scholarly journals The relations between the rainfall erosivity index AI and the hydraulics of overland flow and sediment concentration in sandy soils

2018 ◽  
Vol 51 (1) ◽  
pp. 41
Author(s):  
Maaliou Aziz ◽  
Mouzai Liatim
Keyword(s):  
Overland Flow ◽  
Sandy Soils ◽  
Sediment Concentration ◽  
Rainfall Erosivity ◽  
Erosivity Index

scholarly journals Estimativa da erosividade da chuva na bacia hidrográfica do rio Juma com base em dados do satélite TRMM / Estimation of rain erosion in the Juma river basin based on TRMM satellite data

2019 ◽  
Vol 29 (56) ◽  
pp. 45
Author(s):  
Miqueias Lima Duarte ◽  
Eliomar Pereira da Silva Filho
Keyword(s):  
River Basin ◽  
Soil Degradation ◽  
Prevention And Control ◽  
Rainfall Erosivity ◽  
Territorial Planning ◽  
Surface Data ◽  
Historical Series ◽  
Erosivity Index ◽  
And Control ◽  
Rain Erosion

Conhecer o potencial da chuva em causar erosão do solo é de fundamental importância para a compreensão da fragilidade de uma região, essas informações podem ser utilizadas na prevenção e controle da degradação do solo, auxiliando o planejamento territorial. Este estudo tem por objetivo estimar a erosividade da chuva na bacia hidrográfica do rio Juma, no sul do estado do Amazonas. Foram utilizados dados mensais pluviométricos do produto 3B42-V7 do sensor TRMM obtidos na plataforma Giovanni e comparados com dados de superfície, para a série histórica de 1998 a 2016. O índice de erosividade da chuva foi obtido a partir de um modelo proposto por Oliveira Jr e Medina (1990) desenvolvido para a região. Os resultados obtidos apontam que a variação espacial do índice de erosividade da chuva ao longo da bacia do rio Juma foi pequena (média de 11,66 MJ.mm.ha-1.h-1.ano-1), as maiores variações estão relacionadas a sazonalidade regional, sendo que o mês de julho apresenta o menor índice de erosividade médio (47,74 MJ.mm.ha-1.h-1.ano-1), enquanto que o mês de fevereiro apresentou o maior índice de erosividade (145,73 MJ.mm.ha-1.h-1.ano-1).Palavras–chave: Potencial erosivo da chuva, Degradação do solo, Sensor orbital.Abstract Knowing the potential of rain to cause soil erosion is of fundamental importance to understand the fragility of a region, this information can be used in the prevention and control of soil degradation, assisting the territorial planning. This study aims to estimate the rainfall erosivity in the river basin of the Juma, in the south of the state of Amazonas. Monthly rainfall data from the 3B42-V7 TRMM sensor product obtained from the Giovanni platform and compared with surface data were used for the historical series from 1998 to 2016. The rainfall erosivity index was obtained from a model proposed by Oliveira Jr and Medina (1990) developed for the region. The results indicate that the spatial variation of the rainfall erosivity index along the Juma river basin was small (mean of 11.66 MJ.mm.ha-1.h-1.year-1), the most significant variations are related to regional seasonality, and the month of July It has the lowest mean erosivity index (47.74 MJ.mm.ha-1.h-1.year-1), while February presented the highest erosivity index (145.73 MJ.mm.ha-1.h-1.year-1).Keywords: Erosive potential of rain, Soil degradation, Orbital Sensor.

Scale Effects of Sediment-Related Transport of Phosphorus

1993 ◽  
Vol 28 (3-5) ◽  
pp. 473-481 ◽  
Author(s):  
S. M. Bolton ◽  
T. J. Ward
Keyword(s):  
Total Phosphorus ◽  
Overland Flow ◽  
Sediment Load ◽  
Scale Effects ◽  
Sediment Concentration ◽  
Rainfall Simulation ◽  
Small Rivers ◽  
Phosphorus Transport ◽  
Simulation Experiments ◽  
Stream Type

Sediment and nutrient data from USGS gauged stream sites in New Mexico and from rainfall simulation experiments were compiled and analyzed. Above a suspended sediment concentration of about 500 mg/l, associated concentrations of total phosphorus are highest in overland flow and then progressively decrease from agricultural drains to ephemeral washes to undammed rivers. Within a stream type, sediment-related concentrations of total phosphorus typically differed between larger and smaller basins. Small rivers had higher phosphorus transport per unit of sediment load than larger rivers. Small and medium sized washes had different relationships between phosphorus and sediment than did large and very large washes.

Runooff ratio as a factor in the empirical modelling of soil erosion by individual rainstorms

Soil Research ◽  
1997 ◽  
Vol 35 (1) ◽  
pp. 1 ◽  
Author(s):  
P. I. A. Kinnell
Keyword(s):  
Soil Loss ◽  
Sediment Concentration ◽  
Rill Erosion ◽  
Local Conditions ◽  
Empirical Modelling ◽  
Control Practice ◽  
Number Of Factors ◽  
Erosion Models ◽  
Erosivity Index ◽  
Bare Fallow

A number of factors that influence erosion have separate and differing effects on flow discharge and sediment concentration, depending on local conditions. Empirical erosion models that do not have mechanisms to help account for these separate and differing effects often lack the capacity to predict event erosion adequately in many locations. In this paper, the product of the EI30 index, the erosivity index used in the Universal Soil Loss Equation (USLE) and the revised version (RUSLE), and the runoff ratio (QR) is discussed in relation to its capacity to act as an event erosivity index where sheet and rill erosion occur either separately or together in a rainstorm. An analysis of runoff and soil loss data shows the index to be superior to the EI30 index as an event erosivity index for storms on bare fallow plots at Holly Springs, Mississippi. The inclusion of runoff as an independent term in the USLE/RUSLE results in a need to determine new values for the soil erodibility factor, K. Existing USLE/RUSLE equations for determining L and S (topographic factors), C (a crop and crop management factor), and P (an erosion control practice factor) may be used as first approximations provided that the values of the new index are determined for the unit plot condition. Since many of the factors that determine L, S, C, and P influence runoff, new methods to determine these parameters need to be developed in the future if the new index is to be used most effectively.

scholarly journals Assessing the performance of a plastic optical fibre turbidity sensor for measuring post-fire erosion from plot to catchment scale

SOIL ◽  
2015 ◽  
Vol 1 (2) ◽  
pp. 641-650 ◽  
Author(s):  
J. J. Keizer ◽  
M. A. S. Martins ◽  
S. A. Prats ◽  
L. F. Santos ◽  
D. C. S. Vieira ◽  
...  
Keyword(s):  
Optical Fibre ◽  
Overland Flow ◽  
Sediment Concentration ◽  
First Year ◽  
Power Functions ◽  
Forest Residues ◽  
Catchment Scale ◽  
Light Loss ◽  
Erosion Mitigation ◽  
Study Sites

Abstract. This study is the first comprehensive testing of a novel plastic optical fibre turbidity sensor with runoff samples collected in the field and, more specifically, with a total of 158 streamflow samples and 925 overland flow samples from a recently burnt forest area in north-central Portugal, collected mainly during the first year after the wildfire, as well as with 56 overland flow samples from a nearby long-unburnt study site. Sediment concentrations differed less between overland flow and streamflow samples than between study sites and, at one study site, between plots with and without effective erosion mitigation treatments. Maximum concentrations ranged from 0.91 to 8.19 g L−1 for the micro-plot overland flow samples from the six burnt sites, from 1.74 to 8.99 g L−1 for the slope-scale overland flow samples from these same sites, and amounted to 4.55 g L−1 for the streamflow samples. Power functions provided (reasonably) good fits to the – expected – relationships of increasing normalized light loss with increasing sediment concentrations for the different sample types from individual study sites. The corresponding adjusted R2 values ranged from 0.64 to 0.81 in the case of the micro-plot samples from the six burnt sites, from 0.72 to 0.89 in the case of the slope-scale samples from these same sites, and was 0.85 in the case of the streamflow samples. While the overall performance of the sensor was thus rather satisfactory, the results pointed to the need for scale of site-specific calibrations to maximize the reliability of the predictions of sediment concentration by the POF (plastic optical fibre) sensor. This especially applied to the cases in which sediment concentrations were comparatively low, for example following mulching with forest residues.

Soil erosion processes. I. The relative importance of rainfall detachment and dunoff entrainment

Soil Research ◽  
1991 ◽  
Vol 29 (5) ◽  
pp. 671 ◽  
Author(s):  
APB Proffitt ◽  
CW Rose
Keyword(s):  
Soil Erosion ◽  
Overland Flow ◽  
Water Flux ◽  
Equilibrium Concentration ◽  
Sediment Concentration ◽  
Soil Types ◽  
Relative Importance ◽  
Runoff Water ◽  
Erosion Processes ◽  
Volumetric Flux

Experiments carried out in a simulated-rainfall tilting-flume facility are reported in which sediment concentrations (c) in runoff water resulting from overland flow only, or from a combination of rainfall and overland flow, were measured under controlled conditions using a series of slopes (0.1, 05, 1, 3 and 5%). The mixture of rainfall (of rate 100 mm h-1) and runon of water at the top of the flume were arranged to provide a constant volumetric flux (1.0x10-3 m3 m-l s-1) at exit from the 5.8 m long flume. Two contrasting soil types were studied: a cracking clay (black earth or vertisol), and a slightly dispersive sandy clay loam (solonchak or aridisol). Two major processes which can contribute to soil erosion under rainfall are rainfall detachment and runoff entrainment. For both soil types, c was generally highest for the steepest slope and decreased with slope. For constant rainfall and/or runoff conditions, c generally decreased with time until an equilibrium concentration was reached. At this equilibrium, the relative importance of rainfall detachment and entrainment in terms of soil loss was dependent on soil type and streampower which incorporates effects of slope and water flux. For streampowers <0.1 W m-2 for the black earth, and <0.3 W m-2 for the solonchak, the greatest contribution to c was by rainfall detachment, whilst at greater streampowers entrainment was the dominant contributor to c. At any streampower, the contribution by rainfall detachment was greater for the weakly structured solonchak than for the well aggregated black earth. At lower strearnpowers, the interaction between erosion processes was found to give higher c than the sum of both sediment concentrations resulting from the separately occurring processes. At streampowers greater than approximately 0.5 W m-2, rainfall reduced eroded sediment concentration by suppressing rill development. The findings in this study suggest that both runoff entrainment and rainfall detachment can contribute to sediment concentration from 'interrill' areas.

scholarly journals Regiões pluviométricas homogêneas e a erosividade das chuvas na unidade hidrográfica Pirapó, Paranapanema III e IV-Paraná / Homogeneous rainfall regions and rainfall erosivity in the hydrographic unit Pirapó, Paranapanema III and IV hydrographic (...)

2016 ◽  
Vol 26 (46) ◽  
pp. 507 ◽  
Author(s):  
Paulo Miguel De Bodas Terassi ◽  
Hélio Silveira ◽  
Carlos Henrique Da Graça
Keyword(s):  
Euclidean Distance ◽  
Rainfall Erosivity ◽  
Proximity Measure ◽  
Temporal Segmentation ◽  
Rain Gauges ◽  
Monthly Distribution ◽  
Erosivity Index ◽  
Weather Stations ◽  
Annual Scale ◽  
The Relationship

<p>O presente trabalho objetiva definir regiões pluviométricas homogêneas e investigar a relação entre o regime pluviométrico e o potencial da erosividade para a unidade hidrográfica Pirapó, Paranapanema III e IV - Paraná. Foram obtidos os dados de pluviosidade de trinta e cinco postos pluviométricos do Instituto das Águas do Paraná e de cinco estações meteorológicas do Instituto Agronômico do Paraná (IAPAR), Instituto Nacional de Meteorologia (INMET) e Sistema Meteorológico do Paraná (SIMEPAR), trabalhados com o segmento temporal de 1976 a 2012. O índice de erosividade da chuva utilizado foi calculado a partir da equação apresentada por Rufino, Biscaia e Merten (1993) para o estado do Paraná. Definiu-se que o método de agrupamento mais adequado é o método aglomerativo de Ward, tendo como medida de proximidade a distância euclidiana. A área de estudo apresenta uma variação espacial da pluviosidade que mostra a influência da orografia principalmente para a distribuição espacial na escala anual, enquanto que a localização dos grupos demonstra uma maior associação à dinâmica atmosférica, conforme consultado pela literatura, para a compreensão da distribuição mensal das chuvas. Sobretudo, a delimitação dos grupos pluviométricos homogêneos permitiu compreender a relação entre o relevo, as alturas pluviométricas e o potencial erosivo das chuvas.</p><p><strong>Palavras-chave</strong>: agrupamento, pluviosidade, potencial erosivo, bacia hidrográfica.</p><p> </p><p>Abstract</p><p>This paper aims to define homogeneous rainfall regions and to investigate the relationship between rainfall and the potential erosivity for Pirapó, Paranapanema III and IV hydrographic unit - Paraná. The rainfall data was collected from thirty five rain gauges at Paraná Water Institute and from five weather stations at Paraná Agronomy Institute (IAPAR), National Weather Institute (INMET) and Paraná Meteorological System (SIMEPAR) and were processed within the temporal segmentation 1976 to 2012. The erosivity index rain used was calculated from the equation presented by Rufino, Biscaia and Merten (1993) for the Paraná State. It was defined that the most appropriate clustering method is the agglomerative method of Ward, with the proximity measure the Euclidean distance. The study area presents a spatial variation of rainfall that shows the orography influence mainly to the spatial distribution in the annual scale, while the location of groups shows a greater association with the atmospheric dynamics, as referred in the literature, for understanding the monthly distribution of rainfall. Above all, the delimitation of homogeneous rainfall groups allowed to understand the relationship between relief, the rain heights and the erosive potential of rainfall.</p><p><strong>Keywords</strong>: clustering, rainfall, erosive potential, watershed.</p>

scholarly journals Precipitation Patterns and Rainfall Erosivity Return Period Under Savanna Conditions in Formosa, Goiás, Brazil

2020 ◽  
Vol 8 (4) ◽  
pp. 554
Author(s):  
Aline Franciel de Andrade ◽  
Roriz Luciano Machado ◽  
Cássia Cristina Rezende ◽  
Elizabete Alves Ferreira ◽  
Daniel Fonseca de Carvalho ◽  
...  
Keyword(s):  
Annual Rainfall ◽  
Rainfall Erosivity ◽  
Return Periods ◽  
Tropical Regions ◽  
Average Annual Rainfall ◽  
Physical Attributes ◽  
Erosivity Index ◽  
Rainfall Patterns ◽  
Agricultural Areas ◽  
Intermediate Pattern

Losses of soil and nutrients affect a large part of agricultural areas in tropical regions, regardless of the level of technology adopted. This study evaluated the physical attributes and erosivity indices associated with rainfall patterns and return periods in the region of Formosa, State of Goiás, Brazil. Using series of pluviographic (2002-2008) and pluviometric (1975-1998) data from a station located at municipality of Formosa, the erosive potential (EI30 and KE>25), rainfall patterns (advanced, intermediate and delayed) and the erosivity associated with the rainfall return periods were determined. The average annual rainfall of the region was 1,391.6 mm with 87.4% of the rains concentrated in October to March. The average annual values of EI30 and KE>25 corresponded to 8,041.6 MJ mm ha-1 h-1 year-1 and 125.7 MJ ha-1 year-1, respectively. The months of the year did not differ based on rainfall pattern. The advanced hydrological pattern had the highest frequency of occurrence, followed by the delayed and intermediate patterns. The highest EI30 and KE>25 indices for individual rainfall seasons occurred under the intermediate and the advanced patterns in February and under the intermediate pattern in October for the index KE>25. The average annual erosivity index (R factor of USLE) (8041.6 MJ mm ha-1 h-1 year-1) is expected to occur at least once every 1.89 years, corresponding to a probability of occurrence of 52.84%. The average annual values of EI30 estimated for the return periods of 2, 5, 10, 25, 50 and 100 years were 8,230, 10,225, 10,889, 11,222, 11,421 and 11,488 MJ mm ha-1 h-1 year-1, respectively.

scholarly journals An efficient semi-distributed hillslope erosion model for the sub humid Ethiopian Highlands

2012 ◽  
Vol 9 (2) ◽  
pp. 2121-2155 ◽  
Author(s):  
S. A. Tilahun ◽  
C. D. Guzman ◽  
A. D. Zegeye ◽  
T. A. Engda ◽  
A. S. Collick ◽  
...  
Keyword(s):  
Surface Runoff ◽  
Overland Flow ◽  
Sediment Concentration ◽  
Base Flow ◽  
Nile Basin ◽  
Erosion Model ◽  
Blue Nile ◽  
Ethiopian Highlands ◽  
Source Areas ◽  
Blue Nile Basin

Abstract. During the last two decades, saturated excess runoff has become accepted as the main source for overland flow in humid regions. Erosion modeling has generally not kept up with this new reality and predictions are often not based on landscape topographic position, which is a main variable in saturation excess runoff. In addition, predicting sediment loss in Africa has been hampered by using models that have been developed in western countries and do not perform as well in the monsoon climate prevailing in most of the continent. The objective of this paper is to develop a simple erosion model that can be used in the Ethiopian highlands in Africa. We base our sediment prediction on a simple distributed saturated excess hydrology model that predicts surface runoff from severely degraded lands and from bottom lands that become saturated during the rainy season and estimates interflow and base flow from the remaining portions of the landscape. By developing an equation that relates surface runoff to sediment concentration generated from runoff source areas, assuming that base flow and interflow are sediment free, we were able to predict daily sediment concentrations from the Anjeni Watershed and Blue Nile Basin with a Nash Sutcliffe efficiency ranging from 0.64 to 0.77 using only two calibrated sediment parameters. Anjeni is a 113 ha watershed in the 17.4 million ha Blue Nile Basin in the Ethiopian Highlands. The daily flows were predicted with Nash Sutcliffe efficiency values ranging from 0.80 to 0.93 if degraded areas were assumed the major sediment source areas and covered 14% of the Anjeni watershed and 20% of the Blue Nile basin. The analysis suggests that identifying the runoff source areas and predicting the surface runoff correctly is an important step in predicting the sediment concentration.

Cattle treading and phosphorus and sediment loss in overland flow from grazed cropland

Soil Research ◽  
2003 ◽  
Vol 41 (8) ◽  
pp. 1521 ◽  
Author(s):  
R. W. McDowell ◽  
J. J. Drewry ◽  
R. W. Muirhead ◽  
R. J. Paton
Keyword(s):  
Overland Flow ◽  
Sediment Concentration ◽  
Soil Disturbance ◽  
Cattle Dung ◽  
Forage Crops ◽  
P Loss ◽  
Sediment Loss ◽  
Particulate Form ◽  
Before And After ◽  
Total P

This 1-year study investigated the effect of dairy cow treading on soil physical properties and sediment and phosphorus (P) loss via overland flow from pasture and cultivated soil used for wintering dairy cows in southern New Zealand. Treading decreased soil macroporosity and Ksat, and increased overland flow volumes. Treading increased mean suspended sediment concentration in overland flow in the cultivated + trodden treatment (2.6 g/L) compared with ungrazed pasture (0.44 g/L) and ungrazed cultivated (0.98 g/L) treatments over 2 slope positions. Following grazing in the cultivated + trodden treatment, only 25% more sediment was lost in subsequent overland flow events (2.09 and 2.63 g before and after grazing, respectively), and mean total P (TP) losses increased by >250% (from 0.7 to 2.5 mg P). Meanwhile in the cultivated but ungrazed treatment, sediment and TP loss decreased. The increased loss of sediment and P following grazing in the cultivated + trodden treatment was attributed to P from cattle dung, and soil disturbance. Consequently, wintering of animals on cultivated paddocks with forage crops increases the risk of losing much P, especially in particulate form.

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