Day: June 17, 2010

Impact of Aquaculture on Mangrove Areas in the Northern Pernambuco Coast (Brazil) using Remote Sensing and Geographic Information System

/ Matt Artz / 1 Comment

Aquaculture Research, Volume 41, Issue 6, Date: May 2010, Pages: 828-838

Ariana Silva Guimarães, Paulo Travassos, Pedro Walfir Martins E Souza Filho, Fabrício Dias Gonçalves, and Francisco Costa

“The conversion of mangrove areas into shrimp farming ponds has been indicated as the main activity responsible for the reduction in the area of this ecosystem along the northeastern coast of Brazil. The present study was conducted using remote sensing methods and a geographical information system with the aim of quantifying the participation of this activity in the reduction of the mangrove areas along the northern coast of the State of Pernambuco (northeast, Brazil), where shrimp farming has been implanted in last recent years. From 1973 to 2005, there was reduction of about 2.052 ha of mangrove, 197 ha of which were converted into shrimp ponds. Thus, the real contribution of shrimp farming to this reduction was just 9.6% of the total area. Other anthropogenic activities, such as agriculture, urban expansion and tourism, contributed greatly to the reduction in the mangrove areas along the northern coast of the State of Pernambuco.”

Beyond On-site Mitigation: An Integrated, Multi-scale Approach to Environmental Mitigation and Stewardship for Transportation Projects

/ Matt Artz

Landscape and Urban Planning, Volume 96, Issue 4, 30 June 2010, Pages 240-256

Theodore C. Weber and William L. Allen

“Federal, state, and local governments construct thousands of kilometers of roads each year in the U.S.A., as well as undertaking widening, rerouting or repair projects. Under the National Environmental Policy Act (NEPA), environmental impacts from such construction must be offset by mitigation measures (e.g., stream or wetland restoration). Unfortunately, restoration projects often are opportunistic, do not consider a broad landscape context, and have a low benefit–cost ratio. In 2007, the Maryland State Highway Administration asked The Conservation Fund, the Maryland Department of Natural Resources, and the U.S. Fish and Wildlife Service to help identify and evaluate natural resource stewardship opportunities in four Maryland watersheds that could potentially be affected by construction of a highway bypass. Stewardship activities, including conservation, restoration, or management of natural resources, would go above and beyond required mitigation. After soliciting feedback from stakeholders and reviewing pertinent literature, we modeled and validated a conservation network of high-quality wildlife and plant habitat (core areas), large contiguous natural areas (hubs), and linkages to facilitate wildlife movement and gene flow (corridors). We then ranked elements of this network at multiple scales, and identified high priority areas for conservation and restoration. Finally, we developed and tested protocols for field assessment and benefit–cost optimization. We hope that this approach can be adapted and improved by highway agencies and other entities for environmental planning and protection, and have a report available upon request with full details.”

Seasonal Rainfall Variability in Guinea Savanna, Nigeria: A GIS Approach

/ Matt Artz

International Journal of Climate Change Strategies and Management, Volume: 1; Issue: 3; 2009

Ayansina Ayanlade

“Purpose – This paper aims to use geographical information systems kriging interpolation technique to examine and map the spatiotemporal variation in rainfall in Guinea Savanna of Nigeria.

“Design/methodology/approach – Rainfall data, for the periods between 1970 and 2000, are collected from the archives of the Nigerian Meteorological Services, Oshodi Lagos. In this paper, rainfall is considered as the primary and input for crop yield. It is observed that the most important climatic element is rainfall; particularly inter-annual variation and the spatiotemporal distribution of rainfall. Three spatial interpolation methods are chosen for this research work: inverse distance weighting method and the spline (completely regularized) as the determinist methods; and ordinary kriging as the stochastic methods. In order to analyze the interpolation quality, an evaluation by cross validation has been carried out. Ordinary kriging method was discovered suitable for this paper because it allows the sharpest interpolation rainfall data and is the most representative.

“Findings – The results of the analysis show that rainfall varies both in time and space. Rainfall variability is very high in most of Northern Guinea Savanna (e.g. Yola, Minna, and Ilorin) with values of coefficient of variation (CV) between 26 and 49 percent while in Southern Guinea Savanna, the CV is very low especially, in Enugu (9 percent), and Shaki (8 percent). These anomalies (such as decline in annual rainfall, change in the peak and retreat of rainfall and false start of rainfall) are detrimental to crop germination and yield, resulting in little or no harvest at the end of the season.

“Originality/value – The paper concludes that geospatial techniques are powerful tools that should be explored further for realistic analysis of the effects of seasonal variability in rainfall.”

Spatial Planning on the Semantic Web

/ Matt Artz / 1 Comment

Transactions in GIS, Volume 14, Number 2, April 2010

Rinke Hoekstra, Radboud Winkels, and Erik Hupkes

“Land use regulations are an important but often underrated legal domain. In densely populated regions such as the Netherlands, spatial plans have a profound impact on both (local) governments and citizens. This article describes our work on a ‘Legal Atlas’. Using Semantic Web technology we combine distributed geospatial data, textual data and controlled vocabularies to support users in answering questions such as: “What activity is allowed here?” Spatial norms are represented using OWL 2 in a way that enables intuitive visualisation of their effects: map-based legal case assessment. Users can represent a (simple) case by selecting or drawing an area on the map. Given a designation for that area, the system can assess whether this is allowed or not. The same solution also enables the comparison of two or more sets of spatial norms that govern the same region. We discuss the advantages and drawbacks of a number of alternative solutions for representing and integrating metadata of spatial plans, and the representation of normative conflicts and exceptions between norms.”

West Nile Virus Infection Risk is Associated with Combined Sewer Overflow Streams in Urban Atlanta, Georgia

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Environmental Health Perspectives, 2010

Gonzalo M. Vazquez-Prokopec, Jodi L. Vanden Eng, Rosmarie Kelly, Daniel G. Mead, Priti Kolhe, James Howgate, Uriel Kitron, and Thomas R. Burkot

“Background. At present, the factors favoring transmission and amplification of West Nile Virus (WNV) within urban environments are poorly understood. In urban Atlanta, GA, the highly polluted waters of Combined Sewer Overflow (CSO) affected streams represent significant habitats for the WNV mosquito vector Culex quinquefasciatus. However, their contribution to the risk of WNV infection in humans and birds remains unclear.

“Objectives. Our goals were to describe and quantify the spatial distribution of WNV infection in mosquitoes, humans and corvids (blue jays and American crows, which are particularly susceptible to WNV infection) and to assess the relationship between WNV infection and proximity to CSO-affected streams in the city of Atlanta, Georgia.

“Materials and Methods. We applied spatial statistics to human, corvid and mosquito WNV surveillance data from 2001-2007. Multi-model analysis was used to estimate associations of WNV infection in Cx. quinquefasciatus, humans and dead corvids with selected risk factors including distance to CSO-streams and catch basins, land cover, median household income, and housing characteristics.

“Results. WNV infection in mosquitoes, corvids and humans was spatially clustered and statistically associated with CSO-affected streams. WNV infection in Cx. quinquefasciatus was significantly higher in CSO compared with non-CSO streams, and WNV infection rates in humans and corvids were significantly associated with proximity to CSO-affected streams, the extent of tree cover and median household income.

“Conclusions. Our study strongly suggests that CSO-affected streams are significant sources of Cx. quinquefasciatus mosquitoes that may facilitate WNV transmission to humans within urban environments. Our findings may have direct implications for the surveillance and control of WNV in other urban centers that continue to use CSOs as a waste management practice.”