The nugget/sill ratio shows highly spatially dependence for most parameters studies, i.e. EC, TDS, pH, DO, Cl, NO3, Na, Ca and depth but moderate-weak for SO4 and weak for K and F. Table 1 Result of the semi-variogram function modelling used to create the prediction maps of the water quality Water property TDS pH EC DO Na K Ca Mg Fe F Cl NO3 SO4 HCO3 Depth Model GS Sph.
Taking into consideration spatial dependence, a spatially weighted model accounting for spatial heterogeneity is constructed by including variables to capture the characteristics of nearby neighbourhoods (i.e. spatially lagged variables).
Two broad categories of spatial analytical models include spatially autoregressive (SAR) methods, which deal with spatial dependence [ 19], and geographically weighted (GWR) methods, which deal with spatial non-stationarity [ 20].
Where θ i represented the spatially structured random effects, which account for the spatial dependence with the prior distribution taken as a conditional intrinsic Gaussian autoregressive model.
However, recent developments in the analysis of spatially correlated survival data mean that a multivariate spatial dependence structure has been proposed.
Because of the ill-posedness of the inverse problem, the reconstruction method in fluorescence tomography usually sets up a least square optimization problem minimizing an objective function given by: where λ(r) is a spatially variant regularization parameter to compensate for the spatial dependence of the contrast and resolution in the reconstruction [ 37].
Spatially lagged regression models are employed to analyse whether spatial dependence between proximate inland ports can be observed or, alternatively, whether the density of the inland port network in the Netherlands is leading to diseconomies of scale because of overproximity.
The formal test of spatial dependence was statistically significant at the 0.01 level, implying that distribution of human brucellosis was spatially dependent in mainland China.
As our analysis shows, using models that account for spatial dependence may greatly improve the identification of independent factors that are truly associated with HPV vaccination (as opposed to spatially confounded covariates), particularly when analysing data from varying geographic locations.
The variables that are spatially distributed, such as part-time and location in a vulnerable nitrogen zone, were not significant in explaining HNV, due to the spatial dependence.
It is important to notice, however, that the spatial dependence tests performed for both models indicate the presence of significant spatial dependence, in the form of spatial error autocorrelation or a spatially lagged dependent variable.
