136 research outputs found
Linking land cover and species distribution models to project potential ranges of malaria vectors: an example using Anopheles arabiensis in Sudan and Upper Egypt
Climate change in the Middle East and North Africa (MENA) region and implications for water resources project planning and management
Purpose – To assess the extent of climate change likely to be manifested in the MENA region using statistical tools as well as outputs from physics-based General Circulation Models (GCMs). The application of two diverse approaches and their comparisons should develop greater confidence and understanding of the climate change process among water resources planners and practitioners to respond judiciously in adopting mitigation and adaptation measures. Design/methodology/approach – Atmospheric temperature and precipitation primarily capture climate change features and are considered the drivers of other manifestations of climate change such as rises in sea-level, tropical cyclone intensities, severe floods, prolonged droughts, and retreating ice. Data on atmospheric temperature and precipitation have been statistically analysed for trend, distribution and variability in this study. Long-range prediction is then made using time series analysis. Long-range projections have also been made by many investigators using physics-based GCMs and the Fourth Assessment Report of IPCC provides a summary. IPCC projections are not indisputable because of some inherent limitations of GCMs. A comparative study is made between statistical predictions and IPCC projections, as well as forecasts from some GCMs specifically applied to the region, to develop a more reliable forecast scenario. Water resources projects are quite vulnerable to changes in atmospheric temperature and precipitation amounts. The various aspects of planning, design and management of water resources projects which are likely to be influenced by climate change are discussed. Findings – There is considerable variability in atmospheric temperature and precipitation in recent observations but if the variability is filtered out and the underlying trend extrapolated it is found that there is in general an agreement between IPCC projections and statistical predictions. For rise in atmospheric temperature projections made from many GCMs applied to the region, as well as projections summarised in the Fourth Assessment Report of IPCC, appear to be good estimates to be included in design considerations. For precipitation, statistical predictions are perhaps a better choice because GCM projections are less reliable with precipitation since associated meteorological processes occur at a much smaller scale than the grid size of a GCM. For low-lying coastal regions sea-level rise and more frequent extreme climatic events such as tropical cyclones add to the dimensionality of design considerations especially for infrastructure design. Originality/value – This paper presents a comparative study of possible climate change in the long-term between physics-based model projections and statistical predictions. This should provide greater insight into climate change that is expected in MENA and reduce uncertainty, thereby instilling greater confidence in water resources planners and practitioners to incorporate climate change aspects into decision making. This research is believed to be particularly helpful because of scanty research work done on this part of the globe on climate change
Sustainability in large-scale water resources project planning
Large-scale water resources projects are essentially irreversible human interventions of nature usually requiring huge amount of public investment and affecting large segment of population. It is therefore imperative rather ethical that any such project proposal is thoroughly scrutinised before implementation.The universally accepted criteria for judging the suitability of a large-scale water resources project are economic development, social equity and environmental sustainability. Economic development focuses on monetized gains that the project would deliver, social equity ensures a fair share of water resources to each member of communities in project area, and environmental sustainability aims at preserving the vital components of the resources of the current generation for making these resources available for use by the future generation
Why did the road close for Traveston Crossing dam?
The paper explores the socio-political forces that prevented the construction of Australia's greenest dam, the Traveston Crossing Dam
Optimisation of average rainfall estimation using copulas
Average rainfall estimation over a watershed can be viewed as a multivariate problem. Multivariate distributions are difficult to work with for estimation and decision making especially when the individual variables do not have Gaussian distributions. The complexity of the problem can be considerably reduced by using the technique of copulas, whereby working with marginal distributions computations are simplified to the level of univariate case. In this paper the copula functions are explored and illustrated with a specific application to rainfall estimation of a small catchment in Western Australia
Path analysis technique for strategic irrigation management under adverse climatic conditions
Wasimi, SA ORCiD: 0000-0002-3647-2080Path analysis is a statistical technique widely used for modeling causation among a set of variables. A path diagram sets out the plausible causal relationships, and the path coefficients estimated by solving the relevant structural equations determine the strength of the relationships. The path diagram can be used to assess the change required in one variable to counteract the effect of another variable or several variables. In particular, a path diagram can be used to determine the timing, duration, and rate of irrigation to a crop to compensate for the effects of unfavourable climatic conditions. However, such an approach would assume other factors like soil fertility, microbial activities, and cultural practices to be time invariant. A path diagram has advantages over crop models in that a crop model cannot account for uncertainty, and the latter is restrictive to the particular field conditions in which it has been developed and has been criticised for its inability to be readily translated into regional parameters where the climatic variables are more stable.The study area in which such a path analysis technique has been applied is the Fitzroy river catchment in Central Queensland, Australia. The region has a semi-arid climate. The four major crops grown in the area are wheat, barley, cotton, and sunflower. The critical stages for the yield of these four crops, as reported in published literature, are planting time, flowering time, and harvesting time significantly influenced by the minimum, average, and maximum values of rainfall, temperature, and humidity. Water stress in wheat reduces the duration of grain filling. High temperature adversely affects germination and seedling emergence and reduces grain number/spike and grain weight of wheat. High humidity is known to cause stem rust and leaf rust problems in wheat plants. Climatic requirements for optimal yields of wheat and barley are different. Cotton also requires different climatic conditions for good yield. Cotton is a long-season crop which needs over 160 days with temperatures above 150C and adequate sunshine during the growing season. It can tolerate moderate salinity levels, and therefore, can be irrigated by brackish water or return flows. Sunflower production faces major problems with excess rainfall or moisture. Rust infection is a great concern for sunflower production which is favoured by heavy dews, wet weather, and temperatures above 200C. The path analysis technique applied to the Fitzroy region’s historic data yielded four different models for the four crops. Each model captures the range of optimal climatic variables and provides coefficients for the degree of adjustment required in the endogenous variable (irrigation supply) due to deviations in the exogenous variable(s). Each model can be used to plan the irrigation management strategy to offset the effects when one or more of the climatic variables deviate from ideal conditions. The climate information is available daily from the Bureau of Meteorology, Queensland
Optimisation of average rainfall estimation using copulas
Average rainfall estimation over a watershed can be viewed as a multivariate problem. Multivariate distributions are difficult to work with for estimation and decision making especially when the individual variables do not have Gaussian distributions. The complexity of the problem can be considerably reduced by using the technique of copulas, whereby working with marginal distributions computations are simplified to the level of univariate case. In this paper the copula functions are explored and illustrated with a specific application to rainfall estimation of a small catchment in Western Australia
Identification of e-commerce driving forces in MENA countries and their relevance in policy formulations
E-commerce has been the mainstay of e-economy with the advancement of internet. Worldwide growth of e-commerce has been around 13 percent since 2010. It is high time that MENA nations develop good policies on e-commerce, and review those dynamically due to rapidly changing digital landscape, taking into account the interplay of the driving forces. In broad terms, the driving forces in e-commerce comprise high quality services and social trust given the culture. Services include availability, reliability and performance of web services; infrastructure and institutional framework for prompt delivery of goods; and efficient online payment services across currencies, borders and languages. Social trust includes creditworthiness of the vendors and their marketing strategy alignment with the culture of the society encompassing traits, norms, habits, hedonic motivation, generation divide, etc. Thus, there are technological aspects as well as cultural aspects. In order to promote e-commerce in MENA countries, this study suggests that the technological aspects can be addressed using the theory of constraints as proposed by Goldratt in his book “The Goal”, and the cultural aspects imbue policy developments for online marketing, webpage design and communications. The cultural aspects of some MENA countries are captured through indices such as Hofstede’s cultural dimensions, Hall’s cultural patterns, and Trompenaars’ dimensions of culture. This study further investigates how cultural attributes can influence the adoption of e-commerce in MENA countries. Ultimately, there is the need to develop expressive trust motifs in webpages that can be assigned objective semantics which can substitute face-to-face cues to derive trust
Planning for a large dam project : the case of Traveston Crossing Dam
The approval for a large dam project proposal these days predominantly involves satisfying broadly the criteria of economic development, social equity, and environmental sustainability. It is justified that the criterion of economic development seeks full project cost recovery as well as significant contribution to economic growth of a region. Cost–benefit analysis is normally used as the yardstick for economic development but it has limitations and a better method is warranted. Social equity considerations should embody the need to address the concerns of all sections in communities to be impacted by a project and involve them in the decision-making process. The lapse of this aspect in project planning of the past has led, at least as being partly responsible, to disastrous consequences. Environmental sustainability should seek to ensure that the vital components of the environment are preserved such that the future generation can use the natural resources to their benefit at least as much as the current generation. Environmental sustainability is arguably the most contentious criteria among these. The vagueness in the concept of environmental sustainability and the tendency of the society to err on the safe side have caused many large dam project proposals not reach their fruition. An attempt is made in this paper to define environmental sustainability in a more meaningful way from an analytic viewpoint. The case of Traveston Crossing Dam project in southeast Queensland, Australia is presented as an illustrative example and to evaluate the performance and relevance of the three broad criteria in a real-world application. The case study is also an example of the fact that environmental awareness can lead to enormous level of socio-political forces which can create many hurdles to cross by a democratic government
Planning for a large dam project : the case of Traveston Crossing Dam
The approval for a large dam project proposal these days predominantly involves satisfying broadly the criteria of economic development, social equity, and environmental sustainability. It is justified that the criterion of economic development seeks full project cost recovery as well as significant contribution to economic growth of a region. Cost–benefit analysis is normally used as the yardstick for economic development but it has limitations and a better method is warranted. Social equity considerations should embody the need to address the concerns of all sections in communities to be impacted by a project and involve them in the decision-making process. The lapse of this aspect in project planning of the past has led, at least as being partly responsible, to disastrous consequences. Environmental sustainability should seek to ensure that the vital components of the environment are preserved such that the future generation can use the natural resources to their benefit at least as much as the current generation. Environmental sustainability is arguably the most contentious criteria among these. The vagueness in the concept of environmental sustainability and the tendency of the society to err on the safe side have caused many large dam project proposals not reach their fruition. An attempt is made in this paper to define environmental sustainability in a more meaningful way from an analytic viewpoint. The case of Traveston Crossing Dam project in southeast Queensland, Australia is presented as an illustrative example and to evaluate the performance and relevance of the three broad criteria in a real-world application. The case study is also an example of the fact that environmental awareness can lead to enormous level of socio-political forces which can create many hurdles to cross by a democratic government
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