Hawaii First Water

  • Home
  • About Us
  • Blog
  • Contact

Archives for March 2014

Science Digest: Water supply availability ‘to dominate U.S. natural resource management’

March 24, 2014

Source: University of York,

Date: February 5, 2014

Summary: Water supply is the most pressing environmental issue facing the United States, according to a survey of policy makers and scientists have revealed.

water-3Water supply is the most pressing environmental issue facing the United States according to a survey of policy makers and scientists revealed in a new publication in BioScience by researchers at the University of York and the University of California, Davis.

A question on the water supply necessary to sustain human populations and ecosystem resilience was ranked as having the greatest potential, if it was answered, to increase the effectiveness of policies related to natural resource management in the United States. The publication comes as California suffers its worst drought in nearly half a century.

The question emerged from a previous collaboration among decision makers and scientists that yielded 40 research questions that most reflected the needs of those with jurisdiction over natural resources. That research also was published in BioScience.

The survey, by Dr Murray Rudd of the Environment Department at York and Dr Erica Fleishman, of the John Muir Institute of the Environment at UC Davis, asked managers, policymakers and their advisers, and scientists to rank the questions on the basis of their applicability to policy.  The 602 respondents included 194 policymakers, 70 government scientists, and 228 academic scientists.

Other questions that were ranked as of high importance to policy included those on methods for measuring the benefits humans receive from ecosystems; the effects of sea-level rise, storm surge, erosion and variable precipitation on coastal ecosystems and human communities; and the effect on carbon storage and ecosystem resilience of different management strategies for forests, grasslands, and agricultural systems .

Dr Rudd said, “We found a significant difference in research priorities between respondents. Importantly, there was no evidence of a simple science-policy divide. Priorities did not differ between academics and government employees or between scientists (academic and government) and policymakers.

“Our results suggest that participatory exercises such as this are a robust way of establishing priorities to guide funders of research and researchers who aim to inform policy.”

Dr Fleishman added, “The consensus in priorities is even more striking as California’s current drought leads to unprecedented reductions in water supply and delivery.”


Story Source:

The above story is based on materials provided by University of York. Note: Materials may be edited for content and length.


Journal Reference:

  1. Murray Rudd, Erica Fleishman. ‘Policymakers’ and Scientists’ Ranks of Research Priorities for Resource-Management Policy. BioScience, 2014 DOI: 10.1093/biosci/bit035

Citation:

University of York. “Water supply availability ‘to dominate U.S. natural resource management’.” ScienceDaily. ScienceDaily, 5 February 2014. www.sciencedaily.com/releases/2014/02/140205125411.htm

Filed Under: Water Conservation

Scientists Project Rainfall Frequency and Intensity Over Next 30 Years

March 24, 2014

University of Hawaii; 2011 – Manoa have projected an increased frequency of heavy rainfall events but a decrease in rainfall intensity during the next 30 years (2011-2040) for the southern shoreline of Oahu, according to a recent study published in the Journal of Geophysical Research.

178122558Chase Norton, a Meteorology Research Assistant at the School of Ocean and Earth Science and Technology (SOEST) at UH — Manoa, and colleagues (Professors Pao-Shin Chu and Thomas Schroeder) used a statistical model; rainfall data from rainfall gauges on Oahu, Hawaii; and a suite of General Circulation Models (GCMs) from the Intergovernmental Panel on Climate Change (IPCC) to project future patterns of heavy rainfall events on Oahu. GCMs play a pivotal role in the understanding of climate change and associated local changes in weather.

Heavy rainfall and flash floods are common in the Hawaiian Islands due to their steep terrain, rain‐producing weather systems, and abundant moisture supply. They have caused multimillion dollars damage to homes, properties, roads, agriculture, and other sectors. Environmentally, heavy rainfall and runoff events in Hawaii, which are likely to cause slope and coastal erosion, pollutant discharges to the near shore marine environment, coral reef degradation, among others, are expected to change as Earth undergoes an unprecedented warming. Given the socioeconomic repercussions resulting from past storm events, it is of considerable interest to investigate changes in the frequency and intensity of heavy rainfall events in Hawaii, particularly for Oahu, as it is the most populous island in Hawaii.

“The results presented in this study may benefit many agencies who are concerned with floods and relevant policy-making in the face of climate change,” says Chu, UH – Manoa Meteorology Professor, Hawaii State Climate Office Director, and co-author of the study. “For instance, changes in rainstorm intensity may be a serious consideration in aquifer management – as precipitation is the primary water source for streams and groundwater supply.”

Norton, Chu, and Schroeder would like to use the IPCC GCM simulations and extend the rainfall model to project future events in other locations. They also plan to use a high resolution regional climate model to project future changes in water resources in the Hawaiian Islands.


Story Source:

The above story is based on materials provided by University of Hawaii ‑ SOEST. Note: Materials may be edited for content and length.


Journal Reference:

  1. Chase W. Norton, Pao-Shin Chu, Thomas A. Schroeder. Projecting changes in future heavy rainfall events for Oahu, Hawaii: A statistical downscaling approach. Journal of Geophysical Research, 2011; 116 (D17) DOI: 10.1029/2011JD015641

Filed Under: Climate Change, Rainfall

US Groundwater Declines More Widespread Than Commonly Thought

March 24, 2014

Source; Columbia Water Center, 24 March 2014: Groundwater levels are dropping across a much wider swath of the United States than is generally discussed, according to a new report from the Columbia Water Center.

In addition to confirming alarming depletion in well-known hot spots such as the Great Plains and Central California, the study identifies a number of other regions, including the lower Mississippi, along the Eastern Seaboard and in the Southeast where water tables are falling just as rapidly. Overall, the report concludes, between 1949 and 2009 groundwater levels declined throughout much of the continental U.S., suggesting that the nation’s long-term pattern of groundwater use is broadly unsustainable.

Trends in groundwater levels observed between 1949 and 2009. Negative (red/orange) indicates decline in groundwater level, while positive (blue) indicates a rise in groundwater level. Source: Columbia Water Center

Trends in groundwater levels observed between 1949 and 2009. Negative (red/orange) indicates decline in groundwater level, while positive (blue) indicates a rise in groundwater level. Source: Columbia Water Center

The report was written as part of the Water Center’s new “America’s Water” initiative, a multidisciplinary program designed to bring together industry, government and academic experts to address the country’s looming water challenges.

According to Tess Russo, the study’s lead author, it is impossible to determine the exact volume of depletion for a particular aquifer without knowing its individual storage capacity. Nonetheless, it’s clear, she says, that “we’re using groundwater in an unsustainable way.”

“Management of groundwater needs to be addressed and rethought,” Russo adds. “I think one of the big points in this paper is to show that it’s something that should be addressed across more of the country than most people would think.”

underground-aquifier

In addition to suffering from a long drought, Central California is depleting its underground aquifers. Photo: Wikimedia Commons.

According to Russo, many previous studies of groundwater depletion have relied on groundwater flow models and extrapolation to estimate groundwater declines. By contrast, the new Water Center report directly analyzes county-level historical records of water table levels from 1949 to 2009.

“Groundwater depletion has been very well studied in the Ogallala [the Great Plains] and Central California, and to some extent other areas of the West, and parts of Texas,” says Russo. “But people don’t think of the lower Mississippi or the East Coast or the Southeast—outside of Florida—as being groundwater stressed areas. We tend to think of those areas as having abundant surface water, so we don’t really think that groundwater should be an issue.”

Access to groundwater is critical for regions that do not have access to surface water from lakes or rivers. And even in relatively wet areas, it can provide an important buffer during dry periods. In the United States, 40 percent of the population relies on underground aquifers for its supply of drinking water; groundwater also provides 60 percent of the water used to irrigate crops.

In dry regions where average precipitation is low, natural recharge of deep aquifers can be so slow that groundwater is essentially a non-renewable resource. Previous studies have suggested that in the High Plains Aquifer system water is being extracted at nearly 10 times the rate of recharge, resulting in the largest depletion of groundwater in the country.

As water tables fall, more and more energy is required to pump the water that remains. Eventually, with less water to support underground structures, aquifers can collapse, permanently reducing the amount of water they will ever store. Climate change adds additional risks; as rainfall patterns change across the Untied States, so will the rate at which underground aquifers recharge, potentially putting even more pressure on already-stressed regions.

The study found that for the most part, counties that have increased the amount of water they extract over time are also the most likely to see declines in groundwater levels. But, Russo, says, there were a surprising number of counties that did not follow that trend, and either saw groundwater levels rise in spite of increasing extraction, or saw water tables continue to fall even as extraction slowed.

In the first case, there may be a few areas where water is so abundant that even high levels of extraction do not draw down the supply—though it is difficult to know how long such practices can last, she says.

More concerning are areas that have continued to see water tables fall even as they have slowed the rate of extraction. “I would say for the counties where they’re slowing down their extraction, but still seeing groundwater declines, those are well-suited for more study, to figure out what’s going on, and to figure out how can they actually manage their groundwater, because it’s obviously more complicated than what they’re already doing,” says Russo.

Russo points to Suffolk County, Virginia—an area that receives relatively high annual rainfall— as an example of a place where groundwater levels are declining, in spite of reduced groundwater pumping. Historical data shows water tables falling at around 0.2 meters per year in almost all wells in the county, including those spanning a large depth range. Adjacent counties to the east and northwest are experiencing the same phenomena.

groundwater-extraction-rate

Despite being in an area with relatively high annual rainfall, groundwater in Suffolk County, Virginia is falling at an average of 0.2 meters per year. Source: Columbia Water Center.

groundwater-decline

Suffolk has seen groundwater fall steadily over time, in spite of a decline in groundwater use. Source: Columbia Water Center.

Groundwater declines in places like Suffolk and neighboring counties are particularly concerning, as they could lead to seawater intrusion, permanently contaminating coastal aquifers. Further analysis is needed, Russo says, to determine whether pumping rates are still too high to be sustainable, or whether groundwater declines are due to larger regional processes affecting groundwater availability.

In addition to comparing water extraction with groundwater declines, the study also analyzed the correlation between declining groundwater and short- and long-term climate variations. The authors found no correlation between water levels and short term climate variations, which was not surprising given that the study was limited to deep wells.

They did find a connection, however, between falling water tables and longer-term climate variations, particularly the Pacific Decadal Oscillation (PDO)—a kind of long-lived El Niño pattern of Pacific climate variability that has strong impacts on the North American climate.  The researchers found that a “positive” PDO signal corresponds to wetter periods and lower rates of groundwater decline—either because aquifers are getting recharged or because more available surface water decreases the need to extract water from underground.

Ultimately, Russo says, the most important outcome of the study may be to help direct more targeted research toward at-risk regions. “The results of this study could be used to inform future, smaller-scale studies,” she says, that look much more closely at the complicated dynamics of extraction and recharge in a particular area. These kinds of studies are very intensive, she says, requiring extensive measurements and modeling. “You don’t want to do that for the whole US — you can’t, really. So our study would say, if you’re going to do it, you should probably focus on the lower Mississippi, or the coast in South Carolina — that’s sort of the idea.”

Source: The Earth Institute Columbia University, original article by Lakis Polycarpou
http://blogs.ei.columbia.edu/2014/03/17/us-groundwater-declines-more-widespread-than-commonly-thought/

Filed Under: Groundwater

Documented Decrease in Frequency of Hawaii’s Northeast Trade Winds

March 24, 2014

Source: University of Hawaii ‑ SOEST, Date: October 2012:

Summary: Scientists have observed a decrease in the frequency of northeast trade winds and an increase in eastern trade winds over the past nearly four decades, according to a recent study.

Clouds and rain over Oahu Hawaii

Clouds and rain, as seen here over the island of Oahu, Hawaii, are influenced by trade wind patterns. Credit: Chris Ostrander – University of Hawaii at Manoa, SOEST

Scientists at University of Hawaii at Manoa (UHM) have observed a decrease in the frequency of northeast trade winds and an increase in eastern trade winds over the past nearly four decades, according to a recent study published in the Journal of Geophysical Research. For example, northeast trade wind days, which occurred 291 days per year 37 years ago at the Honolulu International Airport, now only occur 210 days per year.

Jessica Garza, a Meteorology Graduate Assistant at the School of Ocean and Earth Science and Technology (SOEST) at UHM; Pao-Shin Chu, Meteorology Professor and Head of the Hawaii State Climate Office; Chase Norton; and Thomas Schroeder analyzed 37 years of wind speed and direction, and sea level pressure data from land-based weather stations, buoys and reanalysis data.

Persistent northeast trade winds are important to the Hawaiian Islands because they affect wave height, cloud formation, and precipitation over specific areas of the region. When trades fail to develop the air can become dormant and unpleasant weather can develop.

Furthermore, Chu explained that the trades are the primary source of moisture for rain, and that a dramatic reduction could fundamentally change Hawai’i’s overall climate.  “We have seen more frequent drought in the Hawaiian Islands over the last 30 years,” he noted. “Precipitation associated with the moisture-laden northeasterly trades along the windward slopes of the islands contributes much of the overall rainfall in Hawaii.”

According to the National Drought Mitigation Center’s State Drought Monitor, nearly 50% of land in Hawaii has experienced some degree of drought during the past year.  While previous research has focused primarily on changes in trade wind intensities, this work, along with Chu’s 2010 study, is among the first to show changes in trade wind frequencies.

“In 2010, we only studied the trade wind changes at four major airports in Hawaii (Honolulu, Kahului, Hilo, and Lihue). In the current paper, we expanded our study to include four ocean buoys in the vicinity of Hawaii and a large portion of the North Pacific,” Chu commented.  In the future, these scientists will be using model simulated data to further understand the dynamics of rainfall and trade winds, and estimate future patterns.


Story Source:

The above story is based on materials provided by University of Hawaii ‑ SOEST. Note: Materials may be edited for content and length.


Journal Reference:

  1. Jessica A. Garza, Pao-Shin Chu, Chase W. Norton, Thomas A. Schroeder. Changes of the prevailing trade winds over the islands of Hawaii and the North Pacific. Journal of Geophysical Research, 2012; 117 (D11) DOI: 10.1029/2011JD016888

Filed Under: Climate Change, Rainfall

Storing Green Electricity as Natural Gas

March 24, 2014

Reuters May 5, 2010 — Renewable electricity can be transformed into a substitute for natural gas. Until now, electricity was generated from gas. Now, a German-Austrian cooperation wants to go in the opposite direction. In the future, these researchers and entrepreneurs would like to store surplus electricity — such as from wind power or solar energy — as climate-neutral methane, and store it in existing gas storage facilities and the natural gas network.


460589979Throughout the world, electricity generation is based more and more on wind and solar energy. So far, the missing link for integrating renewable energy into the electricity supply is a smart power storage concept. Because when the wind is blowing powerfully, wind turbines generate more electricity than the power grid can absorb. Now, German researchers have succeeded in storing renewable electricity as natural gas. They convert the electricity into synthetic natural gas with the aid of a new process. The process was developed by the Center for Solar Energy and Hydrogen Research Baden-Württemberg (ZSW), in cooperation with the Fraunhofer Institute for Wind Energy and Energy System Technology IWES. Currently, Solar Fuel Technology, the Austria-based partner company, is setting up the industrial implementation of the process. One advantage of the technology:it can use the existing natural gas infrastructure. A demonstration system built on behalf of Solar Fuel in Stuttgart is already operating successfully. By 2012, a substantially larger system — in the double-digit megawatt range — is planned to be launched.

For the first time, the process of natural gas production combines the technology for hydrogen-electrolysis with methanisation. “Our demonstration system in Stuttgart separates water from surplus renewable energy using electrolysis. The result is hydrogen and oxygen,” explains Dr. Michael Specht of ZSW. “A chemical reaction of hydrogen with carbon dioxide generates methane — and that is nothing other than natural gas, produced synthetically.”

With the rapid expansion of renewable energies, the need for new storage technologies grows massively. This is of special interest for energy utilities and power companies. “So far, we converted gas into electricity. Now we also think in the opposite direction, and convert electricity into ‘real natural’ gas,” explains Dr. Michael Sterner of Fraunhofer IWES, who is investigating engineering aspects and energy system analysis of the process. “Surplus wind and solar energy can be stored in this manner. During times of high wind speeds, wind turbines generate more power than is currently needed. This surplus energy is being more frequently reflected at the power exchange market through negative electricity prices.” In such cases, the new technology could soon keep green electricity in stock as natural gas or renewable methane.

“Within the development of this technology, ZSW has been guided by two core issues,” explains Michael Specht: “Which storage systems offer sufficient capacity for fluctuating renewable energies that depend on the wind and weather? And which storage systems can be integrated into the existing infrastructure the easiest?”

The storage reservoir of the natural gas network extending through Germany is vast: It equals more than 200 terawatt hours — enough to satisfy consumption for several months. The power network has only a capacity of 0.04 terawatt hours by itself. The integration into the infrastructure is simple: The natural gas substitute can be stored like conventional natural gas in the supply network, pipelines and storage systems, in order to drive natural gas cars or fire natural gas heating systems.

The new technology aims at facilitating the integration of high shares of fluctuating power generation from renewable energies into the energy system. One goal is to structure the delivery of power from wind parks on a scheduled and regular basis. “The new concept is a game changer and a new significant element for the integration of renewable energies into a sustainable energy system,” adds Sterner. The efficiency of converting power to gas equals more than 60 percent. “In our opinion, this is definitely better than a total loss,” says Michael Specht. A total loss looms if, for instance, wind power has to be curtailed. The predominant storage facility to date — pumped hydro power plants — can only be expanded to a limited extent in Germany.

In order to push the new energy conversion technology forward, the two German research institutes have joined together with the company Solar Fuel Technology of Salzburg. Starting in 2012, they intend to launch a system with a capacity of approximately 10 megawatt.

Filed Under: Renewable Energy, Water Technologies

Slider 2

March 17, 2014

Filed Under: Slider

Slider 3

March 16, 2014

Filed Under: Slider

Slider 1

March 10, 2014

Filed Under: Slider

About Hawaii First Water

This blog focuses on shaping water strategies for the Hawaiian Islands.

Articles

  • Families Demand Answers After Navy Water Main Breaks Near Pearl Harbor
  • The lawsuit over Hawaii’s Red Hill water contamination crisis has drawn in more than 100 new plaintiffs
  • Hawaii Postcards 2050
  • Visions of the Future, Part 2
  • Climate Change In Paradise 2050 Postcards; Visions of the Future?

Categories

  • Climate Change
  • Rainfall
  • Groundwater
  • Water Conservation
  • Water Technologies
  • Renewable Energy

Copyright © 2023 Hawaii First Water · Sitemap · Designed by Websites with Aloha · Log in