Hydrological indices for national environmental reporting
The relevance of flow regimes for both in-stream and out-of-stream values means that national representations of flow regimes may be used in national environmental reporting of New Zealand’s Freshwater state. This report describes:
(1) Observed river flow time-series and river width used in this report.
(2)Indices that may be of use in national environmental reporting to represent various parts of the flow regime:
(a) the 1 in 5 year low flow
(b) the 7-day mean annual low flow
(c) the mean flow
(d) the proportion of flow in February
(e) the frequency of events exceeding three times the median flow
(f) wetted river width at the 7-day mean annual low flow
(3) Methods for calculation of these indices from flow time-series.
(4) Regression models used to relate each index to known catchment characteristics.
(5) Testing and validation of predicted values for each index.
(6) National maps for each index when predicted onto New Zealand’s river network.
(7) The format of data files containing the predicted and observed data
(8) For wetted width, model performance was quantified by comparing predicted values with an independent data set. Model performance for ungauged sites was assessed by comparing observed values with out-of-bag predictions for the remaining hydrological indices. All models showed a good ability to discriminate between-site patterns.
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Citation proposal
Doug Booker (NIWA). . https://dc.niwa.co.nz:/niwa_dc/srv/api/records/ec20c95c-2cf2-a322-f0fd-602fc3809a5d |
Simple
- Date ( Creation )
- 2015-06-17T07:03:00
- Date ( Revision )
- 2015-06-17T07:03:00
- Purpose
- The importance of flow regimes for both in-stream and out-of-stream values means that national representations of flow regimes may be valuable for national environmental reporting of New Zealand’s Freshwater state. This report describes: (a) several hydrological indices that may be of use in national environmental reporting; (b) the calculation of these indices from flow time-series observed at gauging stations across New Zealand; (c) regression models used to relate each hydrological index to known catchment characteristics; and (d) national patterns for each hydrological index when predicted onto New Zealand’s river network.
- Credit
- Booker, D.J. (2015). Hydrological indices for national environmental reporting. Prepared with funding from the Ministry for the Environment. March 2015. NIWA CLIENT REPORT No: CHC2015-015. NIWA Project: MFE14505. p. 37 + appendix.
- Status
- Completed
Author
- Spatial representation type
- Vector
- Topic category
-
- Inland waters
- Description
- New Zealand
N
S
E
W
- TimePeriod
- 1950-10-01T00:00:002010-09-30T00:00:00
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- Hydrological indices, streams, water flow, New Zealand river network, regression models.
- NIWA Project Codes
-
- MFE14505
- Other constraints
- Data from multitude of sources with multiple owners.
- Use limitation
- Water flow series for stream throughout NZ: in- and out-flow plus wetted width. Regression analysis of above to derive hydrodynamic indices to predict stream flows.
- Classification
- Restricted
- Title
- Booker, D.J. (2015). Hydrological indices for national environmental reporting. NIWA CLIENT REPORT No: CHC2015-015. NIWA Project: MFE14505. p. 37 + appendix.
- Association Type
- Larger work citation
- Language
- English
mdb:MD_Metadata
- Metadata identifier
- ec20c95c-2cf2-a322-f0fd-602fc3809a5d
- Language
- English
- Character encoding
- UTF8
Custodian
NIWA National Institute of Water and Atmospheric Research
301 Evans Bay Parade
Hataitai
Wellington
6021
New Zealand
- Resource scope
- Dataset
- Date info ( Creation )
- 2015-06-18T09:07:41
- Title
- ISO 19115-3
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