scholarly journals A river system modelling platform for Murray-Darling Basin, Australia

2012 ◽  
Vol 15 (4) ◽  
pp. 1109-1120 ◽  
Author(s):  
Ang Yang ◽  
Geoff Podger ◽  
Shane Seaton ◽  
Robert Power
Keyword(s):  
Time Series Data ◽  
Local Development ◽  
Global Climate ◽  
Sustainable Use ◽  
River System ◽  
Series Data ◽  
System Modelling ◽  
Hydrological Simulation ◽  
Modelling Framework ◽  
Murray Darling Basin

Global climate change and local development make water supply one of the most vulnerable sectors in Australia. The Australian government has therefore commissioned a series of projects to evaluate water availability and the sustainable use of water resources in Australia. This paper discusses a river system modelling platform that has been used in some of these nationally significant projects. The platform consists of three components: provenance, modelling engine and reporting database. The core component is the modelling engine, an agent-based hydrological simulation system called the Integrated River System Modelling Framework (IRSMF). All configuration information and inputs to IRSMF are recorded in the provenance component so that modelling processes can be reproduced and results audited. The reporting database is used to store key statistics and raw output time series data for selected key parameters. This river system modelling platform has for the first time modelled a river system at the basin level in Australia. It provides practitioners with a unique understanding of the characteristics and emergent behaviours of river systems at the basin level. Although the platform is purpose-built for the Murray-Darling Basin, it would be easy to apply it to other basins by using different river models to model agent behaviours.

Study on Global Burned Forest Areas Based on Landsat Data

2020 ◽  
Vol 86 (8) ◽  
pp. 503-508
Author(s):  
Zhaoming Zhang ◽  
Tengfei Long ◽  
Guojin He ◽  
Mingyue Wei ◽  
Chao Tang ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Forest Cover ◽  
Time Series Data ◽  
Global Climate ◽  
Distribution Patterns ◽  
Forest Degradation ◽  
Forest Monitoring ◽  
Series Data ◽  
Burned Area ◽  
Burned Forest

Forests are an extremely valuable natural resource for human development. Satellite remote sensing technology has been widely used in global and regional forest monitoring and management. Accurate data on forest degradation and disturbances due to forest fire is important to understand forest ecosystem health and forest cover conditions. For a long time, satellite-based global burned area products were only available at coarse native spatial resolution, which was difficult for detecting small and highly fragmented fires. In order to analyze global burned forest areas at finer spatial resolution, in this study a novel, multi-year 30 meter resolution global burned forest area product was generated and released based on Landsat time series data. Statistics indicate that in 2000, 2005, 2010, 2015, and 2018 the total area of burned forest land in the world was 94.14 million hm2, 96.65 million hm2, 59.52 million hm2, 76.42 million hm2, and 83.70 million hm2, respectively, with an average value of 82.09 million hm2. Spatial distribution patterns of global burned forest areas were investigated across different continents and climatic domains. It was found that burned forest areas were mainly distributed in Africa and Oceania, which accounted for approximately 73.85% and 6.81% of the globe, respectively. By climatic domain, the largest burned forest areas occurred in the tropics, with proportions between 88.44% and 95.05% of the world's total during the study period. Multi-year dynamic analysis shows the global burned forest areas varied considerably due to global climate anomalies, e.g., the La Niña phenomenon.

A commentary on 'Long-term ecological trends of flow-dependent ecosystems in a major regulated river basin', by Matthew J. Colloff, Peter Caley, Neil Saintilan, Carmel A. Pollino and Neville D. Crossman

2015 ◽  
Vol 66 (11) ◽  
pp. 970 ◽  
Author(s):  
Richard T. Kingsford ◽  
Ralph Mac Nally ◽  
Alison King ◽  
Keith F. Walker ◽  
Gilad Bino ◽  
...  
Keyword(s):  
Statistical Power ◽  
Time Series Data ◽  
Freshwater Ecosystems ◽  
Model Specification ◽  
Regulated River ◽  
Series Data ◽  
Adequate Model ◽  
Regime Changes ◽  
Murray Darling Basin

Colloff et al. in Marine and Freshwater Research (http:dx.doi.org/10.1071/MF14067) examined time-series data for flow-dependent vegetation, invertebrates, fish, frogs, reptiles and waterbirds in the Murray–Darling Basin, 1905–2013. They concluded that temporal patterns fluctuated, declining during droughts and recovering after floods. They suggested that major changes in land use in the late 19th century permanently modified these freshwater ecosystems, irretrievably degrading them before major water diversions. Restoring water to the environment might then be interpreted as not addressing biotic declines. We argue that their conclusions are inadequately supported, although data quality remains patchy and they neglected the influence of hydrology and the timing and extent of water resource development. We are critical of the lack of adequate model specification and the omission of statistical power analyses. We show that declines of native flow-dependent flora and fauna have continued through the 20th and early 21st centuries, in response to multiple factors, including long-term changes in flow regimes. We argue that flow-regime changes have been critical, but not in isolation. So, returning water to the environment is a prerequisite for sustained recovery but governments need to improve monitoring and analyses to adequately determine effectiveness of management of the rivers and wetlands of the Murray–Darling Basin.

scholarly journals Detection of Trend in Hydrologic Variables Using Non-Parametric Test: A Study on Surma River in Northeastern Bangladesh

2017 ◽  
Vol 9 (3) ◽  
pp. 277-284 ◽  
Author(s):  
M. S. Islam ◽  
M. B. Sikder
Keyword(s):  
Time Series Data ◽  
Sustainable Use ◽  
Kendall Test ◽  
Significant Trend ◽  
Series Data ◽  
Annual Maximum ◽  
Maximum Discharge ◽  
Management Scheme ◽  
Surma River ◽  
Non Parametric

An initiative has been taken to investigate the trends in discharge and water level (WL) of the Surma River in northeastern Bangladesh. The daily time series data of discharge and WL from two stations named Kanairghat and Sylhet with a period of 42 years (1973 – 2014) and 35 years (1980 – 2014) respectively have been analyzed. Non parametric Mann-Kendall Test has been applied to detect the trend and Sen’s slope estimator is used to measure the slope of the trends. In Kanairghat station, annual mean WL has significant trend (P: 0.03); while, annual mean discharge, mean monsoon discharge, annual maximum discharge, mean monsoon WL, and annual maximum WL shows insignificant trend (P: 0.24, 0.46, 0.14, 0.05, and 0.12). In Sylhet station, annual mean discharge, annual maximum discharge, and annual mean WL have significant trend (P: 0.03, 0.004, and 0.02). In other hand, mean monsoon discharge, mean monsoon WL, and annual maximum WL in Sylhet station has insignificant trend (P: 0.46, 0.13, and 0.21). According to Sen’s slope statistics, all of the detected trends, except annual maximum WL at Sylhet station, are downward. This study recommends a comprehensive water management scheme should be taken to ensure sustainable use of the river water.

Start Time Control of Micro Gas Turbine CHP System With Heat Storage

2011 ◽  
Author(s):  
Osamu Kurata ◽  
Norihiko Iki ◽  
Takayuki Matsunuma ◽  
Tetsuhiko Maeda ◽  
Satoshi Hirano ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Room Temperature ◽  
High Efficiency ◽  
Heat Storage ◽  
Time Series Data ◽  
Global Climate ◽  
Series Data ◽  
Start Time ◽  
Micro Gas Turbine ◽  
Chp System

Combined heat and power (CHP) systems are widely used considering the prevention of global climate change and the reduction of energy costs. In distributed CHP systems, both high efficiency of elements and good coordination of the systems are considered as the points to solve. We had been researched and demonstrated the micro gas turbine CHP system with heat storage at Sapporo City University from April 2006 to March 2010. At first, the start times of microturbine (MGT) and heat storage system (HST) was set up by schedule timers. In 2008 the schedule timers were substituted to a new programmable logic controller (PLC) and the start times of MGT and HST were calculated as the function of temperature outside and room temperature. Setting the start time of MGT at maximum 5 hours before 8:00 and interlocking relays of HST on MGT, the start times were calculated from temperature outside and room temperature at 21:00 the day before. Control of start time using PLC was demonstrated from Feb. 21, 2009 to June 1 and from Nov. 16 to Jan. 7, 2010. It is shown the time series data of temperature and analysis of the CHP with the original boiler heating system.

scholarly journals Conceptual design of a measurement network of the global change

2015 ◽  
Vol 15 (15) ◽  
pp. 21063-21093 ◽  
Author(s):  
P. Hari ◽  
T. Petäjä ◽  
J. Bäck ◽  
V.-M. Kerminen ◽  
H. K. Lappalainen ◽  
...  
Keyword(s):  
Conceptual Design ◽  
Driving Forces ◽  
Global Climate ◽  
Spatial Scales ◽  
Sustainable Use ◽  
Water Security ◽  
System Modelling ◽  
Observation Network ◽  
Characteristic Features ◽  
Energy And Momentum

Abstract. The global environment is changing rapidly due to anthropogenic emissions and actions. Such activities modify aerosol and greenhouse gas concentrations in the atmosphere, leading to regional and global climate change and affecting e.g. food and fresh-water security, sustainable use of natural resources and even demography. Here we present a conceptual design of a global, hierarchical observation network that can provide tools and increased understanding to tackle the inter-connected environmental and societal challenges that we will face in the coming decades. The philosophy behind the conceptual design relies on physical conservation laws of mass, energy and momentum, as well as on concentration gradients that act as driving forces for the atmosphere-biosphere exchange. The network is composed of standard, flux/advanced and flagship stations, each of which having specific and identified tasks. Each ecosystem type on the globe has its own characteristic features that have to be taken into consideration. The hierarchical network as a whole is able to tackle problems related to large spatial scales, heterogeneity of ecosystems and their complexity. The most comprehensive observations are envisioned to occur in flag ship stations, with which the process-level understanding can be expanded to continental and global scales together with advanced data analysis, earth system modelling and satellite remote sensing. The denser network of the flux and standard stations allow application and up-scaling of the results obtained from flag ship stations to the global level.

scholarly journals Comparative Angler Catches of Australian Bass (Macquaria novemaculeata) in Three Major River Systems in New South Wales, Australia

2005 ◽  
Vol 18 (2) ◽  
Author(s):  
B. VAN DER WALT ◽  
R. A. FARAGHER ◽  
J. HARRIS
Keyword(s):  
Time Series Data ◽  
New South ◽  
New South Wales ◽  
River System ◽  
Size Composition ◽  
Series Data ◽  
Severe Drought ◽  
Catch Per Unit Effort ◽  
South Wales ◽  
Catch Rates

A joint program between New South Wales Fisheries and three fishing clubs was initiated in 1988 with the aim of collecting standardised catch and effort data during biannual fishing competitions on three major rivers in New South Wales. This paper examines the data to determine trends in the catch of the target species, Australian bass (Macquaria novemaculeata) and to evaluate whether the data can be used to assess Australian bass populations over time. Distinct trends in Australian bass mean length in each river system were evident but catch rates were more variable. Median catch per unit effort was similar (mostly between 0.5 and 1.5 Australian bass·h-1 ) in the Nepean and Williams Rivers although catch rates in the Manning River were nearly always zero. There was an increasing trend in the mean length of Australian bass in all three rivers, possibly representing a recovery in fish populations following severe drought from 1979 to 1983. Low or zero catch rates were continually recorded in the Manning River and size composition data indicated a lack of recruitment through most of the study period. The standardised format of the data collection program provided qualitative and reliable time series data allowing the determination of long-term trends in the population structure of Australian bass which can be used for monitoring and management purposes.

scholarly journals Using GENIE to study a tipping point in the climate system

2008 ◽  
Vol 367 (1890) ◽  
pp. 871-884 ◽  
Author(s):  
Timothy M Lenton ◽  
Richard J Myerscough ◽  
Robert Marsh ◽  
Valerie N Livina ◽  
Andrew R Price ◽  
...  
Keyword(s):  
Thermohaline Circulation ◽  
Time Series Data ◽  
Three Dimensional ◽  
Tipping Point ◽  
Climate System ◽  
Climate Forcing ◽  
Series Data ◽  
Model Parameters ◽  
System Modelling ◽  
Stable States

We have used the Grid ENabled Integrated Earth system modelling framework to study the archetypal example of a tipping point in the climate system; a threshold for the collapse of the Atlantic thermohaline circulation (THC). eScience has been invaluable in this work and we explain how we have made it work for us. Two stable states of the THC have been found to coexist, under the same boundary conditions, in a hierarchy of models. The climate forcing required to collapse the THC and the reversibility or irreversibility of such a collapse depends on uncertain model parameters. Automated methods have been used to assimilate observational data to constrain the pertinent parameters. Anthropogenic climate forcing leads to a robust weakening of the THC and increases the probability of crossing a THC tipping point, but some ensemble members collapse readily, whereas others are extremely resistant. Hence, we test general methods that have been developed to directly diagnose, from time-series data, the proximity of a ‘tipping element’, such as the THC to a bifurcation point. In a three-dimensional ocean–atmosphere model exhibiting THC hysteresis, despite high variability in the THC driven by the dynamical atmosphere, some early warning of an approaching tipping point appears possible.

scholarly journals A convergence based assessment of relative differences in age-stratified susceptibility and infectiousness for SARS-CoV-2 variants of B.1.1.7 lineage

2021 ◽  
Author(s):  
Sarah Dean Rasmussen
Keyword(s):  
Time Series ◽  
Environmental Effects ◽  
Total Population ◽  
Time Series Data ◽  
Relative Increase ◽  
Series Data ◽  
Gene Target ◽  
Modelling Framework ◽  
Time Period ◽  
Relative Differences

We propose (a) a method for aggregating and processing age-stratified subregional time series data for positive tests of infection given partial sampling for variant-of-concern biomarkers, and (b) a simple model-based theoretical framework for interpreting these processed data, to assess whether observed heterogeneity in age-specific relative differences can be explained by environmental effects alone. We then apply this strategy to public-domain subregional time series data with S-gene target failure (SGTF) sampling as a proxy for B.1.1.7 lineage, from weeks 45 to 50 of 2020 from England. For the time period in question, we observe convergence toward a 1.27 (95% CI 1.17-1.38) times higher ratio of SGTF to non-SGTF infection for 0-9-year-olds than for the total population, and a 1.16 (95% CI 1.09-1.23) times higher ratio for 10-19-year-olds. These are roughly comparable to previous findings, but this time we find high significance evidence for adequate compatibility with our proposed modelling framework criteria to conclude that these relative elevations for 0-19-year-olds are very unlikely to be explained by environmental effects alone. We also find possible indications that 0-19-year-olds might experience a higher relative increase in infectiousness than susceptibility for B.1.1.7.

scholarly journals How far climate change affects the Indonesian paddy production and rice price volatility?

2017 ◽  
Vol 1 (1) ◽  
pp. 1 ◽  
Author(s):  
Silvia Sari Busnita, Rina Oktaviani, Tanti Novianti
Keyword(s):  
Climate Change ◽  
Time Series Data ◽  
Global Climate ◽  
Price Volatility ◽  
Series Data ◽  
Security Issue ◽  
Price Fluctuation ◽  
Long Run ◽  
Rice Price ◽  
The Impact

Food security issue after 2008 global-crisis is something relate with the climate change phenomenon which had worsened on the last few decades. The impact of global climate change can be seen from the fluctuation of main crops production yield in tropical countries. This has affected the food price fluctuations particularly on the grain price, both international and domestic markets. The rice-commodity, known for its thin market characteristics, is now also experiencing the fluctuation of production, its productivity and also the rice price. Considering the importance of rice as the main staple food in Indonesia, the purpose of this research is to identify the Indonesia’s rice price fluctuation (volatility) and to investigate how far climate change affects the Indonesian paddy production and rice price volatility. By applying monthly time-series data from 2007 to 2014, this research used ARCH-GARCH methods to find out the rice price volatility and VECM (Vector Error Correction Model) to investigate the impact of climate change phenomenon on the Indonesian paddy production, as well as rice price volatility both in the short-run and long-run. The result is important for the stakeholders and government in preventing the risk and uncertainty condition of paddy production and rice price fluctuation caused by climate change

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