The application of GIS in the management of wetlands
According to Richert S (1996) Wetlands are commonly defined as areas periodically or permanently inundated with water and typically characterized by vegetation requiring saturated soil for growth and reproduction. GIS and remote sensing are tools that are used to conserve and restore wetlands. These tools influence management decision making about wetlands.
One application of GIS to this area is risk analysis and restoration site identification (as in Alexandridis et al. 2007, O’Neill et al. 1997, Russell et al. 1997). GIS assist scientists and manager to determine whether the wetland is in danger of damage, invasive species, retreat or erosion. Future damage of the wetlands can also be modelled using GIS. GIS tool is also effective when it comes to seeing which damaged part of wetlands can be restored.
Several primary data layers are basic components of the wetland mapping process. Primary data are collected through GPS. They are then stored on Microsoft excel as xy coordinates, then change to decimal degrees and then exported to ARCGIS or any software that is able to create maps. This primary data is stored differently in a database, only data which are align with wetland would be analysed and manipulated to create maps of wetland. GIS specialist are able to tell if there are changes on wetlands through comparing different maps drawn using data collected in different time.
The information captured, stored, manipulated, analysed and displayed using GIS are then used for decision making such as wetlands restoration. Layers created through GIS tool such as topography, vegetation, soil cover, hydrology are required for wetland restoration. If the area that need restoration is larger compared to the resources to be used, the only area that can be restored is the one which will have a specific goal.
The applications of GIS in groundwater modelling and contamination tracking
Potable water is one of mankind’s most important resources. Many communities are relying more heavily on groundwater as their main source of potable water. Increasing problems have arisen with groundwater, ranging from contamination, to salt water intrusion, to over pumping. Groundwater models are important to many facets of society. Groundwater models can be used to predict the movement of contaminant plumes, used to place limits on the volume of water pumped from an aquifer, and predict where groundwater resources are most likely to be found (Richard Carlone). GIS also includes numerous tools for acquiring, pre-processing, and transforming data for use in modelling, including data management, format conversion, projection change, resampling, raster–vector conversion, etc.—in fact, all of the tools that would be needed to assemble the data for dynamic simulation. (Goodchild, 1996)
Cavallin and Giuliano (1992) stated that both dynamic and static conditions must be considered and therefore proposed that depth to water table, recharge, aquifer media, soil media and topography should all be included in GIS. Ground water modelling is a difficult task since it requires large amount of data from different sources and of different types.
There are two ways that can be used to model groundwater which are: development of model within GIS and pre or post processing of model data in GIS. models may be developed through collection of data in various boreholes found in an area and then stored in a database, interpolation can be used to determine the areas where ground water is contaminated, pre and post processing lead to the development of maps with layers such as topography, soils information and land use, this assist in finding which land use is causing the problem of ground water contamination. Land use layer is required because activities that occurs around an area my be the cause of ground water contamination.
then exported out into a groundwater model, such as MODFLOW. The creation of GIS databases containing landuse data, , and other geologic data are essential to groundwater modelling. After the model has been run, the results can be exported into GIS for post processing. Post processing allows for data layers to be developed and displayed in map form. This allows model results to be examined easily, in their spatial context. In some cases, modeling may be done directly in a GIS program, by using overlaid data layers to determine relevant groundwater properties, such as recharge. (Richard Carlone).
the role of GIS in zoning and subdivision planning in a municipality
zoning and subdivision is undertaken by local government or municipality following the related legislation procedures. A typical subdivision process begins with the preparation of a zoning plan by the municipality. GIS is used for the storage of land use maps (land use map are maps that provide information about current land use) and plans, socioeconomic data, environmental data, and planning applications.
GIS specialist can extract useful information from the database through spatial query. Information can also be acquired by doing fieldwork using GPS to collect data. Mapping provides the most powerful visualisation tools in GIS. It can be used to explore the distribution of socioeconomic and environmental data and display the results of spatial analysis and modelling exercises. Spatial analysis and modelling are used for spatial statistical analysis, site selection, identification of planning areas, land suitability analysis, land use transport modelling, and impact assessment. Interpolation, map overlay, buffering, and connectivity measurement are the most frequently used GIS functions in spatial analysis and modelling
Collins Chabane local municipality
It was established by the merger of portions of the Thulamela and Makhado Local Municipalities in August 2016.since if is a merger of two municipalities, GIS is needed for bringing in data about properties, land-use, thematic, topographical maps, and from the other related textual records about the municipalities. There is zoning code required for subdividing the area. Cadastral is also useful for subdivision. Data provided by GIS tool are used to for decision making such as where would the municipality start and end as well as how much of an area must be taken from both municipalities.
After zoning and subdivision has been done, GIS is again needed for mapping the new municipality.
4How will you improve Eskom’s electricity distribution planning with the help of GIS? Explain
Any organizations that expect to run efficient day-to-day operation and to manage and develop its service effectively must know what asset it has, where they are, their condition and how they are performing (Pickering, 1993). The knowledge about physical assets of the electricity distribution network is necessary to make strategic and operational decision. Hence to make such informed decision regarding the distribution and management of electricity and its facilities, information must be collected and analysed to its full extent through GIS technique (Ihiabe Y, 2015)
suitability analysis is a type of analysis used in GIS to determine the best place or site for something. Suitability analysis can be use in determine the best place for Eskom electric poles. Topography maps assist Eskom when it come to the elevation of an area, this is useful because they will be able to find the best place to dig holes for electric poles, the place must be gentle so that the poles do not lean.
Use this information for planning, comparative analysis, project feasibility analysis and risk evaluation.
Examine the geographic relationships among the various data components to identify new opportunities.
Incorporate additional layers and proprietary information to increase analytical value.
Create powerful visual presentations for project reporting.
Alexandridis, T. K., V. Takavakoglou, T.L. Crisman, and G. C. Zalidis (2007). “Remote Sensing
and GIS Techniques for Selecting a Sustainable Scenario for Lake Koronia, Greece.” Environmental Management 39: 278-290.Springer Science-Business Media Inc
Crisman T. L., C. Mitraki, G. Zalidis. 2005. Integrating vertical and horizontal approaches for management of shallow lakes and wetlands. Ecol Eng. 24:379–389.Greece, USA.
Fayer, M.J., G.W. Gee, M.L. Rockhold, M.D. Freshley, and T.B. Walters. 1996. Estimating recharge rates for a groundwater model using a GIS. Journal of Environmental Quality 25:510-518. Lasserre,
Ihiabe Y. A., Ajileye O.O, Alaga A.T, Samson A. Samuel and S. O. Onuh.2015. Application of GIS in electrical distribution network system. European International Journal of Science and Technology.vol:4. Nigeria.
Lubczynski, M.W., and J. Gurwin. 2005. Integration of various data sources for transient groundwater modeling with spatio-temporally variable fluxes-Sardon study case, Spain. Journal of Hydrology 306:71-96.
Razack, F., M. and O. Banton. 1999. A GIS-linked model for the assessment of nitrate contamination in groundwater. Journal of Hydrology 224:81-90
Scott E. R., 1996 Wetland and Environmental Applications of GIS Lewis Publishers, 373 pp.
Teso, R.R., P.M. Poe, T. Younglove, and P.M. McCool. 1996. Use of logistic regression and GIS modeling to predict groundwater vulnerability to pesticides. Journal of Environmental Quality 25:425-432.