Climate Indicators

Extreme Precipitation

Extreme precipitation events can be characterized using Extreme Value Analysis (EVA) by return levels, including confidence intervals, using the peak over threshold methodology. See the extreme precipitation tool for more information and charting of the available data.

GET /api/series/{slug}/pot/

Response fields include returnlevels, threshold, and units (unit of measurement). The return levels are summarized over historic, mid, and end of century time frames. Each return interval is a 3-item array of the lower, estimated return level, and upper confidence interval.

Example request:

GET /api/series/pr_day_ACCESS1-0_rcp45/pot/?g=POINT(-121.4687+38.5938)&duration=2 HTTP/1.1
Host: api.cal-adapt.org
Accept: application/json

Example response:

HTTP/1.1 200 OK
Allow: GET, POST, OPTIONS
Content-Type: application/json
Vary: Accept

{
"returnlevels": {
    "1961-10-01:1990-09-30": {
        "10": [ 3.3738083898103706, 3.9522201904266527, 5.228567088406137 ],
        "100": [ 4.792120480767816, 6.491227596207121, 11.655569842787486 ],
        "2": [ 2.317027627106765, 2.5667466512434016, 2.941214643156155 ],
        "20": [ 3.781685742237907, 4.640839376130399, 6.677332244692823 ],
        "5": [ 2.9107509896073562, 3.321044449279986, 4.080450921786112 ],
        "50": [ 4.368586837537248, 5.648252163486491, 9.185085270172545 ],
        "n": 159
    },
    "2035-10-01:2064-09-30": {
        "10": [ 3.7262371212589867, 4.236568397086659, 5.240493845112521 ],
        "100": [ 4.906061402196474, 6.0225286812315595, 9.111781051084918 ],
        "2": [ 2.688362812028139, 2.9617466455337116, 3.315414408012187 ],
        "20": [ 4.134337164339881, 4.778850804514478, 6.252823005631932 ],
        "5": [ 3.312975478107658, 3.690233369085343, 4.342160397675551 ],
        "50": [ 4.571528643603971, 5.4895406091554895, 7.7864184564943955 ],
        "n": 175
    },
    "2070-10-01:2099-09-30": {
      "10": [ 4.241220088665857, 5.0994935705499715, 6.9916568467598665 ],
      "100": [ 6.244111144979032, 8.769602618538272, 16.754704790152964 ],
      "2": [ 2.820991602527356, 3.1581853987832025, 3.650831557730822 ],
      "20": [ 4.851689971070942, 6.081585627582591, 9.144602394922993 ],
      "5": [ 3.631161165606033, 4.209052130230058, 5.315306960831256 ],
      "50": [ 5.653315714995296, 7.536659927706938, 12.944282870291804 ],
      "n": 165
    },
    "threshold": 1.0,
},
"units": "inches"
}
Parameters:
  • slug – series slug identifier
Query Parameters:
 
  • g – a geometry (point, line, polygon) as GeoJSON, WKT, GML or KML
  • stat – one of max, mean, median, min, sum for spatial aggregation by polygon/line provided by the g param, defaults to mean
  • duration (integer) – duration of extreme event in days
  • intervals – comma separated list of return intervals, returns levels for 2, 5, 10, 20, 50, and 100 year events by default
  • pct (float) – percentile to use for exceedance threshold, when not specified the min value from the annual maxima series (AMS) is used