{"id":16923,"date":"2026-05-16T23:00:48","date_gmt":"2026-05-16T23:00:48","guid":{"rendered":"https:\/\/globalnewstoday.uk\/index.php\/2026\/05\/16\/dartmouth-study-intense-rainfall-prolonged-droughts-valley-news\/"},"modified":"2026-05-16T23:00:48","modified_gmt":"2026-05-16T23:00:48","slug":"dartmouth-study-intense-rainfall-prolonged-droughts-valley-news","status":"publish","type":"post","link":"https:\/\/globalnewstoday.uk\/index.php\/2026\/05\/16\/dartmouth-study-intense-rainfall-prolonged-droughts-valley-news\/","title":{"rendered":"Dartmouth study: Intense rainfall, prolonged droughts – Valley News"},"content":{"rendered":"

You can now receive the latest newsletter from the Valley News directly in your inbox and never miss a headline.
Valley News<\/a>
Sign up for the Valley News’ morning newsletter<\/mark> and get essential news each day.<\/em><\/em><\/em>
New research from Dartmouth College confirms something climate scientists in the Northeast have speculated about for some time: Rainfall is happening in shorter, more intense bursts with longer dry spells in between storms.
Climate change is a leading driver of this shift, said author Justin Mankin, a professor of geography at Dartmouth. The paper was recently published in the scientific journal Nature.
\u201cAs we concentrate rainfall, we’re asking the land surface of Vermont to drink from a fire hose, and it just cannot do that,\u201d Mankin said.
This trend is leading to more flooding and more frequent \u201cflash\u201d droughts between storms, like the one Vermont saw last fall when groundwater levels dropped and many wells in the state ran dry.
Until now, Mankin said, much of the established science assumed that how much precipitation a place receives is the biggest driver of how dry the lakes, streams, soil and groundwater there will be. This study upends that.
Award-winning coverage on breaking news and today\u2019s top stories in and around the Upper Valley. Whether it’s arts, sports, opinion, world news, or our archives and e-editions, you\u2019ll have unlimited access to the Valley News’ content.
Among the key findings, Mankin said, is that when and how frequently rain falls is as big a cause of drought as how much precipitation a place sees overall.
Mankin and his coauthor Corey Lesk, a professor of atmospheric science at the University of Quebec in Montreal who was a postdoctoral candidate at Dartmouth at the time of the study, examined precipitation records from around the world over the last 40 years.
Using a combination of statistical analysis and satellite imagery, they mapped how projected changes in rainfall patterns would affect how water accumulates on the landscape, in river and reservoir levels, soil moisture and groundwater.
They found that if the Earth warms by 2 degrees Celsius, roughly a third of the world\u2019s population will be forced to contend with abnormally dry conditions due to rain consolidating, even if overall rainfall increases.
\u201cWhat we found is something pretty counterintuitive, which is that the more precipitation gets concentrated into stronger events, separated by longer dry spells \u2014 which is kind of what we expect with global warming \u2014 the less of that rain tends to stick around on the land,\u201d Lesk said.
This, Lesk said, makes that water less available to ecosystems that have evolved to take it up slowly. It leads to flooding, erosion and water pooling on the land\u2019s surface, where it\u2019s in turn more likely to evaporate at a faster rate because of warmer temperatures driven by climate change.
All of this makes the earth\u2019s surface less resilient to shorter dry spells, and creates uncertainty about whether increased rainfall will lead to wetter conditions.
The northeastern United States and southern Quebec are expected to see more rain due to climate change, but more of it will likely fall during large storms, like those that have caused flooding in recent years.
However, the fraction of that water that the landscape can hold is declining.
\u201cNew England is quite fortunate that the projections suggest additional precipitation, even while the character of that precipitation is going to be delivered in heavier downpours,\u201d Mankin said. \u201cYou can have these two things conspiring, and that\u2019s why you can have a flood, owing to these very, very heavy rain days, even if it sets up a drought later in the summertime.\u201d
The researchers say that, regardless, this marks a stark shift from how rain has historically fallen in New England and southern Quebec: in small, frequent increments throughout the year.
Mankin said this could mean that groundwater takes longer to recharge after a dry spell, necessitating deeper wells and reservoirs. It also means Vermont will need to continue adapting to larger, more frequent floods.
He and Lesk say more research is needed to understand the impact of more precipitation falling as rain rather than snow.
The researchers are next looking into whether this consolidation of rain is leading to more frequent flash droughts.
Customer Service
603-298-7739
circulation@vnews.com<\/a><\/strong>
24 Interchange Dr
West Lebanon, NH 03784<\/strong>
Help support your local news source!
\t\t\t\t\t\t\t\t\t\t \t\t\t\t\t\t\t\t\t\t\tForgot password \/ Create account\t\t\t\t\t\t\t\t\t\t<\/a> \t\t\t\t\t\t\t\t\t
\t\t\t\t\t\t\t\t