The geometry of a stream channel is controlled by both water and sediment movement, which reflect regional climate, geology, and human land use in a given drainage basin.
This series of photos shows common channel geometries. Clockwise from top left: (a) a braided portion of the Pjorsa River in Myrdalssandur, Iceland; (b) a shallow, meandering stream in New Brunswick, Canada; (c) a deeply incised meander bend (305 meters [1,000 feet] below the canyon rim) of the San Juan River in Utah (United States); and (d) the dendritic (branching) drainage network of a stream system in Kakadu National Park, Australia.
The amount and timing of water moving downstream depends on precipitation rates in the drainage basin, and on how water that falls as precipitation moves downslope into stream channels. Some streams alternate between periods of low flow (or no flow) and sudden flash floods
because the drainage basin is normally dry but occasionally receives intensethunderstorm
rainfall that rushes quickly downslope as runoff. Other streams have a fairly constant discharge year-round because they are either supplied or amplified by groundwater
The sediment supplied to valley bottoms is controlled by climate and local geology, which together determine the rate of weathering that transforms bedrock into unconsolidated sediments. Sediment transport in a stream channel is controlled both by the supply of sediment from the hillslopes and valley bottom, and by the energy of flow available to transport the sediment. Depending on particle size, sediment may move asdissolved load, suspended load, or bedload.
By Suzanne Goldenberg, The Guardian
February 11, 2015
Fracking is depleting water supplies in areas susceptible to drought and water shortages. (photo: Susan Heller/Getty Images)
America’s oil and gas rush is depleting water supplies in the driest and most drought-prone areas of the country, from Texas to California, new research has found.
Of the nearly 40,000 oil and gas wells drilled since 2011, three-quarters were located in areas where water is scarce, and 55% were in areas experiencing drought, the report by the Ceres investor network found.
Fracking those wells used 97bn gallons of water, raising new concerns about unforeseen costs of America’s energy rush.
Daniel Griffin1,2, Kevin J Anchukaitis2
Corresponding author: Daniel Griffin, Department of Geography, Environment and Society, University of Minnesota, email@example.com.
1. Department of Geography, Environment and Society, University of Minnesota, MN, USA.
2. Woods Hole Oceanographic Institution, Woods Hole, Massachusetts, USA
Discussion and Conclusions
Evaluated using an integrated soil moisture metric like PDSI, the 2012-2014 drought is the worst in our combined NOAA-NADA estimate and 2014 is the single most arid case in at least the last 1200 years. In contrast, the precipitation deficits of 2014 and the three-year period are not unique in the paleoclimate record (Figure 4). A simple modeling exercise (Figure S6), calculating the average division 4–7 PDSI with observed [Vose et al., 2014] vs. climatological mean temperatures, suggests that temperature could have exacerbated the 2014 drought by approximately 36%. Based on these complementary lines of evidence, we infer that the severity of the 2014 drought is a result of both anoma- lously low – yet not unprecedented – water year precipitation (Figure S4) and record high temperatures (Figure S3). The 2014 JJA PDSI value is ∼3.5 standard deviations below the long-term (800-2014) mean (Figure 1b) and the cumulative 2012-2014 drought is the worst unbroken drought interval of the last millennium (Figure 3a, Figure 4). Precipitation for 2012-2014 was indeed low, but is less than 1.5 standard deviations below the reconstructed long-term normalized regional mean and not unprecedented over the last centuries, neither on the annual nor 3-year time scale. These observations from the paleoclimate record suggest that high temperatures have combined with the low but not yet exceptional precipitation deficits to create the worst short-term drought of the last millennium for the state of California.
On February 4, 2015, the Division of Water Rights issued Drought Informational Order WR 2015-0002-DWR. The Order requires that persons listed in Attachment A of the Order (these persons will receive mailed copies of the Order) provide specific information, using an online form. To assist these persons in compiling the required information, a sample copy of the online form is now available at: http://www.waterboards.ca.gov/waterrights/water_issues/programs/drought/index.shtml. Please see: “Online Informational Order Template”.
Today the Division of Water Rights issued an Informational Order to persons claiming senior water rights in the Sacramento-San Joaquin Delta watershed requesting more detailed information about the water rights they claim. The Order can be found on the Division’s website at: http://www.waterboards.ca.gov/waterrights/water_issues/programs/drought/index.shtml
The obvious solution is to de-fund the State of CA’s ability to test wells for water quality.
No data . . . no problem!
The Division of Water Rights has prepared a report with recommendations to improve the implementation of the water rights priority system in future dry years pursuant to Resolution No. 2014-0031. Presentation of the report to the Board is tentatively scheduled for February 17, 2015 as an informational item at the Board Meeting. The report and additional information are available on the project web page:
By David R. Baker
January 31, 2015
Updated: February 1, 2015 12:11pm
Leah Millis / The Chronicle
Oil companies in drought-ravaged California have, for years, pumped wastewater from their operations into aquifers that had been clean enough for people to drink.
They did it with explicit permission from state regulators, who were supposed to protect the increasingly strained groundwater supplies from contamination.
Instead, the state allowed companies to drill more than 170 waste-disposal wells into aquifers suitable for drinking or irrigation, according to data reviewed by The Chronicle. Hundreds more inject a blend of briny water, hydrocarbons and trace chemicals into lower-quality aquifers that could be used with more intense treatment.
Most of the waste-injection wells lie in California’s parched Central Valley, whose desperate residents are pumping so much groundwater to cope with the historic drought that the land has started to sink.
“It is an unfolding catastrophe, and it’s essential that all oil and gas wastewater injection into underground drinking water stop immediately,” said Kassie Siegel, director of the Climate Law Institute at the Center for Biological Diversity environmental group.
Oakland, Saturday, February 7, 2015
Governor Brown should support and join Gov. Cuomo – BAN FRACKING now
A long, meandering list of some of the known fracking chemicals.
A new California flag?
January 23, 2015 · Will Parrish
From WILL PARRISH, TheAVA
When it comes to areas of the world being racked by drought, one of the few that has had at least as hard a time as California is central and southern Brazil. Whereas the US’s biggest state has gotten a handful of solid drenchings in the past three years, this particular portion of South America has seen almost no rain at all. The most populous city in the Americas, Sao Paolo, is marked by endless, chaotic sprawl that has grown, unchecked, for decades. The main reservoir that supplies the 19 million people who live there has recently gone as low as five percent of capacity.
One of the main factors that has caused the California drought is climate change. The warming of the atmosphere has increased the size and persistence of the high-pressure ridge that historically prevents rain from reaching California’s Mediterranean climes for much of the year.
What about in Brazil? Researchers there have pinpointed the absence of “flying rivers” — vapor clouds from the Amazon rainforest that normally bring rain to the center and south of Brazil — as a main reason for the recent lack of precipitation. These massive volumes of vapor rise from the forest, travel west, and then, blocked by the Andes Mountains, turn south. The Amazon is akin to a gigantic hydrological pump that brings the humidity of the Atlantic Ocean into the continent.