Day: July 8, 2010

Video: Using Spatial Analysis to Prioritize Restoration and Facilitate Collaboration

/ Matt Artz / 1 Comment

Bo Wilmer, Center for Landscape Analysis, Research Department, The Wilderness Society (TWS)

“With thousands of acres of forests in various stages of degradation, choosing the most appropriate areas to restore is a challenging feat. With limited resources and funding, land managers need a way to prioritize these restoration projects. This is where our TWS landscape ecologist Bo Wilmer comes in. He developed a GIS tool that not only helps identify areas for restoration but also better equip the decision-makers in explaining their selection rationale to the public in a simple, intuitive, and transparent framework.”

Where Are My Patients Coming From?

/ Matt Artz / 1 Comment

2010 ESRI Southwest Regional User Group Conference

Kim Dufour

“This presentation will focus on using ArcGIS Desktop to perform spider analyses to better understand geographic patterns in provider/patient relationships. Spider diagrams connect the location of providers with their patients with lines radiating out from the provider location. These analyses can be very useful to healthcare payers and providers for understanding differences in distances traveled for patients in urban and rural locations. For example, this information can be used by Medicare, Medicaid, or insurers to identify areas under-served by a particular type of physician. Further, they help us better understand how far patients may travel when a provider is highly specialized. In addition, these analyses can help us understand geographic patterns between attending physicians and the hospitals in which they treat patients. Spider diagrams are also relevant when looking for potential fraudulent behavior. For example, providers whose patients routinely travel 50 miles or more may be billing for services not rendered. Factors such as specialization and availability of care are critical in such an analysis. The use of ArcGIS provides analysts and executives with clear visualization of provider/patient relationships in order to improve the decision-making process. This presentation is geared for beginner-level users of ArcGIS Desktop and will include a demonstration of the geo-coding using the StreetMap North America data included with the ArcGIS installation disks. It will also include demonstration creating spider diagram.”

ASPHAA: A GIS-Based Algorithm to Calculate Cell Area on a Latitude-Longitude (Geographic) Regular Grid

/ Matt Artz

Transactions in GIS, Volume 14 Issue 3, June 2010, p 351-377

Monia Santini, Andrea Taramelli, Alessandro Sorichetta

“One characteristic of a Geographic Information System (GIS) is that it addresses the necessity to handle a large amount of data at multiple scales. Lands span over an area greater than 15 million km2 all over the globe and information types are highly variable. In addition, multi-scale analyses involve both spatial and temporal integration of datasets deriving from different sources. The currently worldwide used system of latitude and longitude coordinates could avoid limitations in data use due to biases and approximations. In this article a fast and reliable algorithm implemented in Arc Macro Language (AML) is presented to provide an automatic computation of the surface area of the cells in a regularly spaced longitude-latitude (geographic) grid at different resolutions. The approach is based on the well-known approximation of the spheroidal Earth’s surface to the authalic (i.e. equal-area) sphere. After verifying the algorithm’s strength by comparison with a numerical solution for the reference spheroidal model, specific case studies are introduced to evaluate the differences when switching from geographic to projected coordinate systems. This is done at different resolutions and using different formulations to calculate cell areas. Even if the percentage differences are low, they become relevant when reported in absolute terms (hectares).”

Sustainability of Agriculture Land in Eastern Bhutan

/ Matt Artz / 1 Comment

Loday Phuntsho, Graduate Program in Sustainability Science, University of Tokyo

“Agriculture is the mainstay for majority of population in Bhutan with close to 70% of the people being engaged in Agriculture. Agriculture will remain the most important source of employment and rural livelihood of the Bhutanese people for several decades even though the relative contribution of agriculture to GDP is declining (DoA, 2008). The ministry of agriculture and forests has the sustainable utilization of arable land and enhancement of rural livelihood as important policies to enhance food security and reduce rural poverty. However, in recent years agriculture sector has been challenged by many issues like instability of yield, fallow land and land degradation etc. These are apparently implicated to be the result of climate variability like increase in temperature and erratic rainfall pattern. In this regard IPCC’s 4th Assessment report also mentions that in South Asian Sub-Continent, to which Bhutan is a part, agriculture will be one of most sensitive sectors under climate change. However, currently there is lack of study on this issue. Most of the studies have been conducted on reforestation of degraded land and impact of glacier lake outbursts.

“Hence, my study looks at the impact of climate variability on agriculture land sustainability. Many researchers [Kurukulasuriya et al. (AfJARE, 2008) in Africa, M Antle et al (Agriculture and Forest Metereology, 1995) in the US, Reinsborough et al (Canadian Journal of Economics, 2003) in Canada, Seo et al. (Environment and Development economics, 2005) in Sri Lanka] have used temperature and precipitation as two most important factors that affect the agriculture productivity and hence sustainability of agriculture land use. Hence, my study will look at the association between the climate variability and productivity, and spatial relation between the climate variability, land use and land degradation over the last 10-15 years period.”

Analyzing the Efficacy of Subtropical Urban Forests in Offsetting Carbon Emissions from Cities

/ Matt Artz

Environmental Science & Policy, In Press, Corrected Proof, Available online 13 April 2010

Francisco Escobedo, Sebastian Varela, Min Zhao, John E. Wagner, and Wayne Zipperer

“Urban forest management and policies have been promoted as a tool to mitigate carbon dioxide (CO2) emissions. This study used existing CO2 reduction measures from subtropical Miami-Dade and Gainesville, USA and modeled carbon storage and sequestration by trees to analyze policies that use urban forests to offset carbon emissions. Field data were analyzed, modeled, and spatially analyzed to compare CO2 sequestered by managing urban forests to equivalent amounts of CO2 emitted in both urban areas. Urban forests in Gainesville have greater tree density, store more carbon and present lower per-tree sequestration rates than Miami-Dade as a result of environmental conditions and urbanization patterns. Areas characterized by natural pine-oak forests, mangroves, and stands of highly invasive trees were most apt at sequestering CO2. Results indicate that urban tree sequestration offsets CO2 emissions and, relative to total city-wide emissions, is moderately effective at 3.4 percent and 1.8 percent in Gainesville and Miami-Dade, respectively. Moreover, converting available non-treed areas into urban forests would not increase overall CO2 emission reductions substantially. Current CO2 sequestration by trees was comparable to implemented CO2 reduction policies. However, long-term objectives, multiple ecosystem services, costs, community needs, and preservation of existing forests should be considered when managing trees for climate change mitigation and other ecosystem services.”