Archive for March, 2011

Headwaters

Thursday, March 31st, 2011

April 2011 article:Biophysical-Regulatory Classification and Profiling of Streams Across Management Units and Ecoregions,” by Brian S. Caruso and Joshua Haynes.

The National Hydrography Dataset (NHD) in its data-augmented form, NHDPlus probably is the most critical tool in use today for evaluating the state of U.S. waters. But, how good is it, and does it include all the waters of concern? In this paper, streams in semiarid USEPA Region 8 wereclassified based on hydrologic permanence and stream order using NHDPlus and GIS to provide information across broad spatial scales to aid with jurisdictional determinations (JDs).

Here’s what they found: “Based on actual JDs and field information, stream order in the NHDPlus and NHD derived classes is generally accurate, although many first order streams are present that are not indicated in the 1:100k dataset or stream class lengths, and some may also not be in the 1:24k dataset. Similarly, some intermittent or ephemeral streams, especially first order, are not included in the 1:100k dataset or stream class lengths, and some may also not be in the 1:24k dataset. Most of the intermittent streams will require further investigation to evaluate flow duration and/or significant nexus to determine jurisdiction. NHDPlus or NHD have the quality to serve as the primary reference for many perennial stream JDs, but may not for intermittent streams due to errors, omission problems (especially in headwaters), and lack of needed information on flow duration and significant nexus. However, without stream classes or NHDPlus/NHD data, no preliminary information on stream order or flow permanence would be available and field and flow information would typically need to be collected and evaluated for almost every stream for JDs.”

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

Multi-site weather generator

Monday, March 28th, 2011

April 2011 article:Effectiveness of Multi-Site Weather Generator for Hydrological Modeling,” by Malika Khalili, François Brissette, and Robert Leconte.

The multi-site generation approach reproduces the spatial autocorrelations observed between a set of weather stations as well as the correlations between each pair of stations. Its performance has been assessed in two previous studies using both precipitation and temperature data. The main objective of this paper is to assess the efficiency of this multi-site weather generator compared to a uni-site generator with respect to hydrological modeling.

The results of this study indicate an underestimation of summer-autumn peak flows using the uni-site weather generator. However, realistic summer-autumn simulated peak flows were obtained with the multi-site synthetic weather data since the spatial autocorrelations over the watershed and the correlations between each pair of stations were adequately reproduced by the multi-site weather generator.

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

Trends in pesticide concentrations

Saturday, March 26th, 2011

April 2011 article:Trends in Pesticide Concentrations in Streamsof the Western United States, 1993-2005,” by Henry M. Johnson, Joseph L. Domagalski, and Dina K. Saleh.

Trends in pesticide concentrations for 15 streams in California, Oregon, Washington, and Idaho were determined for the organophosphate insecticides chlorpyrifos and diazinon and the herbicides atrazine, s-ethyl diproplythiocarbamate (EPTC), metolachlor, simazine, and trifluralin. A parametric regression model was used to account for flow, seasonality, and antecedent hydrologic conditions and thereby estimate trends in pesticide concentrations in streams arising from changes in use amount and application method in their associated catchments.

After a lot of cool statistical stuff, here’s the bottom line: Significant changes in concentrations of many pesticides in streams of California and the Pacific Northwest were identified during the course of this study. Trends at a site often were not consistent between earlier and later periods, reflecting the dynamic nature of pesticide use and management in the region. However, cohesive regional patterns for some pesticides were identified. It’s too much to show here, so you’ll have to read the paper for the details!

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

Pesticide mass loadings

Tuesday, March 22nd, 2011

April 2011 article:Comparison of Two Parametric Methods to Estimate Pesticide Mass Loads in California’s Central Valley,” by Dina K. Saleh, David L. Lorenz, and Joseph L. Domagalski.

Pesticide applications vary seasonally. In this study, mass loads for four pesticides (carbaryl, diazinon, metolachlor, and molinate) in two watersheds with different size and land uses were calculated using the SeaWave and the SineWave models. Results of the two models were compared in an attempt to identify the most useful tool for analyzing pesticide concentration data under different application conditions.

Unlike the SineWave model, where a standardized sine-cosine signal is applied to simulate pesticides concentrations, the SeaWave model output provides a list of multiple forms of a seasonal wave (W) to account for the variability in pesticide concentrations in the watersheds. The paper concludes, in watersheds with variable and intermittent pesticide applications, the SeaWave model would be more suitable to use, due to its robust capability of describing seasonal variation of pesticides concentrations in the watershed.

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

Turbidity, Solids, and Phosphorus

Friday, March 18th, 2011

April 2011 article:Surrogate Measures for Providing High Frequency Estimates of Total Suspended Solids and Total Phosphorus Concentrations,” by Amber Spackman Jones, David K. Stevens, Jeffery S. Horsburgh, and Nancy O. Mesner.

Surrogate measures like turbidity, which can be observed with high frequency in situ, have potential for generating high frequency estimates of total suspended solids (TSS) and total phosphorus (TP) concentrations. In the semiarid, snowmelt-driven, and irrigation-regulated Little Bear River watershed of northern Utah, high frequency in situ water quality measurements were recorded in conjunction with periodic chemistry sampling. At two study sites, the relationships between turbidity and TP varied between spring snowmelt and base flow conditions while the relationships between TSS and turbidity were consistent across hydrological conditions.

While most of us know a relationship exists between turbidity and solids or phosphorus, I liked the way this paper went further and studied the conditions under which that relationship changed. Increased loading during events such as storms or spring snowmelt, which are often missed by routine sampling programs, is considered without skewing load estimates high as collecting samples disproportionately during storm events can do. Also, there is no need to use complicated load estimation equations that account for long periods between concentration measurements or discharge measured more frequently than concentration.

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

Ireland Waterway

Thursday, March 17th, 2011

It’s St. Patrick’s Day, so I just had to show a photo of the Shannon River at Killaloo. This one never made the JAWRA cover, but maybe some day… Have a happy St. Paddy’s Day!

Herbicide Transport

Thursday, March 17th, 2011

April 2011 articles:Herbicide Transport in Goodwater Creek ExperimentalWatershed: I. Long-Term Research on Atrazine,” by R.N. Lerch, E.J. Sadler, K.A. Sudduth, C. Baffaut and N.R. Kitchen, and “Herbicide Transport in Goodwater Creek Experimental Watershed: II. Long-Term Research on Acetochlor, Alachlor, Metolachlor, and Metribuzin,” by R.N. Lerch, E.J. Sadler, C. Baffaut, N.R. Kitchen, and K.A. Sudduth.

A lot of herbicide studies are basically snapshots, representing conditions in a short time period. This set of two papers covers a longer period: 15 years. Because of the long-term nature of this study, atrazine transport, for example  was studied under a broad range of precipitation and stream discharge conditions, as well as varying land and atrazine use; the results showed no significant time trends, only a correlation with streamflow. Similarly, trends in concentration and load of acetochlor, alachlor, metolachlor, and metribuzin were mainly a function of changes in use and annual variation in second quarter stream discharge.

The second paper also had some significant observations about farming practices: “In spite of extensive education and outreach efforts regarding BMPs to reduce herbicide transport, conservation BMPs implemented within GCEW primarily targeted erosion control, and herbicide BMPs were generally not considered. Based on the data presented, these BMPs had negligible impact on reducing herbicide transport in GCEW.”

Food for thought about food.

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

Associate Editor for Aquatic Ecology

Wednesday, March 16th, 2011

Mark Rains

I am pleased to announce the appointment of Dr. Mark Rains, University of South Florida, as JAWRA Associate Editor for Aquatic Ecology. A number of excellent candidates applied for this position, but Dr. Rains’ publishing experience with JAWRA and his previous work as Guest Associate Editor of our highly successful Featured Collection on Headwaters Hydrology, carried the day.

Thank you to all who applied. And, welcome, Mark, to the JAWRA Editorial Team!

Administrivia

Wednesday, March 9th, 2011

Time to answer a few recurring questions.

1. “Help! I just saw the Early View version and noticed a mistake.”

Once online, an article is considered published, equivalent to print. We can’t have multiple published versions running around! That’s why authors should look at their proof copy beforehand. Any corrections must be in an Erratum: “The doofus first author misspelled his coauthor’s name.”

2. Are reviewer names confidential?

Absolutely! ScholarOne Manuscripts™ is designed to keep this information from authors. (Reviewers may self-disclose, but that’s another matter.) No system is perfect, however. If you must have higher security, you should contact me and arrange to register under a pseudonym. Strong First Amendment rights and the resources of a big publisher make it unlikely a court challenge would succeed in forcing disclosure.

3. Can I have an extension for my review/revision/whatever?

Yes! Email Susan.

4. Can you read this attached article and tell me if you’re interested?

I’m happy to read an abstract only. All articles must be submitted via our ScholarOne Manuscripts™ website. Like many experienced Internet users, I’m wary of opening attachments from strangers. Please include your abstract within your email, not as an attachment.

Hydraulic Fracturing (Hydrofracking)

Saturday, March 5th, 2011

AWRA’s Dick Engberg presents an excellent guest post on Hydrofracking Chemicals in the WaterWired blog. Recommended reading. The economic implications are enormous. A huge amount of natural gas may be available in the Marcellus Shale formation of southern New York and eastern Pennsylvania, very close to the east-coast megalopolis.

Hydraulic fracturing can produce wastewater containing proprietary chemicals added to the process, heavy metals and radon from the formation, and large amounts of dissolved solids. Also, there’s the question whether defective leaky well casings could cross-contaminate upper aquifers. These concerns take on special importance for the Marcellus Shale, as drilling would take place in the headwaters of the Delaware River, which supplies drinking water for New York City and Philadelphia.

How serious is the problem? I searched the peer-reviewed literature. There’s plenty of information in the oil and gas journals on the techniques of hydraulic fracturing, but almost nothing on its impacts. EPA currently has a study underway, but a recent New York Times article raises questions about its thoroughness and objectivity.

This situation cries for exposure in the peer-reviewed water journals. I believe JAWRA, with its multidisciplinary outlook and efficient review process, is the right place.