EverForecast: Six-Month Water Forecasts for Everglades Wildlife

By Saira M. Haider, Stephanie S. Romañach, Mark McKelvy and Kevin Suir (USGS) and Leonard Pearlstine (Everglades National Park). USGS Fact Sheet 2021–3005.

A hard balancing act

The Greater Everglades is a vast subtropical wetland in South Florida. It holds critical protected areas and rich biodiversity, and supplies water to farms and one of the nation's largest urban areas. Canals and levees have greatly altered it, putting threatened and endangered species at risk. And different species need different water depths at different times, so managers must make tough choices about where to send the water.

What EverForecast does

The Everglades Forecasting application (EverForecast), built by the USGS and the National Park Service, forecasts daily water levels across the region 6 months ahead, runs them through ecological models, and shows the tradeoffs — so managers can plan for near-term change by their own priorities.

The EverForecast subregions. Map: USGS.

How it works

1. Rain and history: NOAA precipitation forecasts are combined with historical water levels from the Everglades Depth Estimation Network (EDEN).
2. Most likely outcome: a spatial analysis gives a central forecast of daily water levels on a 400 × 400-meter grid for the next 6 months.
3. Range of outcomes: 150 stochastic simulations add variability drawn from the past 20 years of water-level trends. (EDEN history is the default; other scenarios can be plugged in to test water-management options.)
4. Depth: subtracting EDEN's elevation model turns water levels into water depth.
5. Species: the depth simulations run through models for the species of concern, then are sorted into hydrologic categories by depth and recession rate.
6. Monthly updates: it runs at the start of each month, summarized by category and subregion.

The species: American alligator, Florida applesnail, small fish, wood stork, white ibis, roseate spoonbill, glossy ibis, little blue heron, great blue heron, great egret, Everglades snail kite and Cape Sable seaside sparrow.

Forecast for one species model and one hydrologic category: mean adult apple snails per model grid cell, October 1–15, 2020. Map: USGS.

Helping decisions

EverForecast lets managers weigh how to allocate water among subregions for several species with conflicting needs, seeing exactly where and when tradeoffs arise. With concern growing over more frequent and severe extreme weather, near-term forecasts paired with ecological responses can guide real-time decisions that keep restoration on track.

Forecast conditions for multiple species in each subregion, October 1–15, 2020 (A), with the key to which square is which species (B). Chart: USGS.

Try it: EverForecast and its species models. Methods: Pearlstine and others (2020), Environmental Modelling & Software 132: 104783.

Sources

Based on EverForecast—A Near-Term Forecasting Application for Ecological Decision Support, by Saira M. Haider, Stephanie S. Romañach, Mark McKelvy, Kevin Suir and Leonard Pearlstine, USGS Fact Sheet 2021–3005, U.S. Geological Survey; a work of the United States government in the public domain. The map and charts are taken from the fact sheet's PDF, which also carries NPS photographs.