Month: September 2011

Preliminary Study of a Cluster-based Open-source Parallel GIS based on the GRASS GIS

/ Matt Artz

International Journal of Digital EarthInternational Journal of Digital Earth, Volume 4, Issue 5, 2011

Fang Huang, Dingsheng Liu, Xiaowen Li, Lizhe Wang and Wenbo Xu

“In response to the problem of how to give geographic information system (GIS) high-performance capabilities for certain specific GIS applications, a new GIS research direction, parallel GIS processing, has emerged. However, traditional research has focused mostly on implementing typical GIS parallel algorithms, with little discussion of how to parallelize an entire GIS package on clusters based on theory. Therefore, the authors have chosen the geographic resources analysis support system (GRASS) GIS as the object of their research and have put forward the concept of a cluster-based open-source parallel GIS (cluster-based OP-GIS) as a tool to support Digital Earth construction. The related theory includes not only the parallel computing mode, architecture, and software framework of such a system, but also various parallelization patterns. From experiments on the prototype system, it can be concluded that the parallel system has better efficiency and performance than the conventional system on certain selected modules.”

European Digital Archive on Soil Maps (EuDASM): Preserving Important Soil Data for Public Free Access

/ Matt Artz

International Journal of Digital EarthInternational Journal of Digital Earth, Volume 4, Issue 5, 2011

Panos Panagos, Arwyn Jones, Claudio Bosco, and P.S. Senthil Kumar

“Historical soil survey paper maps are valuable resources that underpin strategies to support soil protection and promote sustainable land use practices, especially in developing countries where digital soil information is often missing. However, many of the soil maps, in particular those for developing countries, are held in traditional archives that are not easily accessible to potential users. Additionally, many of these documents are over 50 years old and are beginning to deteriorate. Realising the need to conserve this information, the Joint Research Centre (JRC) and the ISRIC-World Soil Information foundation have created the European Digital Archive of Soil Maps (EuDASM), through which all archived paper maps of ISRIC has been made accessible to the public through the Internet.

“The immediate objective is to transfer paper-based soil maps into a digital format with the maximum possible resolution and to ensure their preservation and easy disclosure. More than 6,000 maps from 135 countries have been captured and are freely available to users through a user-friendly web-based interface. Initial feedback has been very positive, especially from users in Africa, South America and Asia to whom archived soil maps were made available to local users, often for the first time. Link: http://eusoils.jrc.ec.europa.eu/library/maps/country_maps/list_countries.cfm”

Scenario Generation using Geographical Information System (GIS) based Hydrological Modelling for a Multijurisdictional Indian River Basin

/ Matt Artz

Journal of Oceanography and Marine ScienceJournal of Oceanography and Marine Science, Vol. 2(6), pp. 140-147, July 2011

Singh A. and Gosain A. K.

“Lack of information about the futuristic scenarios of possible water allocations acts as a deterrent in resolving the conflicts pertaining to transboundary watercourses. It is increasingly being felt that technology, in the form of simulation modelling, has a very significant role to play in this context. For water resources engineering problem solving, geographical information system (GIS) offers a cognitive spatial representation of complex hydrologic and hydraulic systems. Of specific interest to decision makers is the capability of GIS to visually display information for interpretation of water resource model inputs and outputs, which enables users to take a more dynamic approach with data input, modification, scenario development, and evaluation (Martin et al., 2005).

Reclassified soil classes for the Cauvery river basin

Reclassified soil classes for the Cauvery river basin

“In the present study, GIS based hydrological modelling has been utilized for the purpose of assessment of the total amount of water available in the study area, as well as prediction of the impact of changes in the land management practices on the water availability in the study area, and consequently the amount of water allocated to each of the riparian states. The hydrological model used for the study is SWAT (soil and water assessment tool). The results of the study show that water yield of the basin is inversely proportional to the amount of forest cover. The study demonstrates that simulation modelling can play a very significant role in water resources management by generating a series of scenarios or options for the stakeholders, so as to enable them to take sound rational decisions.”

GIS based Risk Assessment of Oil Spill in the Coastal Areas of Akwa Ibom State, Nigeria

/ Matt Artz

African Journal of Environmental Science and TechnologyAfrican Journal of Environmental Science and Technology, Vol. 5(3), pp. 205-211, March 2011

J. C. Udoh and E. M. Ekanem

“Assessing the total loss and damages that may result from oil spill constitutes risk assessment. The study area is the coastal Local Government Areas (LGAs) of Akwa Ibom State, located in the Niger Delta of Nigeria. The delta generates the greatest proportion of foreign exchange and internal revenue earnings of the country as the crude oil sector accounts for 90 to 95% of export revenues. Since most of information used for oil spill risk assessment have some form of spatial content, extensive use of Geographic Information System (GIS) capabilities are used in the study.

Final vulnerability map

Final vulnerability map.

“A combination of hazard and vulnerability data layers constitutes the GIS based risk assessment. Hazard was modeled in the study by sources of petroleum oil spill moderated by surface characteristics, while data on crop suitability, socio-economy, environmental sensitivity, accessibility, and settlement development, were used to model vulnerability. The resulting risk layer was classed into four Risk zones of very high, high moderate and marginal risk. Iko and the environs were found to be in the very high risk zone. Based on the fact that increasing investments are being made in the petroleum oil sector in Akwa Ibom State, the study analysis the implications of the findings and stresses the need for a comprehensive GIS based oil spill contingency plan for the area.”

Minimizing Transportation Costs with Location-Allocation Analysis: An Application to Recycling

/ Matt Artz / 1 Comment

URISA2011 URISA Student Competition, Student Paper Awards–Third Place Paper

Laura Reading

“Ecomaine, a regional non-profit waste management company in Portland, Maine, sought to reduce transportation costs to member communities that transport recycling in 30 square yard collection roll-off containers (known as “silver bullets”) to the Ecomaine recycling facility. This study objective was to minimize transportation costs by identifying the minimum number of consolidation locations to serve all silver bullets in fewer than twenty miles and the minimum number of locations to serve all silver bullets in fewer than thirty miles using the location-allocation analysis tool in GIS.

Left, Scenario 1, five facilities serve all silver bullets in fewer than 32 km; right, Scenario 2, three facilities serve all silver bullets in fewer than 48 km. One consolidation location is not shown in either Scenario because it is an outlier.

Left, Scenario 1, five facilities serve all silver bullets in fewer than 32 km; right, Scenario 2, three facilities serve all silver bullets in fewer than 48 km. One consolidation location is not shown in either Scenario because it is an outlier.

“The economic benefits of using the new consolidation locations were calculated by determining the net cost savings based on the reduction in distance traveled. The environmental benefits were also calculated by determining the reduction in greenhouse gas emissions based on the reduction in distance traveled.”

Analysis of MODIS NDVI Time Series to Calculate Indicators of Mediterranean Forest Fire Susceptibility

/ Matt Artz

GIScience & Remote SensingGIScience & Remote Sensing, Volume 48, Number 2 / April-June 2011

V. Chéret and J.-P. Denux

“This study was conducted to assess fire susceptibility of Mediterranean vegetation by analyzing a time series of Moderate Resolution Imaging Spectroradiometer (MODIS) Terra images from 2000 to 2006. Synthetic indicators of vegetation status were defined based on analysis of annual variations of the Normalized Difference Vegetation Index (NDVI) and an understanding of phenological cycles. Spring and annual greenness indicators were calculated by combining NDVI values measured at different key phenological stages. The various fire susceptibility indicators were used to characterize fluctuations of vegetation activity related to changes in photosynthetic activity and fuel dryness. Susceptibility indicators were also mapped, and statistical relationships with meteorological conditions were identified.”

Health-Related Geospatial Data and Social Media: Can You Harvest Geosocial Data?

/ Matt Artz

Journal of Map & Geography LibrariesJournal of Map & Geography Libraries, Volume 7, Issue 3, 2011

John A. Olson

“Social media has been at the forefront of everyone’s mind lately. Some of us are still wondering how to leverage and use social media to further our library’s goals in reaching out to our patrons and users, let alone personal goals. But for some researchers, the question has been, “How can we mine these data and harvest the geospatial components to create meaningful datasets for mapping a specific topic or other need?” This has been on my mind as well. This column will begin to explore what is currently available to help mediate, sift, harvest, package, and display these geosocial data. I hope the sources and links shared here will encourage others to explore more deeply how social media data can be harvested and displayed from various outlets.

Twitter Add-In for ArcGIS Explorer (used with permission from Esri).

Twitter Add-In for ArcGIS Explorer (used with permission from Esri).

“We will focus on searching for health-related data on the Web, determining their currency and assessing the correct level of geography to map it to. Just finding health-related data in this context can be quite a challenge! These health-related data sources will be for specific time periods and are finite in content and size. Conversely, with social media data the content is always growing and moving at a feverish rate, and it is difficult to tease out specific topics related to health. So, let us begin with some of the basic resources first.”

Esri Receives Jane Goodall Global Leadership Award

/ Matt Artz

GIS Company Acknowledged for Contributions to Conservation

Jack Dangermond, Esri, receives the Jane Goodall Global Leadership Award

Jack Dangermond, Esri, receives the Jane Goodall Global Leadership Award

On September 24, 2011, conservationist and primatologist Dr. Jane Goodall, United Nations (UN) Messenger of Peace and founder of the Jane Goodall Institute (JGI), presented Jack Dangermond, president of Esri, the Jane Goodall Global Leadership Award for Excellence in Conservation Science during the Institute’s program, A Conversation with Jane Goodall,in Hollywood, California.

The award pays tribute to extraordinary people and organizations. Esri, the world leader in geographic information systems (GIS), works with organizations throughout the world by supporting conservation research, education, policy development and sustainable practices.

Founded in 1977, the Jane Goodall Institute (www.janegoodall.org) continues Dr. Goodall’s pioneering research on chimpanzee behavior—research that transformed scientific perceptions of the relationship between humans and animals. Today, the Institute is a global leader in the effort to protect chimpanzees and their habitats. It is also widely recognized for establishing innovative community-centered conservation and development programs in Africa and Jane Goodall’s Roots & Shoots, the global environmental and humanitarian youth program, which has groups in more than 120 countries.

“By combining Esri’s geospatial technologies with JGI’s decades’ worth of practical knowledge and experience successfully engaging local communities and decision makers, we were able to design a landscape plan around Gombe National Park in Tanzania that better balances the needs of chimpanzees and people,” says Dr. Lilian Pintea, JGI’s vice president of conservation science.

“The Jane Goodall Institute has made people aware of their connection with species and habitats,” says Dangermond. “It inspires a sense of responsibility that leads us to take positive actions toward preserving the inhabitants of this amazing planet. Esri is honored to be recognized by this outstanding organization.”

Esri’s conservation activities include donating GIS software to conservation organizations around the world; training hundreds of conservationists to use GIS software; providing a free mapping service for data, as well as maps and applications valuable for environment, habitat, and species analysis; and hosting the Society for Conservation GIS.

[Source: Esri press release]

Time-geographic Density Estimation for Home Range Analysis

/ Matt Artz

Annals of GISAnnals of GIS, Volume 17, Issue 3, 2011

Joni A. Downs, Mark W. Horner, and Anton D. Tucker

“This research presents time-geographic density estimation (TGDE) as a new technique of animal home range analysis in geographic information science (GIS). TGDE combines methodologies of time geography and statistical density estimation to produce a continuous probability distribution of an object’s spatial position over time. Once TGDE is applied to animal tracking data to create a density surface, home ranges and core areas can be delineated using specified contours of relative intensity (e.g., 95% or 50%). This article explores the use of TGDE for home range analysis using three data sets: a fixed-interval simulated data set and two variable-interval satellite tracks for a loggerhead sea turtle (Caretta caretta) corresponding to internesting and post-migration foraging periods. These applications are used to illustrate the influence of several parameters, including sample size, temporal sampling scheme, selected distance-weighted geoellipse function, and specified maximum velocity, on home range estimates. The results demonstrate how TGDE produces reasonable home range estimates even given irregular tracking data with wide temporal gaps. The advantages of TGDE as compared with traditional methods of home range estimation such as kernel density estimation are as follows: (1) intensities are not assigned to locations where the animal could not have been located given space and time constraints; (2) the density surface represents the actual uncertainty about an animal’s spatial position during unsampled time periods; (3) the amount of smoothing applied is objectively specified based on the animal’s movement velocity rather than arbitrarily chosen; and (4) uneven sampling intervals are easily accommodated since the density estimates are calculated based on the elapsed time between observed locations. In summary, TGDE is a useful method of home range estimation and shows promise for numerous applications to moving objects in GIS.”

On the Spatio-temporal Analysis of Hydrological Droughts from Global Hydrological Models

/ Matt Artz

Hydrology and Earth System SciencesHydrology and Earth System Sciences, 15, 2963-2978, 2011

G. A. Corzo Perez, M. H. J. van Huijgevoort, F. Voß, and H. A. J. van Lanen

“The recent concerns for world-wide extreme events related to climate change have motivated the development of large scale models that simulate the global water cycle. In this context, analysis of hydrological extremes is important and requires the adaptation of identification methods used for river basin models. This paper presents two methodologies that extend the tools to analyze spatio-temporal drought development and characteristics using large scale gridded time series of hydrometeorological data. The methodologies are classified as non-contiguous and contiguous drought area analyses (i.e. NCDA and CDA). The NCDA presents time series of percentages of areas in drought at the global scale and for pre-defined regions of known hydroclimatology. The CDA is introduced as a complementary method that generates information on the spatial coherence of drought events at the global scale.

Results of the CDA method applied for the analysis of number of drought clusters. (a) Drought clusters for 10 January 1976 (around 800 colors, each color represent a cluster and (b) color-coded table of the number of drought clusters on the whole Earth.

Results of the CDA method applied for the analysis of number of drought clusters. (a) Drought clusters for 10 January 1976 (around 800 colors, each color represent a cluster and (b) color-coded table of the number of drought clusters on the whole Earth.

“Spatial drought events are found through CDA by clustering patterns (contiguous areas). In this study the global hydrological model WaterGAP was used to illustrate the methodology development. Global gridded time series of subsurface runoff (resolution 0.5°) simulated with the WaterGAP model from land points were used. The NCDA and CDA were developed to identify drought events in runoff. The percentages of area in drought calculated with both methods show complementary information on the spatial and temporal events for the last decades of the 20th century. The NCDA provides relevant information on the average number of droughts, duration and severity (deficit volume) for pre-defined regions (globe, 2 selected hydroclimatic regions). Additionally, the CDA provides information on the number of spatially linked areas in drought, maximum spatial event and their geographic location on the globe. Some results capture the overall spatio-temporal drought extremes over the last decades of the 20th century. Events like the El Niño Southern Oscillation (ENSO) in South America and the pan-European drought in 1976 appeared clearly in both analyses. The methodologies introduced provide an important basis for the global characterization of droughts, model inter-comparison of drought identified from global hydrological models and spatial event analyses.”