Name: 2022 ORC Glenorchy Liquefaction Vulnerability and Lateral Spreading Ground Damage Areas
Display Field: Level_
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The 20</SPAN><SPAN>22</SPAN><SPAN> </SPAN><SPAN>liquefaction and lateral spreading vulnerability zones for Glenorchy, </SPAN><SPAN>prepared by </SPAN><SPAN>Tonkin + Taylor </SPAN><SPAN>(T+T) </SPAN><SPAN>under contract to Otago Regional Council (ORC)</SPAN><SPAN>.</SPAN><SPAN>This corresponds to Appendix A of the report titled "Glenorchy Liquefaction Vulnerability Assessment" prepared by T+T for ORC, dated 26th May 2022 (T+T Ref: 1017916).</SPAN></P><P><SPAN>This dataset </SPAN><SPAN>comprises a classification of liquefaction </SPAN><SPAN>vulnerability following the methodology given in the MBIE/MfE guidelines (2017), as well as a classification of lateral spreading vulnerability.</SPAN><SPAN> The vulnerability assessment uses 100-year, 500-year return period events as determined using Module 1 of the Guidelines for earthquake geotechnical engineering practice in New Zealand (NZGS & MBIE 2021), as well as an Alpine Fault Rupture Scenario (with a return period of approximately 30-years).</SPAN></P><P><SPAN>There are five vulnerability levels used in this dataset:</SPAN></P><P><SPAN>1. Low Liquefaction Vulnerability: There is a probability of more than 85 percent that liquefaction-induced ground damage will be None to Minor for 500-year shaking.</SPAN><SPAN>2. Medium Liquefaction Vulnerability: There is a probability of more than 50 percent that liquefaction-induced ground damage will be: Minor to Moderate (or less) for 500-year shaking; and None to Minor for 100-year shaking. </SPAN><SPAN>3. High Liquefaction Vulnerability: There is a probability of more than 50 percent that liquefaction-induced ground damage will be: Moderate to Severe for 500-year shaking; and/or Minor to Moderate (or more) for 100-year shaking. There is no considered to be a significant risk of lateral spreading damage.</SPAN><SPAN>4. High Liquefaction Vulnerability and Major Lateral Spreading Vulnerability: As for category (3), but with a significant risk of major lateral spreading damage (>100mm) in a 500-year shaking event.</SPAN><SPAN>5. High Liquefaction Vulnerability and Severe Lateral Spreading Vulnerability: As for category (3), but with a significant risk of severe lateral spreading damage (>500mm) in a 500-year shaking event.</SPAN></P><P><SPAN>Reference</SPAN><SPAN>s</SPAN><SPAN>:</SPAN></P><P><SPAN>MBIE & MfE. (2017). Planning and Engineering Guidance for Potentially Liquefaction-prone Land. Wellington: New Zealand Ministry of Business, Innovation and Employment, Building System Performance Branch.</SPAN></P><P><SPAN>NZGS & MBIE. (2021). Earthquake geotechnical engineering practice, Module 1: Overview of the Guidelines. Wellington: New Zealand Geotechnical Society and Ministry of Business, Innovation and Employment. </SPAN></P></DIV></DIV></DIV>
Service Item Id: af909eeb17b540d0a1334217af3fac0d
Copyright Text: Copyright Otago Regional Council 2022
Unique Value Renderer: Field 1: Level_ Field 2: N/A Field 3: N/A Field Delimiter: , Default Symbol:
N/A
Default Label: N/A UniqueValueInfos:
Value: Severe Lateral Spreading Ground Damage and High Vulnerability to Liquefaction Ground Damage Label: Severe Lateral Spreading Ground Damage and High Vulnerability to Liquefaction Ground Damage Description: N/A Symbol:
Value: Major Lateral Spreading Ground Damage and High Vulnerability to Liquefaction Ground Damage Label: Major Lateral Spreading Ground Damage and High Vulnerability to Liquefaction Ground Damage Description: N/A Symbol:
Name: 2020 BECA Local Analysis - Liquefaction Risk
Display Field: Source
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 14 0;"><SPAN>This liquefaction risk layer combines data from two studies: Hazards Register Part II Stage 2 Risk Management Study (OPUS 2002) & QLDC 2012 Liquefaction Hazard Assesment (Tonkin & Taylor 2012). Liquefaction Investigation Categories (LIC) have been developed to provide guidelines on the liquefaction risk and recommended level of further investigation for a particular area. The categories range from LIC 1, for areas with an assessed low to nil risk of liquefaction, to LIC 3 (P), for areas which are assessed to have a 'possibly high' risk of liquefaction. The different categories reflect the level of information available for a particular area, and, where feasible, if liquefaction is expected to occur.</SPAN></P></DIV></DIV></DIV>
Name: 2005 Opus Regional Analysis - Liquefaction Susceptibility
Display Field: LIQ_POT
Type: Feature Layer
Geometry Type: esriGeometryPolygon
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>The purpose of the study was to provide high-level information on the recurrence internal and magnitude of damaging earthquakes in Otago, designed to assist Local Territorial Authorities perform future 'lifelines' projects.</SPAN></P><P><SPAN>The liquefaction susceptibility has been mapped into 3 susceptibility classes depending on nature and density of soils:</SPAN></P><P><SPAN>Class A: Not Susceptible - Liquefaction is unlikely in any scenario, but some strength loss may occur in surficial materials in a large earthquake.</SPAN></P><UL><LI><P><SPAN>Material Description: Very Dense/Hard - Alluvium, Moraine Remnants, Marine Terraces. Tertiary & Basement Rocks</SPAN></P></LI></UL><P><SPAN>Class B: Low Susceptibility - Liquefaction and settlement are unlikely, but localised areas may liquefy in a large earthquake.</SPAN></P><UL><LI><P><SPAN>Material Description: Dense/Firm - Alluvium, Fans, Till, Outwash, Old Lake Beaches, Moraine Remnants, Marine Terraces</SPAN></P></LI></UL><P><SPAN>Class C: Possibly Susceptible - Very loose to medium dense sediments, liquefaction and settlement are possible with seismic shaking of sufficient intensity.</SPAN></P><UL><LI><P><SPAN>Material Description: Peat, Mud, Swamp, Tailings, Reclamation, Fill, and Loose/Soft to Medium Dense: Alluvium, Lake Deposits, Beach Gravels and Sands, Scree, Alluvial Fans, Sand Dunes, Till, Alluvium.</SPAN></P></LI></UL><P><SPAN>For more information, see Section 10 and Map 22 & 23 of Seismic Risk in the Otago Region (Mar 2005) - https://qldc.t1cloud.com/T1Default/CiAnywhere/Web/QLDC/ECMCore/Rendition/Get?docsetId=696908&renditionType=pdf&suite=ECM.</SPAN></P></DIV></DIV></DIV>
Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P><SPAN>This liquefaction susceptibility dataset, prepared by GNS Science under contract to Otago Regional Council (ORC), covers the entire extent of the Central Otago District, Clutha District, Queenstown Lakes District, and that part of the Waitaki District lying in the Otago Region. The dataset comprises a four-fold classification of liquefaction susceptibility classes, called 'domains', that identifies areas that are assessed as being underlain by sediments which may have some liquefaction susceptibility. In making the assessment, consideration has been given to whether groundwater levels are likely to be sufficiently close to the ground surface to make liquefaction possible.</SPAN></P><P><SPAN>This dataset does not define hazard zones, but rather identifies liquefaction-susceptibility domains. In terms of the MBIE (2017) guidelines, the mapping approach used to produce this dataset equates to a “Level A” basic desktop assessment, that is aimed at distinguishing between areas where liquefaction damage is unlikely to occur (Domain A) versus areas where liquefaction damage is possible (domains B, B1 and C).</SPAN></P><P><SPAN>The liquefaction-susceptibility domains in this dataset, with reference to MBIE (2017) guidelines, are defined as follows:</SPAN></P><UL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P STYLE="text-align:Justify;margin:7 0 0 0;"><SPAN>Domain A. The ground is predominantly underlain by rock or firm sediments. There is little or no likelihood of damaging liquefaction occurring. In MBIE (2017) terms, liquefaction damage is unlikely; </SPAN></P></LI><LI><P STYLE="text-align:Justify;margin:7 0 0 0;"><SPAN><SPAN>Domain B. The ground is predominantly underlain by poorly consolidated river or stream sediments with a shallow groundwater table. There is considered to be a low to moderate likelihood of liquefaction-susceptible materials being present in some parts of the areas classified as Domain B. In MBIE (2017) terms, liquefaction damage is possible;</SPAN></SPAN></P></LI><LI><P STYLE="text-align:Justify;margin:7 0 0 0;"><SPAN><SPAN>Domain B1. As for Domain B, but there is geotechnical evidence for the presence of liquefaction-susceptible materials at least in some locations in the subsurface; </SPAN></SPAN></P></LI><LI><P STYLE="text-align:Justify;margin:7 0 0 0;"><SPAN><SPAN>Domain C. The ground is predominantly underlain by poorly consolidated marine or estuarine sediments with a shallow groundwater table. There is considered to be a moderate to high likelihood of liquefaction-susceptible materials being present in some parts of the areas classified as Domain C. In MBIE (2017) terms, liquefaction damage is possible.</SPAN></SPAN></P></LI></UL><P><SPAN>Reference: MBIE (2017). Planning and engineering guidance for liquefaction-prone land. Wellington (NZ): Ministry of Business, Innovation and Employment (MBIE). 134 p. Technical report; ISBN (online) 978-1-98-851770-4.</SPAN></P><P STYLE="margin:7 0 0 0;"><SPAN>Accuracy: The positioning of boundaries between domain polygons is based largely on landform features. The main topographic and photographic basemaps used to aid the mapping were the 1:50,000-scale LINZ Topo 50 map series, and high-resolution colour aerial photos, accessed digitally through the ArcGIS software. Unless stated otherwise in the companion report (see Credits), the mapping scale was 1:50 000, and the boundary between each domain polygon should be regarded as being a 100 m wide zone, rather than a line. In areas where lidar coverage was available for the mapping, the mapping scale is 1:10 000, and domain boundaries should be regarded as 20 m wide zones. In towns and villages, where Google Earth Street View was available at the time of mapping, Google Earth ground photography was accessed to help in positioning domain boundaries. In those areas, the assigned mapping scale is 1:1 000, and boundaries are considered accurate at the scale of property parcels and buildings. The commentary in Appendix 2 of the companion report indicates where these more detailed scales apply.</SPAN></P></DIV></DIV></DIV>
Service Item Id: af909eeb17b540d0a1334217af3fac0d
Copyright Text: Dataset compiled by D.J.A. Barrell. Data described and documented in: Barrell, D.J.A. 2019. Assessment of liquefaction hazards in the Queenstown Lakes, Central Otago, Clutha and Waitaki districts of the Otago Region. Lower Hutt (NZ): GNS Science. 97 p. GNS Science Consultancy Report 2018/67.