Summer A 2011 Foundations in GIS Final Project Due Time: Midnight Friday, June 17, 2011 Do not expect that you can answer all of the questions within hours. Comprehensive preparation must be done before you are able to answer the questions. 1. Name : Caitlin Riggs 2. Your college, department and major CLAS, Department of Geological Sciences, B.S. Geological Sciences 3. Title of the project : Critically Eroding Coastlines in Florida 4. Abstract (100 to 250 words) Coastlines are important areas for society. The most heavily populated areas in Florida are coastal zones. Over the years we’ve built structures on these coastlines that I believe to interact with the environment they were built upon. In this project I will analyze critically eroding coastlines by using geospatial analysis skills learned in the course Foundations in GIS to determine if there exists a correlation between urbanization – used in this project to mean the increased amount of built structures in a geographical area due to population growth – and critically eroding coastlines in Florida. A land use change analysis of the area with one of the greatest amounts of critical erosion will then be conducted to show how land use has temporally changed. 5. Keywords (3­6 keywords): Critically Eroding Coastlines, Florida, Long Island, Saint Pete Beach, Upham Beach, Statistical Analysis (Field Calculator), Georeferencing, Raster conversion 6. What is your research question? Is there a correlation between urbanization and critically eroding coastlines, and how has land use temporally changed in a particular area of coastline where it has become critically eroded? 7. Project Conceptualization/Problem Statement : Coastlines sustain millions of people in Florida and many development structures such as the iconic high­rises of South Beach. There is also a large economic value associated with our coastlines because of their status as a major component of the tourism industry. In the recent past, however, many miles of our coastlines have begun to disappear, leaving the ocean to inch (and in some cases ‘meter’!) towards our coastal developments. Something must be done about this problem, but first, analysis on what factors may be causing such a degrading process needs to occur. The Bureau of Beaches and Coastal Protection within the Department of Environment Protection (DEP) is one group who is beginning this analysis of collecting quantitative data on coastlines to determine how much erosion is occurring. Because land coverage has changed so much on Florida’s coastlines in the past fifty years, I will be looking at an area of high erosion and comparing historical data with present land use data to understand what kinds of features existed before urbanization began. 8. Projected audience of your project : The issue of eroding coastlines is relevant to anyone living in Florida. Since this problem heavily affects our tourism industry and taxes, it affects any Florida resident. It costs millions of dollars to nourish beaches and would cost much more to relocate developments lying on eroding coastline. Knowing the causes of such a problem may aid coastal engineers and development planners to more wisely enact future coastal management projects and building structures on coastlines. 9. Study area/site : Describe your study site/area and why the study site/area is of interest to you? Generalized: Florida coastlines Case Study: Long Beach, Pinellas County This location is of interest because it is an area of critical erosion and has had several mitigation projects implemented. Unfortunately, the projects have been unsuccessful. I am curious to see what the area looked like pre­urbanization, and predict that the area looked much different than present day Long Beach. 10. GIS data : Briefly describe the GIS data layers needed to achieve your aims/objectives, how did you find/manage/clean/organize the GIS data, and the information that you will derive from analyzing these data layers. Please fill in the tentative data layer list. Feel free to expand this table to provide your answers! The more detail, the better. Purpose of the Brief data Layer description of Layers Format Data source management and analysis performed CURRENT_LAN
DUSE Shape file http://www.fgdl.org Cities_feb04 Shapefile http://www.fgdl.org Present FL vegetation coverage FL city names Converted to raster to be analyzed w/ aerial images Used in maps for locational points Critbeach_jun10 Shapefile http://www.fgdl.org Cnt_bnd shapefile http://www.fgdl.org Urban_apr07 Shapefile http://www.fgdl.org Urban_coastline Shapefile Critbeach_10 Urban_crit Shapefile Urban_coastline & critbeach_10 Coastline_FL LongIsland Upham Shapefile .tif .tif Critically eroding FL coastlines since 2010 FL county boundaries Urbanized regions in FL since 2007 Coastline that is urbanized Used as base layer Used in selecting data that intersects critical bufferzone Created buffer around urbanized regions. Clipped to coastline. Urbanized critically eroding coastline Digitized polyline based on “Data Source” The entire coastline of FL Digitized polyline based on connecting lines between critically eroding beaches Historical aerial photos Georeferenced to current land use layer Present aerial images Georeferenced to current land use layer Critbeach_10 UF Digital Collections GoogleEarth Used to create other coastline types 11. Procedures and methodologies for the project: This is the most important part of this proposal. Describe the methods and specific GIS techniques you used to process your data. State the assumptions involved in your methods. You do not have to spell out every single GIS command or operative procedure, but you need to point out the relevant GIS techniques you will apply. For example, using buffer/erase analysis to generate development suitability information based on soil and slope data. FL_crit_beach: Files used: cntbnd, urban_apr07, critbeach_10, coastline_FL, urban_crit, urban_coast, cities_feb04 1­ Added critbeach_jun10, urban_apr07, and cntbnd to Layers frame 2­ Added erosion data to critbeach_jun10 (.shp was not published with erosion rates, but was published in a .pdf report) a. Added a new Field (named Erosion) b. Used Editor to edit Attributes and added the erosion data to the new field, Erosion 3­ I selected by attributes only the coastline with description ‘CRITICAL’ and exported these selected features as a new .shp (critbeach_10) 4­
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a. Contained other values such as ‘NONCRITICAL’ and ‘CRITICAL INLET’ so I selected by attributes Created coastline_FL a. Made new polyline shapfile thru ArcCatalog b. Digitized FL coastline using Editor c. Added a ‘Length’ field and used Calculate Geometry to obtain length of FL coastline i. Since polyline contained more than one feature I used Statistics to get the sum of the entire FL coastline Created urban_coast a. Buffered urban_apr07 to account for any coastline that had “fallen off” land b. Clipped coastline_FL to the urban buffer Created urban_crit a. Repeat ‘Step 4’, but digitized line based on overlapping urban and critical coastline I calculated the percentage of each coastline type in relation to another a. % of critically eroding coastline [(length c ritbeach_10 )/(length c oastline_FL )]*100 b. % of urbanized coastline [(length u
rban_coast )/(length coastline_FL )]*100 c. % of urbanized critically eroding coastline [(length u
rban_crit )/(length critbeach_10 )]*100 Next I wanted to find the beaches with the greatest erosion a. Erosion data was the amount of eroding beach but not normalized to the length of the beach studied, so I needed to normalize Erosion to Length i. Added new field (Ersn_norm) ii. Calculated new field using Field Calculator b. Found location of greatest erosion using Attributes > Ersn_norm: Sort Descending FL_higherosion Files used: landuse_stpetebeach (from CURRENT_LANDUSE_LDI_LSI), critbeach_jun10, cities_feb04 1­ Added CURRENT_LANDUSE_LDI_LSI to Layer frame & used the Identify tool to see what types of land use were present in the Saint Pete Beach area 2­ Select by Atrributes: selected the types of land use found in this area and exported data..added the new layer (landuse_stpetebeach) 3­ Buffered 10 mile radius around SAINT PETE BEACH and Clipped Landuse_stpetebeach to this buffer a. Data > Export Data > landuse_spb_10mi 4­ Converted landuse_spb_10mi to Raster so it could be used easily with upcoming aerials a. Reclassify VALUEs i. Spatial Analyst > Reclassify > New Values: (change new values to reflect four values) 1­Developed, 2­Vegetated, 3­Recreational, 4­Water 5­ Georeference historical and current aerials a. Geoferencing > Add Control Points i. Used anywhere from 2 points on smaller, current aerials to 6 points on larger, historical aerials ii. Based control points primarily on road intersections that existed in both time periods. Very distinguishable landforms that appeared to have little to no change were also used in cases where road intersections in both images did not exist or were indistinguishable. 12. Results: Discussion and Conclusion. I expected there to be a correlation between urbanized regions and critically eroding coastline, and there was. 95% of critically eroding coastline is categorized as urbanized. This percentage was much higher than I anticipated. This correlation is not interpreted as causation. More interdisciplinary studies should be conducted before determining if urbanization caused erosion. The surprise came after the land use change analysis on Long Island. I was analyzing historical aerials georeferenced to present land coverage, and was expecting to find wider beaches in the historical images and narrower beaches in the present­day image. In fact, I found just the opposite. The beaches were narrower in the 1940s­1950s and generally wider in present­day. As I continued to study this area I noticed that a lot of land had actually been built onto the island to create the present­day coastline. This extra land was then used by developers who built houses, roads, and other developments over it. When I looked much closer at present­day Upham Beach I noticed that the beach area had changed very significantly over a small time span of about 5 years. I believe this is largely due to the nourishment project ongoing. In 2005, nourishment was provided to this beach and by 2007 was at its peak reach out into the ocean. By 2010, however, Upham Beach is even more eroded than its state in 2005. So I found that while the historical beaches of Long Island were smaller than their present­day counterparts, they more consistently maintained their breadth than present­day beaches. Also, while the present­day beach was generally larger than the historical beach, I believe this is mostly due to the nourishment constantly being provided, and if it were to be left alone and nourishment projects ceased it would revert back to roughly its original state as a narrower, more stable coastline. More research is needed to determine if the beach would actually revert. 13. Limitations and pitfalls: state what could be the limitations of your project and why. (We certainly know that your project will be limited by time/resource/funding, but include other things – limits of the data, the GIS software, etc.) It was very difficult to find the same type of data for two different time periods (e.g. historical critically eroding beaches & present­day critically eroding beaches….I was not able to find the former). Same goes for similar enough land use data (couldn’t find old enough data that contained land use in particular. I was only able to find old [from 1967] vegetation coverage data; the oldest land use data was from 1985 which is after urbanization began occurring in my focus region of Long Beach.) 14. References: list the articles/websites you have read for this project. Don’t go overboard with a literature review, but do find a handful of peer reviewed articles that pertain to your analysis and/or techniques. Formal research websites may also be used in addition to the peer reviewed articles. Bureau of Beaches and Coastal Protection, DEP Critical Erosion Report 2007­2010 Woods Hole Oceanographic Institute, http://www.whoi.edu/page.do?pid=11914 The Moving Coastline Speaking with coastal management professionals at Upham Beach and participating in coastal geology fieldwork 15. Export maps and attach. Print each map as a full page document. (see: http://dl.dropbox.com/u/59573027/Critically%20Eroding%20Florida%20Coastlines%20May­June%2
02011/CriticallyErodingFLCoastlines_2011.png for full­sized image of maps)