{
 "culture": "en-NZ",
 "name": "Flood_Statistics_Henderson_Collins_V2",
 "guid": "028A6039-B139-4A3F-A527-1CDEB866C750",
 "catalogPath": "",
 "snippet": "Map service used in companion web application. Users can extract flood statistics from a regional flood model, at-site flood statistics & annual maximum flows from flow recorders used in model development, and flood estimates based on rain intensity\n",
 "description": "Layer used in public web app <a href='https://niwa.maps.arcgis.com/apps/webappviewer/index.html?id=933e8f24fe9140f99dfb57173087f27d' rel='nofollow ugc' target='_blank'>https://niwa.maps.arcgis.com/apps/webappviewer/index.html?id=933e8f24fe9140f99dfb57173087f27d <\/a> to provide Flood Estimation for New Zealand<p><b> 1. Modelled flood frequency estimates on river lines.<\/b><\/p><ul><li><div style='margin-right: 0px;'>NZREACH NZ digital network 1 ID no.<\/div><\/li><li><div style='margin-right: 0px;'>River name where available<\/div><\/li><li><div style='margin-right: 0px;'>Areakm2 catchment area draining to the downstream end of this reach (square kilometres)<\/div><\/li><li><div style='margin-right: 0px;'>q100_reach ratio of Q100 (1% aep flood) to mean annual flood<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_MAF mean annual flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_5-yr 5-yr (20% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_10y 10-yr (10% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_20y 20-yr (5% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_50y 50-yr (2% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_100y 100-yr (1% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>H&amp;C18_1000y 1000-yr (0.1% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>HCse_MAF standard error of mean annual flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>HCse_5y standard error of 5-yr (20% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>HCse_10y standard error of 10-yr (10% aep) flood (cumecs) <\/div><\/li><li><div style='margin-right: 0px;'>HCse_20y standard error of 20-yr (5% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>HCse_50y standard error of 50-yr (2% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>HCse_100y standard error of 100-yr (1% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>HCse_1000y standard error of 1000-yr (0.1% aep) flood (cumecs)<\/div><\/li><li><div style='margin-right: 0px;'>Strm_Order Strahler stream order (1=headwater, two ones join to make an order 2, etc.) 2.<\/div><\/li><\/ul><p><b> 2. At-site flood statistics at flow recorders used in the model development<\/b><\/p><ul><li> Siteno NIWA reference number for flow recorder <\/li><li>Name Flow recorder name generally 'river' at 'location' <\/li><li>NZTM_E NZTM easting NZTM_N NZTM northing<\/li><li>Region Regional council or unitary authority territory<\/li><li>Operator Organisation that oprates the flow recorder Funder Organisation that funds the flow recorder (can be more than one)<\/li><li>Area_km2 catchment area draining to the flow recorder (square kilometers)<\/li><li>No_years Number of years in the annual flood series (allowing for years with missing data)<\/li><li>L1_mean Mean of the annual flood series (linear moment 1)<\/li><li>L2 Linear moment 2 of the annual flood series (analogous to standard deviation)<\/li><li>Lcv Linear CV of the annual flood series (L2/L1) <\/li><li>T3_Lskew Linear skew ratio of the annual flood series <\/li><li>T4_Lkurt Linear kurtosis ratio of the annual flood series <\/li><li>Gumb_u Gumbel distribution u of the annual flood series <\/li><li>Gumb_alpha Gumbel distribution alpha of the annual flood series <\/li><li>GEV_u Generalised Extreme Value u of the annual flood series<\/li><li>GEV_alpha Generalised Extreme Value alpha of the annual flood series <\/li><li>GEV_k Generalised Extreme Value k of the annual flood series <\/li><li>GEV_z Hosking-Wallis normal standard variate to test significance of GEV-k (is the at-site distribution Gumbel or not?)<\/li><li>Data 2.33y mean annual flood (2.33-yr assuming Gumbel, or 43% aep)<\/li><li>Data 5y 5-yr (20% aep) flood (cumecs)<\/li><li>Data 10y 10-yr (10% aep) flood (cumecs)<\/li><li>Data 20y 20-yr (5% aep) flood (cumecs)<\/li><li>Data 50y 50-yr (2% aep) flood (cumecs)<\/li><li>Data 100y 100-yr (1% aep) flood (cumecs)<\/li><li>Data 250y 250-yr (0.4% aep) flood (cumecs)<\/li><li>Data 500y 500-yr (0.2% aep) flood (cumecs) <\/li><li>Data 1000y 1000-yr (0.1% aep) flood (cumecs)<\/li><li>se_2.33y standard error of mean annual flood (%) <\/li><li>se_5y standard error of 5-yr (20% aep) flood (%)<\/li><li>se_10y standard error of 10-yr (10% aep) flood (%)<\/li><li>se_20y standard error of 20-yr (5% aep) flood (%)<\/li><li>se_50y standard error of 50-yr (2% aep) flood (%)<\/li><li>se_100y standard error of 100-yr (1% aep) flood (%)<\/li><li>se_250y standard error of 250-yr (0.4% aep) flood (%)<\/li><li>se_500y standard error of 500-yr (0.2% aep) flood (%) <\/li><li>se_1000y standard error of 1000-yr (0.1% aep) flood (%)<\/li><\/ul><p><b> 3. Return period estimates of the area-rain intensity values for small catchments.  Where results display '-1' the catchment is greater than 30 square kilometres and no answer is available. Numbers need to be multiplied by the Rational Method 'C' factor to give the required flood magnitude.<\/b> <\/p><ul><li>NZREACH NZ digital network 1 ID no. <\/li><li>AREA_km2 catchment area draining to the flow recorder (square kilometers)<\/li><li>QIA_5y 5-yr (20% aep) IA estimate<\/li><li>QIA_10y 10-yr (10% aep) IA estimate <\/li><li>QIA_20y 20-yr (5% aep) IA estimate<\/li><li>QIA_50y 50-yr (2% aep) IA estimate<\/li><li>QIA_100y 100-yr (1% aep) IA estimate <\/li><li>QIA_1000y 1000-yr (0.1% aep) IA estimate<\/li><\/ul><p><b>4. Annual data values at flow recorders used in the model development. Layer coming later.<\/b><\/p><p><b><br /><\/b><\/p><p><br /><\/p><p><span style='font-weight: bold;'>Spatial Reference: New Zealand Transverse Mercator (NZTM) <\/span><br /><\/p><p>EPSG:2193  (2193) <br /><\/p>XMin: 1090154.6277<br /> YMin: 4748852.6367<br /> XMax: 2089112.8753000004<br /> YMax: 6193369.0554",
 "summary": "Map service used in companion web application. Users can extract flood statistics from a regional flood model, at-site flood statistics & annual maximum flows from flow recorders used in model development, and flood estimates based on rain intensity\n",
 "title": "Map",
 "tags": [
  "floods",
  "annual average",
  "flow recorders",
  "catchments",
  "Catchment",
  "Flood",
  "Flood Estimation",
  "flood statistics",
  "Floods",
  "flow sites",
  "Henderson Collins",
  "REC1",
  "return period",
  "stream order",
  "Topomaps",
  "NZ",
  "New Zealand",
  "model",
  "freshwater",
  "climate"
 ],
 "type": "Map Service",
 "typeKeywords": [
  "Data",
  "Service",
  "Map Service",
  "ArcGIS Server"
 ],
 "thumbnail": "thumbnail/thumbnail.png",
 "url": "",
 "extent": [
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   -47.4137774208629
  ],
  [
   179.462529681408,
   -34.2757766336892
  ]
 ],
 "minScale": 0,
 "maxScale": 1.7976931348623157E308,
 "spatialReference": "NZGD_2000_New_Zealand_Transverse_Mercator",
 "accessInformation": "National Institute of Water and Atmosphere (NIWA)",
 "licenseInfo": "<a href='https://creativecommons.org/licenses/by-nc/4.0/' rel='nofollow ugc'><img alt='Creative Commons License' src='https://i.creativecommons.org/l/by-nc/4.0/88x31.png' style='border-width: 0px;' /><\/a><br />This work is licensed under a <a href='http://creativecommons.org/licenses/by-nc/4.0/' rel='nofollow ugc'>Creative Commons Attribution-NonCommercial 4.0 International  4.0 International License<\/a> <p style='margin: 0cm 0cm 0pt;'><span style='color: rgb(51, 51, 51);'><font size='3'>In preparing The New Zealand River Flood Statistics Tool, all reasonable skill and care was exercised and the best available data and methods were used. Nevertheless, NIWA does not accept any liability, whether direct, indirect or consequential, arising out the use of this tool and its associated data and statistical information.<\/font><\/span><\/p>"
}