{"action":"create","ckan_id":null,"date_created":"Sat, 28 Mar 2026 21:15:22 GMT","date_finished":null,"harvest_job_id":"c87df6d4-55a4-4157-8f97-1f84fe294e8c","harvest_source_id":"31f41541-38a0-400b-b240-10ebcb0acd9a","id":"647a98f6-649b-4944-8948-7976087d2247","identifier":"https://dggs.alaska.gov/webpubs/metadata/RI2020-10-Kotlik.xml","parent_identifier":null,"source_hash":"6bf073b006e616d3921fb1a122c74b9e682e411a6633c145dec6525697c62390","source_raw":"\ufeff\r\n\r\n \r\n \r\n \r\n Overbeck, J.R.\r\n Buzard, R.M.\r\n Turner, M.M.\r\n Miller, K.Y.\r\n Glenn, R.J.\r\n 2020\r\n Shoreline change at Alaska coastal communities, Kotlik, Alaska\r\n report, geodatabase\r\n \r\n Report of Investigation\r\n RI 2020-10\r\n \r\n \r\n Fairbanks, Alaska, United States\r\n Alaska Division of Geological & Geophysical Surveys\r\n \r\n 29 p., 47 sheets\r\n https://doi.org/10.14509/30552\r\n \r\n \r\n \r\n The Division of Geological & Geophysical Surveys has analyzed long-term shoreline change at 48 Alaska communities. Shoreline datasets were compiled from previously published U.S. Geological Survey assessments and created from historical and recent aerial images by the Alaska Division of Geological & Geophysical Surveys. Shorelines were analyzed to calculate shoreline change rates every 25 meters along coastlines and tidally influenced riverbanks using the Digital Shoreline Analysis System (DSAS; Himmelstoss and others, 2018). The geodatabase for each community includes shoreline positions, the alongshore baseline used to cast transects, and transects that include shoreline change rates and statistics. All files can be downloaded free of charge from the Alaska Division of Geological & Geophysical Surveys website (http://doi.org/10.14509/30552).\r\n Many of Alaska's coastal communities are vulnerable to erosion, flooding, and permafrost degradation. However, there are few vulnerability assessment tools available to the public that are complete or that utilize transparent, consistent, and quantitative methods at a scale needed for local planning. This work is an effort to provide numerical shoreline change data to Alaskans for local decision-making and erosion vulnerability assessments.\r\n >Baseline: The Baseline line file gives the location of the alongshore baseline used to cast transects. >Rates: Shoreline change is measured at regular intervals along the coast at transects that are cast orthogonal to shorelines from a baseline. Each method used to calculate shoreline change rates is based on measured differences between shoreline positions through time. The reported rates are expressed as meters of change along transects per year. When the user-selected rate-change calculations are processed, DSAS merges the individual module calculations, and the output is made available as a table in ArcMap. The rate-change statistics provided with DSAS have the standardized field headings. Some of the shoreline statistic values listed below require greater than 3 shoreline positions to calculate the statistic. If the shoreline statistic is a null value, there were not enough shorelines analyzed to compute that statistic. >Shorelines: Shoreline positions are a representation of a linear shoreline feature at a given point in time. These data were visually interpreted from historical and current orthorectified aerial photographs and delineated using ArcGIS.\r\n \r\n \r\n \r\n \r\n 2020\r\n \r\n \r\n ground condition\r\n \r\n \r\n complete\r\n None planned\r\n \r\n \r\n \r\n -163.578168\r\n -163.474656\r\n 63.049783\r\n 63.019065\r\n \r\n \r\n \r\n \r\n ISO 19115 Topic Category\r\n geoscientificInformation\r\n \r\n \r\n Alaska Division of Geological & Geophysical Surveys\r\n Aerial\r\n Aerial Photography\r\n Coastal\r\n DGGS\r\n Emergency Preparedness\r\n Engineering\r\n Environmental\r\n Erosion\r\n Flood\r\n Floodplain\r\n Geology\r\n Hazards\r\n Inundation\r\n Marine Geology\r\n Outreach\r\n Sea Level Changes\r\n Shelf\r\n Shoreface\r\n Storm Surge\r\n Surface\r\n Tides\r\n Topography\r\n Water\r\n \r\n \r\n Alaska Division of Geological & Geophysical Surveys\r\n Alaska\r\n Kotlik\r\n \r\n \r\n This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).\r\n Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.\r\n \r\n \r\n \r\n Alaska Division of Geological & Geophysical Surveys\r\n \r\n GIS Manager\r\n \r\n mailing and physical\r\n
3354 College Rd
\r\n Fairbanks\r\n AK\r\n 99709-3707\r\n USA\r\n \r\n 907-451-5020\r\n dggsgis@alaska.gov\r\n 8 am to 4:30 pm, Monday through Friday, except State holidays\r\n \r\n \r\n This work was funded by FEMA, the State of Alaska, the Denali Commission, and the U.S. Bureau of Indian Affairs. Data were produced by the Alaska Division of Geological & Geophysical Surveys, the U.S. Geological Survey, and the UAF Arctic Coastal Geoscience Lab.\r\n \r\n \r\n Overbeck, J.R.\r\n Hendricks, M.D.\r\n Kinsman, N.E.M.\r\n 2016\r\n Photogrammetric digital surface models and orthoimagery for 26 coastal communities of western Alaska\r\n \r\n Raw Data File\r\n RDF 2016-1\r\n \r\n \r\n Fairbanks, Alaska, United States\r\n Alaska Division of Geological & Geophysical Surveys\r\n \r\n 3 p\r\n https://doi.org/10.14509/29548\r\n \r\n \r\n \r\n \r\n \r\n DGGS staff have performed a visual qualitative assessment of each shoreline file to ensure consistency between digitized lines and originating images. The accompanying delivery report provides additional information about the procedures used to determine uncertainty values for shoreline positions and shoreline change statistics.\r\n \r\n Not applicable.\r\n Gaps in shoreline data and transect data may occur due to gaps in orthoimagery data, location and extent of coastal river channels or lakes, and infrastructure impeding the shoreline such as docks, revetments, and roadways.\r\n \r\n \r\n Shoreline positions are a representation of a linear shoreline feature at a given point in time. These data were visually interpreted from historical and current orthorectified aerial imagery and delineated in ArcGIS. Several factors have the potential to introduce positional uncertainty in the measured or interpreted results. These factors include horizontal uncertainty of the source imagery or ground control and the orthorectified image, spatial uncertainty associated with the imagery's spatial resolution, and uncertainty due to shoreline indicator interpretation during the digitization process. The accompanying delivery report provides additional information about the procedures used to determine uncertainty values for shoreline positions.\r\n \r\n \r\n \r\n \r\n \r\n \r\n Boak, E.H.\r\n Turner, I.L.\r\n 2005\r\n Shoreline definition and detection - A review\r\n \r\n Journal of Coastal Research\r\n v. 21, no. 4\r\n \r\n \r\n Coconut Creek, FL\r\n Coastal Education & Research Foundation\r\n \r\n null\r\n \r\n \r\n paper\r\n \r\n \r\n \r\n 2005\r\n \r\n \r\n publication date\r\n \r\n Boak, E.H. and Turner, I.L., 2005\r\n historical shoreline compilation\r\n \r\n \r\n \r\n \r\n Dolan, Robert\r\n Fenster, M.S.\r\n Holme, S.J.\r\n 1991\r\n Temporal analysis of shoreline recession and accretion:\r\n \r\n Journal of Coastal Research\r\n v. 7, no. 3\r\n \r\n \r\n Coconut Creek, FL\r\n Coastal Education & Research Foundation\r\n \r\n null\r\n \r\n \r\n paper\r\n \r\n \r\n \r\n 1991\r\n \r\n \r\n publication date\r\n \r\n Dolan, Robert and others, 1991\r\n historical shoreline compilation\r\n \r\n \r\n \r\n \r\n Himmelstoss, E.A.\r\n Farris, A.S.\r\n Henderson, R.E.\r\n Kratzmann, M.G.\r\n Ergul, Ayhan\r\n Zhang, Ouya\r\n Zichichi, J.L.\r\n Thieler, E.R.\r\n 2018\r\n Digital Shoreline Analysis System (DSAS) Version 5.0 User Guide\r\n \r\n Open-File Report\r\n OF 2018-1179\r\n \r\n \r\n United States\r\n U.S. Geological Survey\r\n \r\n 110 p\r\n https://dggs.alaska.gov/pubs/id/30649\r\n \r\n \r\n ArcGIS extension\r\n \r\n \r\n \r\n 2018\r\n \r\n \r\n publication date\r\n \r\n Himmelstoss, E.A. and others, 2018\r\n historical shoreline compilation\r\n \r\n \r\n Historical shoreline compilation - Shoreline positions are compiled from previously published U.S. Geological Survey assessments as well as delineated from orthorectified historical and modern aerial imagery. The agency or organization that produced the imagery and shoreline vector are noted in the Shorelines data table.\r\n Boak, E.H. and Turner, I.L., 2005\r\n Dolan, Robert and others, 1991\r\n Himmelstoss, E.A. and others, 2018\r\n 2020\r\n \r\n \r\n Projected shoreline positions - Shoreline change is measured at 25-meter alongshore transects that are cast orthogonal to shorelines from an offshore baseline. At each transect, DSAS marks the shoreline intersection position and measures the distance between shorelines through time to compute statistical rates of change.\r\n 2020\r\n \r\n \r\n \r\n \r\n vector\r\n \r\n \r\n \r\n \r\n \r\n Universal Transverse Mercator\r\n \r\n 3\r\n \r\n 0.999600\r\n -165\r\n 0\r\n 500000.000000\r\n 0\r\n \r\n \r\n \r\n \r\n coordinate pair\r\n \r\n .00000001\r\n .00000001\r\n \r\n Meters\r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n Baseline\r\n The Baseline line file gives the location of the alongshore baseline used to cast transects.\r\n DGGS\r\n Baseline\r\n \r\n \r\n DSAS_ID\r\n Baseline identifier to determine the ordering sequence of transects.\r\n DGGS\r\n \r\n Integer\r\n \r\n \r\n \r\n \r\n \r\n Rates\r\n Shoreline change is measured at regular intervals along the coast at transects that are cast orthogonal to shorelines from a baseline. Each method used to calculate shoreline change rates is based on measured differences between shoreline positions through time. The reported rates are expressed as meters of change along transects per year. When the user-selected rate-change calculations are processed, DSAS merges the individual module calculations, and the output is made available as a table in ArcMap. The rate-change statistics provided with DSAS have the standardized field headings. Some of the shoreline statistic values listed below require greater than 3 shoreline positions to calculate the statistic. If the shoreline statistic is a null value, there were not enough shorelines analyzed to compute that statistic.\r\n DGGS and Himmelstoss and others, 2018\r\n Rates\r\n \r\n \r\n TransectID\r\n The TransectID relates directly to the original transect file Object Identifier\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Integer\r\n \r\n \r\n \r\n BaselineID\r\n Values in this field correlate to the baseline attribute field ID and are assigned by DSAS to identify the baseline segment used to generate the measurement transect. Baseline segments assigned an ID = 0 are ignored by DSAS, and no transects will be cast along those line segments.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Integer\r\n \r\n \r\n \r\n TransOrder\r\n Assigned by DSAS on the basis of transect order along the baseline or baselines. If the user manually adds transects to the file in an edit session, they will be added to the end of the transect attribute table and given a new value for TransID (ObjectID). However, TransOrder will be updated to reflect the position of the new transect with respect to the other transect along the baseline. As such, this field provides the user with a method to sort transect attribute data sequentially alongshore, from the start of the baseline segment with an ID=1 to the end of the final baseline segment.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Integer\r\n \r\n \r\n \r\n Azimuth\r\n Assigned by DSAS to record the azimuth of the transect measure in degrees clockwise from North.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n ShrCount\r\n The total number of shorelines intersected by the transect and used for change analysis.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Integer\r\n \r\n \r\n \r\n TCD\r\n The TCD (total cumulative distance) is the measure (in meters) along the shore from the start of the baseline segment with an ID =1 and measured sequentially alongshore to the end of the final baseline segment.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n SCE\r\n Shoreline change envelope; the \"SCE\" value represents the greatest distance among all the shorelines that intersect a given transect. The value for SCE is always positive. If the proxy-datum bias (PDB) is applied, two versions of this statistic will be reported: SCE will include the PDB in the calculations; NB_SCE will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n NSM\r\n Net shoreline movement (NSM) is the distance between the oldest and youngest shorelines at each transect. If the PDB is applied, two versions of this statistic will be reported: NSM will include the PDB in the calculations; NB_NSM will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n EPR\r\n The end point rate (EPR) is calculated by determining the distance between the oldest and youngest shoreline on a DSAS transect and dividing by the time elapsed between the two shoreline dates. If the PDB is applied, two versions of this statistic will be reported: EPRwill include the PDB in the calculations; NB_EPR will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n EPRunc\r\n An estimate of end point rate uncertainty. The shoreline uncertainties for the two positions used in the end point calculation are each squared, then added together (summation of squares). The square root of the summation of squares is divided by the number of years between the two shorelines. If the PDB is applied, two versions of this statistic will be reported: EPRunc will include the PDB in the calculations; NB_EPRunc will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n LRR\r\n A linear regression rate-of-change statistic was calculated by fitting a least-squares regression line to all shoreline points for a particular transect. The best-fit regression line is placed so that the sum of the squared residuals (determined by squaring the offset distance of each data point from the regression line and adding the squared residuals together) is minimized. The linear regression rate is the slope of the line. The rate is reported in meters per year, with positive values indicating accretion and negative values indicating erosion. If the PDB is applied, two versions of this statistic will be reported: LRR will include the PDB in the calculations; NB_LRR will not include the PDB. If the PDB is not applied, the LRR statistic will not include the bias.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n LR2\r\n The R-squared statistic, or coefficient of determination, is the percentage of variance in the data that is explained by a regression. It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). If the PDB is applied, two versions of this statistic will be reported. LR2 will include the PDB; NB_LR2 will not include the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n LSE\r\n The predicted (or estimated) values of y (the distance from baseline in meters) are computed for each shoreline point by using the values of x (the shoreline date) and solving the equation for the best-fit regression line (y=mx+b). The standard error is also called the standard deviation. This metric evaluates the accuracy of the best-fit regression line in predicting the position of a shoreline for a specific date. If the PDB is applied, two versions of this statistic will be reported. LSE will include the PDB; NB_LSE will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n LCI90\r\n The standard error of the slope with confidence interval describes the uncertainty of the reported rate for the user-selected confidence value captured as part of the attribute name. If the PDB is applied, two versions of this statistic will be reported. LCI90 will include the PDB; NB_LCI90 will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n WLR\r\n In a weighted linear regression (WLR), more reliable data are given greater emphasis or weight towards determining a best-fit line. In the computation of rate-of-change statistics for shorelines, greater emphasis is placed on data points for which the position uncertainty is smaller. If the PDB is applied, two versions of this statistic will be reported: WLR will include the PDB in the calculations: NB_WLR will not include the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n WR2\r\n The R-squared statistic, or coefficient of determination, is the percentage of variance in the WLR that is explained by a regression.It is a dimensionless index that ranges from 1.0 to 0.0 and measures how successfully the best-fit line accounts for variation in the data. The smaller the variability of the residual values around the regression line relative to the overall variability, the better the prediction (and closer the R-squared value is to 1.0). If the PDB is applied, two versions of this statistic will be reported. WR2 will include the PDB; NB_WR2 will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n WSE\r\n The standard error of the estimate for the weighted linear regression rate. The standard error evaluates the accuracy of the best-fit regression line (WLR) in predicting the position of a shoreline for a specific date. If the PDB is applied, two versions of this statistic will be reported. WSE will include the PDB; NB_WSE will not include the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n WCI90\r\n The standard error of the slope with confidence interval describes the uncertainty of the reported rate for the user-selected confidence value captured as part of the attribute name. If the PDB is applied, two versions of this statistic will be reported. WCI90 will include the PDB; NB_WCI90 will omit the PDB.\r\n DGGS and Himmelstoss and others, 2018\r\n \r\n Double\r\n \r\n \r\n \r\n \r\n \r\n Shorelines\r\n Shoreline positions are a representation of a linear shoreline feature at a given point in time. These data were visually interpreted from historical and current orthorectified aerial photographs and delineated using ArcGIS.\r\n DGGS\r\n Shorelines\r\n \r\n \r\n Date\r\n The acquisition date of the imagery that was used to delineate shoreline position.\r\n DGGS\r\n \r\n Date\r\n \r\n \r\n \r\n Uncertainty\r\n Root sum of squares of four uncertainty values associated with shoreline position, including positional uncertainty for ground control used to reference imagery, horizontal uncertainty associated with orthorectification distortions, spatial uncertainty dependent on imagery's spatial resolution, and uncertainty due to shoreline indicator interpretation during the digitization process.\r\n DGGS\r\n \r\n Single\r\n \r\n \r\n \r\n SIndicator\r\n Shoreline indicator used to delineate shoreline position. (e.g., visible wet/dry line or vegetation line); VL = Vegetation Line, HWL = High Water Line, and LWI = land-water interface.\r\n DGGS\r\n \r\n String\r\n \r\n \r\n \r\n Digitizer\r\n Name of the digitizer who delineated the shoreline.\r\n DGGS\r\n \r\n String\r\n \r\n \r\n \r\n Agency\r\n Name of the agency that delineated the shoreline.\r\n DGGS\r\n \r\n String\r\n \r\n \r\n \r\n Source\r\n Source agency or organization of the imagery used to delineate the shoreline position.\r\n DGGS\r\n \r\n String\r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n \r\n State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys\r\n Simone Montayne\r\n \r\n \r\n mailing and physical\r\n
3354 College Road
\r\n Fairbanks\r\n AK\r\n 99709-3707\r\n USA\r\n \r\n 907-451-5020\r\n 907-451-5050\r\n dggspubs@alaska.gov\r\n 8 am to 4:30 pm, Monday through Friday, except State holidays\r\n Please view our website (http://www.dggs.alaska.gov) for the latest information on available data. Please contact us using the e-mail address provided above when possible.\r\n \r\n \r\n RI 2020-10\r\n The State of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity, whether from the use of the electronic services or products, any failure thereof, or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product.\r\n \r\n DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (dggspubs@alaska.gov), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.\r\n see http://dx.doi.org/10.14509/30552\r\n \r\n \r\n \r\n \r\n report and geodatabase\r\n 20210302\r\n vector data\r\n \r\n \r\n \r\n \r\n \r\n http://dx.doi.org/10.14509/30552\r\n \r\n \r\n \r\n \r\n \r\n Free download\r\n \r\n \r\n \r\n 20210302\r\n \r\n \r\n \r\n Simone Montayne\r\n \r\n \r\n mailing and physical\r\n
3354 College Road
\r\n Fairbanks\r\n AK\r\n 99709-3707\r\n USA\r\n \r\n 907-451-5020\r\n \r\n \r\n FGDC Content Standard for Digital Geospatial Metadata\r\n FGDC-STD-001-1998\r\n If the user has modified this metadata file in any way, the user is obligated to describe the types of modifications the user has made. User specifically agrees not to misrepresent this metadata file, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys.\r\n \r\n http://www.dggs.alaska.gov/metadata/dggs.ext\r\n dggs metadata extensions\r\n \r\n \r\n","source_transform":null,"status":"error"}