Archive for May, 2012

Busy, busy, busy!

Wednesday, May 23rd, 2012

This time last year we were sitting back and wondering where all the papers were. For some reason, submittals were down, and we wondered what was going on… and we wished things would  pick up.

Be careful what you wish for! A flood of submissions returned with a vengeance, and we have three featured collections in review on top of everything. My ScholarOne queue is empty for the first time in a month. But, I talked to Susan this morning and there’s more comin’.

So, if I fall a little behind in answering your queries, or seem shorter than normal in my responses, please understand I’m just proverbially treading water here on the 10th floor. Every paper will continue to get our full attention, even if my bicycle has to collect a little dust.

Needed: JAWRA Associate Editor for GIS

Wednesday, May 23rd, 2012

JAWRA Associate Editors (AE’s) serve as primary advisors to the JAWRA Editor. Responsibilities fall into two areas: reviews and subject development. The AE for Geographic Information Systems (GIS) handles between 15 and 20 papers per year. 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. 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 June 18, but early application is encouraged.

Jun Xu is leaving

Wednesday, May 23rd, 2012

Associate Editor for GIS, Jun Xu will be leaving us. He feels foreign travel planned for this fall will interfere with his editorial duties, and has asked to be relieved. We appreciate the work Jun has done for us in this very important area.

I will begin the replacement process shortly. Please join me in wishing Jun the best as he moves on.

Reservoirs and exposure times

Monday, May 21st, 2012

June 2012 article (Early View):Exposure Times to the Spring Atrazine Flush Along a Stream-Reservoir System,” by James A. Stoeckel, Jade Morris, Elizabeth Ames, David C. Glover, Michael J. Vanni, William Renwick, and María J. González.

Reservoirs, in addition to their obvious effects on streamflow, also can affect exposure times of organisms in the streams below.

The authors used enzyme-linked immunosorbent assay to examine reservoir-mediated shifts in spring to fall exposure of aquatic organisms to the spring atrazine pulse over four years in a Midwestern stream-reservoir system. Peak atrazine concentrations in the major inflowing stream exceeded 10 ?g/l in all four years. The reservoir had a beneficial effect in two of four years by diluting atrazine below the 10 ?g/l threshold. However, during the other two years, exposure times above 10 ?g/l were approximately doubled in the reservoir compared to the major inflowing stream. Thresholds of 3 and 5 ?g/l were exceeded during all four years in the reservoir. The uplake and downlake reservoir sites were four to five times more likely to exceed these thresholds and aquatic organisms were subjected to longer exposure times above these thresholds compared to the inflowing stream. Release of elevated atrazine concentrations from the reservoir extended exposure times in the outflowing stream. This effect was most pronounced just below the dam. Aquatic organisms upstream of the reservoir were most likely to experience acute exposures whereas organisms within and immediately downstream of the reservoir were more likely to experience chronic exposures.

The ubiquity of reservoirs and the annual spring herbicide flush highlight the importance of considering the presence and relative location of reservoirs when assessing risk to aquatic communities as well as locations of drinking water intakes.

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

2012 Boggess Finalists

Saturday, May 19th, 2012

I am pleased to announce the finalists for the 2012 Boggess Award. All are really excellent papers, and represent the best of the multidisciplinary science JAWRA brings to its readers. The winner will be selected by the JAWRA Editor and Associate Editors, and announced by the AWRA President.

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.

Stream invertebrate response models

Friday, May 18th, 2012

June 2012 article (Early View):Comparison of Stream Invertebrate Response Models for Bioassessment Metrics,” by Ian R. Waite, Jonathan G. Kennen, Jason T. May, Larry R. Brown, Thomas F. Cuffney, Kimberly A. Jones, and James L. Orlando.

Stream ecologists are trying to understand the spatial scales and processes associated with human and natural disturbances that are affecting the biota. Models provide a useful framework for testing hypotheses, determining potential direct and indirect linkages, and directing where further research is needed.

The authors’ goal was to compare the performance of models developed using multiple linear regression (MLR) techniques with models developed using three relatively new techniques: classification and regression trees (CART), random forest (RF), and boosted regression trees (BRT). We used tolerance of taxa based on richness (RICHTOL) and ratio of observed to expected taxa (O/E) as response variables and land use/land cover as explanatory variables. Responses were generally linear; therefore, there was little improvement to the MLR models when compared to models using CART and RF. In general, the four modeling techniques (MLR, CART, RF, and BRT) consistently selected the same primary explanatory variables for each region. However, results from the BRT models showed significant improvement over the MLR models for each region; increases in R2 from 0.09 to 0.20. The O/E metric that was derived from models specifically calibrated for Oregon consistently had lower R2 values than RICHTOL for the two regions tested. Modeled O/E R2 values were between 0.06 and 0.10 lower for each of the four modeling methods applied in the Willamette Valley and were between 0.19 and 0.36 points lower for the Blue Mountains. As a result, BRT models may indeed represent a good alternative to MLR for modeling species distribution relative to environmental variables.

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

AE, Surface Water Hydrology – search continues

Thursday, May 17th, 2012

We are continuing our search for JAWRA Associate Editor, Surface Water Hydrology. The position will be held open until June 15th. The revised announcement is below. This is an excellent chance to get in on the cutting edge of multidisciplinary water resources. Please consider applying or pass this on to others you consider qualified.

JAWRA Associate Editors (AE’s) serve as primary advisors to the JAWRA Editor. Responsibilities fall into two areas: reviews and subject development. Each AE in the Surface Water Hydrology position handles between 15 and 20 papers per year. All manuscripts are handled 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. 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 June 15, but early application is encouraged.

Estrogen transport from poultry litter

Wednesday, May 16th, 2012

June 2012 article (Early View):Dissolved Organic Carbon and Estrogen Transport in Surface Runoff From Agricultural Land Receiving Poultry Litter,” by Sudarshan Dutta, Shreeram Inamdar, Jerry Tso, Diana S. Aga, and J. Tom Sims.

Poultry litter from concentrated bird-raising operations has become a major issue. This article adds some critical experimental data to the discussion, looking at estrogens and dissolved organic carbon (DOC).

The authors investigated exports of DOC in surface runoff from agricultural fields receiving various treatments of poultry litter (raw vs. pelletized). In addition, they also investigated how estrogens in runoff were associated with DOC. Different forms of estrogens studied were: estrone, 17?-estradiol, estriol, and their conjugates. Experimental agricultural plots were 12 m × 5 m long and had reduced tillage and no-till management practices. The aromatic content of DOC was characterized using specific ultraviolet absorbance (SUVA). Flow-weighted concentrations of DOC and SUVA in surface runoff from plots with poultry litter were significantly (p ? 0.10) greater than the control (no litter) plots. Compared to pelletized poultry litter, reduced-tillage plots with raw litter yielded higher DOC concentrations and SUVA values. No significant differences (p ? 0.10) in DOC and SUVA were observed between litter treatments for plots with no-till. Total estrogen concentrations (including all forms) were positively and significantly (p ? 0.10) correlated with DOC.

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

Stream restoration mitigation

Tuesday, May 15th, 2012

June 2012 article (Early View):Compensatory Mitigation for Streams Under the Clean Water Act: Reassessing Science and Redirecting Policy,” by Martin W. Doyle and F. Douglas Shields.

This article throws down a major challenge for stream restoration programs, basically saying the scale of restoration often is too small. I will let the abstract below speak for itself.

Current stream restoration science is not adequate to assume high rates of success in recovering ecosystem functional integrity. The physical scale of most stream restoration projects is insufficient because watershed land use controls ambient water quality and hydrology, and land use surrounding many restoration projects at the time of their construction, or in the future, do not provide sufficient conditions for functional integrity recovery. Reach scale channel restoration or modification has limited benefits within the broader landscape context. Physical habitat variables are often the basis for indicating success, but are now increasingly seen as poor surrogates for actual biological function; the assumption “if you build it they will come” lacks support of empirical studies. If stream restoration is to play a continued role in compensatory mitigation under the United States Clean Water Act, then significant policy changes are needed to adapt to the limitations of restoration science and the social environment under which most projects are constructed. When used for compensatory mitigation, stream restoration should be held to effectiveness standards for actual and measurable physical, chemical, or biological functional improvement. To achieve improved mitigation results, greater flexibility may be required for the location and funding of restoration projects, the size of projects, and the restoration process itself.

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

Climatic data input for SWAT

Tuesday, May 15th, 2012

June 2012 article (Early View):Improved SWAT Model Performance With Time-Dynamic Voronoi Tessellation of Climatic Input Data in Southern Africa,” by Jafet C.M. Andersson, Alexander J.B. Zehnder, Bernhard Wehrli, and Hong Yang.

Most of our common hydrologic models were developed in regions relatively rich in data. Applying them to regions with more problematic data is a major challenge. Here’s an interesting study working in Southern Africa.

This study compared two approaches to obtain climatic time series for the Soil and Water Assessment Tool (SWAT), namely the conventional centroid method and time-dynamic Voronoi tessellation, and assessed the performance of SWAT in simulating discharge and smallholder maize yields in Southern Africa. Climatic time series were estimated with each method. The Voronoi method utilized all available precipitation and temperature data, but the centroid method used only 14.5 and 82.5%, respectively.

After centroid processing, sub-basin time series were on average 42 and 63% incomplete, respectively. After Voronoi processing, all time series were complete. SWAT was fed with each climate dataset. Each model setup was independently calibrated and validated against discharge and maize yield. Similar model performance was obtained with both methods for yield. The root mean squared error during calibration was 0.26 and 0.27 t ha?1 for the centroid and Voronoi methods, respectively (p-value: 0.80). However, daily discharge simulations improved significantly with the Voronoi method. The coefficient of determination increased from 0.24 to 0.39 in the calibration period (p-value: 9.6 × 10?13) and from 0.41 to 0.48 in the validation period (p-value: 3.1 × 10?3). The Voronoi method improved the simulation of the river flow regime. The largest improvements were obtained in data scarce situations, at high spatial and temporal resolution, and where the centroid method performed the worst.

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