Monitoring Near-Surface Soil Water Storage in Turfgrass using Time Domain Reflectometry and Weighing Lysimetry

1997 ◽  
Vol 61 (4) ◽  
pp. 1138-1146 ◽  
Author(s):  
M. H. Young ◽  
P. J. Wierenga ◽  
C. F. Mancino
Keyword(s):  
Soil Water ◽  
Time Domain ◽  
Surface Soil ◽  
Water Storage ◽  
Time Domain Reflectometry ◽  
Soil Water Storage ◽  
Near Surface

Use of Time-Domain Reflectometry (TDR) to measure the water-content of sandy soils

Soil Research ◽  
1995 ◽  
Vol 33 (2) ◽  
pp. 265 ◽  
Author(s):  
PJ Gregory ◽  
R Poss ◽  
J Eastham ◽  
S Micin
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Transmission Lines ◽  
Time Domain ◽  
Water Storage ◽  
Sandy Soils ◽  
Time Domain Reflectometry ◽  
Soil Water Storage ◽  
Use Of Time ◽  
Daily Evaporation

We investigated the potential sources of error when using time domain reflectometry (TDR) to measure the water content of sandy soils and evaluated the technique as a means of measuring evaporation from columns of soil and changes in soil water storage beneath crops. Inaccurate depth location of the transmission lines or the development of a hole at the tip of the transmission lines introduced an error about 10 times larger than the errors associated with hardware and software. Calibration in two sandy soils gave a curve of similar shape to that found by others except for values of dielectric constant < 6 when measured values of water content were less than those expected. Daily evaporation from soil columns measured by weighing and with TDR showed large differences between the two techniques (up to 32%) but compensating errors over time allowed cumulative evaporation to be estimated with TDR to within 6.6% of that determined by weighing over a 162 h period. Under field conditions, the agreement between TDR and neutron probe measures of changes in soil water storage in the upper 0.3 m was good and generally within 10% over both 14 day and longer periods.

Characterisation of a windbreak system on the south coast of Western Australia. 3. Soil water and hydrology

2002 ◽  
Vol 42 (6) ◽  
pp. 729 ◽  
Author(s):  
D. J. M. Hall ◽  
R. A. Sudmeyer ◽  
C. K. McLernon ◽  
R. J. Short
Keyword(s):  
Ground Water ◽  
Soil Water ◽  
Western Australia ◽  
Surface Soil ◽  
Water Storage ◽  
Time Domain Reflectometry ◽  
Water Levels ◽  
Soil Water Storage ◽  
Neutron Moisture ◽  
Water Contents

This paper describes changes in soil water and ground water at various distances from a Pinus pinaster windbreak in south-western Australia. Soil water contents were measured by neutron moisture meter and time domain reflectometry at distances from a windbreak ranging from 1 to 20 tree heights (H). Within 3 H of the windbreak, soil water storage was reduced by 100–153 mm/1.8 m when compared to unsheltered conditions (20 H) over the 4 years of the experiment. Beyond 3 H, no significant differences in soil water storage were found which could be related to microclimate modification. Relationships between surface soil water storage (mm/0.4 m) at <6�H and 12–24 H were 1 : 1 regardless of the technique used. Similarly, soil water depletion within the crop rootzone (mm/0.6 m) was similar at distances >3 H. Reductions in the depth and duration of perched water levels occurred within 4 H of the windbreak. Despite this, the windbreaks had no effect on the regional ground-water levels.

Soil water storage dynamics in peatlands with shallow water tables

2000 ◽  
Vol 80 (1) ◽  
pp. 43-52 ◽  
Author(s):  
David R. Lapen ◽  
Jonathan S. Price ◽  
Robert Gilbert
Keyword(s):  
Shallow Water ◽  
Soil Water ◽  
Water Table ◽  
Time Domain ◽  
Water Storage ◽  
Time Domain Reflectometry ◽  
Soil Water Storage ◽  
Shallow Water Table ◽  
Moisture Conditions ◽  
Peat Formation

Time domain reflectometry (TDR) was used to estimate soil water storage dynamics in several uncultivated blanket bogs and poor fens in southeastern Newfoundland during the summer growing season. The purpose of the research was to evaluate links between surface moisture conditions, evapotranspiration, and recharge processes in order to elucidate factors that govern blanket peat formation in the region. Water storage changes in the peat/Sphagnum above the water table (ΔSWS) were found to be important storage terms in daily water balance estimates. Daily mean ΔSWS values for bog and fen approximated −0.3 and −0.45 mm, respectively. It was also found that, i) fairly high peat water-holding capacities, ii) frequent atmospheric recharge, iii) atmospheric controls on evapotranspiration, and, iv) the transport of water into the unsaturated zone from the shallow water table via capillary and external wicking processes helped to preclude significant de-watering over the bulk of the peatland surfaces. Recharge via groundwater appears to be an important factor governing moisture conditions requisite for peat accrual and the growth of Sphagnum spp., especially in the fens. Key words: Time domain reflectometry, blanket peats, soil water, evapotranspiration, water table depth

scholarly journals Fractal behavior of soil water storage at multiple depths

2016 ◽  
Author(s):  
Wenjun Ji ◽  
Mi Lin ◽  
Asim Biswas ◽  
Bing C. Si ◽  
Henry W. Chau ◽  
...  
Keyword(s):  
Surface Layer ◽  
Soil Water ◽  
Management Practices ◽  
Surface Soil ◽  
Fractal Theory ◽  
Water Storage ◽  
Water Dynamics ◽  
Soil Water Storage ◽  
Scaling Properties ◽  
Deep Layers

Abstract. Spatio-temporal behavior of soil water is essential to understand the science of hydrodynamics. Data intensive measurement of surface soil water using remote sensing has established that the spatial variability of soil water can be described using the principle of self-similarity (scaling properties) or fractal theory. This information can be used in determining land management practices provided the surface scaling properties hold at deep layer. Current study examined the scaling properties of sub-surface soil water and its relationship to surface soil water, thereby serving as the supporting information for the plant root and vadose zone models. Soil water storage (SWS) down to 1.4 m depth at seven equal intervals was measured along a transect of 576 m for 5 years. The surface SWS showed multifractal nature only during the wet period (from snowmelt until mid to late June with large SWS) indicating the need of multiple scaling indices in transferring soil water variability information over multiple scales. However, with increasing depth, the SWS became monofractal in nature indicating the need of single scaling index to upscale/downscale soil water variability information. The dynamic nature made the surface layer soil water in the wet period highly variable compared to the deep layers. In contrast, all soil layers during the dry period (from late June to the end of the growing season with low SWS) were monofractal in nature, probably resulting from the high evapotranspirative demand of the growing vegetation that surpassed other effects. This strong similarity between the scaling properties at the surface layer and deep layers provides the possibility of inferring about the whole profile soil water dynamics using the scaling properties of the easy-to-measure surface SWS data.

scholarly journals Soil-water dynamics and unsaturated storage during snowmelt following wildfire

2012 ◽  
Vol 9 (1) ◽  
pp. 441-483
Author(s):  
B. A. Ebel ◽  
E. S. Hinckley ◽  
D. A. Martin
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Storage ◽  
Field Capacity ◽  
Water Dynamics ◽  
Soil Water Storage ◽  
Soil Water Dynamics ◽  
Near Surface ◽  
Snowmelt Period

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.

scholarly journals Soil-water dynamics and unsaturated storage during snowmelt following wildfire

2012 ◽  
Vol 16 (5) ◽  
pp. 1401-1417 ◽  
Author(s):  
B. A. Ebel ◽  
E. S. Hinckley ◽  
D. A. Martin
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
Water Storage ◽  
Field Capacity ◽  
Water Dynamics ◽  
Soil Water Storage ◽  
Soil Water Dynamics ◽  
Near Surface ◽  
Snowmelt Period

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.

scholarly journals Analysis of the drought recovery of Andosols on southern Ecuadorian Andean páramos

2016 ◽  
Vol 20 (6) ◽  
pp. 2421-2435 ◽  
Author(s):  
Vicente Iñiguez ◽  
Oscar Morales ◽  
Felipe Cisneros ◽  
Willy Bauwens ◽  
Guido Wyseure
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Potential Evapotranspiration ◽  
Water Storage ◽  
Dry Season ◽  
Time Domain Reflectometry ◽  
Soil Water Storage ◽  
Wet Season ◽  
Catchment Scale ◽  
Normal Value

Abstract. The Neotropical Andean grasslands above 3500 m a.s.l., known as páramo, offer remarkable ecological services for the Andean region. The most important of these is the water supply of excellent quality to many cities and villages in the inter-Andean valleys and along the coast. The páramo ecosystem and especially its soils are under constant and increased threat by human activities and climate change. In this study, the recovery speed of the páramo soils after drought periods are analysed. The observation period includes the droughts of 2009, 2010, 2011, and 2012 together with intermediate wet periods. Two experimental catchments – one with and one without páramo – were investigated. The Probability Distributed Moisture (PDM) model was calibrated and validated in both catchments. Drought periods and its characteristics were identified and quantified by a threshold level approach and complemented by means of a drought propagation analysis. At the plot scale in the páramo region, the soil water content measured by time domain reflectometry (TDR) probes dropped from a normal value of about 0.84 to  ∼ 0.60 cm3 cm−3, while the recovery time was 2–3 months. This did not occur at lower altitudes (Cumbe) where the soils are mineral. Although the soil moisture depletion observed in these soils was similar to that of the Andosols (27 %), decreasing from a normal value of about 0.54 to  ∼ 0.39 cm3 cm−3, the recovery was much slower and took about 8 months for the drought in 2010. At the catchment scale, however, the soil water storage simulated by the PDM model and the drought analysis was not as pronounced. Soil moisture droughts occurred mainly in the dry season in both catchments. The deficit for all cases is small and progressively reduced during the wet season. Vegetation stress periods correspond mainly to the months of September, October and November, which coincides with the dry season. The maximum number of consecutive dry days were reached during the drought of 2009 and 2010 (19 and 22 days), which can be considered to be a long period in the páramo. The main factor in the hydrological response of these experimental catchments is the precipitation relative to the potential evapotranspiration. As the soils never became extremely dry nor close to the wilting point, the soil water storage capacity had a secondary influence.

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