Environmental Reporting, Ministry for the Environment and Statistics New Zealand
Position Name
Analyst
Contact Info
Contact
Address
Address
Delivery Point
23 Kate Sheppard Place, PO Box 10362
City
Wellington 6143
Country
New Zealand
Electronic Mail Address
Environmental.Reporting@mfe.govt.nz
Role
Role Code
distributor
Date Stamp
Date
2016-01-21
Metadata Standard Name
ANZLIC Metadata Profile: An Australian/New Zealand Profile of AS/NZS ISO 19115:2005, Geographic information - Metadata
Metadata Standard Version
1.1
Reference System Info
Reference System
Reference System Identifier
Identifier
Code
2193
Identification Info
Data Identification
Citation
Citation
Title
Water clarity, 1989–2013
Date
Abstract
"Water clarity is a measure of underwater visibility in rivers and streams and can vary due to differences in land use, climate, elevation, and geology. Water clarity can be reduced by the presence of fine particles like silt, mud or organic material in the water. This affects the habitat and feeding of aquatic life like fish and aquatic birds. Water clarity is an important indicator of the health of a waterway, and is also a consideration for recreational activities like swimming and wading. This dataset relates to the ""Geographic pattern of river water clarity"" measure on the Environmental Indicators, Te taiao Aotearoa website. "
Status
Progress Code
completed
Point Of Contact
Responsible Party
Organisation Name
Environmental Reporting, Ministry for the Environment and Statistics New Zealand
Method: "Water clarity is measured using a black disc the size of a soccer ball. The disc is placed in the water, and viewed through an underwater viewing box at increasing distances until the black disc disappears from sight. This provides a consistent measure of the greatest distance an object can be seen through the water (Davies–Colley, 1988). Estimates of median clarity across New Zealand is based on water clarity measurements from 377 river sites monitored by the 16 regional councils and 77 sites along 35 major rivers measured by the National Institute of Water and Atmospheric Research (NIWA). There is considerable natural variability in water clarity throughout New Zealand. ‘Trigger values’ help determine the point when further investigation is needed to see if there is an ecosystem health problem related to water quality. Lowland river measurement sites have been given a trigger value of 0.6 metres. Upland river measurement sites have been given a trigger value of 0.8 metres (ANZECC 2000). National water clarity is inferred from the predominant land cover in a catchment and the surrounding land–scape characteristics, such as, climate, elevation, and geology. The accuracy of the data source is of medium quality.
Reference: Davies–Colley, RJ (1988). Measuring water clarity with a black disc. Limnology and Oceanography, 33(4), 616–623. Accessed 18 August 2015 from www.horizons.govt.nz. "
Metadata Constraints
Legal Constraints
Use Limitation
Creative Commons Attribution 3.0 New Zealand by Ministry for the Environment
Access Constraints
Restriction Code
license
Metadata Constraints
Legal Constraints
Use Limitation
Creative Commons Attribution 3.0 New Zealand by Ministry for the Environment
