scholarly journals An assessment of long-term, multipurpose ecosystem functions and engineering benefits derived from historical dredged sediment beneficial use projects

2021 ◽  
Author(s):  
Jacob Berkowitz ◽  
Nathan Beane ◽  
Kevin Philley ◽  
Nia Hurst ◽  
Jacob Jung
Keyword(s):  
Management Strategies ◽  
Reference Conditions ◽  
Ecosystem Functions ◽  
Dredged Material ◽  
Beneficial Use ◽  
Shoreline Protection ◽  
Navigation Channel ◽  
Ecological Success ◽  
Time Frames

The beneficial use of dredged materials improves environmental outcomes while maximizing navigation benefits and minimizing costs, in accordance with the principles of the Engineering With Nature® (EWN) initiative. Yet, few studies document the long-term benefits of innovative dredged material management strategies or conduct comprehensive life-cycle analysis because of a combination of (1) short monitoring time frames and (2) the paucity of constructed projects that have reached ecological maturity. In response, we conducted an ecological functional and engineering benefit assessment of six historic (>40 years old) dredged material–supported habitat improvement projects where initial postconstruction beneficial use monitoring data was available. Conditions at natural reference locations were also documented to facilitate a comparison between natural and engineered landscape features. Results indicate the projects examined provide valuable habitat for a variety of species in addition to yielding a number of engineering (for example, shoreline protection) and other (for example, carbon storage) benefits. Our findings also suggest establishment of ecological success criteria should not overemphasize replicating reference conditions but remain focused on achieving specific ecological functions (that is, habitat and biogeochemical cycling) and engineering benefits (that is, storm surge reduction, navigation channel maintenance) achievable through project design and operational management.

Connecting Crop Nutrient Use Efficiency to Future Soil Productivity

2018 ◽  
Vol 102 (4) ◽  
pp. 8-10
Author(s):  
Fernando García ◽  
Andrés Grasso ◽  
María González Sanjuan ◽  
Adrián Correndo ◽  
Fernando Salvagiotti
Keyword(s):  
Nutrient Management ◽  
Nutrient Use Efficiency ◽  
Management Strategies ◽  
Crop Productivity ◽  
Soil Productivity ◽  
Nutrient Use ◽  
Grain Crop ◽  
Wide Scale ◽  
Use Efficiency

Trends over the past 25 years indicate that Argentina’s growth in its grain crop productivity has largely been supported by the depletion of the extensive fertility of its Pampean soils. Long-term research provides insight into sustainable nutrient management strategies ready for wide-scale adoption.

Serviços ecossistêmicos prestados por recifes de coral nas ilhas de Tinharé e Boipeba, Baixo Sul da Bahia, Brasil

2018 ◽  
Author(s):  
Carla Isobel Elliff
Keyword(s):  
Ecosystem Services ◽  
Coral Reefs ◽  
Current Model ◽  
Management Strategies ◽  
Environmental Indicators ◽  
Management Actions ◽  
Shoreline Protection ◽  
Fringing Reefs ◽  
Integrated Valuation ◽  
Reef Decline

Coral reefs provide important ecosystem services to coastal communities. The Archipelago of Tinhar?e andBoipeba, Bahia, Brazil, are mostly surrounded by fringing reefs, which have undergone several chronichuman impacts. The objective of the present study was to apply an ecosystem-based approach byanalyzing the ecosystem services provided by the coral reefs of the Archipelago of Tinhar?e and Boipeba inorder to support management actions and serve as a tool for coastal management. Ecosystem serviceswere assessed through the observation of environmental indicators of their occurrence and by using asuite of models from the Integrated Valuation of Environmental Services and Tradeoffs (InVEST) softwarecombined with data from the Atlantic and Gulf Rapid Reef Assessment (AGRRA) protocol database. Theservices of greatest occurrence were food provision, habitat maintenance, shoreline protection andrecreation. While the main stressful factors were tourism activities, the absence of a sewage system andfisheries. The coral reefs presented potential for shoreline protection along 50.5% of the islands. Moreover,46.8% of the shoreline would present moderate to high vulnerability in case of coral reef disappearance.The coincidence of areas with high risk of loss in the capacity to provide services and highvulnerability in the scenario of absence of reefs is concerning. Thus, the current model for tourism usedin the area should be altered, as should new management strategies be implemented, which can bringbenefits and avoid reef decline.

Petroclival meningiomas: long-term outcomes of multimodal treatments and management strategies based on 30 years of experience at a single institution

2020 ◽  
Vol 132 (6) ◽  
pp. 1675-1682 ◽  
Author(s):  
Jin Wook Kim ◽  
Hee-Won Jung ◽  
Yong Hwy Kim ◽  
Chul-Kee Park ◽  
Hyun-Tai Chung ◽  
...  
Keyword(s):  
Adjuvant Treatment ◽  
Management Strategies ◽  
Local Tumor Control ◽  
Tumor Control ◽  
Years Of Experience ◽  
Local Tumor ◽  
Long Term Outcomes ◽  
Single Institution ◽  
Petroclival Meningiomas

OBJECTIVEA thorough investigation of the long-term outcomes and chronological changes of multimodal treatments for petroclival meningiomas is required to establish optimal management strategies. The authors retrospectively reviewed the long-term clinical outcomes of patients with petroclival meningioma according to various treatments, including various surgical approaches, and they suggest treatment strategies based on 30 years of experience at a single institution.METHODSNinety-two patients with petroclival meningiomas were treated surgically at the authors’ institution from 1986 to 2015. Patient demographics, overall survival, local tumor control rates, and functional outcomes according to multimodal treatments, as well as chronological change in management strategies, were evaluated. The mean clinical and radiological follow-up periods were 121 months (range 1–368 months) and 105 months (range 1–348 months), respectively.RESULTSA posterior transpetrosal approach was most frequently selected and was followed in 44 patients (48%); a simple retrosigmoid approach, undertaken in 30 patients, was the second most common. The initial extent of resection and following adjuvant treatment modality were classified into 3 subgroups: gross-total resection (GTR) only in 13 patients; non-GTR treatment followed by adjuvant radiosurgery or radiation therapy (non-GTR+RS/RT) in 56 patients; and non-GTR without adjuvant treatment (non-GTR only) in 23 patients. The overall progression-free survival rate was 85.8% at 5 years and 81.2% at 10 years. Progression or recurrence rates according to each subgroup were 7.7%, 12.5%, and 30.4%, respectively.CONCLUSIONSThe authors’ preferred multimodal treatment strategy, that of planned incomplete resection and subsequent adjuvant radiosurgery, is a feasible option for the management of patients with large petroclival meningiomas, considering both local tumor control and postoperative quality of life.

Investigation of a New Approach to Predict Water Quality Extremes with a Case Study of Chemical Determinands in Stream Water

1991 ◽  
Vol 24 (6) ◽  
pp. 25-33
Author(s):  
A. J. Jakeman ◽  
P. G. Whitehead ◽  
A. Robson ◽  
J. A. Taylor ◽  
J. Bai
Keyword(s):  
Water Quality ◽  
Stream Water ◽  
Probability Distributions ◽  
Management Strategies ◽  
Hybrid Modelling ◽  
Trend Model ◽  
Environmental Extremes ◽  
Modelling Approach

The paper illustrates analysis of the assumptions of the statistical component of a hybrid modelling approach for predicting environmental extremes. This shows how to assess the applicability of the approach to water quality problems. The analysis involves data on stream acidity from the Birkenes catchment in Norway. The modelling approach is hybrid in that it uses: (1) a deterministic or process-based description to simulate (non-stationary) long term trend values of environmental variables, and (2) probability distributions which are superimposed on the trend values to characterise the frequency of shorter term concentrations. This permits assessment of management strategies and of sensitivity to climate variables by adjusting the values of major forcing variables in the trend model. Knowledge of the variability about the trend is provided by: (a) identification of an appropriate parametric form of the probability density function (pdf) of the environmental attribute (e.g. stream acidity variables) whose extremes are of interest, and (b) estimation of pdf parameters using the output of the trend model.

Relocation of dredged material from Hamburg harbour in the River Elbe

1998 ◽  
Vol 37 (6-7) ◽  
pp. 241-248 ◽  
Author(s):  
A. Netzband ◽  
H. Christiansen ◽  
B. Maaß ◽  
G. Werner
Keyword(s):  
Water Quality ◽  
Benthic Community ◽  
Dredged Material ◽  
Far Field ◽  
Beneficial Use ◽  
River Elbe ◽  
Operating Strategies ◽  
Material Circulation

Besides the beneficial use of dredged material, sustainable relocation, which means keeping the sediments in the natural aquatic material circulation, is one goal for handling dredged material in the port of Hamburg. Decreasing contamination the River Elbe and new dredged material guidelines provide a basis for this. With comprehensive investigations, near- and far-field transport and the effects of relocation regarding the water quality and the benthic community were determined thus deveoloping conditions for future operating strategies.

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