Flooding in 2019 - Tale of a Terrible Year
NASA Models and Remote Sensing Datasets Capture Cascading Impacts on Midwest Farmers
Timeline
This case study is powered by incorporating Earth observations of precipitation from GPM, soil moisture from SMAP, snow depth from AMSR2, and leaf area index from MODIS, and MERRA-2 reanalysis within the Land Information System (LIS) framework.
Pre-Flood Conditions
Soggy Soils, Frozen Soils
Across much of the Midwest and Northern Plains, soils were saturated throughout the fall and winter, especially in the Corn Belt.
>> Standardized anomalies for root zone soil moisture for August-October 2018
Huge Blizzard
GPM IMERG captures a huge blizzard in mid-March that blanketed the region in deep snow.
>> GPM IMERG precipitation for March 12-14, 2019
Spring Flooding
The extent of 2019 flooding can be seen over the Missouri River near Omaha, NE when compared with another MODIS-captured scene from 2015.
MODIS Corrected Reflectance from NASA GIBS (Bands 7-2-1) Left: Mar 2015, Right: Mar 2019
Flood inundation is captured by Sentinel-1 imagery, hosted by the NASA Disasters Mapping Portal.
Flood water (red pixels) and permanent water (blue pixels) mapped with Sentinel-1. [Data hosted on NASA Disasters Mapping Portal]
Rapid Snowmelt
The rain-on-snow event on the unusually deep snowpack caused rapid snowmelt which intensified spring flooding.
<< Snow depth on March 10 (left) before the rain-on-snow event and on March 29, 2019 (right) after the rain-on-snow event
The rapid melting of the deep snowpack in mid-March was captured by assimilating snow depth observations from AMSR2 within the LIS framework.
Missouri River Basin (red boundary) where the snow depth timeseries is averaged
Record Flooding
Rapid snowmelt and heavy rainfall resulted in record streamflows in spring and summer.
Streamflow on Missouri River at St. Charles, MO
Soils Too Wet to Plant
Wet soil conditions persisted months after the flooding, leaving farmers with no option but to wait for soils to dry out.
Assimilating downscaled soil moisture from SMAP captures the wet conditions persisting in late-May to early-June.
<< Root zone soil moisture anomaly averaged over May 27-June 2, 2019
Agricultural Impacts
Planting Delays Cause Major Farming Losses
The Midwest 2019 flood coincided with the corn and soybean planting season, causing many farmers to delay planting their crops, switch crops, or not plant at all.
According to the American Farm Bureau Federation, farm subsidies made up 40% of farm income in 2019 — $33 billion out of an expected $88 billion total.
Earth Observations Show Delayed Planting
The abnormally low leaf area index (LAI) from MODIS captures delayed planting in the Cornbelt region.
>> LAI anomaly for Jun 27, 2019 after the flooding event in spring.
Farmers Planted Fewer Acres
According to USDA 2019 Crop Data, the planted fields were reduced by around 12% compared to the five-year average for corn and soybean.
>> Prevented acreage for corn in 2019, in thousands of acres.
Conclusions
The simultaneous use of datasets from GPM, MODIS, AMSR2, and SMAP is necessary to capture the causes and extent of the flooding, as well as its impacts on agriculture.
Using Earth observations to model and understand extreme events improves our ability to better manage water resources, plan for and respond to disasters, and assess food production and security across the globe.
