The influence of diffuser parameters, including the riser spacing, port number in a riser, injection angle, port arrangement, etc., on the surface initial dilution is experimentally investigated. The relative density difference between the effluent and the sea water in the model is the same as that in the prototype, and the effect of the cross current is simulated by an inverse model technique. Based on the result analysis, the arrangement with more ports in a riser and larger riser spacing is suggested to save construction cost. The relationship between the Reynolds number based on the port diameter and velocity, and the surface initial dilution is also explored, and the critical Reynolds number is proposed. 相似文献
The ecological footprint of China’s provinces is calculated in this paper.In general,China’s development is not sustainable because its ecological footprint is beyond its bio-capacity.The sustainability status of each province in China is presented.Ulanowicz’s developmnt capacity formula was introduced to discuss th relation ship of development and ecological footprint’s diversity.The diversity of ecological impacts is related to the efficiency with which an economy uses the source and sink services of the environment and,in this efficiency with which an economy uses the source and sink services of the environment and ,in this view,should be a factor in economic output.Development capacity,calculated from the ecological footprint and its diversity,is used to examine the relationship o economic output with the structure of the ecological footprint.China and its provinces are presented as a case study to investigate this relationship.The analysis shows that footprint capacity is significant in prdicting economic output.Increasing the ecological footprint’s diversity is presented as another way to increase development capacity. 相似文献
Climate change is one of the main factors that affect runoff changes. In the upstream of Minjiang River, the temperature increased significantly in the last 50 years, while the precipitation decreased on the contrary. In order to analyze the effect of climate change on site runoff, watershed runoff depth and evaporation, nine climate scenarios are assumed based on rainfall and temperature indicators. A SWAT model of Minjiang River is constructed, and runoff simulation is carried out with the nine scenarios. The results show that if precipitation increases or decreases 20 %, the change rate of runoff depth will increase or decrease 28–32 %; if temperature increases or decreases 2 °C, the change rate of runoff depth will decrease or increase 1–6 %; if temperature increases or decreases 2 °C, the change rate of the potential evaporation will increase or decrease 5–16 %, and the actual evaporation rate of variation will increase or decrease 1–6 %. Overall, precipitation variation has greater effect on simulated runoff than temperature variation dose. In addition, temperature variation has more obvious effect on the runoff simulation results in dry years than in wet years. The actual evaporation of watershed depends on evaporation capacity and precipitation and increases with the increasing of the potential evaporation and precipitation. The study also shows that the climate change scenarios analysis technology, combined with SWAT hydrological model, can effectively simulate the effect of climate change on runoff.
