keyword
MENU ▼
Read by QxMD icon Read
search

Semivariogram

keyword
https://www.readbyqxmd.com/read/28531962/how-geostatistics-can-help-you-find-lead-and-galvanized-water-service-lines-the-case-of-flint-mi
#1
Pierre Goovaerts
In the aftermath of Flint drinking water crisis, most US cities have been scrambling to locate all lead service lines (LSLs) in their water supply systems. This information, which is most often inaccurate or lacking, is critical to assess compliance with the Lead and Copper Rule and to plan the replacement of lead and galvanized service lines (GSLs) as currently under way in Flint. This paper presents the first geospatial approach to predict the likelihood that a home has a LSL or GSL based on neighboring field data (i...
May 17, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28428829/semivariogram-analysis-of-bone-images-implemented-on-fpga-architectures
#2
Mukul Shirvaikar, Yamuna Lagadapati, Xuanliang Dong
Osteoporotic fractures are a major concern for the healthcare of elderly and female populations. Early diagnosis of patients with a high risk of osteoporotic fractures can be enhanced by introducing second-order statistical analysis of bone image data using techniques such as variogram analysis. Such analysis is computationally intensive thereby creating an impediment for introduction into imaging machines found in common clinical settings. This paper investigates the fast implementation of the semivariogram algorithm, which has been proven to be effective in modeling bone strength, and should be of interest to readers in the areas of computer-aided diagnosis and quantitative image analysis...
March 2017: J Real Time Image Process
https://www.readbyqxmd.com/read/28264424/kriging-with-unknown-variance-components-for-regional-ionospheric-reconstruction
#3
Ling Huang, Hongping Zhang, Peiliang Xu, Jianghui Geng, Cheng Wang, Jingnan Liu
Ionospheric delay effect is a critical issue that limits the accuracy of precise Global Navigation Satellite System (GNSS) positioning and navigation for single-frequency users, especially in mid- and low-latitude regions where variations in the ionosphere are larger. Kriging spatial interpolation techniques have been recently introduced to model the spatial correlation and variability of ionosphere, which intrinsically assume that the ionosphere field is stochastically stationary but does not take the random observational errors into account...
February 27, 2017: Sensors
https://www.readbyqxmd.com/read/28229257/potential-ecological-risk-assessment-and-predicting-zinc-accumulation-in-soils
#4
Agnieszka Baran, Jerzy Wieczorek, Ryszard Mazurek, Krzysztof Urbański, Agnieszka Klimkowicz-Pawlas
The aims of this study were to investigate zinc content in the studied soils; evaluate the efficiency of geostatistics in presenting spatial variability of zinc in the soils; assess bioavailable forms of zinc in the soils and to assess soil-zinc binding ability; and to estimate the potential ecological risk of zinc in soils. The study was conducted in southern Poland, in the Malopolska Province. This area is characterized by a great diversity of geological structures and types of land use and intensity of industrial development...
February 22, 2017: Environmental Geochemistry and Health
https://www.readbyqxmd.com/read/28028098/spatial-distribution-and-coexisting-patterns-of-adults-and-nymphs-of-tibraca-limbativentris-hemiptera-pentatomidae-in-paddy-rice-fields
#5
Tavvs M Alves, Aline H N Maia, José A F Barrigossi
The rice stem stink bug, Tibraca limbativentris Stål (Hemiptera: Pentatomidae), is a primary insect pest of paddy rice in South America. Knowledge of its spatial distribution can support sampling plans needed for timely decisions about pest control. This study aimed to investigate the spatial distribution of adults and nymphs of T. limbativentris and determine the spatial coexistence of these stages of development. Fifteen paddy rice fields were scouted once each season to estimate insect densities. Scouting was performed on regular grids with sampling points separated by ∼50 m...
December 2016: Environmental Entomology
https://www.readbyqxmd.com/read/27920956/grassland-productivity-in-response-to-nutrient-additions-and-herbivory-is-scale-dependent
#6
Erica A H Smithwick, Douglas C Baldwin, Kusum J Naithani
Vegetation response to nutrient addition can vary across space, yet studies that explicitly incorporate spatial pattern into experimental approaches are rare. To explore whether there are unique spatial scales (grains) at which grass response to nutrients and herbivory is best expressed, we imposed a large (∼3.75 ha) experiment in a South African coastal grassland ecosystem. In two of six 60 × 60 m grassland plots, we imposed a scaled sampling design in which fertilizer was added in replicated sub-plots (1 × 1 m, 2 × 2 m, and 4 × 4 m)...
2016: PeerJ
https://www.readbyqxmd.com/read/27747271/spatial-variation-of-arsenic-in-soil-irrigation-water-and-plant-parts-a-microlevel-study
#7
M S Kabir, M A Salam, D N R Paul, M I Hossain, N M F Rahman, Abdullah Aziz, M A Latif
Arsenic pollution became a great problem in the recent past in different countries including Bangladesh. The microlevel studies were conducted to see the spatial variation of arsenic in soils and plant parts contaminated through ground water irrigation. The study was performed in shallow tube well command areas in Sadar Upazila (subdistrict), Faridpur, Bangladesh, where both soil and irrigation water arsenic are high. Semivariogram models were computed to determine the spatial dependency of soil, water, grain, straw, and husk arsenic (As)...
2016: TheScientificWorldJournal
https://www.readbyqxmd.com/read/27695761/kriging-models-predicting-atrazine-concentrations-in-surface-water-draining-agricultural-watersheds
#8
Paul L Mosquin, Jeremy Aldworth, Wenlin Chen
The performance of kriging methods in predicting maximum m-day (m = 1, 7, 14, or 30) rolling averages of atrazine concentrations in 42 site-years of Midwest Corn Belt watersheds under two systematic sampling designs (sampling every 7 or 14 d) was examined. Daily atrazine monitoring data obtained from the Atrazine Ecological Monitoring Program in the Corn Belt region (2009-2014) were used in the evaluation. Both ordinary and universal kriging methods were considered, with the covariate for universal kriging derived from the deterministic Pesticide Root Zone Model (PRZM)...
September 2016: Journal of Environmental Quality
https://www.readbyqxmd.com/read/27510986/assessment-of-the-spatial-variability-in-tall-wheatgrass-forage-using-landsat-8-satellite-imagery-to-delineate-potential-management-zones
#9
Pablo Cicore, João Serrano, Shakib Shahidian, Adelia Sousa, José Luis Costa, José Rafael Marques da Silva
Little information is available on the degree of within-field variability of potential production of Tall wheatgrass (Thinopyrum ponticum) forage under unirrigated conditions. The aim of this study was to characterize the spatial variability of the accumulated biomass (AB) without nutritional limitations through vegetation indexes, and then use this information to determine potential management zones. A 27-×-27-m grid cell size was chosen and 84 biomass sampling areas (BSA), each 2 m(2) in size, were georeferenced...
September 2016: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/27506022/-distribution-characteristics-and-influencing-factors-of-nitrate-pollution-in-shallow-groundwater-of-liujiang-basin
#10
He Wang, Hong-biao Gu, Bao-ming Chi, Hai-jun Li, Hai-ning Jiang
Taking the nitrate in shallow groundwater of Liujiang basin as the research object, a total of 215 groups of shallow groundwater samples were collected during the wet period in July 2014 and the drought period in April 2015 on the basis of groundwater pollution investigation. The characteristics of spatial and temporal variability and the account of nitrate pollution were analyzed based on the model of semivariogram, the geostatistics of ArcGIS and factor analysis, respectively. The results showed that the study region in the southeast was the main nitrate-polluted area, with concentrations of up to 30-120 mg · L⁻¹, in both wet and drought periods, while the nitrate-contaminated area in drought period was about 1...
May 15, 2016: Huan Jing Ke Xue= Huanjing Kexue
https://www.readbyqxmd.com/read/27471983/recent-climatic-events-controlling-the-hydrological-and-the-aquifer-dynamics-at-arid-areas-the-case-of-huasco-river-watershed-northern-chile
#11
I Salas, C Herrera, J A Luque, J Delgado, J Urrutia, T Jordan
The investigation assesses the influence of recent climatic events in the water resources and the aquifer dynamics in the Huasco watershed by means of the analysis of precipitation, streamflow and piezometric levels during the last 50years. These hydrological and hydrogeological parameters were evaluated by an exploratory geostatistical analysis (semivariogram) and a spectral analysis (periodogram). Specifically, the hydrological and hydrogeological data analyses are organized according to three sub-basins, the Del Carmen River (Section I), the El Tránsito River (Section II), and the Huasco River (Section III)...
November 15, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27429872/erratum-to-lessening-the-adverse-effect-of-the-semivariogram-model-selection-on-an-interpolative-survey-using-kriging-technique
#12
Zakari Arétouyap, Philippe Njandjock Nouck, Robert Nouayou, Franck Eithel Ghomsi Kemgang, Axel Dorian Piépi Toko, Jamal Asfahani
[This corrects the article DOI: 10.1186/s40064-016-2142-4.].
2016: SpringerPlus
https://www.readbyqxmd.com/read/27359000/assessment-of-groundwater-quality-using-dea-and-ahp-a-case-study-in-the-sereflikochisar-region-in-turkey
#13
Murat Kavurmaci, A Korkut Üstün
This study investigated the spatial distribution of groundwater quality in Sereflikochisar Basin, in the Central Anatolian region of Turkey using different hydrochemical, statistical, and geostatistical methods. A total of 51 groundwater samples were collected from the observation wells in the study area to evaluate the characteristics of the groundwater quality. As a relatively simple and practical method, a groundwater quality index (GWQI) was developed to evaluate the overall groundwater quality. In this process, complex decision-making techniques such as analytic hierarchy process (AHP) and data envelopment analysis (DEA) were used...
April 2016: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/27190748/lessening-the-adverse-effect-of-the-semivariogram-model-selection-on-an-interpolative-survey-using-kriging-technique
#14
Zakari Arétouyap, Philippe Njandjock Nouck, Robert Nouayou, Franck Eithel Ghomsi Kemgang, Axel Dorian Piépi Toko, Jamal Asfahani
OBJECTIVE: Many parameters in environmental, scientific and human sciences investigations need to be interpolated. Geostatistics, with its structural analysis step, is widely used for this purpose. This precious step that evaluates data correlation and dependency is performed thanks to semivariogram. However, an incorrect choice of a semivariogram model can skew all the prediction results. The main objectives of this paper are (1) to simply illustrate the influence of the choice of an inappropriate semivariogram model and (2) to show how a best-fitted model can be selected...
2016: SpringerPlus
https://www.readbyqxmd.com/read/27110991/geospatial-variability-of-soil-co2-c-exchange-in-the-main-terrestrial-ecosystems-of-keller-peninsula-maritime-antarctica
#15
A Thomazini, M R Francelino, A B Pereira, A L Schünemann, E S Mendonça, P H A Almeida, C E G R Schaefer
Soils and vegetation play an important role in the carbon exchange in Maritime Antarctica but little is known on the spatial variability of carbon processes in Antarctic terrestrial environments. The objective of the current study was to investigate (i) the soil development and (ii) spatial variability of ecosystem respiration (ER), net ecosystem CO2 exchange (NEE), gross primary production (GPP), soil temperature (ST) and soil moisture (SM) under four distinct vegetation types and a bare soil in Keller Peninsula, King George Island, Maritime Antarctica, as follows: site 1: moss-turf community; site 2: moss-carpet community; site 3: phanerogamic antarctic community; site 4: moss-carpet community (predominantly colonized by Sanionia uncinata); site 5: bare soil...
August 15, 2016: Science of the Total Environment
https://www.readbyqxmd.com/read/27078967/-pollution-assessment-and-spatial-distribution-characteristics-of-heavy-metals-in-soils-of-coal-mining-area-in-longkou-city
#16
Shuo Liu, Quan-yuan Wu, Xue-jiang Cao, Ji-ning Wang, Long-long Zhang, Dong-quan Cai, Li-yuan Zhou, Na Liu
The present paper takes the coal mining area of Longkou City as the research area. Thirty-six topsoil (0-20 cm) samples were collected and the contents of 5 kinds of heavy metals were determined, including Cd, As, Ni, Ph, Cr. Geo-statistics analysis was used to analyze the spatial distribution of heavy metals. Principal component analysis (PCA) was used to explore the pollution sources of heavy metals and the degree of heavy metals pollution was evaluated by weighted average comprehensive pollution evaluation method...
January 15, 2016: Huan Jing Ke Xue= Huanjing Kexue
https://www.readbyqxmd.com/read/27069713/spatial-variability-and-distribution-of-the-metals-in-surface-runoff-in-a-nonferrous-metal-mine
#17
Bozhi Ren, Yangbo Chen, Guocheng Zhu, Zhenghua Wang, Xie Zheng
The spatial variation and distribution features of the metals tested in the surface runoff in Xikuangshan Bao Daxing miming area were analyzed by combining statistical methods with a geographic information system (GIS). The results showed that the maximum concentrations of those five kinds of the metals (Sb, Zn, Cu, Pb, and Cd) in the surface runoff of the antimony mining area were lower than the standard value except the concentration of metal Ni. Their concentrations were 497.1, 2.0, 1.8, 22.2, and 22.1 times larger than the standard value, respectively...
2016: Journal of Analytical Methods in Chemistry
https://www.readbyqxmd.com/read/27067017/uncertainty-assessment-of-pm2-5-contamination-mapping-using-spatiotemporal-sequential-indicator-simulations-and-multi-temporal-monitoring-data
#18
Yong Yang, George Christakos, Wei Huang, Chengda Lin, Peihong Fu, Yang Mei
Because of the rapid economic growth in China, many regions are subjected to severe particulate matter pollution. Thus, improving the methods of determining the spatiotemporal distribution and uncertainty of air pollution can provide considerable benefits when developing risk assessments and environmental policies. The uncertainty assessment methods currently in use include the sequential indicator simulation (SIS) and indicator kriging techniques. However, these methods cannot be employed to assess multi-temporal data...
April 12, 2016: Scientific Reports
https://www.readbyqxmd.com/read/27034240/assessment-of-groundwater-quality-using-dea-and-ahp-a-case-study-in-the-sereflikochisar-region-in-turkey
#19
Murat Kavurmaci, A Korkut Üstün
This study investigated the spatial distribution of groundwater quality in Sereflikochisar Basin, in the Central Anatolian region of Turkey using different hydrochemical, statistical, and geostatistical methods. A total of 51 groundwater samples were collected from the observation wells in the study area to evaluate the characteristics of the groundwater quality. As a relatively simple and practical method, a groundwater quality index (GWQI) was developed to evaluate the overall groundwater quality. In this process, complex decision-making techniques such as analytic hierarchy process (AHP) and data envelopment analysis (DEA) were used...
April 2016: Environmental Monitoring and Assessment
https://www.readbyqxmd.com/read/26935208/small-scale-spatio-temporal-distribution-of-bactrocera-minax-enderlein-diptera-tephritidae-using-probability-kriging
#20
S Q Wang, H Y Zhang, Z L Li
Understanding spatio-temporal distribution of pest in orchards can provide important information that could be used to design monitoring schemes and establish better means for pest control. In this study, the spatial and temporal distribution of Bactrocera minax (Enderlein) (Diptera: Tephritidae) was assessed, and activity trends were evaluated by using probability kriging. Adults of B. minax were captured in two successive occurrences in a small-scale citrus orchard by using food bait traps, which were placed both inside and outside the orchard...
October 2016: Neotropical Entomology
keyword
keyword
9515
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"