Prediction of factors affecting activation of soil erosion by mathematical modeling at pedon scale under laboratory conditions

AbstractSoil degradation due to erosion is a significant worldwide problem at different spatial (from pedon to watershed) and temporal scales. All stages and factors in the erosion process must be detected and evaluated to reduce this environmental issue and protect existing fertile soils and natural ecosystems. Laboratory studies using rainfall simulators allow single factors and interactive effects to be investigated under controlled conditions during extreme rainfall events. In this study, three main factors (rainfall intensity, inclination, and rainfall duration) were assessed to obtain empirical data for modeling water erosion during single rainfall events. Each factor was divided into three levels (− 1, 0, + 1), which were applied in different combinations using a rainfall simulator on beds (6 × 1 m) filled with soil from a study plot located in the arid Sistan region, Iran. The rainfall duration levels tested were 3, 5, and 7 min, the rainfall intensity levels were 30, 60, and 90 mm/h, and the inclination levels were 5, 15, and 25%. The results showed that the highest rainfall intensity tested (90 mm/h) for the longest duration (7 min) caused the highest runoff (62 mm3/s) and soil loss (1580 g/m2/h). Based on the empirical results, a quadratic function was the best mathematical model (R2 = 0.90) for predicting runoff (Q) and soil loss. Single-factor analysis revealed that rainfall intensity was more influential for runoff production than changes in time and inclination, while rainfall duration was the most influential single factor for soil loss. Modeling and three-dimensional depictions of the data revealed that sediment production was high and runoff production lower at the beginning of the experiment, but this trend was reversed over time as the soil became saturated. These results indicate that avoiding the initial stage of erosion is critical, so all soil protection measures should be taken to reduce the impact at this stage. The final stages of erosion appeared too complicated to be modeled, because different factors showed differing effects on erosion.

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Herbicide loss in runoff: effects of herbicide properties, slope, and rainfall intensity

Soil Research ◽

10.1071/sr03090 ◽

2004 ◽

Vol 42 (1) ◽

pp. 17 ◽

Cited By ~ 26

Author(s):

K. Müller ◽

M. Trolove ◽

T. K. James ◽

A. Rahman

Keyword(s):

Rainfall Intensity ◽

Water Solubility ◽

Small Scale ◽

Herbicide Application ◽

Rainfall Events ◽

Kd Values ◽

Loam Soil ◽

The Impact ◽

Field Plots ◽

Dissolved Form

Runoff potential of 5 herbicides (acetochlor, atrazine, hexazinone, pendimethalin, and terbuthylazine) was evaluated in a small-scale study under simulated rainfall on a cultivated Hamilton clay loam soil. At 24 h after herbicide application, rainfall events of different intensities were simulated to 0.5-m2 field plots with 20% (70, 88, and 111 mm/h) and 30% (60, 70, and 80 mm/h) slope, respectively. The objective of this study was to compare the behaviour of pesticides covering a range of properties under identical hydrodynamic conditions. Sediment amounts and herbicide concentrations were determined in the runoff samples. As the transported sediment amounts were not sufficient for chemical analyses, herbicide residues attached to sediment were estimated using Kd values determined locally for the soil. Whereas pendimethalin concentrations followed no noticeable pattern, the concentrations for the other herbicides were highest in the first runoff samples, and decreased exponentially with further rain. Results show that herbicides were primarily transported in their dissolved form with the exception of pendimethalin. Slope affected cumulative runoff, sediment, and herbicide losses significantly (P < 0.05). The impact of increased rainfall intensity on runoff initiation followed a similar trend, but herbicide losses from plots exposed to different intensities were not always significant. Losses dissolved in runoff from plots with 20% slope were ≤1% of the applied herbicide, whereas on plots with 30% slope the maximum recorded loss was 65%. Here, losses for all herbicides ranged between 1 and 7% at 60 mm/h and 8 and 65% at 80 mm/h. Exports of herbicides with moderate solubility were negatively correlated with their Kd values and their water solubility.

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Individual Rainfall Change Based on Observed Hourly Precipitation Records on the Chinese Loess Plateau from 1983 to 2012

Water ◽

10.3390/w12082268 ◽

2020 ◽

Vol 12 (8) ◽

pp. 2268

Author(s):

Wenbin Ding ◽

Fei Wang ◽

Kai Jin ◽

Jianqiao Han ◽

Qiang Yu ◽

...

Keyword(s):

Loess Plateau ◽

Heavy Rainfall ◽

Rainfall Intensity ◽

Rainfall Amount ◽

The Loess Plateau ◽

Total Rainfall ◽

Rainfall Events ◽

Rainfall Duration ◽

Rainfall Frequency ◽

Annual Total

The magnitude and spatiotemporal distribution of precipitation are the main drivers of hydrologic and agricultural processes in soil moisture, runoff generation, soil erosion, vegetation growth and agriculture activities on the Loess Plateau (LP). This study detects the spatiotemporal variations of individual rainfall events during a rainy season (RS) from May to September based on the hourly precipitation data measured at 87 stations on the LP from 1983 to 2012. The incidence and contribution rates were calculated for all classes of rainfall duration and intensity to identify the dominant contribution to the rainfall amount and frequency variations. The trend rates of regional mean annual total rainfall amount (ATR) and annual mean rainfall intensity (ARI) were 0.43 mm/year and 0.002 mm/h/year in the RS for 1983–2012, respectively. However, the regional mean annual total rainfall frequency (ARF) and rainfall events (ATE) were −0.27 h/year and −0.11 times/year, respectively. In terms of spatial patterns, an increase in ATR appeared in most areas except for the southwest, while the ARI increased throughout the study region, with particularly higher values in the northwest and southeast. Areas of decreasing ARF occurred mainly in the northwest and central south of the LP, while ATE was found in most areas except for the northeast. Short-duration (≤6 h) and light rainfall events occurred mostly on the LP, accounting for 69.89% and 72.48% of total rainfall events, respectively. Long-duration (≥7 h) and moderate rainfall events contributed to the total rainfall amount by 70.64% and 66.73% of the total rainfall amount, respectively. Rainfall frequency contributed the most to the variations of rainfall amount for light and moderate rainfall events, while rainfall intensity played an important role in heavy rainfall and rainstorms. The variation in rainfall frequency for moderate rainfall, heavy rainfall, and rainstorms is mainly affected by rainfall duration, while rainfall event was identified as a critical factor for light rainfall. The characteristics in rainfall variations on the Loess Plateau revealed in this study can provide useful information for sustainable water resources management and plans.

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Automated reconstruction of rainfall events responsible for shallow landslides

Natural Hazards and Earth System Science ◽

10.5194/nhess-14-2399-2014 ◽

2014 ◽

Vol 14 (9) ◽

pp. 2399-2408 ◽

Cited By ~ 29

Author(s):

G. Vessia ◽

M. Parise ◽

M. T. Brunetti ◽

S. Peruccacci ◽

M. Rossi ◽

...

Keyword(s):

Rainfall Intensity ◽

Shallow Landslides ◽

Threshold Values ◽

Rainfall Thresholds ◽

Rainfall Events ◽

Mean Intensity ◽

Landslide Occurrence ◽

R Language ◽

Rain Gauges ◽

Rainfall Duration

Abstract. Over the last 40 years, many contributions have identified empirical rainfall thresholds (e.g. rainfall intensity (I) vs. rainfall duration (D), cumulated rainfall vs. rainfall duration (ED), cumulated rainfall vs. rainfall intensity (EI)) for the possible initiation of shallow landslides, based on local and global inventories. Although different methods to trace the threshold curves have been proposed and discussed in literature, a systematic study to develop an automated procedure to select the rainfall event responsible for the landslide occurrence has only rarely been addressed. Objective criteria for estimating the rainfall responsible for the landslide occurrence play a prominent role on the threshold values. In this paper, two criteria for the identification of the effective rainfall events are presented. The first criterion is based on the analysis of the time series of rainfall mean intensity values over 1 month preceding the landslide occurrence. The second criterion is based on the analysis of the trend in the time function of the cumulated mean intensity series calculated from the rainfall records measured through rain gauges. The two criteria have been implemented in an automated procedure that is written in the R language. A sample of 100 shallow landslides collected in Italy from 2002 to 2012 was used to calibrate the procedure. The cumulated event rainfall (E) and duration (D) of rainfall events that triggered the documented landslides are calculated through the new procedure and are fitted with power law in the D, E diagram. The results are discussed by comparing the D, E pairs calculated by the automated procedure and the ones by the expert method.

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Extreme rainfall events during and following heatwaves

10.5194/egusphere-egu21-8851 ◽

2021 ◽

Author(s):

Christoph Sauter ◽

Christopher White ◽

Hayley Fowler ◽

Seth Westra

Keyword(s):

Natural Hazards ◽

Rainfall Intensity ◽

Daily Rainfall ◽

Extreme Rainfall ◽

Extreme Rainfall Events ◽

Rainfall Events ◽

Rainfall Extremes ◽

Average Rainfall ◽

Time Of Year ◽

The Impact

Heatwaves and extreme rainfall events are natural hazards that can have severe impacts on society. The relationship between temperature and extreme rainfall has received scientific attention with studies focussing on how single daily or sub-daily rainfall extremes are related to day-to-day temperature variability. However, the impact multi-day heatwaves have on sub-daily extreme rainfall events and how extreme rainfall properties change during different stages of a heatwave remains mostly unexplored.In this study, we analyse sub-daily rainfall records across Australia, a country that experiences severe natural hazards on a frequent basis, and determine their extreme rainfall properties, such as rainfall intensity, duration and frequency during SH-summer heatwaves. These properties are then compared to extreme rainfall properties found outside heatwaves, but during the same time of year, to examine to what extent they differ from normal conditions. We also conduct a spatial analysis to investigate any spatial patterns that arise.We find that rainfall breaking heatwaves is often more extreme than average rainfall during the same time of year. This is especially prominent on the eastern and south-eastern Australian coast, where frequency and intensity of sub-daily rainfall extremes show an increase during the last day or the day immediately after a heatwave. We also find that although during heatwaves the average rainfall amount and duration decreases, there is an increase in sub-daily rainfall intensity when compared to conditions outside heatwaves. This implies that even though Australian heatwaves are generally characterised by dry conditions, rainfall occurrences within heatwaves are more intense.Both heatwaves and extreme rainfall events pose great challenges for many sectors such as agriculture, and especially if they occur together. Understanding how and to what degree these events co-occur could help mitigate the impacts caused by them.

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The impact of land use and rainfall patterns on the soil loss of the hillslope

Scientific Reports ◽

10.1038/s41598-021-95819-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Xianmeng Meng ◽

Yan Zhu ◽

Maosheng Yin ◽

Dengfeng Liu

Keyword(s):

Land Use ◽

Soil Erosion ◽

Soil Loss ◽

Rank Test ◽

Rainfall Events ◽

Significant Difference ◽

Slope Land ◽

Rainfall Patterns ◽

Storm Rainfall ◽

The Impact

AbstractIn order to discuss the effect of rainfall patterns and land use types on soil erosion, the experiment is carried out under natural rainfall events on different kinds of runoff plots in Zhangjiachong watershed. Based on the observed data of 44 individual rainfall events including moderate, heavy and storm rainfall, the differences of erosion modulus among hedgerows plots, terrace plots, and slope plots under different rainfall patterns are analyzed. And the effects of hedgerow and terrace patterns on control of soil loss are revealed by RUSLE. Wilcoxon signed rank test is applied to analyze the significant difference of erosion modulus in different plots and the coefficient of variation is used to compare the characteristics of erosion modulus under different rainfall patterns. The results show that the soil erosion modulus of earth banked terrace has the highest value and the lowest soil erosion modulus occurs in the slope land with hedgerows. The coefficients of variation for soil erosion modulus under heavy and storm rainfall are larger than that of moderate rainfall. Hedgerow pattern can effectively control soil erosion under moderate and heavy rainfall while the effect of hedgerow is considerably weakened under storm rainfall. Earth banked terraces own the highest erosion modulus followed by slope land and stone dike terraces.

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Evolutionary Prediction of Soil Loss from Observed Rainstorm Parameters in an Erosion Watershed Using Genetic Programming

Applied and Environmental Soil Science ◽

10.1155/2021/2630123 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Kennedy C. Onyelowe ◽

Ahmed M. Ebid ◽

Light Nwobia

Keyword(s):

Genetic Programming ◽

Soil Loss ◽

Rainfall Intensity ◽

Coefficient Of Determination ◽

Learning Abilities ◽

Maximum Coefficient ◽

Runoff Rate ◽

Gully Head ◽

The Impact ◽

Gp Model

Various environmental problems such as soil degradation and landform evolutions are initiated by a natural process known as soil erosion. Aggregated soil surfaces are dispersed through the impact of raindrop and its associated parameters, which were considered in this present work as function of soil loss. In an attempt to monitor environmental degradation due to the impact of raindrop and its associated factors, this work has employed the learning abilities of genetic programming (GP) to predict soil loss deploying rainfall amount, kinetic energy, rainfall intensity, gully head advance, soil detachment, factored soil detachment, runoff, and runoff rate database collected over a three-year period as predictors. Three evolutionary trials were executed, and three models were presented considering different permutations of the predictors. The performance evaluation of the three models showed that trial 3 with the highest parametric permutation, i.e., that included the influence of all the studied parameters showed the least error of 0.1 and the maximum coefficient of determination (R2) of 0.97 and as such is the most efficient, robust, and applicable GP model to predict the soil loss value.

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Effect of Multicollinearity on the Bivariate Frequency Analysis of Annual Maximum Rainfall Events

Water ◽

10.3390/w11050905 ◽

2019 ◽

Vol 11 (5) ◽

pp. 905 ◽

Cited By ~ 2

Author(s):

Yoo ◽

Cho

Keyword(s):

Frequency Analysis ◽

Rainfall Intensity ◽

Rainfall Event ◽

Total Rainfall ◽

Maximum Rainfall ◽

Rainfall Events ◽

Rainfall Duration ◽

Rainfall Depth ◽

The Mean ◽

Annual Maximum Rainfall

A rainfall event, simplified by a rectangular pulse, is defined by three components: the rainfall duration, the total rainfall depth, and mean rainfall intensity. However, as the mean rainfall intensity can be calculated by the total rainfall depth divided by the rainfall duration, any two components can fully define the rainfall event (i.e., one component must be redundant). The frequency analysis of a rainfall event also considers just two components selected rather arbitrarily out of these three components. However, this study argues that the two components should be selected properly or the result of frequency analysis can be significantly biased. This study fully discusses this selection problem with the annual maximum rainfall events from Seoul, Korea. In fact, this issue is closely related with the multicollinearity in the multivariate regression analysis, which indicates that as interdependency among variables grows the variance of the regression coefficient also increases to result in the low quality of resulting estimate. The findings of this study are summarized as follows: (1) The results of frequency analysis are totally different according to the selected two variables out of three. (2) Among three results, the result considering the total rainfall depth and the mean rainfall intensity is found to be the most reasonable. (3) This result is fully supported by the multicollinearity issue among the correlated variables. The rainfall duration should be excluded in the frequency analysis of a rainfall event as its variance inflation factor is very high.

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Spatial and temporal estimation of the erosivity factor R based on daily rainfall data for the department of Atlántico, Colombia

Ingeniería e Investigación ◽

10.15446/ing.investig.v35n2.47773 ◽

2015 ◽

Vol 35 (2) ◽

pp. 23-29 ◽

Cited By ~ 3

Author(s):

Humberto Fabián Avila Rangel ◽

Boris Daniel Avila Rangel

Keyword(s):

Soil Loss ◽

Rainfall Intensity ◽

Temporal Distribution ◽

Daily Rainfall ◽

Specific Area ◽

R Factor ◽

Temporal Estimation ◽

Erosion Factor ◽

The Impact ◽

Soil Loss Equation

Soil erosion caused by rain is the detachment and movement of soil particles caused by the impact of raindrops on the surface. Erosivity factor R is a measure of the rain erosive power used for estimating the erosion rate with the RUSLE method (Revised Universal Soil Loss Equation). Estimating R factor requires rainfall intensity records of storms greater than 12.5 mm or greater than 6 mm but longer than 15 min. However, most of the Colombian rainfall stations have daily rainfall records with which it is not possible to estimate the intensity of each storm and, therefore, makes it difficult to estimate the R factor for a specific area. In this paper a methodology for estimating the erosivity factor R for the department of Atlántico, Colombia from daily records of 16 IDEAM stations is presented. The spatial distribution of the erosivity factor R in the department and its temporal distribution throughout the year are also shown. The results showed a minimum erosivity factor R of 6,894 MJ∙mm∙Ha-1∙Hr-1∙yr-1 and a maximum of 10,925 MJ∙mm∙Ha-1∙Hr-1∙yr-1. The average erosivity factor R for the department of Atlántico was 8,697 MJ∙mm∙Ha-1∙Hr-1∙yr-1. This methodology might be used for estimating the erosion factor R in different Colombian regions where high-resolution precipitation data is limited, but seasonal and orographic conditions should be considered for selecting the rain gages and the area of study.

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Field studies on the soil loss reduction effectiveness of three biodegradable geotextiles

Journal of Agricultural Engineering ◽

10.4081/jae.2018.799 ◽

2018 ◽

Vol 49 (2) ◽

pp. 117-123 ◽

Cited By ~ 1

Author(s):

Flavia Tauro ◽

Paolo Cornelini ◽

Salvatore Grimaldi ◽

Andrea Petroselli

Keyword(s):

Soil Conservation ◽

Soil Loss ◽

Ad Hoc ◽

Rainfall Intensity ◽

Field Studies ◽

Loss Reduction ◽

Rainfall Events ◽

Average Rainfall ◽

Experimental Findings ◽

Precipitation Events

Biodegradable geotextiles have the potential to significantly reduce soil loss and ensure slope stability in areas at risk. Here, we focus on three biodegradable textiles (namely, jute net, jute mat, and wool mat), and study their response in terms of soil loss to diverse precipitation events (average rainfall intensity from 3.7 mmh−1 to 70 mmh−1 and duration from 0.5 h to 11.6 h). Experiments are conducted in an ad hoc developed outdoor steep slope (more than 60%). Soil loss reduction from the treatments is found to be very remarkable (up to 98%), thus supporting the potential of natural materials for soil conservation. Also, experimental findings confirm that the maximum intensity of rainfall events plays an important role in driving soil erosion.

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Interactive effects of appeal type and social distance on helping intention

Social Behavior and Personality An International Journal ◽

10.2224/sbp.6070 ◽

2017 ◽

Vol 45 (5) ◽

pp. 785-794

Author(s):

Jin Zhang ◽

Lijun Zhao

Keyword(s):

Prosocial Behavior ◽

Social Distance ◽

Interactive Effects ◽

Single Factor ◽

The Social ◽

Factor Design ◽

The Impact ◽

Practical Implications

We examined the interplay of appeal type and social distance in prosocial behavior in 3 studies. Results of Study 1, which was a single-factor design, showed that participants (n = 85) were more likely to evaluate the impact of their help on recipients when they were socially distant than when they were socially close. Results of Study 2 (n = 250) and Study 3 (n = 162), each of which was a 2 (appeal type: significance appeal vs. control appeal) × 2 (social distance: high vs. low) between-subjects design, showed that when the helper and recipient were socially distant, appeals that emphasized the significance of the help to the recipient increased helping intention, because there was a greater likelihood that the favor would be returned. However, such effect was mitigated when the social distance was small. Results suggest that the principles that are applied in interaction with others vary according to social distance. Theoretical and practical implications are discussed.

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