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Full report: Memorandum on implementing a national index for susceptibility to streambank erosion: environment.govt.nz/publications/national-index-st...

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This dataset contains predictions of the susceptibility to streambank erosion for every stream link in the RECv2.5 digital river network. Streambank erosion susceptibility is computed as a dimensionless index (range 0-100) for each stream link based on factors that may influence reach-scale bank erosion. These factors comprise stream power, the extent of riparian woody vegetation, valley confinement, channel sinuosity, and the erodibility of stream banks based on soil texture. The approach for determining streambank erosion susceptibility is described by Smith & Betts (2021) and based on the bank erosion model developed by Smith et al. (2019).

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***Smith HG, Spiekermann R, Dymond J, Basher L 2019. Predicting spatial patterns in riverbank erosion for catchment sediment budgets. New Zealand Journal of Marine and Freshwater Management 53: 338–362.

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***Smith HG, Betts H 2021. Memorandum on implementing a national index for susceptibility to streambank erosion. Technical memorandum prepared for the Ministry for the Environment by Manaaki Whenua – Landcare Research.

11 June 2021: A revised version of this dataset has been published to correct the terminology used to compare nitrate-nitrogen values to the 3 g/m3 guideline value. The field name has been changed from “reference_condition” to “n_n_guideline”, and values in this field will now be either “Does not exceed” or “Exceeds”, instead of “Meets” or “Does not meet”.

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20 July 2020: We corrected the data about drinking water standards for E. coli and nitrate-nitrogen in the key findings for groundwater quality.

For the five-year period 2014‒2018:

• 68 percent of 364 sites failed to meet the E.coli drinking water standards (changed from 98 percent of 145 sites failed to meet the E. coli drinking water standards)
• 19 percent of 433 sites didn’t meet nitrate-nitrogen standards (changed from 28 percent of 403 sites failed to meet the nitrate-nitrogen drinking water standards).

This indicator measures groundwater quality in New Zealand’s aquifers and how it is changing over time, based on measurements made at monitored sites. We report on nitrate-nitrogen, ammoniacal nitrogen, dissolved reactive phosphorus, chloride, conductivity and Escherichia coli (E. coli) including:

• median values for the period 2014–18
• nitrate-nitrogen median values compared to a guideline value of 3 grams per cubic metre (g/m3). This value is defined as a concentration that indicates groundwater has been influenced by industrialised agriculture and is highly likely to have been impacted by human activity (per Morgenstern & Daughney, 2012 and Daughney & Reeves, 2005).
• the proportion of samples from each site that have concentrations of nitrate-nitrogen or E. coli in excess of the Maximum Acceptable Values for protection of human health (Ministry of Health, 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.

11 June 2021: A revised version of this dataset has been published to correct the terminology used to compare nitrate-nitrogen values to the 3 g/m3 guideline value. The field name has been changed from “ref_meet” to “n_n_guideline”, and values in this field will now be either “Does not exceed” or “Exceeds”, instead of “Meets” or “Does not meet”.

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This dataset measures groundwater quality in New Zealand’s aquifers based on measurements made at monitored sites. Many factors influence the quality of our groundwater. Nitrogen, which occurs naturally in groundwater, can increase in concentrations due to agricultural and urban land use, and infrastructure such as waste treatment plants. High concentrations of nitrate-nitrogen in groundwater can affect human health and the quality of surrounding rivers and lakes that receive inflows from groundwater. Ammoniacal nitrogen can cause an undesirable smell that may make groundwater unsuitable for drinking water. Natural processes in groundwater can convert nitrate-nitrogen into ammoniacal nitrogen or other forms under some chemical conditions. Surplus phosphorus drains (leaches) into groundwater as dissolved reactive phosphorus. Too much nitrate-nitrogen, ammoniacal nitrogen, and phosphorus can lead to excessive plant and algae growth where groundwater flows into surface water. E. coli in groundwater is measured in colony forming units (cfu) and can indicate the presence of pathogens (disease-causing organisms) from animal or human faeces. The pathogens can cause illness for anyone who ingests them.

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.

The REC groups rivers and parts of river networks that share similar ecological characteristics, including physical and biological. Rivers that share the same class can be treated as similar to one another and different to rivers in other classes. The REC classification system groups rivers according to several environmental factors that strongly influence or cause the rivers’ physical and ecological characteristics (climate, topography, geology and land cover). A catchment is a polygon that defines the upstream watershed of a river system or sub-system. Land cover within the catchment was used to populate the river classification factors (see table 1.1 of the User Guide data.mfe.govt.nz/document/123-rec-user-guide-2010/ ).

Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas...

The New Zealand River Environment Classification (REC) organises information about the physical characteristics of New Zealand's rivers. Individual river sections are mapped according to physical factors such as climate, source of flow for the river water, topography, and geology, and catchment land cover eg, forest, pasture or urban. Sections of river that have similar ecological characteristics can then be grouped together, no matter where they are.

This information is mapped for New Zealand's entire river network - over 425,000 kilometres of river. Different types of rivers respond differently to the pressures placed on them - the REC can be used to highlight the most appropriate management tools and approaches to reduce these pressures for each river type. Information from the classification is used to develop policy, assess the environment, and report on the quality of river water.

Stream order is the numerical position of a tributary or section of a river within the entire network. Headwater streams are assigned a stream order of 1. When two tributaries of the same stream order meet, the order increments by one for the next section downstream. However, if two sections meet where one section has higher order than the other, the next section downstream has the same order as the highest upstream section.

The User Guide is available from data.mfe.govt.nz/document/123-rec-user-guide-2010/ . Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas... .

The New Zealand River Environment Classification (REC) organises information about the physical characteristics of New Zealand's rivers. Individual river sections are mapped according to physical factors such as climate, source of flow for the river water, topography, and geology, and catchment land cover eg, forest, pasture or urban. Sections of river that have similar ecological characteristics can then be grouped together, no matter where they are.

This information is mapped for New Zealand's entire river network - over 425,000 kilometres of river. Different types of rivers respond differently to the pressures placed on them - the REC can be used to highlight the most appropriate management tools and approaches to reduce these pressures for each river type. Information from the classification is used to develop policy, assess the environment, and report on the quality of river water.

Stream order is the numerical position of a tributary or section of a river within the entire network. Headwater streams are assigned a stream order of 1. When two tributaries of the same stream order meet, the order increments by one for the next section downstream. However, if two sections meet where one section has higher order than the other, the next section downstream has the same order as the highest upstream section.

The User Guide is available from data.mfe.govt.nz/document/123-rec-user-guide-2010/ . Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas... .

The New Zealand River Environment Classification (REC) organises information about the physical characteristics of New Zealand's rivers. Individual river sections are mapped according to physical factors such as climate, source of flow for the river water, topography, and geology, and catchment land cover eg, forest, pasture or urban. Sections of river that have similar ecological characteristics can then be grouped together, no matter where they are.

This information is mapped for New Zealand's entire river network - over 425,000 kilometres of river. Different types of rivers respond differently to the pressures placed on them - the REC can be used to highlight the most appropriate management tools and approaches to reduce these pressures for each river type. Information from the classification is used to develop policy, assess the environment, and report on the quality of river water.

Stream order is the numerical position of a tributary or section of a river within the entire network. Headwater streams are assigned a stream order of 1. When two tributaries of the same stream order meet, the order increments by one for the next section downstream. However, if two sections meet where one section has higher order than the other, the next section downstream has the same order as the highest upstream section.

The User Guide is available from data.mfe.govt.nz/document/123-rec-user-guide-2010/ . Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas... .

The New Zealand River Environment Classification (REC) organises information about the physical characteristics of New Zealand's rivers. Individual river sections are mapped according to physical factors such as climate, source of flow for the river water, topography, and geology, and catchment land cover eg, forest, pasture or urban. Sections of river that have similar ecological characteristics can then be grouped together, no matter where they are.

This information is mapped for New Zealand's entire river network - over 425,000 kilometres of river. Different types of rivers respond differently to the pressures placed on them - the REC can be used to highlight the most appropriate management tools and approaches to reduce these pressures for each river type. Information from the classification is used to develop policy, assess the environment, and report on the quality of river water.

Stream order is the numerical position of a tributary or section of a river within the entire network. Headwater streams are assigned a stream order of 1. When two tributaries of the same stream order meet, the order increments by one for the next section downstream. However, if two sections meet where one section has higher order than the other, the next section downstream has the same order as the highest upstream section.

The User Guide is available from data.mfe.govt.nz/document/123-rec-user-guide-2010/ . Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas... .

The New Zealand River Environment Classification (REC) organises information about the physical characteristics of New Zealand's rivers. Individual river sections are mapped according to physical factors such as climate, source of flow for the river water, topography, and geology, and catchment land cover eg, forest, pasture or urban. Sections of river that have similar ecological characteristics can then be grouped together, no matter where they are.

This information is mapped for New Zealand's entire river network - over 425,000 kilometres of river. Different types of rivers respond differently to the pressures placed on them - the REC can be used to highlight the most appropriate management tools and approaches to reduce these pressures for each river type. Information from the classification is used to develop policy, assess the environment, and report on the quality of river water.

Stream order is the numerical position of a tributary or section of a river within the entire network. Headwater streams are assigned a stream order of 1. When two tributaries of the same stream order meet, the order increments by one for the next section downstream. However, if two sections meet where one section has higher order than the other, the next section downstream has the same order as the highest upstream section.

The User Guide is available from data.mfe.govt.nz/document/123-rec-user-guide-2010/ . Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas... .

The New Zealand River Environment Classification (REC) organises information about the physical characteristics of New Zealand's rivers. Individual river sections are mapped according to physical factors such as climate, source of flow for the river water, topography, and geology, and catchment land cover eg, forest, pasture or urban. Sections of river that have similar ecological characteristics can then be grouped together, no matter where they are.

This information is mapped for New Zealand's entire river network - over 425,000 kilometres of river. Different types of rivers respond differently to the pressures placed on them - the REC can be used to highlight the most appropriate management tools and approaches to reduce these pressures for each river type. Information from the classification is used to develop policy, assess the environment, and report on the quality of river water.

Stream order is the numerical position of a tributary or section of a river within the entire network. Headwater streams are assigned a stream order of 1. When two tributaries of the same stream order meet, the order increments by one for the next section downstream. However, if two sections meet where one section has higher order than the other, the next section downstream has the same order as the highest upstream section.

The User Guide is available from data.mfe.govt.nz/document/123-rec-user-guide-2010/ . Additional metadata can be found at www.mfe.govt.nz/publications/ser/metadata/env-clas... .