scholarly journals The role of forests in regulating water: The Turkey Lakes Watershed case study

2005 ◽  
Vol 81 (1) ◽  
pp. 142-148 ◽  
Author(s):  
N W Foster ◽  
F D Beall ◽  
D P Kreutzweiser
Keyword(s):  
Water Quality ◽  
Acid Rain ◽  
Surface Waters ◽  
Large Scale ◽  
Water Yield ◽  
Research Approach ◽  
Management Decisions ◽  
Turkey Lakes Watershed

Long-term experimental catchment studies, applied to relatively undisturbed ecosystems, provide reliable hydrologic data that are highly relevant to forest management decisions on water supply and quality. A number of large-scale, long term catchment studies have been conducted in North America to examine these linkages and processes in support of watershed management decisions. Among these the Turkey Lakes Watershed (TLW), a rare example of a long-term fully integrated examination of the biology and chemistry of the atmosphere, forests, soils, streams, and lakes, is presented as a case study. Multi-agency, interdisciplinary research at the TLW, which has strong links nationally and internationally, has included hydrological studies, examination of landscape influences on nutrient export to surface waters, and impacts of catchment disturbance on water yield, nutrient flux, carbon cycling, and sedimentation in streams. Application of partial cut harvest systems in the TLW tolerant hardwood forest resulted in reduced runoff and improved water quality (sediment, nitrate and calcium concentrations) relative to clearcut harvest. Twenty years after the initiation of reductions in atmospheric S emissions losses of SO42- from some headwater basins remain high and there is little evidence of acidification recovery in TLW surface waters. The TLW research approach can be used globally to scientifically assess how natural and human actions affect the important services provided by forested watersheds. For example, TLW results have contributed to international policy on acid rain reductions and air quality agreements. Key words: forest hydrology, water quality, hydrochemistry, forest disturbance, forest harvest, acid rain

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.

scholarly journals A Combined Approach for Model-Based PV Power Plant Failure Detection and Diagnostic

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1261
Author(s):  
Christopher Gradwohl ◽  
Vesna Dimitrievska ◽  
Federico Pittino ◽  
Wolfgang Muehleisen ◽  
András Montvay ◽  
...  
Keyword(s):  
Power Plants ◽  
Large Scale ◽  
Failure Detection ◽  
Energy Yield ◽  
Combined Approach ◽  
Levelized Cost Of Electricity ◽  
Term Operation ◽  
Model Based

Photovoltaic (PV) technology allows large-scale investments in a renewable power-generating system at a competitive levelized cost of electricity (LCOE) and with a low environmental impact. Large-scale PV installations operate in a highly competitive market environment where even small performance losses have a high impact on profit margins. Therefore, operation at maximum performance is the key for long-term profitability. This can be achieved by advanced performance monitoring and instant or gradual failure detection methodologies. We present in this paper a combined approach on model-based fault detection by means of physical and statistical models and failure diagnosis based on physics of failure. Both approaches contribute to optimized PV plant operation and maintenance based on typically available supervisory control and data acquisition (SCADA) data. The failure detection and diagnosis capabilities were demonstrated in a case study based on six years of SCADA data from a PV plant in Slovenia. In this case study, underperforming values of the inverters of the PV plant were reliably detected and possible root causes were identified. Our work has led us to conclude that the combined approach can contribute to an efficient and long-term operation of photovoltaic power plants with a maximum energy yield and can be applied to the monitoring of photovoltaic plants.

scholarly journals ENVIRONMENTAL POLLUTION BY WASTEWATER FROM BROWN COAL PROCESSING ¬ A REMEDIATION CASE STUDY IN GERMANY

2014 ◽  
Vol 22 (1) ◽  
pp. 71-83 ◽  
Author(s):  
Arndt Wiessner ◽  
Jochen A. Müller ◽  
Peter Kuschk ◽  
Uwe Kappelmeyer ◽  
Matthias Kästner ◽  
...  
Keyword(s):  
Environmental Pollution ◽  
Large Scale ◽  
Pilot Scale ◽  
Wastewater Disposal ◽  
Interdisciplinary Approaches ◽  
Phenolic Wastewater ◽  
Term Monitoring

The large scale of the contamination by the former carbo-chemical industry in Germany requires new and often interdisciplinary approaches for performing an economically sustainable remediation. For example, a highly toxic and dark-colored phenolic wastewater from a lignite pyrolysis factory was filled into a former open-cast pit, forming a large wastewater disposal pond. This caused an extensive environmental pollution, calling for an ecologically and economically acceptable strategy for remediation. Laboratory-scale investigations and pilot-scale tests were carried out. The result was the development of a strategy for an implementation of full-scale enhanced in situ natural attenuation on the basis of separate habitats in a meromictic pond. Long-term monitoring of the chemical and biological dynamics of the pond demonstrates the metamorphosis of a former highly polluted industrial waste deposition into a nature-integrated ecosystem with reduced danger for the environment, and confirmed the strategy for the chosen remediation management.

scholarly journals TO THE QUESTION OF COMPREHENSIVE ASSESSMENT OF SURFACE WATER IN THE CENTRAL CAUCASUS DURING WINTER BETWEEN AND SUMMER FLOOD

2021 ◽  
Vol 6 (5(55)) ◽  
pp. 22-27
Author(s):  
Liliya Zuberovna Zhinzhakova ◽  
Elena Alexandrovna Cherednik
Keyword(s):  
Water Quality ◽  
Surface Waters ◽  
Inorganic Nitrogen ◽  
High Water ◽  
Polluted Water ◽  
Trace Impurities ◽  
Central Caucasus ◽  
Summer Flood

Based on long-term observations, the assessment of the pollution of the rivers of the Central Caucasus was carried out by comparing the calculated coefficients of the complexity of pollution and the specific combinatorial index of pollution of surface waters, and the quality classes were determined. The results of chemical analysis of the concentration levels of trace impurities (Mo, Pb, Zn, V, Ni, Cr, Mn, Ag) and inorganic nitrogen compounds (NO2 -, NO3 — and NH4 +) in the waters of 13 rivers in two permanent sections of each watercourse were used. The results of calculating the indicators of pollution in the waters of rivers of winter low water and summer high water are presented. The most polluted watercourses and the frequency of pollution in each river are identified, estimated by the values of the specific combinatorial index of water pollution, the coefficient of complexity of pollution, and the class of water quality is presented. The assessment of the most polluted water bodies during the winter low-water period and summer flood is given according to the classification of water quality. According to long-term observations, the features of watercourses and their differences in terms of pollution are presented.

Numerical Modelling of a District Scale Groundwater Heat Pump Operation: Case Study from Colchester, UK

2021 ◽  
Author(s):  
Taha Sezer ◽  
Abubakar Kawuwa Sani ◽  
Rao Martand Singh ◽  
David P. Boon
Keyword(s):  
Large Scale ◽  
District Level ◽  
Thermal Plume ◽  
Injection Wells ◽  
Term Operation ◽  
Heating And Cooling ◽  
Groundwater Heat Pump ◽  
The Impact

<p>Groundwater heat pumps (GWHP) are an environmentally friendly and highly efficient low carbon heating technology that can benefit from low-temperature groundwater sources lying in the shallow depths to provide heating and cooling to buildings. However, the utilisation of groundwater for heating and cooling, especially in large scale (district level), can create a thermal plume around injection wells. If a plume reaches the production well this may result in a decrease in the system performance or even failure in the long-term operation. This research aims to investigate the impact of GWHP usage in district-level heating by using a numerical approach and considering a GWHP system being constructed in Colchester, UK as a case study, which will be the largest GWHP system in the UK. Transient 3D simulations have been performed pre-construction to investigate the long-term effect of injecting water at 5°C, into a chalk bedrock aquifer. Modelling suggests a thermal plume develops but does not reach the production wells after 10 years of operation. The model result can be attributed to the low hydraulic gradient, assumed lack of interconnecting fractures, and large (>500m) spacing between the production and injection wells. Model validation may be possible after a period operational monitoring.</p>

scholarly journals Challenges in modelling isoprene and monoterpene emission dynamics of Arctic plants: a case study from a subarctic tundra heath

2016 ◽  
Vol 13 (24) ◽  
pp. 6651-6667 ◽  
Author(s):  
Jing Tang ◽  
Guy Schurgers ◽  
Hanna Valolahti ◽  
Patrick Faubert ◽  
Päivi Tiiva ◽  
...  
Keyword(s):  
Response Curve ◽  
Large Scale ◽  
Ecosystem Model ◽  
The Arctic ◽  
Short Term ◽  
Response Curves ◽  
Arctic Plants ◽  
Scale Modelling

Abstract. The Arctic is warming at twice the global average speed, and the warming-induced increases in biogenic volatile organic compounds (BVOCs) emissions from Arctic plants are expected to be drastic. The current global models' estimations of minimal BVOC emissions from the Arctic are based on very few observations and have been challenged increasingly by field data. This study applied a dynamic ecosystem model, LPJ-GUESS, as a platform to investigate short-term and long-term BVOC emission responses to Arctic climate warming. Field observations in a subarctic tundra heath with long-term (13-year) warming treatments were extensively used for parameterizing and evaluating BVOC-related processes (photosynthesis, emission responses to temperature and vegetation composition). We propose an adjusted temperature (T) response curve for Arctic plants with much stronger T sensitivity than the commonly used algorithms for large-scale modelling. The simulated emission responses to 2 °C warming between the adjusted and original T response curves were evaluated against the observed warming responses (WRs) at short-term scales. Moreover, the model responses to warming by 4 and 8 °C were also investigated as a sensitivity test. The model showed reasonable agreement to the observed vegetation CO2 fluxes in the main growing season as well as day-to-day variability of isoprene and monoterpene emissions. The observed relatively high WRs were better captured by the adjusted T response curve than by the common one. During 1999–2012, the modelled annual mean isoprene and monoterpene emissions were 20 and 8 mg C m−2 yr−1, with an increase by 55 and 57 % for 2 °C summertime warming, respectively. Warming by 4 and 8 °C for the same period further elevated isoprene emission for all years, but the impacts on monoterpene emissions levelled off during the last few years. At hour-day scale, the WRs seem to be strongly impacted by canopy air T, while at the day–year scale, the WRs are a combined effect of plant functional type (PFT) dynamics and instantaneous BVOC responses to warming. The identified challenges in estimating Arctic BVOC emissions are (1) correct leaf T estimation, (2) PFT parameterization accounting for plant emission features as well as physiological responses to warming, and (3) representation of long-term vegetation changes in the past and the future.

scholarly journals South Africa’s Community Work Programme: Local Peacebuilding Innovation Within a National Developmental Architecture

2019 ◽  
Vol 14 (1) ◽  
pp. 49-62
Author(s):  
Hugo van der Merwe ◽  
Malose Langa
Keyword(s):  
Large Scale ◽  
Public Employment ◽  
Local Ownership ◽  
Community Work ◽  
Employment Sector ◽  
Local Actors ◽  
Work Programme ◽  
Local Safety

This article examines South Africa’s Community Work Programme (CWP) as a case study of an attempt to address two key dilemmas facing peacebuilding theory and practise: (a) balancing the need to address immediate and long-term causes of conflict and violence and (b) balancing the need for a large-scale systematic approach whilst creating space for local ownership and agency. Drawing on in-depth case studies of six CWP community interventions, it demonstrates how this national public employment sector programme has been shaped into a vehicle for peacebuilding by local actors. Whilst these initiatives still face resistance to local ownership and innovation, they demonstrate how local agency can integrate national developmental priorities with local safety and security priorities.

Implementing the Challenger Sales Model at Cars.com: a case study

2019 ◽  
Vol 34 (2) ◽  
pp. 291-302 ◽  
Author(s):  
Mathew S. Isaac ◽  
Ajay T. Abraham ◽  
Elaine Y. Richards
Keyword(s):  
Large Scale ◽  
Academic Research ◽  
Vice President ◽  
Sales Force ◽  
Research Approach ◽  
Successful Implementation ◽  
Content Type ◽  
Sales Teams ◽  
Sales Model

Purpose The purpose of this paper is to review the recent implementation of the Challenger Sales Model (CSM) at Cars.com, an online automotive marketplace that generated $633m in sales in 2016 with a sales force of over 500 representatives, and to identify insights related to the implementation that may be relevant to sales researchers and other organizations considering similar implementations. A more specific aim is to determine whether establishing “constructive tension” between salespeople and their customers, which is a key tenet of the CSM, was perceived as a source of value for Cars.com. Design/methodology/approach The case study is based primarily on in-depth interviews with 15 employees spanning different sales and/or training responsibilities in the organization, from the current CEO (previously the former Senior Vice President of Sales) to sales representatives from different sales teams. Findings Five major insights emerged from this research: (1) Because it represents a change in the established norms governing interpersonal dynamics, constructive tension is often more difficult for salespeople to foster when interacting with existing (vs prospective) customers. (2) Whereas leading with insights is more difficult when interacting with prospective (vs existing) customers, sustaining meaningful insights over time is a major challenge when dealing with existing customers. (3 )Products that are more transactional or price-driven are ineffective at creating constructive tension and incompatible with the CSM. (4) Creating value from constructive tension requires the entire sales organization to share a common vision of what it means to be a Challenger and to adopt consistent nomenclature and formal programs for training and coaching. (5) Even more than other consultative sales models, the successful implementation of the CSM demands company-wide integration and makes it untenable for most indirect sales teams. Originality/value Although prior academic research has offered critiques of the CSM, the present paper is one of the first to use a discovery-oriented, qualitative research approach to provide a retrospective look at the actual implementation of the CSM within an organization. This approach results in novel insights, such as the identification of conditions when high-pressure versus low-pressure selling techniques are likely to be more successful, that may be of interest to sales researchers and to other companies considering a large-scale implementation of the CSM or related sales methodologies.

scholarly journals Major Lessons From Large-Scale Trap Cropping Demonstrations for Pest Reduction in Vegetables

2019 ◽  
Vol 112 (4) ◽  
pp. 298-301 ◽  
Author(s):  
Ayanava Majumdar ◽  
Matthew Price
Keyword(s):  
Large Scale ◽  
Insect Pests ◽  
Research Approach ◽  
Vegetable Production ◽  
Trap Crop ◽  
Trap Crops ◽  
Trap Cropping ◽  
Small Plot ◽  
Participatory Research Approach

Abstract Vegetable production in the Southeast is always at high risk from insect pests. Alternative integrated pest management (IPM) systems have to be effective in small plot as well as at the farming scale. This article explores the recent studies on large-scale trap crops using single or multiple cultivars and innovative layouts for long-term pest reduction. Trap crops must be planned carefully under high pest pressure and drought conditions along with an insecticide use strategy that minimizes external inputs and conserves natural enemies. Through participatory research approach, trap crop systems continue to evolve into practical solutions for the vegetable producers.

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