Digital computer solutions of groundwater flow     

K.R. RushtonL.M. Tomlinson 《Journal of Hydrology》1971

This paper examines critically the use of the alternating direction implicit method for solving groundwater flow problems. Comparisons with alternative solutions show that inaccuracies can arise if the time increments are too large. A method is suggested whereby the computer chooses an optimum time increment. The representation of recharge, infiltration and wells is considered and a detailed example compares the alternating direction implicit, the explicit and the resistance-capacitance network methods.  相似文献   

Can the gold coast beaches withstand extreme events?     

Bruno?CastelleEmail author  Yann?Le?Corre  Rodger?Tomlinson 《Geo-Marine Letters》2008,28(1):23-30

The Gold Coast sandy beaches of Queensland (Australia) are exposed to energetic wave conditions. Storms, particularly tropical cyclones, have a high potential of destruction. The Gold Coast has not experienced excessive erosive events over the past 30 years. However, some climate indicators suggest that cyclone frequency is likely to increase in response to global climate change within the near future. Over a 2-month period in early 2006, beach surveys were undertaken with a theodolite total station at four different sites. Offshore wave conditions were provided by SWAN regional wave modelling. During this study, the Gold Coast was exposed to three major storms, the first one being the second most energetic over the past 30 years. Results show a substantial variability of the beach response to these events along the Gold Coast, and that engineering structures do not have marked effects. Easterly swells have the greatest impact on the Gold Coast sub-aerial beach morphology. When low wave-energy conditions prevail, the southern Gold Coast beaches recover more quickly than the northern ones, as they are sheltered from high SE waves and draw advantage from the artificial sand bypassing system. Nevertheless, the data show that the Gold Coast beaches are exceedingly fragile. For instance, the early March decadal event considerably weakened the beaches, which resulted in surprisingly high erosion rates all along the Gold Coast during the two following annual wave events. This study suggests that the Gold Coast beaches would not be able to withstand the impact of an increased frequency of extreme events similar in scale to those of 1967.  相似文献   

黄金岸线海滩能否抵挡极端事件的冲击     

Bruno Castelle  Yann Le Corre  刘锐 《海洋地质前沿》2008,24(9):21-24

砂质海滩是最变化莫测和脆弱的海岸带类型之一。众所周知,海滩在高能环境中会被侵蚀,但海滩上不同位置点对于极端事件的抵御能力则大不相同。而且,侵蚀速率通常受控于海滩状况、机械结构和前期补给。  相似文献