A scoping review on the multiplicity of scale in spatial analysis

Journal of Geographical Systems - Scale is a central concept in the geographical sciences and is an intrinsic property of many spatial systems. It also serves as an essential thread in the fabric...     

An Integrated Moral Obligation Model for Landowner Conservation Norms

This study applies an integrated moral obligation model to examine the role of environmental and cultural values, and beliefs in the activation of landowner conservation norms. Data for this study were collected through a self-administered survey of riparian landowners in two Minnesota watersheds: Sand Creek and Vermillion River watersheds. Study findings suggest that collectivistic and biospheric–altruistic values form the bases for the activation of personal norms. Further, beliefs about local responsibility and ability to act influence personal norms to protect water resources. Findings suggest that landowners’ personal norms of water conservation are more likely to be activated by conservation strategies that appeal to biospheric–altruistic and collectivistic values, emphasize adverse consequences of water pollution, highlight water resource protection as a local responsibility, and provide the resources needed to protect water resources.     

A High-accuracy, Small Field of View Star Guider with Application to SNAP

To accomplish its mission, the spaceborne observatory SNAP (SuperNova Acceleration Probe) requires a pointing stability of <0.03 arcseconds during exposures lasting up to 500 sec. A Monte Carlo simulation of the photoelectron statistics from the guiding star investigates geometrical (such as the pixel size of the detector or the plate scale) and physical parameters (such as the magnitude of the star). It is shown that simple centroiding calculations can lead to the desired accuracy with guide stars as faint as magnitude 16. Availability of these stars is verified thanks to the HST Guide Star Catalog complemented with a statistical model of the distribution of stars. Thus a through-the-lens sensor that uses stars as faint as magnitude 16 to provide the necessary guiding signals is feasible. This revised version was published online in July 2006 with corrections to the Cover Date.     

Calculation of transverse hydrodynamic coefficients using computational fluid dynamic approach

Computational Fluid Dynamic (CFD) based on Reynolds Averaged Navier–Stokes equation is used for determining the transverse hydrodynamic damping force and moment coefficients that are needed in the maneuverability study of marine vehicles. Computations are performed for two geometrical shapes representing typical AUVs presently in use. Results are compared with available data on similar geometries and from some of the available semi-empirical relations. It is found that the CFD predictions compares reasonable well with these results. In particular, the CFD predictions of forces and moments are found to be nonlinear with respect to the transverse velocity, and therefore both linear and nonlinear coefficients can be derived. A discussion on the sources of the component forces reveal that the total force and moment variations should in fact be nonlinear.     

Assessing the state of homogeneity,variability and trends in the rainfall time series from 1969 to 2017 and its significance for groundwater in north-east India

Natural Hazards - Rainfall is the key climatic variable, on which water availability, food security and livelihood depend, especially in an agrarian society like the northeast region of India. It...     

Assessment of tunnel instability—a numerical approach

This paper outlines the application of numerical modeling to predict deformation and stability of tunnel to be excavated in Bansagar, M.P., India. To meet the ever-increasing demand of transportation, energy, and other infrastructure projects, a large volume of rock tunneling is being carried out throughout the world. The geotechnical properties along the route of the 1,800-m long tunnel in the Bansagar region of India have been studied. The rock mass rating and rock mass quality systems were employed for empirical rock mass quality determination. Numerical analysis for the stress–strain distribution of the tunnel excavation and support systems was also carried out. In order to simulate the excavation of tunnel (NATM) at a depth of 150 m below the ground , a series of finite element analyses using Mohr-coulomb elasto-plastic constitutive model has been carried out using PLAXIS 2D. The stability of tunnel has been analyzed, and stress pattern have been discussed.     

Significance of model credibility in estimating climate projection distributions for regional hydroclimatological risk assessments

Ensembles of historical climate simulations and climate projections from the World Climate Research Programme’s (WCRP’s) Coupled Model Intercomparison Project phase 3 (CMIP3) multi-model dataset were investigated to determine how model credibility affects apparent relative scenario likelihoods in regional risk assessments. Methods were developed and applied in a Northern California case study. An ensemble of 59 twentieth century climate simulations from 17 WCRP CMIP3 models was analyzed to evaluate relative model credibility associated with a 75-member projection ensemble from the same 17 models. Credibility was assessed based on how models realistically reproduced selected statistics of historical climate relevant to California climatology. Metrics of this credibility were used to derive relative model weights leading to weight-threshold culling of models contributing to the projection ensemble. Density functions were then estimated for two projected quantities (temperature and precipitation), with and without considering credibility-based ensemble reductions. An analysis for Northern California showed that, while some models seem more capable at recreating limited aspects twentieth century climate, the overall tendency is for comparable model performance when several credibility measures are combined. Use of these metrics to decide which models to include in density function development led to local adjustments to function shapes, but led to limited affect on breadth and central tendency, which were found to be more influenced by “completeness” of the original ensemble in terms of models and emissions pathways.