Review of “Landscape metrics and topographical determinants of large-scale forest dynamics in a Mediterranean landscape”
The purpose of this paper is to understand the dynamics of forest cover in the Province of Siena, Italy (Mediterranean) through a comparison of two maps, 1933 and 2000. Because the region of the study has been one of the most altered areas on the planet Geri, Rocchini and Chiarucci aim to produce a report for future resource management and policy making to address the problems of human-induced landscape changes resulting in forest fragmentation. One key point is that only 4.7% of the Mediterranean landscape remained unaltered and even the “natural” land cover types such as agricultural land, evergreen woodlands and maquis shrublands are a result of anthropogenic disturbances. A common pattern in landscape dynamic analysis like this one is due to plains are often used for human activities while mountains are becoming abandoned while simultaneously undergoing natural reforestation processes.
Two maps were used in the analysis, one from 1933 and the other from 2000. The 1933 map shows forest typologies, silvicultural practice and dominant species in the area. The map was scanned and digitised with GIS and in order to reduce any errors, it was aligned with a recent 1992 topographic map, calculated the residual points and used a higher pixel size than the spatial error. 100 randomly scattered control points were inputted onto the map and landscape features that remained unchanged during the time period were found. Deviations were calculated by the Root Mean Squared Error (RMSE) which indicates the accuracy of the spatial analysis for the study (essentially measuring the predicted value against the actual value). Through the analysis a transition matrix shows the comparison and quantifying changes in landscape forest composition that is done through the process of overlaying both maps for the corresponding year then for each pixel it derives the change from one class to another class or if the class remains constant. Landscape metrics quantifies spatial characteristics of the patches and edges. Patch metrics were used to analyze landscape structure with the number of patches evaluating weight of landscape change through ecological processes and patch shape showing the dynamics of inter-patch processes like small species migration, plant colonization and animal foraging patterns. Meanwhile, edge metrics (total edge and mean patch edge) were used for habitat loss and forest fragmentation. The relation between topography and forest dynamics was analyzed first by creating a DEM (75 m resolution) to find the differences between the two years of areas that were impacted by afforestation or deforestation. The DEM was then changed to a 100 m spatial resolution to match the landscape change analysis previously done. The dynamic processes (afforestation, deforestation and conservation) was compared to the topographical variables (slope, elevation and indirect radiation). Three Boolean maps were created for each forest dynamic with pixels associated with a Boolean value illustrating the extent of each dynamic process on the map. The topographical variables were extracted for each dynamic process then compared by the differences in elevation, slope and indirect radiation. The results show that the larger forest patches remained unchanged between 1933 and 2000 while small patches were considered as a result of deforestation and afforestation occurred in small and large patches. Conservation and afforestation occurred in high elevation areas such as mountain and hills. Plains remained without significant forest over during the time period. Overall, forest cover actually increased by 300 sq km due to broad-leaved forests and significant forest fragmentation in 1933 decreased by 2000 (less number of patches) likely due to an increase in patch size of broad-leaved and coniferous forests. On the other hand, mixed forests saw a decrease in patch size. For the topographical analysis, Areas that experienced afforestation had higher elevation and steeper slope but affected by lower radiation compared to areas of deforestation. Conserved areas were more elevated and steeper than afforestation areas.
The authors themselves suggest there is bias in the study from the minimum mapping unit, uncertainty in thematic attributes and lack of information in reproducing mapping processes. The increase of forests in the Mediterranean area was due to the lack of agricultural activities on elevated areas; and afforestation on productive soils that could instead be used for cultivation. Small forest patches that were scattered in agricultural and plain areas disappeared over the period along with a disappearance of open area patches in elevated areas (hills and mountains) replaced by forests and merged with smaller forest patches in its surrounding. Finally the dynamics of forestry in the area from the impact of humans can be explained by the pressure on plain areas through deforestation; conservation in areas with unsuitable conditions for agriculture and land use such as steep slopes and high elevations that would otherwise require greater costs of development and advancements in agricultural practices; and the desires for agriculture in areas with higher solar radiation in which forested areas do not provide.
Review of “The application of geographical information systems to important public health problems in Africa”
The purpose of the paper is to examine and understand the spatial variation of diseases in Africa by using GIS technology for health research and management. Tanser and le Sueur identifies poor and lack of adequate health care services in Africa that requires more cost-effective planning and better allocation of resources.
The political, social and geographical climate of Africa makes it susceptible to life threatening diseases. The three leading causes of mortality in Africa has been HIV, malaria and tuberculosis. For example, HIV in African countries have a risk of death of about one in every three persons. Tuberculosis is the leading cause of death globally in which the World Health Organization (WHO) called for immediate effective treatment. The case of malaria is also the most concentrated in Africa (90% of worldwide cases). Here GIS can play an important role in improving the health system faced by complex problems.
The use of GIS tools such as spatial analysis was applied to understand the spatial variation of diseases in relation to the environment and public health system enforced by the government. GIS as an innovative technology allows information to be distributed to take action. In the case of malaria that is borne from mosquitoes and affected by climate. Meanwhile HIV and tuberculosis are transmitted via human contact in a social environment hence the different GIS methodologies. GIS applications in the study of malaria has been used to model occurrences, seasonality and transmission intensity by using climatic and remote sensing data, and population data. Analysis has resulted in evaluating the different effects of strategies aimed towards managing malaria outbreaks. GIS application in tuberculosis management creates a distribution of treatment centers in areas of high tuberculosis numbers.
The bias in this report concerns the accuracy of reported diseases as estimates. The authors are able to present several key issues at the end of the report. The report emphasizes only one available study that could be used in the GIS analysis of HIV. An argument is made for the use of GIS by local professionals rather than international agencies who understand the context of technological and socio-economic applications in the research location. Spatial data that is available is also limited due to the expensive nature of collection and funding.
GIS provides tools for spatial and temporation analysis in environmentally induced diseases. Planning and strategies can be mapped to highlight areas of the most important. Overall I would rate this paper an 8 out of 10 because it provides a clear and thorough analysis although it is very generalized without a solid focus on a specific area.
Tanser, Frank C., & Le Sueur, David. (2002). The application of geographical information systems to important public health problems in Africa. International Journal of Health Geographics, 1(4). doi:10.1186/1476-072X-1-4
Review of “Crime Mapping in Nigeria Using GIS.”
In the paper by Balogun, Okeke and Chukwukere, the purpose is to examine the crime in the city of Benin, Nigeria. One of the main issues of combating crime in Nigeria is the lack of computerized data storage that allows for easier information retrieval and strategic anti-crime planning. The city has seen growth in land size and population along with it crime.
By using and utilizing geographic information science (GIS) the authors are able to shed light on the status of crime and hotspots based on information collected by the general public and local police force. Crime mapping allows the police and the public to understand areas of high crime rates regardless of social class distinctions. One of the highest types of crime is kidnapping in Benin. The use of GIS in fighting crime reduces time and cost of ‘traditional’ crime mapping analysis. Because crime is human nature, it does not have a random distribution pattern therefore crime has a spatial aspect to it based on location and time. GIS allows for real-time or up-to-date information to understand different types of criminal behaviors and geographic pattern.
The procedure taken by the authors involved two methods. The first step was to conduct a questionnaire between the public and police officers. The second method involved data collection including crime and location relative to the location of police stations, drug related crimes, census data, housing data, land use and road maps. The results of the questionnaire shows the majority of the public awareness to ongoing crime in the city with a reported high of armed robbery and burglaries while murder is the lowest type of crime. To create a crime hotspot map, the first step was to convert a thematic road map to digital for use in ArcMap. Following is creation of a geodatabase then a design phase of how to proceed with the analysis. Queries for buffer zones were created in order for the spatial pattern to be visualized. The maps produced show a spatial pattern of crime zones where overlapping buffer zones indicate high risk of crime and those overlapping buffers within areas of police stations show that the police force in the jurisdiction do not have have adequate control over the criminal hotspots.
The authors argue the lack of technology used in crime analysis and recommends the use of GIS for crime management. This will provide better and more efficient policing by utilizing standard methods over outdated manual procedures. The paper makes a valid claim for undeveloped countries and their lack of advanced technology use. One problem with using GIS is supplying the entire police force with the tools and education to run crime analysis and mapping especially if there is inadequate funding. I would rate the paper a 8 out of 10 being a easy to follow report to understand, providing sufficient background information to why there needs to be a change in crime management and future strategic planning to ensure the safety of the public.
Balogun, T. J., Okeke, H., Chukwukere, C. I. (2014). Crime Mapping in Nigeria Using GIS. Journal of Geographic Information System, 6, 453-466. http://dx.doi.org/10.4236/jgis.2014.65039