Taichung, Taiwan
Taichung, Taiwan

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Hilton R.G.,CNRS Paris Institute of Global Physics | Hilton R.G.,Durham University | Galy A.,University of Cambridge | Hovius N.,University of Cambridge | And 2 more authors.
Geology | Year: 2011

Mountain building exposes fossil organic carbon (OCfossil) in exhumed sedimentary rocks. Oxidation of this material releases carbon dioxide from long-term geological storage to the atmosphere. OCfossil is mobilized on hillslopes by mass wasting and transferred to the particulate load of rivers. In large fluvial systems, it is thought to be oxidised in transit, but in short, steep rivers that drain mountain islands, OCfossil may escape oxidation and re-enter geological storage due to rapid fluvial transfer to the ocean. In these settings, the rates of OCfossil transfer and their controls remain poorly constrained. Here we quantify the erosion of OCfossil from the Taiwan mountain belt, combining discharge statistics with measurements of particulate organic carbon load and source in 11 rivers. Annual OCfossil yields in Taiwan vary from 12 ± 1 to 246 ± 22 tC km-2 yr-1, controlled by the high physical erosion rates that accompany rapid crustal shortening and frequent typhoon impacts. Efficient transfer of this material ensures that 1.3 ± 0.1 × 106 tC yr-1 of OCfossil exhumed in Taiwan is delivered to the ocean, with <15% loss due to weathering in transit. Our findings suggest that erosion of coastal mountain ranges can force efficient transfer and long-term re-accumulation of OCfossil in marine sediments, further enhancing the role of mountain building in the long-term storage of carbon in the lithosphere. © 2011 Geological Society of America.


Chang F.-J.,National Taiwan University | Tsai W.-P.,National Taiwan University | Chen H.-K.,Water Resources Agency | Yam R.S.W.,National Taiwan University | Herricks E.E.,University of Illinois at Urbana - Champaign
Journal of Hydrology | Year: 2013

In aquatic ecosystems, particularly rivers, hydrology plays a key role in structuring and maintaining habitats and flow regimes that influence ecological sustainability. Flow regime assessment in Taiwan has been facilitated recently by the Taiwan Eco-hydrologic Indicator System (TEIS). In this study, the self-organizing feature map (SOM) and radial basis function (RBF) neural network are combined to produce a self-organizing radial basis network (SORBN) that takes the advantages of both methods for strengthening the power of presentation and reliability of estimation. The SORBN is proposed to estimate the diversity of fish communities based on the TEIS and historic fish community composition at 36 locations in Taiwan. The discharge data are available for a minimum of 20. years. Data analysis applying a moving average method to the TEIS statistics is used to reflect the effects of antecedent flow conditions on fish diversity. Results indicate the hybrid SORBN not only effectively categorizes stream flow data but also reasonably identifies relationships between flow regime and fish community diversity. Results are encouraging so that it is possible to better relate flow and ecosystem conditions, and the proposed method can be used to quantify how flow influences river ecosystems. © 2012 Elsevier B.V.


Hilton R.G.,Durham University | Galy A.,University of Cambridge | Hovius N.,University of Cambridge | Kao S.-J.,Academia Sinica, Taiwan | And 2 more authors.
Global Biogeochemical Cycles | Year: 2012

Erosion of particulate organic carbon (POC) occurs at very high rates in mountain river catchments, yet the proportion derived recently from atmospheric CO2 in the terrestrial biosphere (POCnon-fossil) remains poorly constrained. Here we examine the transport of POCnon-fossil in mountain rivers of Taiwan and its climatic and geomorphic controls. In 11 catchments we have combined previous geochemical quantification of POC source (accounting for fossil POC from bedrock), with measurements of water discharge (Qw) and suspended sediment concentration over 2 years. In these catchments, POCnon-fossil concentration (mg L-1) was positively correlated with Qw, with enhanced loads at high flow attributed to rainfall driven supply of POCnon-fossil from forested hillslopes. This climatic control on POCnon-fossil transport was moderated by catchment geomorphology: the gradient of a linear relation of POCnon-fossil concentration and Qw increased as the proportion of steep hillslopes (>35) in the catchment increased. The data suggest enhanced supply of POCnon-fossil by erosion processes which act most efficiently on the steepest sections of forest. Across Taiwan, POC non-fossil yield was correlated with suspended sediment yield, with a mean of 21 10 tC km-2 yr-1. At this rate, export of POCnon-fossil imparts an upper bound on the time available for biospheric growth, of ∼800 yr. Over longer time periods, POC non-fossil transferred with large amounts of clastic sediment can contribute to sequestration of atmospheric CO2 if buried in marine sediments. Our results show that this carbon transfer should be enhanced in a wetter and stormier climate, and the rates moderated on geological timescales by the regional tectonic setting. © 2012. American Geophysical Union. All Rights Reserved.


SAN FRANCISCO--(BUSINESS WIRE)--An 18-acre wetland in Castroville was re-flooded today through a partnership between the Monterey County Water Resources Agency, Central Coast Wetlands Group (CCWG) at Moss Landing Marine Labs and Pacific Gas and Electric Company (PG&E). The restored wetland will provide an ecosystem that will be able to naturally clean 80,000 gallons of surface water for the community every day. “Wetlands provide important natural resources for our communities, create natural habitats for wildlife, native plants and clean water, remove pollution and help to combat the effects of climate change,” said CCWG Director Ross Clark. The wetland is part of the Moro Cojo Slough watershed. Water is being pumped from the Castroville Ditch, which drains approximately 600 acres of land farmed predominantly in artichokes and Brussels sprouts. The water is then gravity-fed through a channel that provides a habitat for wetland plants. These plants will remove nitrates, naturally filtering and cleaning the water. Coastal Conservation and Research grew and has planted 30,000 native wetland plants. Bridget Hoover, water quality protection program director for the Monterey Bay National Marine Sanctuary, said, “Wetlands are a natural filter that help to improve the quality of water that flows through watersheds by removing contaminants, such as nutrients, fecal bacteria, pesticides, and metals that pollute our ocean. This wetland will be a tremendous resource for the Monterey Bay.” The California State Water Resources Control Board provided Proposition 84 grant funding to construct the project. The land was provided by PG&E. In 1996, Moss Landing Marine Labs and PG&E partnered to restore an 11-acre wetland adjacent to this site. Earlier this year, PG&E Corporation contributed $250,000 to the successful Measure AA for a Clean and Healthy Bay campaign that will fund the restoration of 15,000 acres of San Francisco Bay Area wetlands. “PG&E is committed to continuing to protect California’s unique ecosystems, an important part of our strong and enduring commitment to the environment. This wetland will directly benefit our customers by providing this community with clean surface water and a restored ecosystem,” said PG&E Vice President of Safety, Health and Environment Andy Williams. After water flow is restored, additional native plants and seeds will be planted over the next two years. Scientists will monitor the downstream water to evaluate the success of the project, and later the site will be made available to train students and agricultural professionals. Moss Landing Marine Laboratories (MLML) administers the Master of Science in marine science program for California State Universities in northern and central California, and is dedicated to the pursuit of excellence in both education and research. CCWG is a wetland research group at Moss Landing Marine Labs serving the Central Coast of California. CCWG works closely with regional and state partners to expand wetland science and develop collaborative wetland enhancement opportunities among resource managers, policy makers and the agriculture industry. Pacific Gas and Electric Company, a subsidiary of PG&E Corporation (NYSE:PCG), is one of the largest combined natural gas and electric energy companies in the United States. Based in San Francisco, with more than 20,000 employees, the company delivers some of the nation’s cleanest energy to nearly 16 million people in Northern and Central California. For more information, visit www.pge.com/ and pge.com/news.


Hilton R.G.,CNRS Paris Institute of Global Physics | Hilton R.G.,University of Cambridge | Galy A.,University of Cambridge | Hovius N.,University of Cambridge | And 2 more authors.
Geochimica et Cosmochimica Acta | Year: 2010

Small rivers draining mountain islands are important in the transfer of terrestrial particulate organic carbon (POC) to the oceans. This input has implications for the geochemical stratigraphic record. We have investigated the stable isotopic composition of POC (δ13Corg) in rivers draining the mountains of Taiwan. In 15 rivers, the suspended load has a mean δ13Corg that ranges from - 28.1±0.8‰ to - 22.0±0.2‰ (on average 37 samples per river) over the interval of our study. To investigate this variability we have supplemented suspended load data with measurements of POC in bedrock and river bed materials, and constraints on the composition of the terrestrial biomass. Fossil POC in bedrock has a range in δ13Corg from - 25.4±1.5‰ to - 19.7±2.3‰ between the major geological formations. Using coupled δ13Corg and N/C we have found evidence in the suspended load for mixing of fossil POC with non-fossil POC from the biosphere. In two rivers outside the Taiwan Central Range anthropogenic land use appears to influence δ13Corg, resulting in more variable and lower values than elsewhere. In all other catchments, we have found that 5‰ variability in δ13Corg is not controlled by the variable composition of the biomass, but instead by heterogeneous fossil POC.In order to quantify the fraction of suspended load POC derived from non-fossil sources (Fnf) as well as the isotopic composition of fossil POC (δ13Cfossil) carried by rivers, we adapt an end-member mixing model. River suspended sediments and bed sediments indicate that mixing of fossil POC results in a negative trend between N/C and δ13Corg that is distinct from the addition of non-fossil POC, collapsing multiple fossil POC end-members onto a single mixing trend. As an independent test of the model, Fnf reproduces the fraction modern (Fmod) in our samples, determined from 14C measurements, to within 0.09 at the 95% confidence level. Over the sampling period, the mean Fnf of suspended load POC was low (0.29 ± 0.02, n=459), in agreement with observations from other mountain rivers where physical erosion rates are high and fossil POC enters river channels. The mean δ13Cfossil in suspended POC varied between - 25.2±0.5‰ and - 20.2±0.6‰ from catchment to catchment. This variability is primarily controlled by the distribution of the major geological formations. It also covers entirely the range of δ13Corg found in marine sediments which is commonly thought to derive from mixing between marine and terrigenous POC. If land-sourced POC is preserved in marine sediments, then changes in the bulk δ13Corg observed offshore Taiwan could instead be explained by changes in the onshore provenance of sediment. The range in δ13Corg of fossil organic matter in sedimentary rocks exposed at the surface is large and given the importance of these rocks as a source of clastic sediment to the oceans, care should be taken in accounting for fossil POC in marine deposits supplied by active mountain belts. © 2010.


Hovius N.,University of Cambridge | Meunier P.,CNRS ENS Geology Laboratory | Lin C.-W.,National Cheng Kung University | Chen H.,National Taiwan University | And 4 more authors.
Earth and Planetary Science Letters | Year: 2011

Large earthquakes deform the Earth's surface and drive topographic growth in the frontal zones of mountain belts. They also induce widespread mass wasting, reducing relief. The sum of these two opposing effects is unknown. Using a time series of landslide maps and suspended sediment transport data, we show that the MW7.6 Chi-Chi earthquake in Taiwan was followed by a period of enhanced mass wasting and fluvial sediment evacuation, peaking at more than five times the background rate and returning progressively to pre-earthquake levels in about six years. Therefore it is now possible to calculate the mass balance and topographic effect of the earthquake. The Choshui River has removed sediment representing more than 30% of the added rock mass from the epicentral area. This has resulted in a reduction of surface uplift by up to 0.25m, or 35% of local elevation change, and a reduction of the area where the Chi-Chi earthquake has built topography. For other large earthquakes, erosion may evolve in similar, predictable ways, reducing the efficiency of mountain building in fold-and-thrust belts and the topographic expression of seismogenic faults, prolonging the risk of triggered processes, and impeding economic regeneration of epicentral areas. © 2011 Elsevier B.V.


News Article | February 15, 2017
Site: www.prweb.com

The American Water Resources Association (AWRA), the premier non-governmental organization dedicated to the advancement of multidisciplinary water resources management and research, is pleased to announce that Rafael Frias, III, client director with the global water business of Black & Veatch Corporation, began his tenure as national president of the organization on January 1, 2017. He succeeds Martha Corrozi Narvaez, associate policy scientist, University of Delaware Water Resources Agency, who transitioned to her role as immediate past-president. When asked about his goals in the next year, Frias responded, “I’m very proud to be part of AWRA and to have the privilege to lead this great organization during 2017. As we move forward, I look to continue to increase the value we provide to our members. AWRA is about our members and how they can leverage the organization for professional development and growth.” AWRA is also happy to confirm that Brenda O. Bateman, senior public policy coordinator for the Oregon Water Resources Department assumed her seat as president-elect at that time, as did newly elected National Board of Directors members Sharon Megdal, University of Arizona and Jared Bales, Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI). “I am so honored to be entrusted with this role,” commented Bateman when asked her reaction to being voted president-elect. “AWRA has a great reputation as a professional organization, but it is my family as well. I hope to continue the tradition of leadership that Rafael Frias, Martha Narvaez, and others before me have demonstrated, building a healthy and valuable organization.” The following officers and directors began their terms of service on January 1, 2017: President – Rafael E. Frias III, Black & Veatch, Coral Springs, FL President-Elect – Brenda O. Bateman, Oregon Water Resources Department, Salem, OR Director – Sharon Megdal, University of Arizona, Tuscon, AZ Director – Jared Bales, Consortium of Universities for the Advancement of Hydrologic Science (CUAHSI), Arlington, MA Continuing their remaining terms as AWRA Board members for 2017 are: Past-President – Martha Corrozi Narvaez, University of Delaware, Newark, DE Secretary-Treasurer – Noel Gollehon, USDA-NRCS, Beltsville, MD Director – Betsy Cody, Congressional Research Service, Washington, DC Director – Laurel Stadjuhar, West Sage Water Consultants, Denver, CO Director – Lisa Beutler, MWH Global a part of Stantec, Sacramento, CA Director – Wayne S. Wright, Stantec, Seattle, WA For more information on AWRA’s Officers and Board of Directors, including bios., visit the Board of Directors page on the AWRA website. About AWRA Since 1964, American Water Resources Association has been dedicated to the advancement of water resources management, research and education, as well as a balanced approach toward solving water resources challenges. AWRA’s membership is comprised of professionals who share a common interest in working and learning across a wide range of disciplines focused on water resources policy, practice and education. Visit AWRA.


Lai Y.G.,Bureau of Reclamation | Greimann B.P.,Bureau of Reclamation | Wu K.,Water Resources Agency
Journal of Hydraulic Engineering | Year: 2011

Many rivers in Taiwan have steep slopes, are subject to typhoon-induced flood flows, and contain soft bedrock that is exposed at many locations and easily erodible. The occurrence of extensive bedrock erosion has been a major threat to river infrastructure at many locations. Soft bedrock erosion, therefore, is an important process to consider for river projects in Taiwan. In this study, bedrock erosion models are reviewed. A specific model is proposed by combining two existing models incorporating both the hydraulic and abrasive scour mechanisms. The proposed bedrock erosion model is incorporated into a two-dimensional mobile-bed model, and the integrated model is tested by simulating bedrock erosion downstream of the Chi-Chi weir on the Choshui River in Taiwan. A calibration study is performed to determine appropriate values of the model parameters based on two and a half years of measured data. The model is then assessed based on a verification study that compares model predictions of bedrock erosion of the same reach to two additional years of measured data. The bedrock erosion model is found to be suitable for the river reach studied. Further improvement, however, is still necessary, which points to potential future research. © 2011 American Society of Civil Engineers.


Cheng S.-J.,Diwan University | Lee C.-F.,Diwan University | Lee J.-H.,Water Resources Agency
Water Resources Management | Year: 2010

This study mainly explores effects of urbanization factors on hydrograph parameters. Urbanization impacts of the developing watershed are evaluated based on rainfall-runoff simulations. A total of 51 rainfall-runoff events occurred from 1966 to 2002. Forty of these were calibrated, and effects of urbanization factors on runoff hydrographs resulting from a simple hydrological model were assessed. The block Kriging method was used to estimate the mean rainfall of the Wu-Tu watershed, and its hourly excesses were calculated by using the non-linear programming method. The remaining 11 cases were used to test the established relationships. The calibration and verification results confirm that the integral methods used in this study effectively illustrate the hydrological and geomorphic conditions in complex urbanization processes. Parameter n responds more sensitively than parameter k to increasing impervious areas and population densities. Additionally, parameter n responds more strongly to imperviousness than to population. Therefore, an impervious area is an important reference for analyzing hydrological changes of urbanization in the Wu-Tu watershed. © Springer Science+Business Media B.V. 2009.


Patent
Water Resources Agency | Date: 2013-09-24

A method for controlling pumping of a plurality of pump units in a wet well is disclosed. The method uses a genetic algorithm to determine which of the pump units is to be started and its initial operating frequency when the liquid level in the wet well reaches a first predetermined level for pumping. During the pumping process, the pumping control method monitors the liquid level in the wet well in real time to obtain real-time state information and fine-adjusts the initial operating frequency of the pump unit to be started according to the real-time state information. Therefore, the present disclosure achieves optimum efficiency and energy saving.

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