Four Things to Think About When Heavy Spring Rains Fall

, Kendall Science Fellow | May 18, 2016, 3:48 pm EST
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Spoiler alert: It’s more than just packing an umbrella.

As a kid I remember repeating the phrase in the spring “April showers bring May flowers.” Now, in my adult life as a weather-conscious agricultural scientist, I cannot help but think about how spring rain brings with it not just the promise of pretty flowers, but also the damage of floods.

Plus, it’s been raining a lot as of late, and everywhere across the U.S. it seems. Last week, it was reported that in my current home of Washington, D.C. it rained for a record 15 consecutive days between late April and mid-May. Across the Midwest and Great Plains, well above average precipitation has fallen in the same period. At the same time, despite some rain relief in California, the state’s exceptional drought drags on.

Really, floods and droughts are part of the same problem: the wrong amount of water at the wrong time. It is well established by scientists that rainfall variability is increasing with climate change and as my colleagues Erika Spanger-Siegfried and Astrid Caldas have written previously, we shouldn’t expect more severe floods and their subsequent impacts to go away any time soon. I want to share four things to ponder when you see spring rain, what it means for agriculture, the broader society, and solutions to reduce negative flood effects.

1. We can reduce flooding impacts through soil management

A flooded corn field from Northwest Iowa taken earlier this month. This matters in an agricultural region because floods cause crop damage and soil structural deterioration, not to mention potential downstream effects such as urban flooding. Photo: David Weisberger and Matthew Roby.

A flooded corn field from Northwest Iowa taken earlier this month. This matters in an agricultural region because floods cause crop damage and soil structural deterioration, not to mention potential downstream effects such as urban flooding. Photo: David Weisberger and Matthew Roby.

My research with UCS is investigating to what extent ecological agriculture can reduce risks related to climate. In my work I am in the process of analyzing dozens and dozens of studies where soil water properties are measured by contrasting the more conventional practices with ecological alternatives. While my results are preliminary, I’ve found that the speed with which water enters the soil (the infiltration rate) is between 2 and 5 times greater when agricultural fields include continuous cover, either through a cover crop, perennial crops or agroforestry.

Interestingly, a lot of studies I am analyzing come from areas with monsoon rains. Other agricultural regions might learn from such examples; water management is critical when rainfall is in excess for a short time of the year and sparse the rest.

2. Your surrounding landscape matters

It may be an occupational hazard of mine, but it is impossible for me to ignore my surrounding environment, or the evidence of water impacts. When I lived in Iowa for graduate school I frequently lamented the tell-tale signs of impending flooding when low-lying spots in agricultural fields would pond. If you’ve ever taken note of heavy rains rushing down your sidewalks and streets, overwhelming the capacity of their engineered drainage, you’re observing the same thing in your own environment!

But there are things land managers can do to prevent flooding, even if we can’t control the weather. The idea of ecological flood control is not a new one. For example, it is well known that wetlands offer flood protection when designed appropriately in and around developed areas. I hope to see such ideas about ecological flood control continue to expand into the agricultural world, namely in how landscape management contributes to reducing the negative imprint of floods.

3. Flooding is expensive, dangerous and sometimes fatal

Heavy rain is more than just a nuisance interrupting day-to-day plans. A painful reminder of this came with last month’s tragic flooding in Houston. Sadly, as we’ve seen time and time again, the heavy burdens of these types of events disproportionately affect communities of color and the poor, who have limited economic options for coping.

Historic flooding in my former home of Iowa has caused tremendous damage in the recent past as well, prominently when downtown Cedar Rapids was deluged in summer 2008. Businesses flooded, jobs were lost and many thousands of homes destroyed. At the height of the June flooding that year, approximately 10% of corn and soybean fields in the state were under water. Estimates for damages have ranged in the multi-billions, and it’s taken many years for the region to recover from the damages.

The state of Iowa is a recent recipient of a disaster resilience grant from the Department of Housing and Urban Development, which looks to be an encouraging investment that takes watershed or landscape approach to flood management. This type of public investment, which reverses decades of development that ignored dominant hydrological and landscape dynamics, is so critical. In an analysis of historic stream gauge data, University of Iowa hydrologists note an increased frequency of flooding in the Midwest over the last 50 years. The quicker we work to improve flood resiliency, the better.

Are these images of lakes or corn fields? It’s hard to tell. If you look closely here, you can spot seagulls! Friends shared these photos with me from the Northwest Iowa in early May. Photos: David Weisberger and Matthew Roby.

Are these images of lakes or corn fields? It’s hard to tell. If you look closely here, you can spot seagulls! Friends shared these photos with me from the Northwest Iowa in early May. When I would see similar scenes, I wondered why some areas of a field and not others would “pond” that way. Was it the natural properties of the soil, the type of plowing, or the crops being grown? Photo: David Weisberger and Matthew Roby.

4. Climate adaptation and risk reduction deserve a bigger share of the conversation

I was heartened to learn last week that USDA is dedicating more dollars toward soil health, with news that they’ve allocated 72.3 million more dollars to boost carbon storage in healthy soils. That is an encouraging sign of change in the right direction. Many practices that increase carbon in the soil, mitigating climate change, are also good for climate adaptation, and can reduce the influence of floods. However, these increased dollars do not explicitly recognize that adaptation is of equal importance as a public investment.

AND, for a comparison that provides perspective about the dollars this announcement trumpets, under the current Farm Bill, the Federal Government spends more than 8 billion per year on crop insurance. This is billions in public monies meant to offset risk in the agricultural sector. However, many people, including those within USDA, recognize that increased crop insurance subsidies over the last few decades incentivized previously uncultivated land (often lands that had perennial grasses, which keep the land covered all year, a climate-buffering opportunity) to be brought “into production.”

This is quite the opposite of a holistic view of risk reduction. We ought to make climate adaptation an explicit priority of federal policy, knowing that current water woes will very likely be even bleaker in the future.

Posted in: Food and Agriculture, Global Warming Tags: , , , ,

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  • Andrea Basche

    Hi, thanks for your comment! I don’t doubt that these could be low lying parts of the field which contributes to what you see in the photos. But the properties of the soil there would play a part in the water movement as well.

  • michae evans

    If you look at the picture… your comments below posing a question… made me ask one of my own… is it me or does the field as shown in the picture not provide a simple answer… the pond is a result of the fact that the field is sloped… with the pond being the lowest point the water could reach… and that the volume of water was not enough to flow over the edge of the field to what appears to be the lowest point overall?