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.

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.

scholarly journals Soil water regime estimated from the soil water storage monitored in time

2008 ◽  
Vol 3 (Special Issue No. 1) ◽  
pp. S139-S146 ◽  
Author(s):  
J. Šútor ◽  
M. Gomboš ◽  
M. Kutílek ◽  
M. Krejča
Keyword(s):  
Ground Water ◽  
Water Level ◽  
Soil Water ◽  
Soil Profile ◽  
Water Regime ◽  
Water Storage ◽  
Ground Water Level ◽  
Soil Water Storage ◽  
Aeration Zone ◽  
Soil Water Regime

During the vegetation season, the water storage in the soil aeration zone is influenced by meteorological phenomena and by the vegetated cover. If the groundwater table is in contact with the soil profile, its contribution to water storage must be considered. This impact can be either monitored directly or the mathematical model of the soil moisture regime can be used to simulate it. We present the results of monitoring soil water content in the aeration zone of the East Slovakian Lowland. The main problem is the evaluation of the soil water storage in seasons and in years in the soil profile. Until now, classification systems of the soil water regime evaluation have been mainly based upon climatological factors and soil morphology where the classification has been realized on the basis of indirect indicators. Here, a new classification system based upon quantified data sets is introduced and applied for the measured data. The system considers the degree of accessibility of soil water to plants, including the excess of soil water related to the duration for those characteristic periods. The time span is hierarchically arranged to differentiate between the dominant water storage periods and short-term fluctuations. The lowest taxonomic units characterize the vertical fluxes over time periods. The system allows the comparison of soil water regime taxons over several years and under different types of vegetative cover, or due to various types of land use. We monitored soil water content on two localities, one with a deep ground water level, one with a shallow ground water level. The profile with a shallow ground water level keeps a more uniform taxons and subtaxons of soil water regime due to the crop variation than the profile with a deep ground water level.

Soil water changes under fallow-crop treatments in relation to soil type, rainfall and yield of wheat

1971 ◽  
Vol 11 (49) ◽  
pp. 236 ◽  
Author(s):  
JE Schultz
Keyword(s):  
Water Content ◽  
Soil Water ◽  
Water Storage ◽  
South Australia ◽  
Soil Types ◽  
Soil Water Storage ◽  
Fallow Period ◽  
One Year ◽  
Water Contents ◽  
Soil Water Contents

Soil water changes under fallow (initial cultivation in spring), grassland (initial cultivation in autumn) and the succeeding wheat crops were recorded at two to three weekly intervals in three consecutive seasons in three soil types representing the range of wheat-growing soils in South Australia. Differences in water content between the two treatments developed soon after the start of fallowing due to the greater loss of water from grassland in spring. Rainfall during the fallow period contributed little to soil water storage except in one year when heavy spring rains were recorded. In some instances the water content in the fallowed soils at seeding was less than at the start of fallowing, but the fallowed soils consistently retained more water than the grassland soils. Soil water contents decreased after August of the crop year (end of tillering) and by harvest the wheat crops had commonly dried the soil to a depth of 150 cm. Fallow crops used more water and produced significantly higher wheat yields with a greater efficiency of water use in all trials.

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.

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

Water use and drainage under phalaris, annual pasture, and crops on a duplex soil in Western Australia

2001 ◽  
Vol 52 (2) ◽  
pp. 305 ◽  
Author(s):  
P. J. Dolling
Keyword(s):  
Soil Water ◽  
Water Use ◽  
Western Australia ◽  
Water Storage ◽  
Growing Season ◽  
Early Summer ◽  
Late Spring ◽  
Soil Water Storage ◽  
Annual Rainfall ◽  
Annual Crops

Rising water tables in southern Western Australia are causing waterlogging and salinity problems. These issues are related to a lower level of water use by annual plants than by the native vegetation. Phalaris can use more water than annual pastures and crops because of deeper rooting characteristics and longer growing season. However, there is limited information on the water use of phalaris in the Western Australian environment. There is also very little information on water balances under annual crops and pastures outside the growing season. A field experiment was carried out on a duplex soil between March 1994 and March 1999. Annual rainfall varied between 321 and 572 mm. The study examined soil water content, deep drainage, and productivity of phalaris-based pasture, continuous annual pasture, annual pasture–wheat rotation, and a wheat–lupin rotation. The results showed that the phalaris-based pasture after the establishment year was 25% (1.9 t dry matter/ha) more productive than continuous annual pasture, with the main difference occurring in late spring–early summer. The phalaris-based pasture used, on average, 45 mm/year more water and reduced drainage below 1 m by 44 mm/year compared with the annual pastures and crops. Total drainage below 1 m was 30 mm under the phalaris-based pasture and 74 mm under annual pasture. The greater water use in the phalaris-based pasture occurred in late spring and early summer. Although differences in total biomass per year occurred between wheat in different rotations there was no difference in the soil water storage prior to the break of the season. There was also no difference in the soil water balance between any of the annual crops and pastures. Differences in soil water storage did occur in some years in October but disappeared by May the following year.

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.

Evaluation of soil water storage efficiency for rainfall harvesting on hillslope micro-basins built using time domain reflectometry measurements

2010 ◽  
Vol 97 (3) ◽  
pp. 449-456 ◽  
Author(s):  
M. Previati ◽  
I. Bevilacqua ◽  
D. Canone ◽  
S. Ferraris ◽  
R. Haverkamp
Keyword(s):  
Soil Water ◽  
Time Domain ◽  
Water Storage ◽  
Time Domain Reflectometry ◽  
Soil Water Storage ◽  
Storage Efficiency

scholarly journals Fractal behavior of soil water storage at multiple depths

2016 ◽  
Vol 23 (4) ◽  
pp. 269-284 ◽  
Author(s):  
Wenjun Ji ◽  
Mi Lin ◽  
Asim Biswas ◽  
Bing C. Si ◽  
Henry W. Chau ◽  
...  
Keyword(s):  
Soil Water ◽  
Management Practices ◽  
Surface Soil ◽  
Multiple Scales ◽  
Fractal Theory ◽  
Water Storage ◽  
Water Dynamics ◽  
Soil Water Storage ◽  
Scaling Properties ◽  
Deep Layers

Abstract. Spatiotemporal 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 are kept at deep layers. The current study examined the scaling properties of sub-surface soil water and their relationship to surface soil water, thereby serving as supporting information for 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 in Saskatchewan. The surface SWS showed multifractal nature only during the wet period (from snowmelt until mid- to late June) indicating the need for 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 for a single scaling index to upscale/downscale soil water variability information. In contrast, all soil layers during the dry period (from late June to the end of the growing season in early November) 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.

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