scholarly journals Determination of Spatial Variability in Sunflower Production

2018 ◽  
Author(s):  
Fatih Bakanogulları ◽  
Ulaş Ay ◽  
Bahattin Akdemir
Keyword(s):  
Spatial Variability ◽  
Sunflower Production

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 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

scholarly journals Small relief shape variations influence spatial variability of soil chemical attributes

2006 ◽  
Vol 63 (2) ◽  
pp. 161-168 ◽  
Author(s):  
Zigomar Menezes de Souza ◽  
José Marques Júnior ◽  
Gener Tadeu Pereira ◽  
Diogo Mazza Barbieri
Keyword(s):  
Spatial Variability ◽  
Cation Exchange ◽  
Sugar Cane ◽  
Management System ◽  
Cation Exchange Capacity ◽  
Exchange Capacity ◽  
Soil Samples ◽  
Base Saturation ◽  
Chemical Attributes

Soils with small variations in relief and under the same management system present differentiated spatial variabilities of their attributes. This variability is a function of soil position in the landscape, even if the relief has little expression. The aim of this work was to investigate the effects of relief shape and depth on spatial variability of soil chemical attributes in a Typic Hapludox cultivated with sugar cane at two landscape compartments. Soil samples were collected in the intercrossing points of a grid, in the traffic line, at 0-0.2 m and 0.6-0.8 m depths, comprising a set of 100 georeferenced points. The spatial variabilities of pH, P, K, Ca, Mg, cation exchange capacity and base saturation were quantified. Small relief shape variations lead to differentiated variability in soil chemical attributes as indicated by the dependence on pedoform found for chemical attributes at both 0-0.2 m and 0.6-0.8 m depths. Because of the higher variability, it is advisable to collect large number of samples in areas with concave and convex shapes. Combining relief shapes and geostatistics allows the determination of areas with different spatial variability for soil chemical attributes.

scholarly journals The GEOBASI (Geochemical Database of Tuscany) open source tools

2016 ◽  
Author(s):  
Manuela Corongiu ◽  
Brunella Raco ◽  
Antonella Buccianti ◽  
Patrizia Macera ◽  
Riccardo Mari ◽  
...  
Keyword(s):  
Detection Limit ◽  
Spatial Variability ◽  
Chemical Species ◽  
Geographic Location ◽  
Web Gis ◽  
Geochemical Data ◽  
Private Companies ◽  
Public And Private ◽  
Numerical Tools

The tools implemented for the new Regional Geochemical Database, called GEOBASI, are hereafter presented. The database has permitted the construction of a repository where the geochemical information (compositional and isotopic) has been stored in a structured way so that it can be available for different groups of users (e.g. institutional, public and private companies). The information contained in the database can in fact be downloaded freely and queried to correlate geochemistry to other non compositional variables. The repository has been aimed at promoting the use of the geochemical data already available from previous investigations through a powerful Web-GIS interface. The resulting graphical-numerical tools in such a complex database have been developed to: 1) analyse the spatial variability of the investigated context, 2) highlight the geographic location of data pertaining to classes of values or single cases, 3) compare the results of different analytical methodologies applied to the determination of the same element and/or chemical species, 4) extract the geochemical data related to specific monitoring plans and/or geographical areas, and finally 5) recover information about data below the detection limit to understand their impact on the behaviour of the investigated variable.

scholarly journals Determination of homogeneous zones for liming recommendations of black pepper using geostatistics

2016 ◽  
Vol 20 (10) ◽  
pp. 918-924 ◽  
Author(s):  
Ivoney Gontijo ◽  
Eduardo O. de J. Santos ◽  
Fábio L. Partelli ◽  
Andreia B. P. L. Gontijo ◽  
Fábio R. Pires
Keyword(s):  
Spatial Variability ◽  
Crop Productivity ◽  
Black Pepper ◽  
Piper Nigrum ◽  
Sampling Point ◽  
Spatial Dependency ◽  
Soil Liming ◽  
Definition Of ◽  
Agricultural Input

ABSTRACT Studies aimed at determining homogeneous zones and the spatial variability of soil characteristics may improve the efficiency of agricultural input applications. The purpose of this study was to determine homogeneous zones for liming applications and to characterize the spatial variability of characteristics related to soil acidity and productivity in an Oxisol cultivated with black pepper (Piper nigrum L.). This study was carried out in São Mateus, state of Espírito Santo, Brazil. The experimental site was 100 x 120 m. A grid with 126 sampling points was established. Three soil sub-samples were collected at each sampling point in the black pepper canopy areas, at a 0-0.20 m depth. Crop productivity was estimated by harvesting the three plants neighboring each sampling point. Descriptive statistics and geostatistical analyses were performed. Homogeneous management zones were defined based on map of liming needs. Mathematical models adjusted to semivariograms indicated that all of the studied variables exhibited spatial dependency. An analysis of the spatial variability together with the definition of homogeneous zones can be used to increase the efficiency of soil liming.

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
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