Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measu...Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measured and must be obtained using other information. This paper presents a case study of data generation for the computation of thermal conditions in the Joumine Reservoir, Tunisia. Data from the Wind Finder web site and daily sunshine duration at the nearest weather stations were utilized to generate cloud cover and solar radiation data based on meteorological correlations obtained in Japan, which is located at the same latitude as Tunisia. A time series of inflow water temperature was estimated from air temperature using a numerical filter expressed as a linear second-order differential equation. A numerical simulation using a vertical 2-D （two-dimensional） turbulent flow model for a stratified water body with generated data successfully reproduced seasonal thermal conditions in the reservoir, which were monitored using a thermistor chain.展开更多
Reservoirs are installed as long-term assets to guarantee water and energy security for decades,if not centuries.However,the effect of siltation undermines reservoirs’sustainability because it significantly reduces t...Reservoirs are installed as long-term assets to guarantee water and energy security for decades,if not centuries.However,the effect of siltation undermines reservoirs’sustainability because it significantly reduces the reservoirs’original capacity.The present paper attempts to evaluate the global reservoir siltation problem with the optimism bias theorem introduced by Kahneman and Tversky and applied to infrastructural mega-projects by Flyvbjerg and Ansar using artificial neural networks(ANNs)algorithms for large Japanese reservoirs.Japan possesses suitable long-term data and a legal directive concerning the sediment capacity siltation duration,which serves as a valid guide to check whether,over the past 100 years,engineers,planners and managers were capable of judging the sediment input correctly.Various ANN models were established to emulate Japanese reservoir siltation behavior.The networks demonstrate that reservoirs in Japan suffer from optimism bias.In contrast to the law,the dead storage volume of an average dam is supposed to reach capacity after 52 years.This finding joins the overall observation that mega-projects generally and globally suffer from optimism bias.The emulations were subsequently screened for a presumed influence of governance actions,namely,indicating plus monitoring and the change in the market competition situation.While reservoir siltation appears to continue regardless of the level of competition in public procurement,monitoring directives appear to have a considerable impact on improved siltation management,which demonstrates that dedicated governance action can significantly strengthen the sustainable behavior of key infrastructure elements such as reservoirs.展开更多
文摘Dynamic numerical simulation of water conditions is useful for reservoir management. In remote semi-arid areas, however, meteorological and hydrological time-series data needed for computation are not frequently measured and must be obtained using other information. This paper presents a case study of data generation for the computation of thermal conditions in the Joumine Reservoir, Tunisia. Data from the Wind Finder web site and daily sunshine duration at the nearest weather stations were utilized to generate cloud cover and solar radiation data based on meteorological correlations obtained in Japan, which is located at the same latitude as Tunisia. A time series of inflow water temperature was estimated from air temperature using a numerical filter expressed as a linear second-order differential equation. A numerical simulation using a vertical 2-D （two-dimensional） turbulent flow model for a stratified water body with generated data successfully reproduced seasonal thermal conditions in the reservoir, which were monitored using a thermistor chain.
基金This work was supported by the Sievert Stiftung fur Wissenschaft und KulturJapanese Society for the Promotion of Science[PE18737].
文摘Reservoirs are installed as long-term assets to guarantee water and energy security for decades,if not centuries.However,the effect of siltation undermines reservoirs’sustainability because it significantly reduces the reservoirs’original capacity.The present paper attempts to evaluate the global reservoir siltation problem with the optimism bias theorem introduced by Kahneman and Tversky and applied to infrastructural mega-projects by Flyvbjerg and Ansar using artificial neural networks(ANNs)algorithms for large Japanese reservoirs.Japan possesses suitable long-term data and a legal directive concerning the sediment capacity siltation duration,which serves as a valid guide to check whether,over the past 100 years,engineers,planners and managers were capable of judging the sediment input correctly.Various ANN models were established to emulate Japanese reservoir siltation behavior.The networks demonstrate that reservoirs in Japan suffer from optimism bias.In contrast to the law,the dead storage volume of an average dam is supposed to reach capacity after 52 years.This finding joins the overall observation that mega-projects generally and globally suffer from optimism bias.The emulations were subsequently screened for a presumed influence of governance actions,namely,indicating plus monitoring and the change in the market competition situation.While reservoir siltation appears to continue regardless of the level of competition in public procurement,monitoring directives appear to have a considerable impact on improved siltation management,which demonstrates that dedicated governance action can significantly strengthen the sustainable behavior of key infrastructure elements such as reservoirs.
