Archive for November, 2010

Bay Journal

Tuesday, November 30th, 2010

Karl Blankenship just wrote a nice summary in the Alliance for Chesapeake Bay’s Bay Journal of the Hirsch et al. trends article published in the October JAWRA. What amazed me, though, is he credits the authors but never mentions JAWRA!

So, get this picture: Blankenship’s telling his readers about important stuff, it’s all based on peer-reviewed science, and he doesn’t point the readers to the source document which is online and free. Go figure!

School landscape irrigation

Friday, November 19th, 2010

December 2010 article:Implementing Landscape Water Conservation in Public School Institutional Settings: A Case for Situational Problem Solving,” by Douglas C. Kilgren, Joanna Endter-Wada, Roger K. Kjelgren, and Paul G. Johnson

The authors studied irrigated landscape water conservation at public schools in Utah, controlling for type of irrigation and water conservation interventions. Their findings suggest ways for school districts to decide where, when, and how to intervene in promoting water conservation. To me, they seem a good combination of science and common sense.

Water conservation programs targeted at large institutional landscapes like public school grounds are likely to produce water savings mainly because of the size of irrigated acreage. However, water savings might best be realized by focusing resources and education primarily on locations that have historically over irrigated. Locations with high capacity to conserve water can be identified through analysis of water billing data and comparison to ETo-based thresholds that categorize landscape water use as conserving, acceptable, or wasteful. Absent the resources to conduct such analyses, conservation interventions would likely be most effective if they are targeted at schools that fit certain profiles (automated-irrigation systems, smaller grounds, high water pressure, and nine-month calendar) and at schools in certain circumstances (in transition from manual to automated-irrigation systems, experiencing custodian turn-over, exhibiting high water use variability between years). Monitoring water use and being strategic about when as well as where to undertake conservation efforts is important for achieving larger system efficiencies in water use and conservation program administration.

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

Sediment budget

Thursday, November 18th, 2010

December 2010 article:Sediment Source Assessment in a Lowland Watershed Using Nitrogen Stable Isotopes,” by James F. Fox, Charles M. Davis, and Darren K. Martin.

This study provides the first attempt to assess the sediment budget in a lowland watershed using Nitrogen-15  tracer analysis. Sediment sources and transported sediments were sampled in a lowland watershed with pronounced fine sediment storage in the streambed. Sediments were analyzed for carbon and nitrogen content and stable nitrogen isotopic composition. Analysis of the data shows that temporarily stored streambed sediments dominate the sediment load during moderate- and low-flow hydrologic events.

Graph from paper

During very high-flow hydrologic events, however, deposition is pronounced in the streambed and sediment is replenished to the bed. Nitrogen model results show that elemental and isotopic nitrogen of streambed sediments vary substantially over the simulation period. In this manner, the streambed in a lowland watershed functions as a temporary storage zone that, in turn, can impact the nitrogen elemental and isotopic signature of sediments. The variation could significantly impact estimates of sediment provenance using nitrogen tracer-based methods.

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

Land cover and hydrologic indices

Wednesday, November 17th, 2010

December 2010 article:Impact of 20 Years of Land-Cover Change on the Hydrology of Streams in the Southeastern United States,” by James F. Cruise, Charles A. Laymon, and Osama Z. Al-Hamdan.

The authors look at land-cover changes and hydrologic indices for 12 watersheds in the southeastern U.S. They conclude land-cover effects on hydrologic variables may be nuanced and can sometimes be only indirectly evident.

Land-cover changes for portions of Alabama, Georgia, and Tennessee were estimated for the years 1980, 1990, and 2000 using classified Landsat images, and associated with hydrologic indices for 12 watersheds in the region. Results indicate that several of the watersheds had undergone significant (>20%) reductions in agricultural land cover with a coincident increase in forested land. Change like this is a common occurrence over much of the eastern United States for a variety of reasons. The hydrologic response was determined in terms of four variables: mean annual streamflow, precipitation minus runoff, frequency of inundation, and duration of inundation.

Once again nature shows her complexity. You might think the changes would be pretty straightforward. However, attempts to correlate the hydrologic results with the land-cover changes were only partially successful. It was not possible to relate definitively changing streamflow indices with land-cover change on an individual basin scale due to other factors such as soil characteristics and unavoidable deficiencies in the land-cover classification (e.g., fixed time scales). Changes in hydrology coincident with land-cover change can be evident in more subtle indices such as frequency of inundation in addition to, or in lieu of, direct measurements of annual runoff.

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

JAWRA December 2010 Highlights

Tuesday, November 16th, 2010

Here are the Article Highlights from the back cover of the December 2010 issue of JAWRA:

Boggs et al. develop a general understanding of how variations in aquifer recharge are reflected in discharge. | view abstract »

Speelman et al. report on a contingent ranking experiment to study how smallholder irrigators in South Africa would value potential changes in water rights. | view abstract »

Cruise et al. look at land-cover changes for portions of Alabama, Georgia, and Tennessee for the years 1980, 1990, and 2000 and hydrologic indices for 12 watersheds in the region. They conclude land-cover effects on hydrologic variables may be nuanced and can sometimes be only indirectly evident. | view abstract »

Fox et al. sampled sediment sources and transported sediments in a lowland watershed with pronounced fine sediment storage in the streambed. Stable nitrogen isotopic composition results show elemental and isotopic nitrogen of streambed sediments vary substantially over the simulation period. | view abstract »

Kilgren et al. studied irrigated landscape water conservation at public schools, controlling for type of irrigation and water conservation interventions. Their findings suggest ways for school districts to decide where, when, and how to intervene in promoting water conservation. | view abstract »

Meierdiercks et al. examine the changing patterns of streamflow associated with urbanization through analyses of discharge and rainfall records for the study watersheds of the Baltimore Ecosystem Study (BES). | view abstract »

Colby et al. gather performance and cost data from arsenic treatment systems in California to compare with data from the USEPA demonstration sites as well as with the USEPA affordability metrics for drinking water. | view abstract »

Herr et al. present a comparison of watershed model simulations generated using measured meteorological data at multiple NCDC stations and using modeled meteorological variables from the mesoscale meteorology model MM5. | view abstract »

Water Rights: South Africa

Tuesday, November 16th, 2010

December 2010 article:Valuing Improvements in The Water Rights System in South Africa: A Contingent Ranking Approach,” by Stijn Speelman, Stefano Farolfi, Aymen Frija, and Guido Van Huylenbroeck.

This study carried out a contingent ranking experiment to study how smallholder irrigators in South Africa would value potential changes in water rights. It is based on detailed information regarding irrigation activities, income sources, and institutional aspects of water management.

The study demonstrates that contingent ranking is a promising tool to measure the effect of improving water rights along different dimensions. Although this sector of smallholder irrigators in South Africa is considered important for poverty reduction in rural areas, it clearly struggles with problems of low water use efficiency and insufficient cost recovery. Taking into account this context, it is highly relevant to evaluate the expected impact of water right reforms on this specific stakeholder. Overall, the estimations of the willingness to pay (WTP) indicate that farmers experience significant inefficiencies in the current water rights system, with significant economic gains attached to the improvement of the water rights. Tackling these inefficiencies will not only be favorable for the efficiency of water use of smallholder irrigators, but given the size of the benefits, it can also add significantly to the government objective of cost recovery. With a higher WTP for water, there is more room for government to increase water prices and reach a higher level of cost recovery.

Policy makers can clearly use such results to guide water right reforms. Besides the information on the economic gains, it gives them direct information concerning the priorities of a target group. This knowledge can help government to increase support for the interventions.

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

Philly Papers

Monday, November 15th, 2010

The AWRA 2010 Annual Conference in Philadelphia was a great success. You can see some of the photos at http://www.his.com/~lanfear/AWRANov2010/index.html .

Philadelphia

Philadelphia

Besides photographing the events and meeting with the Board and our Associate Editors, my job is to scout out those talks which might possibly turn in to JAWRA papers. With 5 concurrent sessions often running, I needed my sneakers! I’ve already sent out encouraging emails to quite few authors whose talks I heard, and to some of the poster presenters. I’m still working my way through the abstracts to see all the good stuff I missed!

Some authors already have asked if we’re interested in their talks becoming papers. See my blog entry on Proceedings.

Recharge and Aquifer Discharge

Monday, November 15th, 2010

December 2010 article: “Analytical Solutions to the Linearized Boussinesq Equation for Assessing the Effects of Recharge on Aquifer Discharge,” by Kevin G. Boggs, Robert W. Van Kirk, Gary S. Johnson, Jerry P. Fairley, and P. Steve Porter.

The authors develop a general understanding of how variations in aquifer recharge are reflected in discharge. Analytical solutions to the linearized Boussinesq equation governing flow in an unconfined

Eastern Snake River Aquifer

aquifer provide a unified mathematical framework to quantify relationships among lag time, attenuation and distance between aquifer recharge and discharge and the effect of an up-gradient no-flow boundary.

Don’t you just love modeling-speak? In plain terms, the authors look at how quickly recharge events affect an aquifer and how far away the effects are felt. The mathematics may make sense only to us geeks, but the findings can be important.

They illustrate their results with application to the economically critical Eastern Snake River Plain Aquifer in Idaho. In this aquifer, detectable annual and decadal cycles in discharge can result from recharge no farther than 20 and 60 km away from the discharge point, respectively. The effects of more distant, long-term recharge can be detected only after a time lag of several decades.

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

AWRA Fellow Joe Delfino

Monday, November 1st, 2010

I’m at the AWRA 2010 Annual Conference in Philadelphia. Great weather, great food, great program!

This evening, at the AWRA President’s Reception, 2010 AWRA President Ari Michelsen awarded JAWRA Associate Editor Joe Delfino the status as an AWRA Fellow. This is a well-deserved honor for Joe. Besides his sterling academic record, Joe has been one of our hardest working Associate Editors and one of my most valued confidants. I’ve always said, if you like JAWRA, thank an Associate Editor, and Joe is one of the best. Congratulations, Joe!

P.S. The President’s Reception was on Halloween.

MORE PHOTOS OF THE CONFERENCE ARE ONLINE!