Determination of Spatial Variability of Nutrient Composition of Soil Solutions in Greenhouses by Using Suction Cups

2003 ◽  
Vol 34 (5-6) ◽  
pp. 865-879 ◽  
Author(s):  
M. T. Lao ◽  
S. Jiménez ◽  
E. Eymar ◽  
E. J. Fernández ◽  
R. Jiménez
Keyword(s):  
Spatial Variability ◽  
Nutrient Composition ◽  
Soil Solutions ◽  
Suction Cups

scholarly journals Experimental investigation to characterize simple versus multi scaling analysis of hydraulic conductivity at a mesoscale

2021 ◽  
Author(s):  
Guglielmo Federico Antonio Brunetti ◽  
Samuele De Bartolo ◽  
Carmine Fallico ◽  
Ferdinando Frega ◽  
Maria Fernanda Rivera Velásquez ◽  
...  
Keyword(s):  
Hydraulic Conductivity ◽  
Spatial Variability ◽  
Hydraulic Properties ◽  
Scaling Laws ◽  
Scaling Analysis ◽  
Field Scale ◽  
Porous Formation ◽  
Proper Design ◽  
First Time

AbstractThe spatial variability of the aquifers' hydraulic properties can be satisfactorily described by means of scaling laws. The latter enable one to relate the small (typically laboratory) scale to the larger (typically formation/regional) ones, therefore leading de facto to an upscaling procedure. In the present study, we are concerned with the spatial variability of the hydraulic conductivity K into a strongly heterogeneous porous formation. A strategy, allowing one to identify correctly the single/multiple scaling of K, is applied for the first time to a large caisson, where the medium was packed. In particular, we show how to identify the various scaling ranges with special emphasis on the determination of the related cut-off limits. Finally, we illustrate how the heterogeneity enhances with the increasing scale of observation, by identifying the proper law accounting for the transition from the laboratory to the field scale. Results of the present study are of paramount utility for the proper design of pumping tests in formations where the degree of spatial variability of the hydraulic conductivity does not allow regarding them as “weakly heterogeneous”, as well as for the study of dispersion mechanisms.

scholarly journals Properties, processes and regimes of soil solutions and surface waters

2020 ◽  
Vol 175 ◽  
pp. 12022
Author(s):  
Guriyat Podvolotskaya ◽  
Sergey Belopukhov ◽  
Vitaly Savich ◽  
Andrey Sorokin ◽  
Nikolay Tyutrin
Keyword(s):  
Biological Activity ◽  
Surface Water ◽  
Surface Waters ◽  
Pair Correlation ◽  
Rate Of Change ◽  
Water Soluble ◽  
Soil Solutions ◽  
Different Depths ◽  
Different Soils

Soil solutions and the surface waters are characterized by properties, processes and regimes. Soil solutions of different soils and their surface water have different biological activity and change the activity of dissolved stimulants and inhibitors. The object of the study are soil solutions of the main types of soils obtained in the model experiments with the ratio of soils: water equal to 1:1 and 1: 2, soil solutions and surface water in the flooding of soils with water for 1 week – 3 months. The research method consisted in the assessment of pH, Eh, activity of K, NO3, NH4, Ca, Mg by conventional methods, assessment of concentrations of water-soluble compounds extracted from soils by ionite membranes, in the assessment of biological activity of solutions using biotests. The following is suggested for additional evaluation: the using of cation and anion membranes, determination of interrelation between the properties of waters, equation of pair correlation and multiply regression. The informative value of the gradient of surface water concentrations at different distances from the floor of the reservoir, at different depths of the overwatered soils is shown. The mobility of Ca, Mg, Fe, Mn in soils and the content of their water-soluble forms depends on both pH and Eh, whose influence on the content of water-soluble forms of the considered cations shows the effects of synergy and antagonism. The rate of change in the composition of soil solutions during soil flooding depends on a combination of soil properties, temperature, and duration of flooding. Soil solutions of different soils and their surface waters have differentrates.

scholarly journals SCS-CN parameter determination using rainfall-runoff data in heterogeneous watersheds – the two-CN system approach

2012 ◽  
Vol 16 (3) ◽  
pp. 1001-1015 ◽  
Author(s):  
K. X. Soulis ◽  
J. D. Valiantzas
Keyword(s):  
Land Cover ◽  
Spatial Variability ◽  
System Approach ◽  
Parameter Determination ◽  
Rainfall Runoff ◽  
Simple Method ◽  
Rainfall Depth ◽  
Natural Watersheds ◽  
Scs Cn

Abstract. The Soil Conservation Service Curve Number (SCS-CN) approach is widely used as a simple method for predicting direct runoff volume for a given rainfall event. The CN parameter values corresponding to various soil, land cover, and land management conditions can be selected from tables, but it is preferable to estimate the CN value from measured rainfall-runoff data if available. However, previous researchers indicated that the CN values calculated from measured rainfall-runoff data vary systematically with the rainfall depth. Hence, they suggested the determination of a single asymptotic CN value observed for very high rainfall depths to characterize the watersheds' runoff response. In this paper, the hypothesis that the observed correlation between the calculated CN value and the rainfall depth in a watershed reflects the effect of soils and land cover spatial variability on its hydrologic response is being tested. Based on this hypothesis, the simplified concept of a two-CN heterogeneous system is introduced to model the observed CN-rainfall variation by reducing the CN spatial variability into two classes. The behaviour of the CN-rainfall function produced by the simplified two-CN system is approached theoretically, it is analysed systematically, and it is found to be similar to the variation observed in natural watersheds. Synthetic data tests, natural watersheds examples, and detailed study of two natural experimental watersheds with known spatial heterogeneity characteristics were used to evaluate the method. The results indicate that the determination of CN values from rainfall runoff data using the proposed two-CN system approach provides reasonable accuracy and it over performs the previous methods based on the determination of a single asymptotic CN value. Although the suggested method increases the number of unknown parameters to three (instead of one), a clear physical reasoning for them is presented.

scholarly journals Space geodetic determination of spatial variability in relative sea level change, Los Angeles basin

2007 ◽  
Vol 34 (1) ◽  
Author(s):  
B. A. Brooks ◽  
M. A. Merrifield ◽  
J. Foster ◽  
C. L. Werner ◽  
F. Gomez ◽  
...  
Keyword(s):  
Los Angeles ◽  
Spatial Variability ◽  
Sea Level ◽  
Sea Level Change ◽  
Los Angeles Basin ◽  
Relative Sea Level ◽  
Level Change
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