Hillforts in the Chilterns Landscape
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Hillforts in the Chilterns Landscape Introductory Meet & Greets 14th & 15th July 2018 Henley on Thames – Redbourn – Pitstone – High Wycombe Chilterns Conservation Board Chilterns are one of 46 AONBs in UK, established in 1965 CCB established by Parliamentary Order in 2004 • To conserve and enhance natural beauty • To promote understanding and enjoyment of special qualities • To promote social and economic well being The Beacons of the Past project 3.5 years, part HLF Funded, part matched funding from the Chiltern Society, the National Trust, local county and parish councils, and private donors. Three aims or “beacons” – discovery, learning, protection. LiDAR survey as key component Focus on the Iron Age hillforts of the Chilterns Three Beacons Beacon of Discovery LiDAR Geophysics Excavation Survey Beacon of Learning Training volunteers School workshops/community events Augmented reality apps New interpretation boards Beacon of Protection Conservation management Heritage Watch Ecological survey J Morris West Wycombe hillfort Hillforts of the Chilterns* *Not all hillforts… Sharpenhoe Clappers Maiden Bower Pulpit Hill Courtesy C Rose Chilterns hillforts are varied Boddington Hillfort Pulpit Hillfort . Large (c. 6 ha.) . Small (< 1 ha.) . Univallate . Bivallate Courtesy C Rose Why so varied? P Shreeves, Creative Commons licence Wikimedia Commons licence A British Holocene Calendar – Hillforts are constructed largely from end of September to Late October, a greater chunk of time than what separated the 1940s prefab from Windsor Castle – yet we could label both as ‘houses’. This highlights the difficulty of the label ‘hillfort! Why are we looking at them . Limited knowledge . Neglect / damage . Inappropriate management . Variable public access . Lack of interpretation . Low public awareness . Limited public engagement Mature trees at Cholesbury Camp courtesy C Rose Neglect / lack of management Desborough Castle Ravensburgh Castle . Fly tipping and fallen trees . Trees and undergrowth courtesy C Rose Damage Ivinghoe Beacon Whelpley Hill . Erosion scars . Virtually ploughed out courtesy C Rose Damage Pulpit Hill . Beech trees on banks © CADW © John Morris What is LiDAR? “Light Detection and Ranging”, aka “Airborne Laser Scanning” A survey technique developed in the 1960s, and first used in meteorology. Used in 1971 by the Apollo 15 astronauts to map the surface of the moon. Used since the turn of the millennium for archaeology: Discovery of new sites; Increased knowledge and better locational accuracy of known sites; Visualisation of features thought destroyed by ploughing; Filtering of vegetation for survey in woodland. Stonehenge Cursus west end and the Fargo Plantation. Figs. 2 and 3 from Bewley et al. (2005) “New light on an ancient landscape: lidar survey in the Stonehenge World Heritage Site” Antiquity 79: 636-647 What is LiDAR? A plane flying across a landscape, with a laser scanner sending pulses of light down to the ground, and sensing the reflections from whatever those pulses hit. Up to 1 MHz pulse rate. 100-200 Hz scan rate (side to side). Combination of: GPS (global positioning system) IMU (inertial measurement unit) plus sensor calculations of time taken for pulses to be reflected … gives us accurate 3D location for everything off which the laser bounces. Credit: NOS/NCCOS/CCMA, reused under a creative commons licence What is LiDAR? Multiple returns with differing energy levels. Credit: NEON Science, reused under a creative commons licence What is LiDAR? Point clouds Credit: NEON Science, reused under a creative commons licence LiDAR Visualisations Relief Model Boddington Camp, Wendover Woods LiDAR Data: Environment Agency; Map Data: Ordnance Survey; Aerial Photograph: APGB. LiDAR Visualisations Relief Model Boddington Camp, Wendover Woods LiDAR Data: Environment Agency; Map Data: Ordnance Survey; Aerial Photograph: APGB. LiDAR Visualisations Single Directional Hillshade LiDAR Data: Environment Agency; Map Data: Ordnance Survey; Aerial Photograph: APGB. LiDAR Visualisations Multi Directional Hillshade LiDAR Data: Environment Agency; Map Data: Ordnance Survey; Aerial Photograph: APGB. LiDAR Visualisations Sky View Factor LiDAR Data: Environment Agency; Map Data: Ordnance Survey; Aerial Photograph: APGB. LiDAR Visualisations Local Relief Model LiDAR Data: Environment Agency; Map Data: Ordnance Survey; Aerial Photograph: APGB. 1300 km2 0.25m resolution Flown between Nov 2018- Feb 2019 Processed visualisations will be available through the online portal from May 2019 Ways to get involved Digital Volunteering Practical Volunteering Skills training throughout Digital Volunteering Database management and feature recording with GIS Archival research for the sites and vicinities of the hillforts Crowdsourced LiDAR digitisation Practical Volunteering Archaeological Field Survey Topographical Survey Geophysical Survey Excavation Palaeo-Environmental Coring Ground Truthing LiDAR Results Visitor Surveys Environmental Scrub Clearance Footpath Maintenance Hedge Laying Field Survey: Michigan State University - Site Clean-ups https://msu.edu/~aarondan/methodsofarchaeology.htm Erosion Surveys Wildlife Surveys Practical Volunteering Archaeological Field Survey Topographical Survey Geophysical Survey Excavation Palaeo-Environmental Coring Ground Truthing LiDAR Results Visitor Surveys Environmental Scrub Clearance Footpath Maintenance Hedge Laying Magnetometry survey from Hod Hill, Dorset: Stewart Site Clean-ups and Russell (2018) Erosion Surveys Wildlife Surveys Practical Volunteering Archaeological Field Survey Topographical Survey Geophysical Survey Excavation Palaeo-Environmental Coring Ground Truthing LiDAR Results Visitor Surveys Environmental Scrub Clearance Footpath Maintenance Scrub Clearance: Chilterns Conservation Board Hedge Laying Site Clean-ups Erosion Surveys Wildlife Surveys More information Sign up for our Hillforts mailing list https://share.hsforms.com/1OBFHZOdMSKivehZfN_m9yQ2orgq Follow us on social media: Facebook: Chilterns Area of Outstanding Natural Beauty Twitter: @ChilternsAONB, #Chilforts Instagram: @chilternsaonb Visit our website: www.chilternsaonb.org.