scholarly journals The significance and lag-time of deep through flow: an example from a small, ephemeral catchment with contrasting soil types in the Adelaide Hills, South Australia

2009 ◽  
Vol 13 (7) ◽  
pp. 1201-1214 ◽  
Author(s):  
E. Bestland ◽  
S. Milgate ◽  
D. Chittleborough ◽  
J. VanLeeuwen ◽  
M. Pichler ◽  
...  
Keyword(s):  
Stream Flow ◽  
Overland Flow ◽  
Clayey Soil ◽  
South Australia ◽  
Sandy Soils ◽  
Lag Time ◽  
Soil Horizons ◽  
Deep Soil ◽  
Soil System ◽  
Through Flow

Abstract. The importance of deep soil-regolith through flow in a small (3.4 km2) ephemeral catchment in the Adelaide Hills of South Australia was investigated by detailed hydrochemical analysis of soil water and stream flow during autumn and early winter rains. In this Mediterranean climate with strong summer moisture deficits, several significant rainfalls are required to generate soil through flow and stream flow [in ephemeral streams]. During autumn 2007, a large (127 mm) drought-breaking rain occurred in April followed by significant May rains; most of this April and May precipitation occurred prior to the initiation of stream flow in late May. These early events, especially the 127 mm April event, had low stable water isotope values compared with later rains during June and July and average winter precipitation. Thus, this large early autumn rain event with low isotopic values (δ18O, δD) provided an excellent natural tracer. During later June and July rainfall events, daily stream and soil water samples were collected and analysed. Results from major and trace elements, water isotopes (δ18O, δD), and dissolved organic carbon analysis clearly demonstrate that a large component of this early April and May rain was stored and later pushed out of deep soil and regolith zones. This pre-event water was identified in the stream as well as identified in deep soil horizons due to its different isotopic signature which contrasted sharply with the June–July event water. Based on this data, the soil-regolith hydrologic system for this catchment has been re-thought. The catchment area consists of about 60% sandy and 40% clayey soils. Regolith flow in the sandy soil system and not the clayey soil system is now thought to dominate the deep subsurface flow in this catchment. The clayey texture contrast soils had rapid response to rain events and saturation excess overland flow. The sandy soils had delayed soil through flow and infiltration excess overland flow. A pulse of macropore through flow was observed in the sandy soils three days after the rainfall event largely ended. The macropore water was a mixture of pre-event and event water, demonstrating the lag-time and mixing of the water masses in the sandy soil system. By contrast, the clayey soil horizons were not dominated by pre-event water, demonstrating the quicker response and shallow through flow of the clayey soil system. Thus, the sandy terrain has a greater vadose zone storage and greater lag time of through flow than the clayey terrain.

scholarly journals The significance and lag-time of deep throughflow: an example from a small, ephemeral catchment with contrasting soil types in the Adelaide Hills, South Australia

2009 ◽  
Vol 6 (2) ◽  
pp. 2599-2632 ◽  
Author(s):  
E. Bestland ◽  
S. Milgate ◽  
D. Chittleborough ◽  
J. VanLeeuwen ◽  
M. Pichler ◽  
...  
Keyword(s):  
Soil Water ◽  
Sandy Soil ◽  
Stream Flow ◽  
Overland Flow ◽  
Clayey Soil ◽  
South Australia ◽  
Sandy Soils ◽  
Lag Time ◽  
Soil Horizons ◽  
Soil System

Abstract. The importance of deep throughflow in a small (3.4 km2) ephemeral catchment in the Adelaide Hills of South Australia was investigated by detailed hydrochemical analysis of soil water and stream flow during autumn and early winter rains. In this Mediterranean climate with strong summer moisture deficits, several significant rainfalls are required to generate soil throughflow and stream flow (in ephemeral streams). During Autumn 2007, a large (127 mm) drought-breaking rain occurred in April followed by significant May rains; most of this precipitation occurred prior to the initiation of stream flow in late May. These early events, especially the 127 mm event, had low (depleted) stable water isotope values compared with both later rains and average winter precipitation. Thus, this large depleted early rain event provided an excellent natural tracer. During the June and July rainfall events, daily stream and soil water samples were collected and analysed. Results from major and trace elements, water isotopes (δ18O, δD), and dissolved organic carbon analysis clearly demonstrate that a large component of this early April and May rain was stored and later pushed out of deep soil or regolith zones. This pre-event water was identified in the stream as well as identified in deeper soil horizons due to its different isotopic signature which contrasted sharply with the June–July event water. Based on this data, the regolith and throughflow system for this catchment has been re-thought. The catchment area consists of about half sandy and half clayey soils. Regolith flow is now thought to be dominated by the sandy soil system not the clayey soil system. The clayey duplex soils had rapid response to rain events and saturation excess overland flow. The sandy soils had delayed soil throughflow and infiltration excess overland flow. A pulse of macropore throughflow was observed in the sandy soils three days after the rainfall event largely ended. The macropore water was a mixture of pre-event and event water, demonstrating the lag-time and mixing of the water masses in the sandy soil system. By contrast, the clayey soil horizons were dominated by pre-event water to a much lesser degree, demonstrating the quicker response and shallow flow through of the clayey soil system. Thus, the sandy terrain has a greater vadose zone storage and greater lag time of through-flow than the clayey terrain.

Pathways of phosphorus, nitrogen, and carbon movement over and through texturally differentiated soils, South Australia

Soil Research ◽  
1999 ◽  
Vol 37 (4) ◽  
pp. 679 ◽  
Author(s):  
D. J. Chittleborough ◽  
J. W. Cox ◽  
D. P. Stevens
Keyword(s):  
Organic Carbon ◽  
Overland Flow ◽  
South Australia ◽  
Catchment Management ◽  
Catchment Scale ◽  
Through Flow ◽  
Close Proximity ◽  
Significant Loading ◽  
Restrict Movement ◽  
Texture Contrast

One method for preventing the degradation of water supplies through contamination with phosphorus (P), nitrate (NO3), and dissolved organic carbon (DOC) is to restrict movement of these contaminants from the catchment into water bodies. The purpose of the study was to quantify and characterise the proportion of NO3, P, and DOC moving from duplex soils by overland flow and through-flow on a sub-catchment scale, and to characterise soil properties that influence their movement. Two sites in the Adelaide Hills (South Australia) with contrasting duplex soils were instrumented to collect overland flow and through-flow from the soils A and B horizon. Each site contained 2 sub-catchments in close proximity. Sub-catchments were well defined by the natural topography sloping from hillcrest to a stream headwater. Soil type, especially the degree of texture contrast, the macroporosity, and the proportion of clay in the B horizon, had a large influence on the pathways of water, and therefore P, DOC, and NO3 movement. Environmentally significant concentrations of P (>0�1 mg/L) and NO3-N (>0�5 mg/L) moved overland and through these soils in 1997. High DOC loads (25 mg/L), which would also impact on water treatment costs, moved through some soils. Significant loading of P moved through and over soils in both dissolved (0�5 mg/L) and particulate (0�3 mg/L) forms. Consequently, through-flow cannot be ignored as a contributor to P in streams and both dissolved and particulate P must be measured under these conditions to define the full impact of P. The findings from this research have implications for research on catchment management to restrict DOC and nutrient movement into waterways.

scholarly journals Comparison of Drivers of Soil Microbial Communities Developed in Karst Ecosystems with Shallow and Deep Soil Depths

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 173
Author(s):  
Huiling Guan ◽  
Jiangwen Fan ◽  
Haiyan Zhang ◽  
Warwick Harris
Keyword(s):  
Microbial Community ◽  
Microbial Communities ◽  
Soil Depth ◽  
Phospholipid Fatty Acid ◽  
Soil Microbial Communities ◽  
Deep Soil ◽  
Soil System ◽  
Soil Microbial ◽  
Total Soil ◽  
Karst Ecosystems

Soil erosion is prevalent in karst areas, but few studies have compared the differences in the drivers for soil microbial communities among karst ecosystems with different soil depths, and most studies have focused on the local scale. To fill this research gap, we investigated the upper 20 cm soil layers of 10 shallow–soil depth (shallow–SDC, total soil depth less than 100 cm) and 11 deep–soil depth communities (deep–SDC, total soil depth more than 100 cm), covering a broad range of vegetation types, soils, and climates. The microbial community characteristics of both the shallow–SDC and deep–SDC soils were tested by phospholipid fatty acid (PLFAs) analysis, and the key drivers of the microbial communities were illustrated by forward selection and variance partitioning analysis. Our findings demonstrated that more abundant soil nutrients supported higher fungal PLFA in shallow–SDC than in deep–SDC (p < 0.05). Furthermore, stronger correlation between the microbial community and the plant–soil system was found in shallow–SDC: the pure plant effect explained the 43.2% of variance in microbial biomass and 57.8% of the variance in the ratio of Gram–positive bacteria to Gram–negative bacteria (G+/G−), and the ratio of fungi to total bacteria (F/B); the pure soil effect accounted for 68.6% variance in the microbial diversity. The ratio of microbial PLFA cyclopropyl to precursors (Cy/Pr) and the ratio of saturated PLFA to monounsaturated PLFA (S/M) as indicators of microbial stress were controlled by pH, but high pH was not conducive to microorganisms in this area. Meanwhile, Cy/Pr in all communities was >0.1, indicating that microorganisms were under environmental stress. Therefore, the further ecological restoration of degraded karst communities is needed to improve their microbial communities.

PSXI-21 Soil emission of carbon dioxide and behavior of microorganisms in soils of Western Kazakhstan

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 345-347
Author(s):  
Aliya Nagiyeva ◽  
Nurlan Sergaliyev ◽  
Anuarbek T Bissembayev
Keyword(s):  
Microbial Communities ◽  
Co2 Emissions ◽  
Humus Content ◽  
Chestnut Soil ◽  
Co2 Flux ◽  
Critical Conditions ◽  
Soil Co2 ◽  
Soil Horizons ◽  
Deep Soil ◽  
Co2 Intensity

Abstract Kazakhstan Western ecosystems are intensively used in agricultural production. Assessing greenhouse gas emissions from soils, especially CO2, is important. In the upper stages, microbiology, characteristics and condition of the soil change. Biological intensity indicators are soil respiration processes, numerous microbiocenoses species composition. Soil CO2 emissions were measured 5 times monthly during three years. The CO2 flow rate from soil surface is measured by a closed dynamic chamber method with Li-8100A field respirometer. Metagenomic soil testing used bacteria DNA, archaea, real-time PCR, 16SrRNA sequencing. The soil CO2 monthly dynamics fluxes varied among the lands, within the season. In 2020, the CO2 emissions soil peak noted in the pasture. There is a slight decline in summer with a decrease towards the cold season. Comparison between the CO2 flux pasture soils is less in virgin soil. The minimum CO2 flux was recorded in November - February; in the spring, the flux increases. The above CO2 emissions were recorded in summer. In soils, there is wide variety of microorganisms with opposite and incompatible properties for one habitat. The microbial communities structure identified at the family level. The taxonomic samples structure ominated by phylae - Actinobacteria, Proteobacteria, Chloroflexi, Acidobacteria, Gemmatimonadetes, Firmicutes, Actinobacteria. The spread explained by increased actinomycetes resistance characteristic to low moisture content with long dry period. For comparative evaluation microbial communities results comparing by cenoses of upper horizons with dark chestnut soil indicators. This violation caused microorganisms resistance to disturbing factors. On anthropogenically disturbed saline soils, the bacteria found were specific and resistant to critical conditions. CO2 emission in soil varied cenosis type. The CO2 intensity factors were precipitation deficit, high temperature. The profile microorganisms distribution corresponded to the soil horizons humus content. During summer soil drying, the deep soil horizons abundance occurred where moisture is retained.

The distribution of trace elements in some South Australian red-brown earths

1957 ◽  
Vol 8 (3) ◽  
pp. 246 ◽  
Author(s):  
RM McKenzie
Keyword(s):  
Trace Elements ◽  
South Australia ◽  
Mobile Elements ◽  
Soil Horizons ◽  
Surface Soils ◽  
Mean Values ◽  
Pattern Of Variation ◽  
Individual Profiles ◽  
Maximum Minimum ◽  
Distribution Of Trace Elements

The maximum, minimum, and mean values for six trace elements in four soil horizons are reported for 14 profiles of red-brown earths from South Australia, and the pattern of variation and distribution of these elements discussed. The elements studied could be arranged in a series of decreasing mobility in the soil, the order being cobalt > copper > gallium > vanadium > molybdenum > manganese. The most mobile elements had greater variations within profiles and, except for manganese, greater variations between profiles. Gallium, vanadium, and molybdenum contents were correlated with the amount of clay present in all surface soils, as well as in individual profiles, whereas cobalt and copper contents were correlated with clay only in individual profiles.

Studies on some deep sandy soils in Cape York Peninsula, North Queensland. 3. Losses of applied phosphorus and sulphur

1973 ◽  
Vol 13 (63) ◽  
pp. 418 ◽  
Author(s):  
GP Gillman
Keyword(s):  
Sandy Soil ◽  
Sandy Soils ◽  
Soil Horizons ◽  
Al Content ◽  
P Accumulation ◽  
Cape York ◽  
Legume Growth

Losses of applied phosphorus and sulphur from a 100 cm profile of a deep siliceous sandy soil in Cape York Peninsula have been studied in the field over a period of three wet seasons. The P and S was applied in two treatments: superphosphate (880 kg ha-1) and 'biosuper' (1072 kg ha-1). About 50 per cent of the applied P was lost from the top 30 cm of the profile but all remained in the 100 cm depth. Only 10-30 per cent of the applied S was recovered in the 100 cm profile. Zones of P accumulation were generally related to Fe and Al content of the soil horizons. Legume growth and composition over the three seasons was adequate, and reasons for this are discussed.

Influence of Spud-Can-Soil Interaction Modeling and Parameters on the Reliability Index of Neka Drilling Jack-Up Platform

2010 ◽  
Vol 132 (3) ◽  
Author(s):  
M. R. Emami Azadi
Keyword(s):  
Reliability Index ◽  
Clayey Soil ◽  
Interaction Model ◽  
Soil Parameters ◽  
The Caspian Sea ◽  
Foundation Soil ◽  
Soil System ◽  
Dense Sand ◽  
Interaction Modeling ◽  
Jack Up

In the present study, the influence of spud-can-soil modeling and parameters on the reliability index of jack-up platform is investigated. Neka platform is studied as a case, which is a three-leg drilling jack-up type platform located in water depth of about 91 m in the Caspian Sea region. Various spud-can-soil interaction models such as pinned, fixed-base, hyperelastic, and nonlinear elastoplastic spud-can models are applied. The soil type is varied from loose to dense sand and also from soft NC clay to very stiff OC Clay. The effect of bias and coefficient of variation (COV) of the spud-can-soil interaction modeling and also the soil parameters such as the effective interface soil friction angle and also the undrained shear strength of clayey soil are studied. The results showed that inclusion of spud-can-soil interaction may have a considerable effect on the reliability of the jack-up platform. In particular, the bias and COV of soil have shown to have more significant effect on the reliability of jack-up platform in loose sand and soft clayey type soils. It is also found that bias in strength modeling of jack-up itself has less profound effect on the reliability index of the jack-up-foundation-soil system. Importance factors of spud-can-soil modeling are found to be quite considerable. The key aspect is that the inclusion of jack-up-spud-can-soil interaction is more crucial with respect to the reliability of jack-up platform than the choice of interaction model itself.

Evaluation of Deep Soil Mixing Efficiency in Stabilizing Loose Sandy Soils Using Laboratory Tests

2014 ◽  
Vol 37 (5) ◽  
pp. 20130099 ◽  
Author(s):  
Morteza Esmaeili ◽  
Morteza Gharouni-Nik ◽  
Hamid Khajehei
Keyword(s):  
Laboratory Tests ◽  
Sandy Soils ◽  
Mixing Efficiency ◽  
Deep Soil ◽  
Soil Mixing ◽  
Deep Soil Mixing
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