Flooding

As a hydrologist, spring is my favorite time of year.  Not in the same way that most people enjoy spring, the nicer weather is wonderful of course, but it is rather the opportunities that this season brings to a hydrologist.  The opportunity to really see the power of Mother Nature in full force as the rivers rise, flooding out fields, towns and people’s livelihood.  This is the only time of year when we are “on call.”  When a river floods, who are you going to call? (please ignore the Ghostbuster reference)  A hydrologist of course!  We are the ones who spend long hours trying to understand the river, how it responds to rainfall, at what stage is it impacting that road or someone’s home and when at what stage is it considered a flood?  Our efforts are valuable during time of crisis yet our labors are sometimes misunderstood.

It is spring in the Midwest now and I am glued to the media streams in an effort to hear about the flooding going on around me.  It is a little ironic that a devastating natural disaster such as a flood can bring such joy to a scientist, but ask any of us water geeks and we will all agree – floods are exciting.  The other night I was watching the news listening for the latest flood update when a meteorologist stated the following, “what can these flood predictions tell us?  After all Hydrology is not an exact science.”   The term exact science is a double standard in and of itself since the definition of science is – systematic knowledge of the physical or material world gained through observation.  According to this definition hydrology is a science, ground in to its true definition.  A science that uses the observations obtained on a regular basis to understand the physical world, which in this case would be a river system.  However I do understand why people continue to question our work – it is the unpredictability of Mother Nature that we continue to try to capture mathematically.  Sometimes Mother Nature does not want to play by our rules or be defined by our equations. 

To understand the complexity of a watershed a multi-faceted world of hydrology has been developed. There are two types of hydrologist, the first of who work primarily in the field: recording water levels, measuring flow and ensuring working condition of all field equipment.  The second type of hydrologist works in the office, analyzing data and running hydrologic models.  In fact as you develop your skills in the hydrology field you move from the field to the office to establish you expertise and advance your career.  Currently I have the most experience as a field hydrologist although with time I have been making the transition towards the office.  With a little experience in both I will now attempt to describe to you the different fields and how they work together to ensure the safety and livelihoods of those who resolve to live a life in constant flux with their local river systems.

A field hydrologist measures water quantity (discharge) at a variety of water levels (stages).  This is accomplished using a variety of equipment that continues to develop with technology and increase in difficulty.  During low flow conditions a hydrologist will wade in the water, by standing and facing the flow we are able to measure the amount of water flowing towards us with a small error of inaccuracy.  During high flows we use more advance equipment to get a detailed picture of the flow and to protect ourselves from dangerously high velocities.  We measure flow at all water levels over several years, using this information to develop a relationship between stage and discharge.  This relationship is called a rating curve.  Knowing the amount of water flowing through a river at all times is a difficult to obtain since a discharge measurement will take two hydrologists almost an hour to complete.  However water levels can be measured in real-time (taken every 15 minutes is the standard practice).  These stages are converted to discharge values based on the rating curve developed.  A rating curve is used in many fields from the engineering designing a bridge, to a biologist managing a pool for bird migration, to a city using the discharge from a river to supply water and even an office hydrologist using the rating curve to calculate the quantify the amount of water that will be moving downstream during a flood.  A rule of thumb is it takes three years of monthly measurements at a site (longer in the Midwest due to the winter months) to develop a good rating curve, and even then we are not entirely sure of the relationship between Mother Nature and our equation.

Office hydrologists, for example those who work at the National Weather Service (NWS) putting out flood forecasts, use technology, science and mathematics to provide the services needed in their field of expertise.  To predict flood levels hydrologists run models which help them simulate a variety of scenarios determining when the river will peak using a variety of weather patterns.  These office hydrologists rely on the field hydrologists to be their eyes and ears on the ground; measuring discharge, maintaining equipment measuring stage data in real time and reporting on obstructions on the river such as ice jams or debris piles.

Together these two areas of expertise in the hydrology world combine to be a powerful force behind the general public keeping them cognizant of rising waters. Stay away – Don’t die!

Go Wildcats! - Interesting Stories From the Southeastern Arizona Dessert

Today is New Year's Day, the first sacred moments of 2011 have commenced.  As others around me are making resolutions and reflecting on the glories of 2010 I too must admit that  these thoughts are filling my head.  2010 was a great year for me, a year when the dreams I set for myself did come true.  This has not been the case, like most normal people I have had many years where my resolutions are vanishing before my eyes as December rolls around.  One of the more memorable resolutions was to complete my never-ending thesis.  Three long years it took me to complete it and interesting stories from Arizona now come to mind.

When I tell people my graduate degree in water resources was from the University of Arizona, they chuckle and ignorantly say, "how can you study water in the desert?" All joking aside, my reply is "we always brought water with us."  My research at the U of A entailed using a rainfall simulator to study post-fire runoff and erosion.  We hauled tanks of water out to remote areas with us, using them to supply our rainfall simulator, which simulated the high intensity rainfall rates similiar to a monsoon storm.  The goal of the project was to analyze and model how wildfires impacted erosion rates in semi-arid desert environments.  My research was rather dull in most regards and to prevent you, the reader, from now closing my blog I will skip the details of my thesis work to engage you in stories from the border.

The wildfires we worked on weren't started by your typical lightning strikes.  More interestingly they were all started by drug runners - accidents or diversion tactics - working in remote areas of Arizona near the Mexican border always lent itself to an element of danger.

The San Rafael Valley near Patagonia, Arizona is controlled by drug runners, ask any local rancher or ranch hand.  Stopping by the rancher's home for a casual visit lends itself to several stories about the recent run-ins with Mexican out-laws.  I saw this first hand and lived to tell the story.  Picture your normal hot Arizona summer day, it's 90 plus degrees outside and the only shade you can find is the occasionaly tree or the shadowy side of that work truck.  It is 7 am in the morning and we are just approaching our work site where we have several 6m x 2m plots prepared for a rainfall simulator experiment.  We have been granted access by a local rancher to conduct these experiments on his private land.  A morning in a remote part of Southeastern Arizona is beautiful with the occasional sighting of an antelope heard, jack rabbits or that beautiful bird that I have no idea what it is (I am a hydrologist not a biologist).  Even the tarantula homes are strikingly beautiful especially with the combination of morning dew and a beautiful sunrise highlighting their webs and creating a unique sparkle across the prairie landscape.  Back to my story...on this particular morning my beautiful daydream is quickly interrupted by the site of two border patrol trucks flying by our convoy at an alarming rate.  It was not unusal to see a border patrol vehiclez out in the area but never had they seemed to be in such a rush.  A hiccup in our day but our convoy continues.  Further into the private property we find another two or three border patrol vehicles huddled together near a hillside.  They do not stop us but let us continue on our way uninterrupted - maybe it was the sight of two white vehicles with federal plates that lent them to not pay attention to us.  We continue to work that day all the while discussing what we had missed this morning.  Mid-afternoon a 4-wheeler makes a drive by.  The man driving the off road vehicle is white and clearly not dressed for a day of off-roading with his khaki shorts and white short sleeved polo shirt (I should mention here that in Arizona most of those who spend several hours in the sun daily usually cover up from the sun with pants and long sleeve shirts.  The theory is that you will dehydrate faster with a sunburn than with the added heat from the layers of clothing.  Plus who wants that farmers tan?)  The man driving the 4-wheeler does not stop but merely pauses for a brief moment to take in our operation before continuing on into oblivion as far as we are concerned.  He never returns the same way he came.  What an interesting day we had!  Once we arrive back at Sonoita, to our hotel, I catch a quick glimpse of the newspaper headline for that day.  The headline read Border Patrol Shot and the article went on to discuss the Border Patrol's encounter that day with a drug lord shoot out, where two drug lords were fighting over control of the San Rafael Valley for transporting drugs into the United States.  Finally we had our answer to the plethora of Border Patrol vehicles we had witnessed.  Maybe the urgency of the vehicles we had witnessed this morning was their answer to an ambulance ride.

One or two days later while working at the same site we actually got to witness the transport of drugs or so maybe I would like to think.  It was a hot afternoon and we had just stopped for a break between experiments.  We sat under a tree for lunch discussing whatever nerdy hydrologists talk about, when one of us notices two hikers (of Mexican decent) walking along an adjacent hillside near us.  We watched them until they disappeared behind a tree.  We continue working for another two or three hours constantly checking on that tree for a glimpse of these so-called hikers.  Finally they re-emerge from behind the tree with two large white sacks being carried upon their backs.  They hike back away from the tree and disappear from view.  Now my assumption is that these hikers were drug runners and they just had just picked up there stash.  How exciting!  We never ran into anything else unusual after that, but I dare say that was enough to get my blood pumping everytime I had to returned to the site.  At the end of the season we brought in one of our trucks to the shop of its annual post-season maintainence.  Upon careful inspection we found several bullet holes in the side of the truck (the truck we usually left overnight at our sites) which we had never noticed before.  Coincidence or was someone trying to send us a message?

Several stories along these lines are shared amongst graduate students conducting research out of the University of Arizona.  Mine was actually mild compared to most.  However it was not something I could write home to my mother about.  "Mom, yeah funny thing happened today we witnessed some drug runners.  No don't worry they weren't on our hillside and  they only left a few gunshots in the work truck."
As a hydrologist in the Midwest I have rarely encountered such dangerous work conditions.  Once in awhile I would witness a border patrol truck near the Canadian border or the occasionally crazy person who wants to talk to you about how it is your fault his life sucks.  No my life as a hydrologist now is only dangerous when it floods and that is another story.

It is February now and I am finally finishing my blog - so much for my new year's resolution of spending more time on it.  However I have already been inspired as to the topic of my next post.  Look for a discussion of the 2011 spring flood predictions for Minnesota!