPH treatments can reduce soil loss by 37–55%. One-pass hilling initiated runoff earlier than CH. The water runoff and soil loss with respect to the elapsed time since initialization of water runoff and soil loss could be modeled by a three-parameter Sigmoid function with r 2≥0.94. The information generated from this study could be used in landscape modeling to study the impacts of potato production on soil and stream water quality.


Author(s):  
Cristian Valeriu PATRICHE ◽  
Radu Gabriel PáŽRNÄ‚U ◽  
Bogdan ROȘCA ◽  
Dan Laurentiu STOICA

The purpose of this study is to quantify soil surface erosion using the Universal Soil Loss Equation in GIS environment and to assess its impact on soil humus reserve. The quantifying of soil surface erosion was performed by integrating in GIS the thematic raster representations of the erosion control parameters which exhibit spatial variability within the limi ts of the study region (Dobrovăţ Basin, The Central Moldavian Plateau, eastern Romania). Soil erodibility was computed according to ICPA (1987) standards, on the basis of soil type, texture and erosion degree, using a soil map of the basin at scale 1: 5000. Slope length was derived from a 20m resolution digital elevation model using SAGA-GIS software, while slope factor was determined according to the Romanian methodology by raising the slope values at the power of 1.5. Finally, the vegetation factor was computed on the basis of the normalized difference vegetation index derived from a 2001 Landsat image, using the equation proposed by Van der Knijff et al. (1999). Subsequently, we derived the potential soil erosion, controlled exclusively by soil-relief factors and the effective soil erosion, by integrating the effect of vegetation. The potential soil erosion show a mean value of 15.6 t/ha yr and a standard deviation of 16.6 t/ha yr. The integration of the vegetation effect decreases the mean value to 5.4 t/ha yr and the standard deviation to 6.7 t/ha yr. Most of the basin’s surface (48.7%) falls into the reduced erosion risk class (2-8 t/ha yr), while the high and very high erosion risk classes group 7.3% of the basin. The assessment of the erosion impact on soil carbon stock was performed by coupling the USLE model with a Hénin -Dupuis mono-compartmental humus evolution model. The simulation was performed for the first 20cm of the soil profile, using a database of 224 soil profiles. The results of the simulation show that 76% of the soil profiles display a regressive evolution of the humus reserve under the impact of the soil erosion. The mean humus loss for these profiles is 36.3 t/ha for 100 years of simulation.


2020 ◽  
Vol 12 (1) ◽  
pp. 232-241
Author(s):  
Na Ta ◽  
Chutian Zhang ◽  
Hongru Ding ◽  
Qingfeng Zhang

AbstractTillage and slope will influence soil surface roughness that changes during rainfall events. This study tests this effect under controlled conditions quantified by geostatistical and fractal indices. When four commonly adopted tillage practices, namely, artificial backhoe (AB), artificial digging (AD), contour tillage (CT), and linear slope (CK), were prepared on soil surfaces at 2 × 1 × 0.5 m soil pans at 5°, 10°, or 20° slope gradients, artificial rainfall with an intensity of 60 or 90 mm h−1 was applied to it. Measurements of the difference in elevation points of the surface profiles were taken before rainfall and after rainfall events for sheet erosion. Tillage practices had a relationship with fractal indices that the surface treated with CT exhibited the biggest fractal dimension D value, followed by the surfaces AD, AB, and CK. Surfaces under a stronger rainfall tended to have a greater D value. Tillage treatments affected anisotropy differently and the surface CT had the strongest effect on anisotropy, followed by the surfaces AD, AB, and CK. A steeper surface would have less effect on anisotropy. Since the surface CT had the strongest effect on spatial variability or the weakest spatial autocorrelation, it had the smallest effect on runoff and sediment yield. Therefore, tillage CT could make a better tillage practice of conserving water and soil. Simultaneously, changes in semivariogram and fractal parameters for surface roughness were examined and evaluated. Fractal parameter – crossover length l – is more sensitive than fractal dimension D to rainfall action to describe vertical differences in soil surface roughness evolution.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 974
Author(s):  
Rafael Blanco-Sepúlveda ◽  
Amilcar Aguilar-Carrillo ◽  
Francisco Lima

In conservation agriculture, the no-tillage cultivation system and the retention of permanent vegetal cover are crucial to the control of soil erosion by water. This paper analyses the cultivation of maize under no-tillage, with particular reference to the effect produced on soil erosion when weed control is performed by a hand tool (machete), which disturbs the surface of the soil, and to the behavior of the soil cover in these circumstances. The study area is located in the humid tropical mountains of northern Nicaragua (Peñas Blancas Massif Nature Reserve). The results obtained show that 59.2% of the soil surface was affected by appreciable levels of sheet and splash erosion, although the vegetal cover of the soil was relatively high (with average weed and litter cover of 33.9% and 33.8%, respectively). The use of machetes for weed control provoked considerable soil disturbance, which explained the high rates of erosion observed. Moreover, this form of soil management disturbs the litter layer, making it less effective in preventing erosion. The litter remains loose on the soil surface, and so an increase in soil cover does not achieve a proportionate reduction in the area affected by erosion; thus, even with 80–100% weed and litter cover, 42% of the cultivated area continued to present soil erosion.


Soil Research ◽  
1983 ◽  
Vol 21 (2) ◽  
pp. 109 ◽  
Author(s):  
MJ Singer ◽  
PH Walker

The 20-100 mm portion of a yellow podzolic soil (Albaqualf) from the Ginninderra Experiment Station (A.C.T.) was used in a rainfall simulator and flume facility to elucidate the interactions between raindrop impact, overland water flow and straw cover as they affect soil erosion. A replicated factorial design compared soil loss in splash and runoff from 50 and 100 mm h-1 rainfall, the equivalent of 100 mm h-1 overland flow, and 50 and 100 mm h-1 rainfall plus the equivalent of 100 mm h-' overland flow, all at 0, 40 and 80% straw cover on a 9% slope. As rainfall intensity increased, soil loss in splash and runoff increased. Within cover levels, the effect of added overland flow was to decrease splash but to increase total soil loss. This is due to an interaction between raindrops and runoff which produces a powerful detaching and transporting mechanism within the flow known as rain-flow transportation. Airsplash is reduced, in part, because of the changes in splash characteristics which accompany changes in depths of runoff water. Rain-flow transportation accounted for at least 64% of soil transport in the experiment and airsplash accounted for no more than 25% of soil transport The effects of rainfall, overland flow and cover treatments, rather than being additive, were found to correlate with a natural log transform of the soil loss data.


2019 ◽  
Vol 16 (32) ◽  
pp. 263-278
Author(s):  
Vanessa Machado Babinski RAMOS ◽  
Maurício Gammertt RÖHNELT ◽  
Rodrigo BRAMBILLA

This paper reports the main results concerning the synthesis and characterization of methylsilane and octylsilane-modified silicas. The modification of the silicas with these groups aims to make the silica surface hydrophobic and thus compatible with high-density polyethylene (HDPE) in HDPE/silica composites. In the present work, two types of silica were organofunctionalized: a pyrogenic silica and a silica gel. The silicas were characterized by a series of complementary techniques with the objective of investigating the nature of the surface species and their textural and morphological characteristics. The SEM images showed that the modification of the silicas with organosilanes has been not resulted in changes on the morphology and on the size of silica particles. In relation to the texture properties, determined by N2 adsorption-desorption porosimetry, the silica modification resulted in a decrease of the specific area (SBET) and the mean pore volume, a behavior attributed to the partial coverage of the adsorption sites by the organosilane molecules. The TGA analysis showed that both the methylsilane groups and the octylsilane groups on the surface of silica and silica gel are thermally stable up to 200 ° C, which enables the organofunctionalized silicas in terms of thermal stability, for the process of preparing the composites by extrusion. The results of applying these organofunctionalized silicas in the development of HDPE/silica composites will be presented in a subsequent article, part II of this research.


2018 ◽  
Vol 96 (9) ◽  
pp. 939-954 ◽  
Author(s):  
M.K. Obrist ◽  
R. Boesch

BatScope is a free application for processing acoustic high-frequency recordings of bats. It can import data, including meta-data information, from recorders such as Batlogger. The resulting content can be filtered visually as spectrograms or according to data fields and can be displayed. Automated processing includes detecting and extracting of echolocation calls, filtering noise, and measuring statistical parameters. Calls are classified to species by statistically matching to a reference database. A weighted list of classifiers helps to assign the most likely species per call. Classifiers were trained on 19 636 echolocation calls of 27 European bat species. When classifiers all agree on a species (76.4% of all cases), the mean correct classification rate reaches 95.7%. A sequence’s summary statistic indicates the most likely species occurring therein. Classifications can be verified visually, by filtering, and by acoustic comparison with reference calls. Procedures are available for, e.g., excluding dubious cutouts from the statistics and for accepting or overriding the proposed species assignment. Acoustic recordings can be exported and exchanged with other users. Finally, the verified results can be exported to spreadsheets for further analyses and reporting. We currently reprogram BatScope using Java, PostgreSQL, and R to reach a unified and portable software architecture.


The creation of a selection material for oil flax with a large number of stems, side shoots and an optimal height for cultivation is an urgent task, since the formation of additional bolls on the side shoots will increase the yield of seeds, and an increase in the vegetative mass of plants will increase its competitiveness against weeds and reduce moisture evaporation. from the soil surface. The use of genetic and statistical parameters allows to efficiently plan and carry out breeding work for oil flax, purposefully select parental pairs in crosses, select valuable genotypes, and reject low-value material at the first stages of breeding. The purpose of this study is to identify promising interspecific hybrid combinations based on breeding and genetic parameters for creating a new breeding material for multi-stem and multi-shoot forms. The studies were carried out at the Institute of Oilseeds NAАS of Ukraine in 2018-2020. The material of the research was F1 and F2 hybrids obtained in a system of dialle crosses with the participation of two wild species (L. angustifolium and L. hispanicum) and three samples of cultivated flax – L 6 (India), M 32/2 (Ukraine), L 5 (Czech Republic). The degree of dominance of traits in hybrids of the first generation was determined by the formula (Beil, Atkins 1965). The degree of heterosis is according to the formula (Rasul et al 2002). The coefficient of heritability in hybrids of the second generation – according to the formula (Ayala 1984). As a result of the research, interspecific hybrid combinations have been identified that are promising for obtaining breeding material with a modified habit: – with the effect of heterosis: by plant height – seven combinations of F1 (Ht = 3,58-13,76%); the number of stems per plant – one (Ht = 35,77%); the number of side shoots is six (Ht = 5,68-43,79%). The most valuable are combinations in which the effect of heterosis manifested itself simultaneously on two grounds – the height of the plants and the number of lateral shoots on the plant – L. angustifolium / L 6, L 5 / L. angustifolium, L. hispanicum / L 6, L 6 / L. hispanicum; plant height and number of stems per plant – M 32/2 / L. hispanicum; – with high coefficients of heritability: by plant height – four combinations of F2 (H = 0,67-0,87); the number of stems per plant – six (H = 0,66-0,81); the number of side shoots is four (H = 0,66-0,72). Interspecific combinations of L. hispanicum / M 32/2 and M 32/2 / L. hispanicum were distinguished by high rates of heritability by two characteristics – the number of stems and the number of lateral shoots on the plant. The potential of the selected combinations will be used in the further breeding process for increased branching.


2021 ◽  
Author(s):  
Qi Guo ◽  
Zhanli Wang

&lt;p&gt;Sheet erosion has been the major erosion process on steep grassland since the Grain-for-Green project was implemented in 1999 in the Loess Plateau with serious soil erosion, in China. Quantifying sheet erosion rate on steep grassland could improve soil erosion estimation on loess hillslopes and provide scientific support for effectively controlling soil erosion and rationally managing grassland. Simulated rainfall experiments were conducted on grassland plot with vegetation coverage of 40% under complete combination of rainfall intensities of 0.7, 1.0, 1.5, 2.0 and 2.5 mm min&lt;sup&gt;-1&lt;/sup&gt; and slope gradients of 7&amp;#176;, 10&amp;#176;, 15&amp;#176;, 20&amp;#176; and 25&amp;#176;. Results showed that sheet erosion rate (&lt;em&gt;SE&lt;/em&gt;), varying from 0.0048 to 0.0578 kg m&lt;sup&gt;-2&lt;/sup&gt; min&lt;sup&gt;-1&lt;/sup&gt;, was well described by binary power function equation (&lt;em&gt;SE&lt;/em&gt; = 0.0026 &lt;em&gt;I&lt;/em&gt;&lt;sup&gt;1.306&lt;/sup&gt;&lt;em&gt;S&lt;/em&gt;&lt;sup&gt;0.662&lt;/sup&gt;) containing rainfall intensity and slope gradient with &lt;em&gt;R&lt;sup&gt;2&lt;/sup&gt;&lt;/em&gt; = 0.940. The logarithmic equation of shear stress (&lt;em&gt;SE&lt;/em&gt; = 0.084 + Ln (&lt;em&gt;&amp;#964;&lt;/em&gt;)) and the power function equation of stream power (&lt;em&gt;SE&lt;/em&gt; = 1.141 &lt;em&gt;&amp;#631;&lt;/em&gt;&lt;sup&gt;1.073&lt;/sup&gt;) could be used to predict sheet erosion rate. Stream power (&lt;em&gt;R&lt;sup&gt;2&lt;/sup&gt;&lt;/em&gt; = 0.903) was a better predictor of sheet erosion than shear stress (&lt;em&gt;R&lt;sup&gt;2&lt;/sup&gt;&lt;/em&gt; = 0.882). However, predictions based on flow velocity, unit stream power, and unit energy were unsatisfactory. The stream power was an excellent hydrodynamic parameter for predicting sheet erosion rate. The sheet erosion process of grassland slope was also affected by the raindrop impact except the dynamic action of sheet flow. The combination of stream power and rainfall kinetic energy (&lt;em&gt;KE&lt;/em&gt;) among different rainfall physical parameters had the most closely relationship with the sheet erosion rates, which is also better than the stream power only, and a binary power function equation (&lt;em&gt;SE&lt;/em&gt; = 0.221 &lt;em&gt;&amp;#969;&lt;/em&gt;&lt;sup&gt;0.831&lt;/sup&gt;&lt;em&gt;KE&lt;/em&gt;&lt;sup&gt;0.416&lt;/sup&gt;) could be used to predict sheet erosion rate on grassland slope with &lt;em&gt;R&lt;sup&gt;2&lt;/sup&gt;&lt;/em&gt; = 0.930. The study results revealed the dynamic mechanism of the sheet erosion process on steep grassland in the loess region of China.&lt;/p&gt;


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