Post-fire runoff

June 19th, 2013

Early View article:Examining Modeling Approaches for the Rainfall-Runoff Process in Wildfire-Affected Watersheds: Using San Dimas Experimental Forest,” by Li Chen, Markus Berli, and Karletta Chief.

The goal of this study was to evaluate the predictive capability of hydrological models in estimating post-fire runoff using data from the San Dimas Experimental Forest (SDEF), San Dimas, California. Four methods were chosen representing different types of post-fire runoff prediction methods, including a Rule of Thumb, Modified Rational Method (MODRAT), HEC-HMS Curve Number, and KINematic Runoff and EROSion Model 2 (KINEROS2). Results showed that simple, empirical peak flow models performed acceptably if calibrated correctly. However, these models do not reflect hydrological mechanisms and may not be applicable for predictions outside the area where they were calibrated.

Position opening: AE, Water Quality Modeling

June 18th, 2013

AWRA is looking for an Associate Editor for Water Quality Modeling. This position typically handles papers dealing with all kinds of models, both stochastic and deterministic. Many have a multidisciplinary aspect.

JAWRA Associate Editors (AEs) serve as primary advisors to the JAWRA Editor. Responsibilities fall into two areas: reviews and subject development. The AEs for Water Quality Modeling handle about 20-25 papers per year, which would be divided between the two incumbents. All manuscripts are processed through our ScholarOne Manuscripts™ system, with the AE selecting reviewers and, when reviews return, making a recommendation to the Editor. AE’s are encouraged to seek out qualified authors in their subject areas and encourage them to submit papers to JAWRA. These could be individual submittals or as featured collections of related papers organized around an introduction.

Associate editorship is a volunteer position earning our heartfelt thanks and an invitation to our annual AE luncheon. It also offers the opportunity to make a difference on the cutting edge of multidisciplinary water resources. Many AE’s have found the experience of making decisions on manuscripts helpful in sharpening their own professional writing skills. The term of an AE is three years, but may be extended by mutual agreement.

Interested individuals should email their CV to the Editor at editor@awra.org. We are happy to answer any questions. We will hold this position open at a minimum until July 1, 2013.

TMDL balance

June 18th, 2013

Early View article:TMDL Balance: A Model for Coastal Water Pollutant Loadings,” by Stephanie L. Johnson, David R. Maidment, and Mary J. Kirisits

The application highlights an example of distributing bacterial sources spatially based on land use data. The authors developed a TMDL Balance model using a steady state, mass balance, GIS-based model for simulating pollutant loads and concentrations in coastal systems. The model uses plug-flow reactor and continuously-stirred tank reactor equations to route spatially distributed point and nonpoint source loads through a watershed via overland flow, non-tidal flow, and tidal flow, decaying the loads via first-order kinetics. In this paper, they explain the development of the watershed loading portion of the TMDL Balance model, demonstrating the methodology through a case study: computing bacterial loads in the Copano Bay watershed of southeast Texas.

[Please note: I have quoted and paraphrased freely from the article, but the interpretation is my own.]

AE Xing Fang is stepping down.

June 17th, 2013

Xing Fang is stepping down as Associate Editor for Water Quality Modeling. Xing has served since 2007, first as AE for Surface Water Hydrology, then moving over to his current position. He’s been a real workhorse for us, always there when we needed him with excellent judgement. Auburn University obviously recognizes his value, because Xing has become very busy with many other tasks in the department, research, and advising graduate students. We will miss him. Please join me in wishing Xing the best as he moves on to greater responsibilities.

Rainwater harvesting

June 13th, 2013

Early View article: “Water Supply and Stormwater Management Benefits of Residential Rainwater Harvesting in U.S. Cities,” by Jennifer Steffen, Mark Jensen Herriman, Christine A. Pomeroy, and Steven J. Burian.

[Abstract] This article presents an analysis of the projected performance of urban residential rainwater harvesting systems in the United States (U.S.). The objectives are to quantify for 23 cities in seven climatic regions (1) water supply provided from rainwater harvested at a residential parcel and (2) stormwater runoff reduction from a residential drainage catchment. Water-saving efficiency is determined using a water-balance approach applied at a daily time step for a range of rainwater cistern sizes. The results show that performance is a function of cistern size and climatic pattern. A single rain barrel (190 l [50 gal]) installed at a residential parcel is able to provide approximately 50% water-saving efficiency for the nonpotable indoor water demand scenario in cities of the East Coast, Southeast, Midwest, and Pacific Northwest, but <30% water-saving efficiency in cities of the Mountain West, Southwest, and most of California. Stormwater management benefits are quantified using the U.S. Environmental Protection Agency Storm Water Management Model. The results indicate that rainwater harvesting can reduce stormwater runoff volume up to 20% in semiarid regions, and less in regions receiving greater rainfall amounts for a long-term simulation. Overall, the results suggest that U.S. cities and individual residents can benefit from implementing rainwater harvesting as a stormwater control measure and as an alternative source of water.

Diurnal sag for E. coli

June 10th, 2013

Early View article:Escherichia coli Concentrations in Urban Watersheds Exhibit Diurnal Sag: Implications for Water-Quality Monitoring and Assessment,” by Anuradha M. Desai and Hanadi S. Rifai.

Timing is everything. And, if you’re collecting E. coli samples, this study shows you need to be aware of diurnal changes.

The authors collected more than 700 Escherichia coli samples at a 10- and 30-min resolution in an urban watershed in Houston. A Bacteria Diurnal Sag (BDS) marked with daytime exponential decay followed by an exponential nighttime regeneration was observed. This pattern was observed during all sampled events but varied depending on other variables. The concentrations during a 24-h period varied 1 to 5 orders of magnitude and the fecal load was at least 10 times lower than what would be obtained using a single morning E. coli measurement, the typical sampling scheme in most monitoring programs.

[Please note: I have quoted and paraphrased freely from the article, but the interpretation is my own.]

Quality of water from rain barrels

June 7th, 2013

Early View article:Assessment of Residential Rain Barrel Water Quality and Use in Cincinnati, Ohio,” by William D. Shuster, Dennis Lye, Armah De La Cruz, Lee K. Rhea, Katharine O’Connell, and Amanda Kelty.

Water from rain barrels can have a lot of uses, but drinking it is not one of them. In this study, rainwater reuse and levels of select microbial indicators were monitored for six residential rain barrels located in the Shepherd Creek watershed of Cincinnati, Ohio. Water from rain barrels typically had poor microbial quality and was used for watering indoor and outdoor plants. Water from rain barrels typically had poor microbial quality and was used for watering indoor and outdoor plants. Rain barrel water chemistry was slightly acidic, exhibited wide ranges in conductivity, turbidity, and total organic carbon (TOC) concentrations and gave no evidence of the presence of cyanobacterial microcystin toxins. Selected microbial water-quality indicators indicated that counts of total coliform and enterococci were consistently above U.S. Environmental Protection Agency standards for secondary recreational contact water-quality standards.

[Please note: I have quoted and paraphrased freely from the article, but the interpretation is my own.]

“Only a model.”

June 4th, 2013

After all, it’s only a model.” I suspect most mathematical modelers have heard these words. And with that put-down, thousands of hours of highly skilled work and a huge amount of useful knowledge goes down the drain.

Mathematical modeling is a highly technical field. You take a physical system and express how it behaves in terms of equations. You fit parameters to those equations, and run different alternatives. Then, you convert the mathematics back to conclusions about the physical world. Geek heaven! And, that’s exactly the problem. The typical decision maker, and certainly the average person, has no good way of knowing whether to believe a mathematical model. It’s too far removed from their knowledge system. Trust the scientists? Maybe, but not usually the case, especially where the model tells them something they really don’t want to hear.

The solution, then, is to build trust based on some degree of understanding. That’s exactly what collaborative modeling tries to do. Guest Associate Editors Elizabeth Bourget, Stacy Langsdale, and Marjan van den Belt have put together a featured collection, “Collaborative Modeling for Decision Support as a Tool to Implement IWRM.” They note, “Distilled to its essence, collaborative modeling is building models with rather than for participants.” The papers in the featured collection show how trust is built in a gradual process of technical and political participants interacting.

This featured collection originated from the June 2011 AWRA Summer Specialty Conference, “Integrated Water Resources Management: The Emperor’s New Clothes or Indispensable Process?” The conference featured a full-day symposium on Collaborative Modeling for Decision Support as a tool to implement IWRM, convened by the U.S. Army Corps of Engineers Institute for Water Resources, Sandia National Laboratories, and the U.S. Institute for Environmental Conflict Resolution.

In addition to a transcript of the conference keynote address by Jerome Delli Priscoli, eight papers explore and critically discuss the appropriateness of Collaborative Modeling for Decision Support as a means of doing Integrated Water Resources Management (IWRM). The objective is to: (1) develop an understanding of how applications of the method vary in different contexts around the world, and to (2) identify commonalities that inform and build a set of common best practices.

I think the collection hits its mark. As I read through the drafts, I realized, here is a way around the “only a model” conrundrum. There are practical solutions in these papers, and sometimes they work. To me, this could herald a whole new relationship between modelers and those needing the results of models. As Rick said to Captain Renault, “I think this is the beginning of a beautiful friendship.”

ET, the residual

June 4th, 2013

Evapotranspiration (ET) is the residual of the water balance equation. Take precipitation, subtract runoff and infiltration, and, voila!, what’s left over is ET. Of course, any error in computing the other components affects ET. And, not directly knowing ET precludes computing the real residual error in a water balance. Wouldn’t it be nice to have a good independent measurement of ET?

There’s a good reason ET is treated as a residual: it’s devilishly hard to measure. ET varies field-to-field and hour-to-hour. ET depends upon precipitation, temperature, solar radiation, wind speed, humidity, soil characteristics, climate, land management, water-supply, vegetation, and vegetative condition. However, use of aerial imagery (especially satellite-based) now provides the potential to directly capture much of the spatial and temporal variability of ET across the landscape.

Guest Associate Editors Steve Wolff and Bern Hinckley address this question with the featured collection, Assessing Consumptive Water Use via Satellite Data. The idea for this collection came from a special session convened at the AWRA Annual Conference in Albuquerque, NM, November 2011. Eight papers represent two broad categories: application and research.  The first four papers present work where remotely sensed data were used to help assess real-life management needs related to water consumptive use.  The last four papers are more research in nature, presenting specific topics on how to refine or advance the use of remotely sensed data in applied methods.

The Guest Associate Editors note, “… the migration of this work from research to full management application is just beginning.  As the competition for water intensifies, the better the tools and data resource managers have at their disposal, the better will be their management decisions.  Our hope for this collection is to facilitate the important continuing transfer of information and tools from the researcher to the water resource manager.”

2013 Boggess Award

June 1st, 2013

I am pleased to announce the winner of the 2013 William R. Boggess award: Martin W. Doyle, for “America’s Rivers and the American Experiment,” published in the August 2012 issue.

Doyle is a frequent JAWRA contributor, and actually authored two of this year’s finalists. He looks at things from an unusual angle to present ideas that make the reader think — and often result in a Discussion! This year’s winner is no exception. His main point is the diversity of actors in US water policy, although complicating decisions, really is a strength that keeps us from making colossal mistakes. Recommended reading.

The award will be presented on Wednesday, November 6, 2013 at the awards luncheon of the AWRA Annual Conference, in Portland, OR. Please join me in congratulating Martin W. Doyle.

The William R. Boggess Award is given to the author or authors of the paper, published in the Journal of the American Water Resources Association during the preceding year, that best describes, delineates, or analyzes a major problem or aspect of water resources from either a theoretical, applied, or philosophical standpoint. Established in 1973, the Award honors William R. “Randy” Boggess, a member of AWRA, one of the first Directors, and a former President of the Association, who has also made significant contributions to AWRA as an Editor of JAWRA.