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Database Title

9.1 Beach profiles
Keywords
Type1.
Type 11.		 Open coast, physical processes, erosion, beaches
Beach profiles
Abstract

The core of the database consists of monthly coastal profile analyses for 26 Bay of Plenty coastal sites for 14 -- 16 years. This data is being linked with climate data to explain current beach processes, identify past beach condition and forecast future trends.

A database is being built for the Coromandel. This currently consists of monthly (initially)and then two monthly coastal profile analysis for a selection of Coromandel sites for more than 3 years.

To compare West Coast Beach processes a database is being established. This currently consists of a three-year record of coastal profiles for Ruapuki Beach (West Coast south of Raglan).
Geographical Coverage Bay of Plenty, Coramandel, Raglan area, West Coast- North Island
Dataset start date. 1985 (BOP); others later
Dataset end date. Ongoing
Status/currency. In progress
Update frequency. BOP Monthly. Coromandel 2 monthly
Maintenance. Maintained regularly by Keith Smith

 

Technical Evaluation

  
Parameters- what is measured Distance and elevation from a known point which is a benchmark for the site.
Parameters- what is calculated
  • Outline surface shape of the beach
  • Beach volume and slope
  • How far the beach is moving seawards or landwards between each survey
  • Seasonal changes in on shore and offshore storms and storm frequency.
  • Effects of storms on beaches and recovery time for beaches after storms.
Methods used to measure parameters The Emery (2 pole )method is used. Two poles marked in cm intervals are lined up. The distance between the poles is measured with tape. Elevation is measured on the poles. This method has been calibrated with precision survey methodology.
Scale of use. N/A
Number of records Monthly records for 28 Bay of Plenty sites for 14 years. Three years data for Coromandel and North Island West Coast.
GIS compatibility. BOP sites use the NZ Geodetic Datum.
Coromandel sites have not yet had their locations coordinated but that is a relatively simple task.
North Island West Coast calibration has yet to be done.
Available formats for users. Electronic database
Access constraints. Information from the database needs to be purchased.
Measurement Accuracy To be completed by database manager.
Completeness of dataset To be completed by database manager.
Positional accuracy To be completed by database manager.
Database steward Keith Smith/NIWA
Database custodian Keith Smith/NIWA
Database custodian contact person Keith Smith
Database custodian Contact
Address
Phone
Fax
Email		 Box 11-115
Hamilton
+64 7 856 7026
+64 7 856 1731
k.smith@niwa.cri.nz
References Smith, R.K.; Benson,A.K. 2000. Coastline monitoring -- how frequently is sufficient? Paper presented to NZ Coastal Society Conference. Rotorua, Easter 2000.
Anon. 2000. Dedicated to assessing coastal hazards- Aniwaniwa interviews Keith Smith.. Aniwaniwa Issue 13
Date metadata record prepared. June 2000
Author of metadata record. Victoria Froude

 

Management Evaluation

  
Original purpose. To answer long-term questions about coastal physical processes, e.g. is a beach responding to seasonal or climatic changes?
Relationships with classification systems. N/A
Relationships with other databases Links with Environment Bay Of Plenty, Environment Waikato and Auckland Regional Council Beach Profile Databases.
Known relationships with proposed EPIP indicators. Not known
Database uses? Regional and district councils
  • coastal hazards assessment
  • assessing the impacts of beach sand and gravel mining.
Those appealing regional and district council decisions on coastal hazards and beach mining operations
Public awareness of the database Low level
Database strengths.
  • The most efficient and sensitive way to track coastline changes provided that the data is entered and analyzed as it is collected.
  • Relatively long-term data record allows trends to be modeled and some long-term questions on beach processes to be answered.
  • The database can be linked to major climate changes.
  • Regular monthly monitoring allows sufficient time between monitoring intervals to be able to observe changes due to wave action but not too long for key changes to be missed.
Database limitations.
  • The database does not include data for areas below mean low water.
  • The record only covers some parts of New Zealand
  • While a relatively long-term data set it still only covers 16 years. To get the full combination of sun spot cycles(10.5 yr), tidal cycles (18.6 yr) and the LaNina/El Nino cycles (3-7 yr) requires additional years of data (eg 23 or 39 yrs in total)

 

What are the Current and Emerging Uses of the Database for:

  
Assisting with determining historic state/baseline. The database can be used to assist with determining historic beach condition. If linked with climate data it can also provide an important guideline to the size of historic storms.
Assisting with determining current state/baseline. The database provides a good measure of current beach processes and beach profile changes for Bay of Plenty and selected Coramandel beaches. Interpretations of the trends observed for West Coast beaches are proving difficult to determine at this stage.
Assisting with modeling possible future outcomes. The database is sufficiently long-term to allow trends to be modeled, especially when it is combined with climate data. The database can be used to relate sporadic data from sites in Northland and Coromandel to changes in the Bay of Plenty. Because the beaches are on the same coast a model can be used to estimate how the beach with a small amount of data may change over a period of time or as a result of a particular event. At present the Coromandel database is being built to a stage that will allow it to be used to predict changes for other beaches. In the long-term it is intended that the entire database will be used to estimate what is happening along the entire coast from the Bay of Plenty to Northland.
Risk assessment. The database can be used for hazard/risk assessment. If it is combined with climate data it can be used to predict the future magnitude and frequency of storms. The database can also be used to assess risks associated with beach sand mining.
Monitoring site selection and sample design. N/A. It can be used to select sites for comparison purposes.
Aggregating and reporting data locally, regionally or nationally. Data can be aggregated to show trends locally and regionally. It cannot be used to show national trends because it does not include sites representative of the whole country.