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Tracking Raindrops


RAIN. FOR THOUSANDS OF YEARS, IT'S BEEN THE INSPIRATION FOR COUNTLESS POEMS, DANCES AND PRAYERS AS WELL AS THE SUBJECT OF SCIENTIFIC STUDY. BUT FOR ALL THE ATTENTION HUMANS HAVE LAVISHED UPON IT, THERE ARE STILL SOME DETAILS ABOUT THIS UBIQUITOUS LITTLE RAINDROP THAT HAVE REMAINED A MYSTERY.

(crossbow fires arrow)
-got it again
-let's hope this one falls free
DAWSON: -that was a nice shot, it went right over the branch you wanted it to.

THESE RESEARCHERS FROM THE UNIVERSITY OF CALIFORNIA AT BERKELEY ARE TAKING PART IN A LANDMARK STUDY THAT WILL DELVE DEEP INTO THE SECRET LIFE OF A RAINDROP. AND WHAT THEY LEARN MAY HOLD THE KEY TO PREDICTING THE EFFECTS OF GLOBAL WARMING ON THE EARTH'S FRESH WATER SUPPLY.
Dawson: That's great cos it's right in the middle of the watershed. That'll be a great vertical gradient for microclimate.

THE KECK HYDROWATCH PROJECT IS A FOUR-YEAR EFFORT DESIGNED TO PRECISELY MONITOR AND MEASURE THE PATHWAYS OF WATER IN TWO CONTRASTING WATERSHEDS: COASTAL MENDOCINO COUNTY AND IN A MOUNTAINOUS AREA NORTH OF LAKE TAHOE.
Dawson: We really want to understand how water gets there, and then once it's there, how it moves through that watershed, how much of it goes into the ground water, how much of it actually goes back out in the streams, goes out as evaporation, or even as transpiration, used by the vegetation that occupy those different watersheds.
THE UNIQUE PROJECT WILL RANK AMONG THE MOST COMPREHENSIVE HYDROLOGY STUDIES EVER DONE.
TODD DAWSON: ....It involves Earth scientists, atmospheric scientists, plant biologists, soil scientists, isotope bio-geo-chemists, people that work in computer science, people that are working in electrical engineering, and then people who are also doing modeling on various processes. So it really is an interdisciplinary team effort, to try to understand the hydrologic cycle from many different scientific perspectives.

TOGETHER, THESE SCIENTISTS WILL STRIVE TO FIND THE ANSWER TO A SURPRISINGLY FUNDAMENTAL QUESTION.

INEZ FUNG: I asked what I thought was a very simple question, how old is the water in the stream? Is it from yesterday's rain, is it from last year's rain or this season's rain, or is it a hundred, thousand years old?

EVERY SCHOOL CHILD LEARNS ABOUT THE WATER CYCLE. OCEAN WATER --HEATED BY THE SUN -- EVAPORATES AND FORMS CLOUDS, WHICH ARE MADE UP OF MILLIONS OF TINY WATER DROPLETS. LAND FORMATIONS AND CHANGING AIR TEMPERATURES FORCE CLOUDS TO RISE AND COOL. THIS TRIGGERS THE RELEASE OF PRECIPITATION. THE WATER ENTERS SOIL, STREAMS, AND UNDERGROUND AQUIFERS. SOME FLOWS BACK INTO THE OCEAN. SOME EVAPORATES BACK INTO THE ATMOSPHERE FROM PLANTS IN A PROCESS CALLED TRANSPIRATION.

TODD DAWSON: So what we don't know about the water cycle is the various roles that different organisms play, or the different pieces of the hydrologic cycle play as driving the magnitude or the speed at which water moves through the hydrologic cycle.
Guy in tree: I'm parallel with the data logger..

TODD DAWSON IS A PLANT GUY. HIS PART IN THE PROJECT IS TO PROVIDE INFORMATION ON THE ROLE THAT THE PLANTS AND TREES ARE PLAYING IN HOW WATER MOVES THROUGH THIS WATERSHED.
TODD DAWSON: Seventy-five to eighty percent of the water on this planet is recycled through agriculture, through forests, through the plants. You take those plants away, you remove that straw in the Earth, that conduit for water to move out of the soil and back into the atmosphere, and that eventually can lead to deserts expanding. It changes the climate. We know for example when trees were cut down in the Amazon, there was less precipitation.

TODD DAWSON: Our hope is that we can take the information from these two watershed studies here in California and with the use of models which one of my colleagues in Inez Fung is developing, really then be able to provide a template that can be used in other areas of the globe.


INEZ FUNG IS THE LEADER OF THE HYDROWATCH PROJECT. AS AN ATMOSPHERIC SCIENTIST AND THE CO-DIRECTOR OF UC BERKELEY'S INSTITUTE OF THE ENVIRONMENT, SHE'S BEEN ON THE FOREFRONT OF GLOBAL CLIMATE CHANGE RESEARCH FOR 25 YEARS.
INEZ FUNG: I like solving puzzles. And the Earth is just a gigantic puzzle, it's about how things work... why it rains, why there are warm days and cold days...water comes from, where the water goes...it is a marvelous puzzle.

TO HELP SOLVE PART OF THAT PUZZLE, DAWSON AND HIS TEAM AT THE ANGELO RESERVE ARE CLIMBING TREES ... PLACING SPECIAL ELECTRONIC SENSORS HUNDREDS OF FEET UP THAT WILL GATHER WATER SAMPLES FROM VARIOUS PARTS OF THE CANOPY.

Todd: there should be a big Doug Fir, next to that box is the one that we'll use
Climber: right, that's the one I'm calling Stumpy
Todd: OK, it lost it's top.


SOLAR-POWERED MONITORS BEING INSTALLED THROUGHOUT THE WATERSHED WILL SEND RESEARCHERS REAL-TIME DATA VIA SATELLITE UPLINK ON THINGS LIKE AIR MOISTURE, SOIL COMPOSITION, STREAM FLOW AND RAINFALL. WHEN INSTRUMENTATION IS COMPLETE, THE RESERVES WILL FUNCTION AS WIRELESS WATERSHEDS.

BACK IN HIS LAB AT UC BERKELEY, DAWSON IS LIKE A DETECTIVE LOOKING FOR CLUES.
TODD DAWSON: 1:29:47 So we take the isotopes in water and in the hydrologic cycle, and we use them like a tracer. And the neat thing about water, as it undergoes evaporation, condensation or even sublimation into things like snow or ice, it changes its isotope values. When it changes its value and it falls into the environment, we can use it like a tracer.


SO, WHAT'S AN ISOTOPE? WELL, LET'S LOOK AT A WATER MOLECULE. IT'S MADE UP OF ONE OXYGEN AND TWO HYDROGEN ATOMS-H2O. THE NUCLEUS OF AN ATOM, LIKE THIS OXYGEN ATOM, MOST COMMONLY CARRIES AN EQUAL NUMBER OF PROTONS AND NEUTRONS. AS WATER CHANGES FORM WHEN IT MOVES THROUGH THE ENVIRONMENT- LIKE GOING FROM LIQUID TO VAPOR- THE OXYGEN IN THAT WATER CAN BE SWAPPED OUT WITH OXYGEN ATOMS THAT HAVE AN EXTRA NEUTRON OR TWO. THESE OXYGEN ATOMS WITH VARYING NUMBERS OF NEUTRONS ARE CALLED ISOTOPES OF OXYGEN AND THEY CAN PROVIDE INSIGHT INTO THE PATH THAT WATER HAS TAKEN IN ITS CYCLE.
TODD DAWSON: ... And we can actually ask, ah, was that a cold storm, was that a warm storm? Was that snow, was that fog? They take on unique fingerprints, and we trace that fingerprint, then, as the water moves through our different watersheds.


FOR EXAMPLE, A HIGH CONCENTRATION OF CARBON, NITROGEN OR IRON INDICATES THE WATER CAME FROM SURFACE SOIL. ISOTOPE RATIOS CAN ALSO TELL IF WATER HAS EVAPORATED FROM A PLANT OR SPENT YEARS IN ROCKS. KNOWING WHERE THE WATER COMES FROM AND HOW FAST IT'S MOVING THROUGH THE WATERSHED ENABLES FUNG TO CREATE COMPUTER SIMULATIONS OF DIFFERENT WEATHER SCENARIOS. FROM THESE, SHE'S ABLE TO PREDICT HOW GLOBAL WARMING MIGHT CHANGE OUR CLIMATE - AND HOW IT MIGHT AFFECT OUR FRESH WATER SUPPLIES.
INEZ FUNG: We are predicting where it is warm or hot, it's gonna be hotter and drier.

... and so that means less water available to the plants. And if the plants are not there, then we have less transpiration, less communication of water from the soil to the atmosphere, and we're in for a drought. And that's what we're predicting. Which is rather grim.
TODD DAWSON: So one of the things that's been happening on Earth since humans began to expand their populations is that of course, we reconfigure what the land surface looks like.

We have a lot more rainfall now over the ocean than there used to be, and largely because land surfaces have been modified so dramatically that there's more heating, if there's more heating, that pushes away the atmospheric moisture, clouds, so less rainfall is falling onto the land itself. So through land use change that also has climate change associated with it, we're redistributing water around the planet, a lot less of that water is becoming available for human use, for agricultural use.
AND WHEN YOU COMBINE LESS AVAILABLE FRESH WATER WITH A RAPIDLY GROWING HUMAN POPULATION, YOU'VE GOT A RECIPE FOR DISASTER. AT THE CRUX OF THE PROBLEM IS ONE SIMPLE FACT: THE EARTH WON'T EVER MAKE ANY NEW WATER. BUT HOPEFULLY, KEEPING BETTER TRACK OF THE WATER WE DO HAVE WILL HELP US ADJUST TO THE DRIER TIMES AHEAD.

INEZ FUNG: I have to be hopeful. I think the last year there's been tremendous awareness around the world about the crisis that we're in. And I think that together we can do something about it.

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This video features footage from the University of California Natural Reserve System's “Mapping the Future,” a one-hour television documentary funded by the National Science Foundation, which illustrates the value of the UC NRS by focusing on the Heath and Marjorie Angelo Coast Range Reserve in northern California where large multidisciplinary scientific teams are conducting a number of ground-breaking studies.