Possible Effects of Forestry on Inland Waters of Tasmania: A Review

1984 ◽  
Vol 11 (4) ◽  
pp. 331-344 ◽  
Author(s):  
Frances B. Michaelis
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Field Studies ◽  
Physical Structure ◽  
Inorganic Materials ◽  
Water Yield ◽  
Inland Waters ◽  
Political Debate ◽  
Harvesting Method ◽  
The Impact

Considerable public and political debate over the environmental consequences of large-scale operations associated with Tasmania's export forest industries prompted the present review and continuing field-studies. There are no known publications on the effect of forestry on inland waters of Tasmania, but relevant research in the Northern Hemisphere, the Australian mainland, and New Zealand, is summarized.Forest operations considered are roading, logging, and burning. In general, roading increases water-yield, reduces water quality, and modifies the physical structure of streams—particularly at bridge-sites. The impact of logging depends on the harvesting method used (generally, tractor and skidder-logging in Tasmania), the proportion of trees felled, the proportion of the catchment logged, and the precautions taken. However, stream-flows, sediment loads, nutrient levels, dissolved inorganic materials, and wood debris, all increase with logging. If riparian vegetation is cut, water temperature usually increases in summer and decreases slightly in winter, but temperature tolerances of most aquatic animals in Tasmania remain unknown. The effects of burning Australian forests are poorly understood, but there are changes in water-yield and a decrease in water quality.

Forming Canonical 8D Data Clouds to Explore the Transient Dynamics of Physical Stiffened Plates: A Machine Learning Approach for Complex Mechanical Structures

2020 ◽  
Author(s):  
Ioannis T. Georgiou
Keyword(s):  
Machine Learning ◽  
Large Scale ◽  
Complex Structure ◽  
Spatial Dimension ◽  
Physical Structure ◽  
Transient Dynamics ◽  
Alloy Plate ◽  
Considerable Uncertainty ◽  
Acceleration Signal ◽  
The Impact

Abstract This work presents a data-driven explorative study of the physics of the dynamics of a physical structure of complicated geometry. The geometric complexity of the physical system renders the typical single sensor acceleration signal quite complicated for a physics interpretation. We need the spatial dimension to resolve the single sensory signal over its entire time horizon. Thus we are introducing the spatial dimension by the canonical eight-dimensional data cloud (Canonical 8D-Data Cloud) concept to build methods to explore the impact-induced free dynamics of physical complex mechanical structures. The complex structure in this study is a large scale aluminum alloy plate stiffened by a frame made of T-section beams. The Canonical 8D-Data Cloud is identified with the simultaneous acceleration measurements by eight piezoelectric sensors equally spaced and attached on the periphery of a circular material curve drawn on the uniform surface of the stiffened plate. The Data Cloud approach leads to a systematic exploration-discovery-quantification of uncertainty in this physical complex structure. It is found that considerable uncertainty is stemming from the sensitivity of transient dynamics on the parameters of space-time localized force pulses, the latter being used as a means to diagnose the presence of structural anomalies. The Data Cloud approach leads to aspects of machine learning such as reduced dynamics analytics of big sensory data by means of heavenly machine-assisted computations to carry out the unparalleled data reduction analysis enabled by the Advanced Proper Orthogonal Decomposition Transform. Emphasized is the connection between the characteristic geometric features of high-dimensional datasets as a whole, the Data Cloud, and the modal physics of the dynamics.

scholarly journals Hydrological Alteration Index as an Indicator of the Calibration Complexity of Water Quantity and Quality Modeling in the Context of Global Change

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 115 ◽  
Author(s):  
Roxelane Cakir ◽  
Mélanie Raimonet ◽  
Sabine Sauvage ◽  
Javier Paredes-Arquiola ◽  
Youen Grusson ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Water Resources ◽  
Stream Water ◽  
Swat Model ◽  
Water Yield ◽  
Observation Data ◽  
Hydrological Alteration ◽  
Water Quality And Quantity ◽  
The Impact

Modeling is a useful way to understand human and climate change impacts on the water resources of agricultural watersheds. Calibration and validation methodologies are crucial in forecasting assessments. This study explores the best calibration methodology depending on the level of hydrological alteration due to human-derived stressors. The Soil and Water Assessment Tool (SWAT) model is used to evaluate hydrology in South-West Europe in a context of intensive agriculture and water scarcity. The Index of Hydrological Alteration (IHA) is calculated using discharge observation data. A comparison of two SWAT calibration methodologies are done; a conventional calibration (CC) based on recorded in-stream water quality and quantity and an additional calibration (AC) adding crop managements practices. Even if the water quality and quantity trends are similar between CC and AC, water balance, irrigation and crop yields are different. In the context of rainfall decrease, water yield decreases in both CC and AC, while crop productions present opposite trends (+33% in CC and −31% in AC). Hydrological performance between CC and AC is correlated to IHA: When the level of IHA is under 80%, AC methodology is necessary. The combination of both calibrations appears essential to better constrain the model and to forecast the impact of climate change or anthropogenic influences on water resources.

scholarly journals Impact of network sectorisation on water quality management

2017 ◽  
Vol 20 (2) ◽  
pp. 424-439 ◽  
Author(s):  
Hooman Armand ◽  
Ivan Stoianov ◽  
Nigel Graham
Keyword(s):  
Water Quality ◽  
Large Scale ◽  
Water Quality Management ◽  
Cost Effective ◽  
Pressure Control ◽  
Supply Networks ◽  
Potential Impact ◽  
And Control ◽  
The Impact ◽  
Hydraulic Variables

Abstract The sectorisation of water supply networks (WSNs) includes the permanent closure of valves in order to achieve a cost-effective leakage management and simplify pressure control. The impact of networks sectorisation, also known as district metered areas (DMAs), on water quality and discolouration has not been extensively studied and it remains unknown. In addition, hydraulic variables used in the literature for assessing the likelihood of potential discolouration are limited and inconclusive. This paper investigates a methodology to evaluate the impact of networks sectorisation (DMAs) on water quality and the likelihood of discolouration incidents. The methodology utilises a set of surrogate hydraulic variables and an analysis of the hydraulic condition in pipes with historic discolouration complaints. The proposed methodology has been applied to a large-scale WSN, with and without sectors, in order to assess the potential impact of DMAs on water quality. The results demonstrate that the sectorisation of WSN (DMAs) could compromise the overall water quality and increase the likelihood of discolouration incidents. The results of this study and the proposed surrogate hydraulic variables facilitate the formulation of optimisation problems for the re-design and control of WSNs with sectorised topologies.

scholarly journals Impact of increasing vegetarian availability on meal selection and sales in cafeterias

2019 ◽  
Vol 116 (42) ◽  
pp. 20923-20929 ◽  
Author(s):  
Emma E. Garnett ◽  
Andrew Balmford ◽  
Chris Sandbrook ◽  
Mark A. Pilling ◽  
Theresa M. Marteau
Keyword(s):  
Large Scale ◽  
Population Level ◽  
Field Studies ◽  
Individual Level ◽  
Rebound Effects ◽  
Percentage Points ◽  
Physical Environments ◽  
Meat Meal ◽  
Level Data ◽  
The Impact

Shifting people in higher income countries toward more plant-based diets would protect the natural environment and improve population health. Research in other domains suggests altering the physical environments in which people make decisions (“nudging”) holds promise for achieving socially desirable behavior change. Here, we examine the impact of attempting to nudge meal selection by increasing the proportion of vegetarian meals offered in a year-long large-scale series of observational and experimental field studies. Anonymized individual-level data from 94,644 meals purchased in 2017 were collected from 3 cafeterias at an English university. Doubling the proportion of vegetarian meals available from 25 to 50% (e.g., from 1 in 4 to 2 in 4 options) increased vegetarian meal sales (and decreased meat meal sales) by 14.9 and 14.5 percentage points in the observational study (2 cafeterias) and by 7.8 percentage points in the experimental study (1 cafeteria), equivalent to proportional increases in vegetarian meal sales of 61.8%, 78.8%, and 40.8%, respectively. Linking sales data to participants’ previous meal purchases revealed that the largest effects were found in the quartile of diners with the lowest prior levels of vegetarian meal selection. Moreover, serving more vegetarian options had little impact on overall sales and did not lead to detectable rebound effects: Vegetarian sales were not lower at other mealtimes. These results provide robust evidence to support the potential for simple changes to catering practices to make an important contribution to achieving more sustainable diets at the population level.

scholarly journals Detection and attribution of global change effects on river nutrient dynamics in a large Mediterranean basin

2015 ◽  
Vol 12 (13) ◽  
pp. 4085-4098 ◽  
Author(s):  
R. Aguilera ◽  
R. Marcé ◽  
S. Sabater
Keyword(s):  
Water Quality ◽  
Time Series ◽  
Global Change ◽  
Large Scale ◽  
Nutrient Dynamics ◽  
Anthropogenic Impacts ◽  
Spatial Scales ◽  
Phosphate Concentration ◽  
Dynamic Factor ◽  
The Impact

Abstract. Attributing changes in river water quality to specific factors is challenging because multiple factors act at different temporal and spatial scales, and it often requires examining long-term series of continuous data. Data consistency is sometimes hindered by the lack of observations of relevant water quality variables and the low and uneven sampling frequency that characterizes many water quality monitoring schemes. Nitrate and dissolved phosphate concentration time series (1980–2011) from 50 sampling stations across a large Mediterranean river basin were analyzed to disentangle the role of hydrology, land-use practices, and global climatic phenomena on the observed nutrient patterns, with the final aim of understanding how the different aspects of global change affected nutrient dynamics in the basin. Dynamic factor analysis (DFA) provided the methodological framework to extract underlying common patterns in nutrient time series with missing observations. Using complementary methods such as frequency and trend analyses, we sought to further characterize the common patterns and identify the drivers behind their variability across time and space. Seasonal and other cyclic patterns were identified as well as trends of increase or decrease of nutrient concentration in particular areas of the basin. Overall, the impact of global change, which includes both climate change and anthropogenic impacts, on the dynamics of nitrate concentration across the study basin was found to be a multifaceted process including regional and global factors, such as climatic oscillations and agricultural irrigation practices, whereas impacts on phosphate concentration seemed to depend more on local impacts, such as urban and industrial activities, and less on large-scale factors.

scholarly journals Assessment of water quality and state of waterbasins of different types from characteristics of benthic animal communities

2016 ◽  
Vol 320 (3) ◽  
pp. 262-279
Author(s):  
E.V. Balushkina
Keyword(s):  
Water Quality ◽  
Primary Production ◽  
Large Scale ◽  
Structural Parameters ◽  
Benthic Communities ◽  
River Estuary ◽  
Neva River ◽  
Relationship Of ◽  
The Impact ◽  
Neva Bay

Studies on waterbasins of different type have shown the impact of eutrophication and pollution by toxic and organic matter on the structural and functional characteristics of zoobenthos. A major factor determining quantitative development of non-predatory zoobenthos in lakes is, undoubtedly, the level of development of primary producers. Relationship of zoobenthos biomass and primary production is particularly pronounced in shallow lakes. Analysis of relationship of zoobenthos with abiotic and biotic factors in shallow hyperhaline lakes of Crimea has shown that the most significant parameters determining the values of biomass of macrozoobenthos were salinity and primary production, second in significance were oxygen concentration and depth. The changes in structure and quantitative characteristics of benthic communities of the Neva River estuary occur under impact of a complex combination of organic and toxic pollution. For the assessment of water quality and state of ecosystem in the Neva River estuary we used IP' integrated index specially devised by us for water-bodies and watercourses of north-western Russia. It is based on structural parameters of zoobenthic communities and makes it possible to take into consideration pollution with toxic and organic substances. On average the water quality of the Neva Bay judging from IP' values was relatively stable during 1982–2014. It was assessed as “polluted” with exception for abnormality in 2006 (“polluted–dirty”) caused by large-scale dredging work. As a result of stronger pollution, species diversity of benthic animals in the Resort District of the eastern part of the Gulf of Finland is lower than in the Neva Bay.

Defining a cold pool-resolving scale for numerical simulations of convective self-organisation

2021 ◽  
Author(s):  
Romain Fiévet ◽  
Bettina Meyer ◽  
Jan Olaf Haerter
Keyword(s):  
Numerical Simulations ◽  
Large Scale ◽  
Field Studies ◽  
Cold Pool ◽  
Small Scale ◽  
Convective Systems ◽  
Mesoscale Convective ◽  
Gust Fronts ◽  
Self Organisation ◽  
The Impact

<p>Spontaneous aggregation of clouds is a puzzling phenomenon observed in field studies [Holloway et al. (2017)] and idealized simulations alike [Held et al. (1993), Bretherton et al. (2005)]. With its relevance to climate sensitivity and extreme events, aggregation continues to be heavily studied, [Wing et al., 2017 for a review], with radiative-convective feedbacks emerging as main drivers of simulated convective self-aggregation (CSA) [Mueller & Bony (2015)].</p><p>In state-of-the art cloud-resolving models, CSA finds itself consistently hampered by finer horizontal resolutions [Muller & Held (2012), Yanase et al. (2020)]. This feature was ascribed to the effect of cold pool (CP) gust fronts in opposing the positive moisture feedback underlying CSA [Jeevanjee & Romps (2013)]. In contrast, recent numerical experiments [Haerter et al. (2020)] with diurnally oscillating surface temperature highlights an orthogonal effect: stronger CPs, driven by small-scale density gradients, promote cloud field self-organization into mesoscale convective systems (MCS). Interestingly, this upscale growth, which we here term diurnal self-organisation (DSO), differs from classical CSA as it is driven by CPs rather than large-scale radiative imbalances. In stark contrast to CSA, strengthening CPs promotes this organization effect.</p><p>Hence, numerical simulations of CSA and DSO should go beyond the typical cloud-resolving paradigm and achieve cold pool-resolving capabilities. The current study systematically examines the impact of model resolution on CP effects. First, numerical convergence is probed in a 12km x 20km laterally periodic domain where a single CP propagates and self-collides at the domain's edges. As the spatial resolution is stepwise increased from 250 to 25m, it is shown that the initially coarsely resolved density current dissipates and collision and updraft effects are weak. As finer resolution is approached, we identify a cold pool resolving resolution D, which is deemed satisfactory for propagation and collision properties. Second, convergence for a (250km)2 domain under a diurnal radiative cycle is assessed at various spatial resolutions, including the scale D. This mesoscale configuration allows us to quantify the impact of resolution of cold pool dynamics on DSO.</p><p>Together, this work systematically lays out the numerical requirements to study mesoscale clustering by means of explicit numerical simulations.</p>

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

Sign in / Sign up

Export Citation Format

Share Document