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A more efficient noise filtering technique is needed in ensemble data assimilation, to improve traditional spectral filtering methods that cannot reflect the local characteristics of spatial scales. In this paper, we present the design of a novel constrained wavelet threshold denoising method (CWTDNM) by introducing an improved threshold value and a new constraining parameter. The proposed method aims to filter noise swamped over different scales. We prepared an ideal experiment object based on the two-dimensional barotropic vorticity equation. A suitable wavelet basis function (i.e., Db11) and the optimal number of decomposition levels (i.e., five) were first selected. The results show that, given the wavelet coefficients are constrained by the parameter, the CWTDNM can produce better filtering results with the smallest root mean square error (RMSE) compared to similar methods. In addition, the filtering accuracy of 10 ensemble sample variances using the CWTDNM is equivalent to that estimated directly from 80 ensemble samples, but with the runtime reduced to approximately one-seventh. Furthermore, a large peak signal-to-noise ratio, which implies a low RMSE, suggests that the proposed method suitably preserves most of the information after denoising.

This paper presents a model for the evaluation of marine sites that utilize site specific spatial datasets in the estimation of ecosystem cumulative effects. The model is motivated by the evaluation of marine sites for aquaculture. Maps of the coastal zone of Grand Manan Island, New Brunswick in the Bay of Fundy along Canada's Atlantic coast are utilized for the purpose of illustrating the model. The data sets, processed as thematic layers in a Geographic Information System (GIS) describing the marine site, represent natural resource abundance, habitat inventory, valuations from economic and recreational activities, and influence plumes from sources of effluents. The valuation methodology assigns quantitative yields by layer-area of each selected site, as well as yields for the pairwise overlapping “cumulative effects” layers of the datasets based on defined yield impact functions. Results are presented that validate the model as an effective decision support tool for defining aquaculture sites of interest.

In assigning value to marine sites, the multiple, overlapping layers of the site’s spatial ecosystem components that produce cumulative effects need to be taken into account. This paper presents a model for the evaluation of marine sites that utilizes site specific spatial datasets in the estimation of cumulative effects. The model is applied to the coastal zone of Grand Manan Island, New Brunswick situated in the Bay of Fundy. Model results are motivated by an aquaculture site evaluation case study used to illustrate its application. The model utilizes site specific spatial datasets representing natural resources abundance, habitat inventoty, values from commercial and recreational activities, and influence plumes from sources of effluents present at the site. These datasets are processed as thematic layers in a GIS describing the marine site. Experiments determined that the model works well in estimating the cumulative effects of interacting component layers associated with various marine sites.

Following a scheme developed for a subduction zone by Savage in 1983, which was successfully applied to a transform plate boundary by Matsu’ura and others in 1986, a dislocation model for a plate collision zone is formulated. The solution consists of a rigid plate motion and a tensile dislocation. In addition to this, a strike-slip dislocation is needed when the collision boundary is not perpendicular to the plate converging direction. Theoretically predicted gradual change in horizontal displacements over the collision zone well explains the results of GPS continuous observation in central Japan where the Eurasian and Okhotsk plates are thought to be colliding. The maximum uplift rate is predicted as 1/π times that of converging velocity, however the observed uplift rate is much smaller than that, although vertical movements observed by GPS network is much less accurate than horizontal movements. A comparison of the theoretical results with the observation suggests relatively thin elastic plates, whose thickness is about 30 km. The obtained dislocation model has a close connection with a horizontal detachment fault. The displacement fields above the advancing and retreating edges of a horizontal rectangular detachment fault are mathematically equivalent to those of collision and rift zones, respectively, and lateral edges to a transform fault boundary. The displacement fields at a colliding and a rifting boundaries are the same except for their signs.