scholarly journals Formation of runoff at the hillslope scale during intense precipitation

2006 ◽  
Vol 3 (4) ◽  
pp. 2523-2558 ◽  
Author(s):  
S. Scherrer ◽  
F. Naef ◽  
A. O. Faeh ◽  
I. Cordery

Abstract. On 60 m2 hillslope plots at 18 mainly grassland locations in Switzerland rain was applied at rates of 50–100 mm/h for between 3 and 6 h. The generated flows were measured, overland flow near surface and subsurface flow in 0.5–1.3 m below surface. At some locations less than 2% of the rain flowed down the slope either on or below the surface, whereas at some others more than 90% of the rain ran off. At the majority of sites most runoff was overland flow, though at a few sites subsurface flow, usually via macropores was dominant. Data collected during each of 48 high intensity sprinkling experiments were used to distinguish which processes were dominant in each experiment. Which dominant and subsidiary processes occurred depended on interactions between infiltration rate, change in soil water storage and drainage of the soil water. These attributes were often not directly linked to parameters usually considered important like vegetation, slope, soil clay content and antecedent soil moisture. In many cases, process determination was fairly straightforward, indicating the possibility to reliably predict runoff processes at a site. However, at some sites, effects occurred that were not easily recognizable and led to surprising results.

2007 ◽  
Vol 11 (2) ◽  
pp. 907-922 ◽  
Author(s):  
S. Scherrer ◽  
F. Naef ◽  
A. O. Faeh ◽  
I. Cordery

Abstract. On 60 m2 hillslope plots, at 18 mainly grassland locations in Switzerland rain was applied at rates of 50–100 mm/h for between 3 and 6 h. The generated flows were measured, including overland flow, near surface and subsurface flow 0.5–1.3 m below the surface. At some locations less than 2% of the rain flowed down the slope either on or below the surface, whereas at some others more than 90% of the rain ran off. At the majority of sites most runoff was overland flow, though at a few sites subsurface flow, usually via macropores was dominant. Data collected during each of 48 high intensity sprinkling experiments were used to distinguish, which processes were dominant in each experiment. Which dominant and subsidiary processes occurred depended on interactions between infiltration rate, change in soil water storage and drainage of the soil water. These attributes were often not directly linked to parameters usually considered important like vegetation, slope, soil clay content and antecedent soil moisture. Considering the structure of the soil in combination with these attributes, process determination was in many cases fairly straightforward, indicating the possibility of reliably predicting runoff processes at a site. However, at some sites, effects occurred that were not easily recognizable and led to surprising results.


2005 ◽  
Vol 56 (4) ◽  
pp. 389 ◽  
Author(s):  
P. J. Dolling ◽  
R. A. Latta ◽  
P. R. Ward ◽  
M. J. Robertson ◽  
S. Asseng

To understand the factors involved in lucerne reducing drainage below the root-zone and influencing lucerne biomass production and water extraction were analysed in the south of Western Australia. The lucerne was grown for 3 years before removal. The factors investigated as part of the water extraction analysis included the rate of advance of the extraction front or extraction front velocity (EFV, mm/day), the soil plant-available water-holding capacity (PAWC, mm/m soil), and the temporal change in soil water deficit (drainage buffer, mm). The drainage buffer is related to the EFV and PAWC. A site with deep sand had the highest EFV (mean of 9.2 mm/day) but the lowest PAWC (mean of 32 mm/m soil) to a depth of 4 m. In the duplex soils the EFV was 18–34% of the deep sand EFV and the PAWC was 60–222% higher than the deep sand PAWC to a depth of 1.6–2.1 m. The EFV was reduced by the higher clay content and sodicity in the B horizon of the duplex soils. The highest drainage buffer measurements occurred in the deep sand site and the better structured duplex soils and therefore these soils will have the greater effect on reducing drainage below the root-zone. However, lucerne was able to create a drainage buffer to at least a depth of 1.5 m over 3 years and therefore contribute to a reduced drainage even on the most sodic and saline sites. Low soil pH did not affect the drainage buffer as much as soil texture and structure. Variation in biomass production of lucerne-based pastures was positively related to rainfall and water use (taking into account soil water storage and drainage losses) across sites, explaining approximately 50% of the biomass variation. Rainfall and water use could therefore be used for predicting lucerne biomass production in Western Australia. Biomass water use efficiency was highest in spring (15 kg/ha.mm) and least during autumn (4.5 kg/ha.mm).


Agro-Science ◽  
2020 ◽  
Vol 19 (2) ◽  
pp. 23-30
Author(s):  
P.I. Ogban ◽  
A.X. Okon

Soil infiltrability is an important hydrological process that enhances soil water storage and the minimization of runoff. A study was conducted to evaluate the effect of slope aspect (north, NfS and south, SfS) and positions [(crest (CR), upper (US), middle (MS) and lower (LS)] on soil infiltrability,  that is, initial infiltration rate (io), steady-state infiltration rate (ic) and cumulative infiltration (I), and sorptivity (S) and transmissivity (A) on the University of Uyo Teaching and Research Farm (T&SF) located on an Ultisol in Akwa Ibom State, southern Nigeria. Results show that the initial  infiltration rate (io) was 43.20 cm h−1 on SfS and significantly (p < 0.05) higher than 36.60 cm h−1 on NfS. The final infiltration rate (ic) was not significantly different between NfS (9.60 cm h−1) and SfS (7.20 cm h−1). The Cumulative depth of water (I) infiltrated was similar between NfS (28.18 cm) and SfS (21.46 cm). Soil water sorptivity (S) was moderately high on the two slopes but significantly (p < 0.05) lower in NfS (0.49 cm min−1/2)  than in SfS (0.70 cm min−1/2) soil. Soil water transmissivity (A) was similar in NfS (0.19 cm h−1) and SfS (0.16 cm h−1) soil. The results indicate that the aspects were similar in io, ic, I, S and A. However, since soil texture is similar among the aspects, similar soil management practices, example tillage  and mulching, could be adopted to enhance water infiltration to improve ic for increases in soil water conservation and crop production on the  T&SF. Key words: slope aspect and position, soil infiltrability, sorptivity and transmissivity, soil water management


2012 ◽  
Vol 9 (1) ◽  
pp. 441-483
Author(s):  
B. A. Ebel ◽  
E. S. Hinckley ◽  
D. A. Martin

Abstract. Many forested watersheds with a substantial fraction of precipitation delivered as snow have the potential for landscape disturbance by wildfire. Little is known about the immediate effects of wildfire on snowmelt and near-surface hydrologic responses, including soil-water storage. Montane systems at the rain-snow transition have soil-water dynamics that are further complicated during the snowmelt period by strong aspect controls on snowmelt and soil thawing. Here we present data and analysis from field measurements of snow hydrology and subsurface hydrologic and temperature responses during the first winter and spring after the September 2010 Fourmile Canyon Fire in Colorado, USA. Our observations of soil-water content and soil temperature show sharp contrasts in hydrologic and thermal conditions between north- and south-facing slopes. South-facing burned soils were ~1–2 °C warmer on average than north-facing burned soils and ~1.5 °C warmer than south-facing unburned soils, which affected soil thawing during the snowmelt period. Soil-water dynamics also differed by aspect: in response to soil thawing, soil-water content increased approximately one month earlier on south-facing burned slopes than on north-facing burned slopes. While aspect and wildfire affect soil-water dynamics during snowmelt, soil-water storage at the end of the snowmelt period reached the value at field capacity for each plot, suggesting that post-snowmelt unsaturated storage was not substantially influenced by aspect in wildfire-affected areas. Our data and analysis indicate that snowmelt-driven groundwater recharge may be larger in wildfire-impacted areas, especially on south-facing slopes, because of earlier soil thaw and longer durations of soil-water contents above field capacity in those areas.


2016 ◽  
Vol 30 (4) ◽  
pp. 533-543 ◽  
Author(s):  
Xiuwei Liu ◽  
Xuejun Dong ◽  
Daniel I. Leskovar

Abstract Belowground properties strongly affect agricultural productivity. Traditional methods for quantifying belowground properties are destructive, labor-intensive and pointbased. Ground penetrating radar can provide non-invasive, areal, and repeatable underground measurements. This article reviews the application of ground penetrating radar for soil and root measurements and discusses potential approaches to overcome challenges facing ground penetrating radar-based sensing in agriculture, especially for soil physical characteristics and crop root measurements. Though advanced data-analysis has been developed for ground penetrating radar-based sensing of soil moisture and soil clay content in civil engineering and geosciences, it has not been used widely in agricultural research. Also, past studies using ground penetrating radar in root research have been focused mainly on coarse root measurement. Currently, it is difficult to measure individual crop roots directly using ground penetrating radar, but it is possible to sense root cohorts within a soil volume grid as a functional constituent modifying bulk soil dielectric permittivity. Alternatively, ground penetrating radarbased sensing of soil water content, soil nutrition and texture can be utilized to inversely estimate root development by coupling soil water flow modeling with the seasonality of plant root growth patterns. Further benefits of ground penetrating radar applications in agriculture rely on the knowledge, discovery, and integration among differing disciplines adapted to research in agricultural management.


Soil Research ◽  
2008 ◽  
Vol 46 (5) ◽  
pp. 476 ◽  
Author(s):  
Partha Pratim Adhikary ◽  
Debashis Chakraborty ◽  
Naveen Kalra ◽  
C. B. Sachdev ◽  
A. K. Patra ◽  
...  

Most of the data pertaining to Indian soils are limited to the major soil separates, sand, silt, and clay. We examined the possibilities of using these parameters to describe the hydraulic characteristics of the soils of India. The final or steady-state infiltration rate, which is mainly profile-controlled, showed a power function relationship with the maximum and the average clay content in the soil profile. The saturated hydraulic conductivity also showed a similar relationship with the silt + clay content. The soil water content at a given suction could be satisfactorily predicted using the percentage of major soil separates, sand, silt, and clay. The coefficients in the soil water function ψ(θ) were linearly related to the sand content. Non-linear regression equations were developed to predict these coefficients using the percentages of sand and clay in soils. The equations proved to be quite satisfactory for a wide range of textures and provided reasonably accurate estimates of the soil water characteristic curve from a minimum of readily available data.


2012 ◽  
Vol 16 (5) ◽  
pp. 1401-1417 ◽  
Author(s):  
B. A. Ebel ◽  
E. S. Hinckley ◽  
D. A. Martin

Abstract. Many forested watersheds with a substantial fraction of precipitation delivered as snow have the potential for landscape disturbance by wildfire. Little is known about the immediate effects of wildfire on snowmelt and near-surface hydrologic responses, including soil-water storage. Montane systems at the rain-snow transition have soil-water dynamics that are further complicated during the snowmelt period by strong aspect controls on snowmelt and soil thawing. Here we present data from field measurements of snow hydrology and subsurface hydrologic and temperature responses during the first winter and spring after the September 2010 Fourmile Canyon Fire in Colorado, USA. Our observations of soil-water content and soil temperature show sharp contrasts in hydrologic and thermal conditions between north- and south-facing slopes. South-facing burned soils were ∼1–2 °C warmer on average than north-facing burned soils and ∼1.5 °C warmer than south-facing unburned soils, which affected soil thawing during the snowmelt period. Soil-water dynamics also differed by aspect: in response to soil thawing, soil-water content increased approximately one month earlier on south-facing burned slopes than on north-facing burned slopes. While aspect and wildfire affect soil-water dynamics during snowmelt, soil-water storage at the end of the snowmelt period reached the value at field capacity for each plot, suggesting that post-snowmelt unsaturated storage was not substantially influenced by aspect in wildfire-affected areas. Our data and analysis indicate that the amount of snowmelt-driven groundwater recharge may be larger in wildfire-impacted areas, especially on south-facing slopes, because of earlier soil thaw and longer durations of soil-water contents above field capacity in those areas.


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