An evaluation of potential sampling locations in a reservoir with emphasis on conserved spatial correlation structure

2015-01-01
YENİLMEZ, Firdes
Duzgun, Sebnem
Aksoy, Ayşegül
In this study, kernel density estimation (KDE) was coupled with ordinary two-dimensional kriging (OK) to reduce the number of sampling locations in measurement and kriging of dissolved oxygen (DO) concentrations in Porsuk Dam Reservoir (PDR). Conservation of the spatial correlation structure in the DO distribution was a target. KDE was used as a tool to aid in identification of the sampling locations that would be removed from the sampling network in order to decrease the total number of samples. Accordingly, several networks were generated in which sampling locations were reduced from 65 to 10 in increments of 4 or 5 points at a time based on kernel density maps. DO variograms were constructed, and DO values in PDR were kriged. Performance of the networks in DO estimations were evaluated through various error metrics, standard error maps (SEM), and whether the spatial correlation structure was conserved or not. Results indicated that smaller number of sampling points resulted in loss of information in regard to spatial correlation structure in DO. The minimum representative sampling points for PDR was 35. Efficacy of the sampling location selection method was tested against the networks generated by experts. It was shown that the evaluation approach proposed in this study provided a better sampling network design in which the spatial correlation structure of DO was sustained for kriging.
ENVIRONMENTAL MONITORING AND ASSESSMENT

Suggestions

A comparative experimental and density functional study of glucose adsorption and electrooxidation on the Au-graphene and Pt-graphene electrodes
Caglar, Aykut; Duzenli, Derya; Önal, Işık; Tersevin, Ilker; Sahin, Ozlem; Demir Kıvrak, Hilal (2020-01-01)
At present, the graphene is covered on Cu foil with the 5 sccm hexane (C6H14) flow rate, 50 sccm hydrogen (H-2) flow rate, and 20 min deposition time parameters by the CVD method. The graphene on the Cu foil is then covered onto few-layer ITO electrode. Furthermore, the Pt and Au metals are electrodeposited on graphene/ITO electrode with electrochemical method. These electrodes are characterized by Raman spectroscopy and Scanning Electron Microscopy-Energy Dispersive X-Ray analysis (SEM-EDX). The graphene s...
An ONIOM and DFT Study of Water and Ammonia Adsorption on Anatase TiO2 (001) Cluster
Erdogan, Rezan; Önal, Işık (2011-08-05)
Density functional theory (DFT) calculations at ONIOM DFT B3LYP/6-31G**-MD/UFF level are employed to study molecular and dissociative water and ammonia adsorption on anatase TiO2 (001) surface represented by partially relaxed Ti20O35 ONIOM cluster. DFT calculations indicate that water molecule is dissociated on anatase TiO2 (001) surface by a nonactivated process with an exothermic relative energy difference of 58.12 kcal/mol. Dissociation of ammonia molecule on the same surface is energetically more favora...
Employing Imino-Bis-Propane Diol Functional Polymers for Boron Removal from Geothermal Waters via Polymer Enhanced Ultrafiltration
Zerze, Hasan; Ozbelge, H. Onder; Bicak, Niyazi; Yılmaz, Levent (2015-09-02)
In this study, polymer enhanced ultrafiltration (PEUF) was used to remove boron from a geothermal water sample. The effect of co-ions such as chloride and sulfate on boron removal was investigated using previously synthesized poly (vinyl amino-N, N'-bis-propane diol) (GPVA) and its copolymers with DADMAC. The presence of co-anions and use of real waste water did not significantly reduce boron retentions and permeate fluxes. At optimum operating conditions 98% boron removal was achieved. It was demonstrated ...
A comparative study of spectrophotometric and iodometric back titration methods for hydrogen sulfide determination in anoxic basins
Basturk, O; Romanov, A; Gokmen, S; Konovalov, S (2000-01-01)
Iodometric Back Titration (TBT) and Spectrophotometric (SPM) methods are two common methods used in the determination of hydrogen sulfide concentrations in anoxic basins, like in the upper sections of the Black Sea anoxic waters. Although the results obtained by both methods are in agreement when the concentrations of sulfide are higher than 30 mu M/l, IBT analysis gives more reproducible results compared to SPM analysis. On the other hand, the reproducibility of the SPM is better than that of IBT method wh...
An Investigation of the increase in variability of standard penetration test results for gravelly soils
Pehlivan, Alper; Yılmaz, Mustafa Tolga; Department of Engineering Sciences (2019)
Variability in the results of standard penetration tests (SPT) due to nonuniformity of particle size distribution in soil layers is a known issue in geotechnical applications. Such phenomenon may result in artificial increase in penetration resistance in silts, clays and sands due to encountering large particles. An analysis of SPT variability in such cases can be conducted by dividing the total penetration distance into two smaller segments. In this study, the difference between number of blow counts for t...
Citation Formats
F. YENİLMEZ, S. Duzgun, and A. Aksoy, “An evaluation of potential sampling locations in a reservoir with emphasis on conserved spatial correlation structure,” ENVIRONMENTAL MONITORING AND ASSESSMENT, pp. 0–0, 2015, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/39475.