Day: July 20, 2010

Comparative Study of Land Cover using Multi-temporal Satellite Images

/ Matt Artz

3rd International Conferecne on Cartography and GIS

15-20 June, 2010, Nessebar, Bulgaria

Borislav Marinov and Margarita Mondeshka

“The comparative study of land cover and soil status are provided using space images with middle resolution. The Landsat TM+ and SPOT 5 images are included in analysis. The unsupervised and supervised classifications are applied for determination of different types of land cover. The terrain investigations are made by taking and analysing the soil samples for typical soil types presenting in the area of investigation. The analysed images are taken at different time moments in autumn and spring seasons to avoid the influence of crop stage of vegetation and snow coverage. The influence of used channels and space resolution of images on the reliability and accuracy of classified areas are investigated. The improvement of interpretation is established in the case of applying the combination of unsupervised and supervised classification. The recommendations are formulated for appropriate properties of utilised space images. The diversity and amount of terrain investigations are suggested for obtaining the reliable and representative results.”

A Spatial Analysis System for Integrating Data, Methods and Models on Environmental Risks and Health Outcomes

/ Matt Artz / 1 Comment

Transactions in GIS, Volume 14 Issue s1, Pages 177 – 195

Chetan Tiwari and Gerard Rushton

“Integrating data on health outcomes with methods of disease mapping and spatially explicit models of environmental contaminants are important aspects of environmental health surveillance. In this article, we describe a modular, web-based spatial analysis system that uses GIS, spatial analysis methods and software services delivered over computer networks to achieve this end. The Environmental Health Surveillance System (EHSS) is a prototype system that is designed to serve three purposes: a secure environment for producing maps of disease outcomes from individual-level data while preserving privacy; an automated process of linking environmental data, environmental models, and GIS tasks like geocoding for the purposes of estimating individual exposures to environmental contaminants; and mechanisms to visualize the spatial patterns of disease outcomes via Web-based mapping interfaces and interactive tools like Google Earth.”

Bi-criteria Evaluation of the MIKE SHE Model for a Forested Watershed on the South Carolina Coastal Plain

/ Matt Artz

Hydrology and Earth System Sciences, 14, 1033–1046, 2010

Z. Dai, C. Li, C. Trettin, G. Sun, D. Amatya, and H. Li

“Hydrological models are important tools for effective management, conservation and restoration of forested wetlands. The objective of this study was to test a distributed hydrological model,MIKE SHE, by using bi-criteria (i.e., two measurable variables, streamflow and water table depth) to describe the hydrological processes in a forested watershed that is characteristic of the lower Atlantic Coastal Plain. Simulations were compared against observations of both streamflow and water table depth measured on a firstorder watershed (WS80) on the Santee Experimental Forest in South Carolina, USA. Model performance was evaluated using coefficient of determination (R2) and Nash-Sutcliffe’s model efficiency (E). The E and root mean squared error (RMSE) were chosen as objective functions for sensitivity analysis of parameters. The model calibration and validation results demonstrated that the streamflow and water table depth were sensitive to most of the model input parameters, especially to surface detention storage, drainage depth, soil hydraulic properties, plant rooting depth, and surface roughness. Furthermore, the bi-criteria approach used for distributed model calibration and validation was shown to be better than the single-criterion in obtaining optimum model input parameters, especially for those parameters that were only sensitive to some specific conditions. Model calibration using the bi-criteria approach should be advantageous for constructing the uncertainty bounds of model inputs to simulate the hydrology for this type of forested watersheds. R2 varied from 0.60–0.99 for daily and monthly streamflow, and from 0.52–0.91 for daily water table depth. E changed from 0.53–0.96 for calibration and 0.51–0.98 for validation of daily and monthly streamflow, while E varied from 0.50–0.90 for calibration and 0.66–0.80 for validation of daily water table depth. This study showed that MIKE SHE could be a good candidate for simulating streamflow and water table depth in coastal plain watersheds.”