ec20c95c-2cf2-a322-f0fd-602fc3809a5d eng utf8 dataset custodian NIWA National Institute of Water and Atmospheric Research +64 4 386 0300 voice +64 4 386 0574 facsimile 301 Evans Bay Parade Hataitai Wellington 6021 New Zealand curator@niwa.co.nz http://www.niwa.co.nz Website of the National Institute of Water and Atmospheric Research, New Zealand - Enhancing the benefits of New Zealand's natural resources. Data curator 2015-06-18T09:07:41 creation ISO 19115-3 urn:ogc:def:crs:EPSG::4326 OGP NZST/NZDT Hydrological indices for national environmental reporting 2015-06-17T07:03:00 creation 2015-06-17T07:03:00 revision 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. 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. 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. completed author NIWA Doug.Booker@niwa.co.nz Doug Booker Scientist vector inlandWaters New Zealand 165.5 184.5 -52.8 -29.000000000000004 1950-10-01T00:00:00 2010-09-30T00:00:00 Hydrological indices streams water flow New Zealand river network regression models. MFE14505 theme NIWA Project Codes 2012-01-01 publication NIWA_ProjectCode Data from multitude of sources with multiple owners. 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. restricted Booker, D.J. (2015). Hydrological indices for national environmental reporting. NIWA CLIENT REPORT No: CHC2015-015. NIWA Project: MFE14505. p. 37 + appendix. largerWorkCitation eng https://dc.niwa.co.nz/niwa_dc/srv/metadata/ec20c95c-2cf2-a322-f0fd-602fc3809a5d WWW:LINK-1.0-http--metadata-URL Point of truth URL of this metadata record O Drive, Christchurch MFE14505, PRESSURE STATE IMPACT MODEL dataset Data on in- and out-flow series and wetted width for stream networks throughout New Zealand. restricted