River water quality Data - Page 5

23 April 2021: A new version of this data set has been published. It includes data on 4 parameters (Ammoniacal nitrogen (adjusted), Escherichia coli, Macroinvertebrate Community Index and Total Phosphorus) that had been missing from the file that was published as part of the Our freshwater 2020 release in April 16 2020. The updated data set also includes data on DRP for all 593,337 REC segments, since the file from April 16 2020 only had data for 255,860 of these segments.

16 April 2020: Subsequent to publication in April 2019 we discovered two small errors with this dataset. These included:

• Errors in the coordinates of some sites and their associated metadata (such as landcover and elevation).
• Errors in our calculation of dominant landcover.

In addition, flow data from TopNet has also been updated.

These changes have a minor impact on overall results. These changes have have been corrected, and are republished here, as part of the Our freshwater 2020 release.

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IMPORTANT INFORMATION

1) The main (cleaned) dataset is structured by each row having a nzsegment and np_id combination. A large dataset (~ 1 GB) has resulted, due to the inclusion of the ANZG/NOF columns and the 10 different np_id values. There are ~ 6 million rows to this dataset, however a 32-bit version of Microsoft Excel will only display/download ~ 1 million rows. __A DBMS, statistical or GIS application is needed to view the entire dataset__.

2) A smaller raw dataset (see attachments) is provided which structures each row relating to a river segment and drops the ANZG/NOF columns.

3) The attached metadata/date quality report provides further information on the NOF, ANZG and the "McDowell meet/doesnt meet" attachment.

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This dataset contains ten parameters of water quality based on measurements made at monitored river sites:

• Nitrate-nitrogen
• Ammoniacal nitrogen
• Ammoniacal nitrogen (adjusted)
• Total nitrogen
• Total phosphorus
• Dissolved reactive phosphorus
• Water clarity
• Turbidity
• Escherichia coli
• Macroinvertebrate community index These parameters are used to measure:
• Modelled median values for all of New Zealand’s river length for the period 2013 to 2017
• For selected indicators, how the modelled values compare to the National Objectives Framework (NOF) (MfE, 2017) bands related to ecosystem health and human health for recreation, and to expected concentrations in natural conditions, as shown by the default guideline values in the Australian and New Zealand guidelines for fresh and marine water quality (ANZG, 2018)

More information on this dataset and how it relates to our environmental reporting indicators and topics can be found in the attached data quality pdf.

Summary report available at www.mfe.govt.nz/publications/fresh-water/spatial-m...

River water quality is valued for many reasons including ecological function and habitat, recreational value, its role in supporting people and industry, and its cultural significance. Nutrients such as nitrogen and phosphorus are essential for plant growth, however too much in rivers can lead to excessive growth of river algae, which can degrade habitat.

High concentrations of nitrogen in the form of ammoniacal nitrogen and nitrate-nitrogen can be toxic to fish and other aquatic animals, and nitrate-nitrogen can be toxic to humans. Water clarity is a measure of underwater visibility, and affects habitat of aquatic life such as fish and birds, and can also impact on aesthetic values and recreational use of rivers and streams. Escherichia coli (E.coli) can indicate the presence of pathogens (disease-causing organisms) from animal or human faeces, which can cause illness.

File contains the model outputs for river water quality indicators as medians for each river segment in New Zealand’s digital river network.

"Macroinvertebrates are small animals without backbones that live on and under submerged logs, rocks, and aquatic plants in the stream bed during some period of their life cycle. They play a central role in stream ecosystems by feeding on periphyton (algae or slime), macrophytes (aquatic plants), dead leaves and wood, or on each other. High Macroinvertebrate Community Index (MCI) scores generally indicate better stream health. Macroinvertebrates are good continuous indicators of the health of their stream environment. This is because they are relatively sedentary and long–lived (a year or more) which means they live with any stresses or changes that occur in their location (eg, pollution, habitat removal, floods and droughts). They complement discrete measures like chemical monitoring, which only reflects the condition at the exact time and place of sampling. Such monitoring might miss effects of a short–lived pollutant or an unanticipated type of disturbance.
This dataset relates to the ""River water quality: benthic macroinvertebrates"" measure on the Environmental Indicators, Te taiao Aotearoa website. "

"Small amounts of nitrogen are a natural component of healthy rivers. Nitrogen in rivers can vary due to differences in land use, climate, elevation, and geology. Nitrogen is transferred from land to water and is cycled through different forms, which can have different effects. Moderate concentrations of nitrate can cause weeds and algae to grow too fast. High concentrations of ammoniacal and nitrate nitrogen can be toxic to fish and other aquatic animals.
This dataset relates to the ""Geographic pattern of nitrogen in river water"" measure on the Environmental Indicators, Te taiao Aotearoa website. "

Small amounts of nitrogen are a natural component of healthy rivers. Nitrogen is transferred from land to water and is cycled through different forms, which can have different effects. Moderate concentrations of nitrate can cause weeds and algae to grow too fast. High concentrations of ammoniacal and nitrate nitrogen can be toxic to fish and other aquatic animals.
This dataset relates to the "River water quality trends: nitrogen" measure on the Environmental Indicators, Te taiao Aotearoa website.