Iterative method of finding hydraulic conductivity characteristics of soil moisture

2016 ◽  
Author(s):  
Bolatbek Rysbaiuly ◽  
Abilmazhin Adamov
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Iterative Method

scholarly journals Large-scale lateral saturated soil hydraulic conductivity as metric for the connectivity of the subsurface flow paths at hillslope scale

2021 ◽  
Author(s):  
Mario Pirastru ◽  
Massimo Iovino ◽  
Hassan Awada ◽  
Roberto Marrosu ◽  
Simone Di Prima ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Spatial Scale ◽  
Water Table ◽  
Subsurface Flow ◽  
Lateral Flow ◽  
Saturated Soil ◽  
Flow Paths ◽  
Soil Hydraulic Conductivity ◽  
Hillslope Scale

Lateral saturated soil hydraulic conductivity, Ks,l, is the soil property governing subsurface water transfer in hillslopes, and the key parameter in many numerical models simulating hydrological processes both at the hillslope and catchment scales. Likewise, the hydrological connectivity of lateral flow paths plays a significant role in determining the intensity of the subsurface flow at various spatial scales. The objective of the study is to investigate the relationship between Ks,l and hydraulic connectivity at the hillslope spatial scale. Ks,l was determined by the subsurface flow rates intercepted by drains, and by water table depths observed in a well network. Hydraulic connectivity of the lateral flow paths was evaluated by the synchronicity among piezometric peaks, and between the latter and the peaks of drained flow. Soil moisture and precipitation data were used to investigate the influence of the transient hydrological soil condition on connectivity and Ks,l. It was found that the higher was the synchronicity of the water table response between wells, the lower was the time lag between the peaks of water levels and those of the drained subsurface flow. Moreover, the most synchronic water table rises determined the highest drainage rates. The relationships between Ks,l and water table depths were highly non-linear, with a sharp increase of the values for water table levels close to the soil surface. Estimated Ks,l values for the full saturated soil were in the order of thousands of mm h-1, suggesting the activation of macropores in the root zone. The Ks,l values determined at the peak of the drainage events were correlated with the indicators of synchronicity. The sum of the antecedent soil moisture and of the precipitation was correlated with the indicators of connectivity and with Ks,l. We suggest that, for simulating realistic processes at the hillslope scale, the hydraulic connectivity could be implicitly considered in hydrological modelling through an evaluation of Ks,l at the same spatial scale.

scholarly journals Effect of Water Quality and Date Palm Biochar on Evaporation and Specific Hydrological Characteristics of Sandy Soil

Agriculture ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 300
Author(s):  
Arafat Alkhasha ◽  
Abdulrasoul Al-Omran ◽  
and Abdulaziz G. Alghamdi
Keyword(s):  
Water Quality ◽  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Date Palm ◽  
Saline Water ◽  
Sandy Soils ◽  
Infiltration Rate ◽  
Hydrological Characteristics ◽  
Arid Conditions ◽  
Cumulative Infiltration

Experiments were conducted in a soil laboratory using transparent columns (5 and 40 cm in diameter and length, respectively) to evaluate the effects of water quality (i.e., fresh or saline water) with the addition of biochar on soil moisture characteristics. Soil and biochar were gently combined and added into the top 10 cm of each column at a rate of 2%, 4%, 6%, and 8% (w/w). The results show a decrease in cumulative evaporation by 29.27%, 16.47%, 14.17%, and 14.61% with freshwater, and by 21.24%, 12.22%, 21.08%, and 12.67% with saline water for B1, B2, B3, and B4, respectively, compared with unamended soil (B1, B2, B3 and B4 represent the treatments with the biochar rate of 2, 4, 6, and 8%, respectively). Cumulative infiltration was reduced by 34.38%, 43.37%, 58.89%, and 57.07% with freshwater, and by 30.18%, 44.38%, 54.44%, and 49.11% with saline water for B1, B2, B3, and B4, respectively. The infiltration rate was reduced by 32.73%, 42.17%, 57.82%, and 56.85% with freshwater, and 42.09%, 54.6%1, 62.68%, and 58.41% with saline water for T1, T2, T3, and T4, respectively, compared with the control. The saturated hydraulic conductivity of B1 decreased significantly by 92.8% and 67.72% with fresh and saline water, respectively. Biochar, as a soil conditioner, could be used in arid conditions with fresh and saline water to enhance the hydrological properties of sandy soils.

scholarly journals Modeling the hydrophysical soil properties and comparative analysis for three systems of functions

2020 ◽  
Vol 175 ◽  
pp. 09016
Author(s):  
Vitaly Terleev ◽  
Roman Ginevsky ◽  
Viktor Lazarev ◽  
Aleksandr Nikonorov ◽  
Alexander Topaj ◽  
...  
Keyword(s):  
Porous Medium ◽  
Soil Moisture ◽  
Comparative Analysis ◽  
Hydraulic Conductivity ◽  
Soil Properties ◽  
Water Retention ◽  
Field Measurements ◽  
Practical Significance ◽  
Water Retention Capacity ◽  
Retention Capacity

A functional description of the hydrophysical properties of the soil as a capillary-porous medium is presented. The described functions of water retention capacity and hydraulic conductivity of the soil have common parameters, which are interpreted within the framework of physical and statistical concepts. The practical significance of the proposed functions lies in the fact that the volume of labor-intensive field measurements necessary, for example, for modeling the dynamics of soil moisture, is significantly reduced. To identify the parameters of these functions, it is sufficient to use data only on the water retention capacity of the soil. The parameters identified in this way can be used to predict the ratio of the hydraulic conductivity of the soil to the moisture filtration coefficient. The presented system of the hydrophysical functions of the soil is compared with world analogues using literature data on soils of different texture.

COMPARISON OF METHODS FOR DETERMINING SATURATED HYDRAULIC CONDUCTIVITY AND DRAINABLE POROSITY OF TWO SOUTHERN ALBERTA SOILS

1986 ◽  
Vol 66 (2) ◽  
pp. 249-259 ◽  
Author(s):  
G. D. BUCKLAND ◽  
D. B. HARKER ◽  
T. G. SOMMERFELDT
Keyword(s):  
Soil Moisture ◽  
Hydraulic Conductivity ◽  
Characteristic Curve ◽  
Subsurface Drainage ◽  
Saturated Hydraulic Conductivity ◽  
Drainage Design ◽  
Moisture Characteristic ◽  
Constant Head ◽  
Subsurface Drains ◽  
Drainable Porosity

Saturated hydraulic conductivity (Ks) and drainable porosity (f) determined by different methods and for different depths were compared with those determined from the performance of drainage systems installed at two locations. These comparisons were made to determine which methods are suitable for use in subsurface drainage design. Auger hole and constant-head well permeameter Ks were 140 and 110%, respectively, of Ks determined from subsurface drains. Agreement of horizontal or vertical Ks, from in situ falling-head permeameters; to other methods was satisfactory providing sample numbers were large. Ks by Tempe cells was only 3–10% of drain Ks and in one instance was significantly lower than Ks determined by all other methods. At one site a profile-averaged value of f determined from the soil moisture characteristic curve (0–5 kPa) of semidisturbed cores agreed with that determined from drainage trials. At the other site, a satisfactory value of f was found only when the zone in which the water table fluctuated was considered. Results indicate that Ks determined by the auger hole and constant-head well permeameter methods, and f determined from the soil moisture characteristic curve of semidisturbed cores, are sufficiently reliable and practical for subsurface drainage design. Key words: Subsurface drainage, hydraulic conductivity, drainable porosity

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