Purpose: Shorelines derived from historic aerial photography dating from 1940s to present. This data can be used in conjunction with the separate feature SCIENCE.sdeadmin.COASTAL_SHORELINE_2017, a feature of dataset Coastal Shoreline and Intertidal Area - GIS Layer. The purpose is to indicate shoreline change over time.Intended Use Scale: Data should not be used at scales greater than 1:5,000.Data Use Limits: Shorelines have only been digitised from historical aerial photography where its location is measurably different from the complete 2017 shoreline, and where the shoreline change is beyond the likely error of the photograph. Significant stretches of coast backed by hard rock cliffs, and estuaries away from the main populated areas, where shoreline change is not significant has therefore not been re-mapped for this dataset.Priority has been given to areas where shorelines are highly changeable, and/or development is at risk from coastal erosion.Please note that the indicative line work does not constitute the actual legal boundary of the coastal marine area. CMA is defined as mean high water springs, which can change over time and has not been adequately surveyed across the region.While the estimated error in the older (1940s and 1950s) orthorectifed images may be large (≤ ±30 m), observations made during the mapping process suggests that the historical photography aligns with the 2012 WRAPS images very closely (to within just a few meters in most areas). Where there is a clear problem with orthorectification (i.e. error is clearly more than 5 m) then a shoreline was not digitised from that photograph. This most commonly occurs on older (1940s and 1950s) photographs, where there is little or no development near the coast and therefore it is very difficult to find ground control points in the images. There is additional potential error in identifying the toe of dune from poor quality or overexposed photography. When using these shorelines from hazard assessment or other analysis, these potential errors need to be recognised and accounted for.Data Specific Disclaimers:The standard Waikato Regional Council Disclaimer applies to this data “While Waikato Regional Council has exercised all reasonable skill and care in controlling the contents of this information, Waikato Regional Council accepts no liability in contract, tort or otherwise howsoever, for any loss, damage, injury or expense (whether direct, indirect or consequential) arising out of the provision of this information or its use by you.”WRC Metadata: For the full metadata please refer to SCIENCE.sdeadmin.HISTORIC_SHORELINES - Historic Foreshore - GIS LayerTerms of Use:This work is licensed under CC BY 4.0This work is licensed under a Creative Commons Attribution 4.0 International License(c) Waikato Regional Council 2021. Historic Shorelines derived from Historic Aerial Photographs Data Sourced from https://retrolens.nz and licensed by LINZ CC-BY 4.0.See the Waikato Regional Hazards Portal Terms of use here Waikato Regional Hazards Portal - Terms of use | Waikato Regional Council.
