Handling Spatial Data Uncertainty Using a Fuzzy Geostatistical Approach for Modelling Methane Emissions at the Island of Java

2006 ◽  
pp. 173-187 ◽  
Author(s):  
Alfred Stein ◽  
Mamta Verma
Water ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3269
Author(s):  
Marianna Cangemi ◽  
Valentina Censi ◽  
Paolo Madonia ◽  
Rocco Favara

Sources of groundwater contaminants in inhabited areas, located in complex geo-tectonic contexts, are often deeply interlocked, thus, making the discrimination between anthropic and natural origins difficult. In this study, we investigate the Peloritani Mountain aquifers (Sicily, Italy), using the combination of probability plots with concentration contour maps to retrieve an overall view of the groundwater geo-chemistry with a special focus on the flux of heavy metals. In particular, we present a methodology for integrating spatial data with very different levels of precision, acquired before and during the “geomatic era”. Our results depict a complex geochemical layout driven by a geo-puzzle of rocks with very different lithological natures, hydraulically connected by a dense tectonic network that is also responsible for the mixing of deep hydrothermal fluids with the meteoric recharge. Moreover, a double source, geogenic or anthropogenic, was individuated for many chemicals delivered to groundwater bodies. The concentration contour maps, based on the different data groups identified by the probability plots, fit the coherency and congruency criteria with the distribution of both rock matrices and anthropogenic sources for chemicals, indicating the success of our geostatistical approach.


2006 ◽  
Vol 32 (4) ◽  
pp. 316-323 ◽  
Author(s):  
Y. F. Shi ◽  
F. X. Jin ◽  
M. Y. Li

2021 ◽  
Author(s):  
Laurie Jayne Kurilla ◽  
Giandomenico Fubelli

Abstract. In a study of debris flow susceptibility on the European continent, an analysis of the impact between known location and a location accuracy offset for 99 debris flows, demonstrates the impact of uncertainty in defining appropriate predisposing factors, and consequent analysis for areas of susceptibility. The dominant predisposing environmental factors, as determined through Maximum Entropy modeling, are presented, and analyzed with respect to the values found at debris flow event points versus a buffered distance of locational uncertainty around each point. Five Maximum Entropy susceptibility models are developed utilizing the original debris flow inventory of points, randomly generated points, and two models utilizing a subset of points with an uncertainty of 5 km, 1 km, and a model utilizing only points with a known location of “exact”. The AUCs are 0.891, 0.893, 0.896, 0.921, and 0.93, respectively. The “exact” model, with the highest AUC, is ignored in final analyses due to the small number of points, and localized distribution, and hence susceptibility results likely non-representational of the continent. Each model is analyzed with respect to the AUC, highest contributing factors, factor classes, susceptibility impact, and comparisons of the susceptibility distributions and susceptibility value differences. Based on model comparisons, geographic extent and context of this study, the models utilizing points with a location uncertainty of less than or equal to 5 km best represent debris flow susceptibility of the continent of Europe. A novel representation of the uncertainty is expressed, and included in a final susceptibility map, as an overlay of standard deviation and mean of susceptibility values for the two best models, providing additional insight for subsequent action.


Author(s):  
Linna Li ◽  
Hyowon Ban ◽  
Suzanne P. Wechsler ◽  
Bo Xu

Author(s):  
N. R. Stéphenne ◽  
B. Beaumont ◽  
M. Veschkens ◽  
S. Palm ◽  
C. Charlemagne

This paper describes a WebGIS prototype developed for the Walloon administration to improve the communication and the management of sediments dredging actions carried out in rivers and lakes. In Wallonia, levelling dredged sediments on banks requires an official authorization from the administration. This request refers to geospatial datasets such as the official land use map, the cadastral map or the distance to potential pollution sources. Centralising geodatabases within a web interface facilitate the management of these authorizations for the managers and the central administration. The proposed system integrates various data from disparate sources. Some issues in map scale, spatial search quality and cartographic visualisation are discussed in this paper with the solutions provided. The prototype web application is currently discussed with some potential users in order to understand in which way this tool facilitate the communication, the management and the quality of the authorisation process. The structure of the paper states the why, what, who and how of this communication tool with a special focus on errors and uncertainties.


2017 ◽  
Vol 2017 (Q4) ◽  
Author(s):  
Linna Li

2017 ◽  
Vol 8 (2) ◽  
pp. 594-599 ◽  
Author(s):  
A. Castrignanò ◽  
R. Quarto ◽  
A. Venezia ◽  
G. Buttafuoco

The paper proposes a geostatistical framework to solve the issues of heterogeneous support for spatial estimation. Apparent soil electrical conductivity (ECa) was measured in a field cropped with San Marzano tomato using a multiple frequency electromagnetic profiler with 6 operating frequencies. Mixed support kriging was used to estimate ECa taking into account the change of support. The method includes punctual kriging with the error being the dispersion variance associated with each frequency. The individual ECa maps were weighted by the dispersion variance to obtain a map which was used for field partition in management zones.


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