The amount of human-caused environmental impact can be evaluated by the degree of pollution. Active coastal marine environmental exploitation has given rise to another problem： marine litter. The period of time allow...The amount of human-caused environmental impact can be evaluated by the degree of pollution. Active coastal marine environmental exploitation has given rise to another problem： marine litter. The period of time allowing to evaluate the change in the degree of the shore pollution with litter is that from 1999 till 2014. Litter can be classified both by qualitative and quantitative character. Regarding qualitative character litter is divided into organic substance （garbage, wood） and non-organic substance （glass, plastics, rubber, metal）. As to the size there are three categories： small, middle, large. As to small litter it is still predominating in the litter structure of the shoreline pollution but its average amount has been decreased significantly. As to the litter distribution, it is mostly concentrated within the beach zone. It is thus natural to assume the land-based origin of the litter, such as litter brought by holiday-makers or introduced by nearby enterprises.展开更多
In most cases, the slope stability of reservoir bank is analyzed on the premise that the location of phreatic surface is obtained. But many designers generalize a line as the phreatie surface through their experience ...In most cases, the slope stability of reservoir bank is analyzed on the premise that the location of phreatic surface is obtained. But many designers generalize a line as the phreatie surface through their experience to analyze the stability, which is unsafe in the project. To find a solution of the phreatic surface which is convenient to put into use and in accordance with the practice, the article, based on Boussinesq equation, infers analytic solutions suitable to the water level at different ratios and achieves an analytic solution equation through fitting curves. The correctness of the equation is also proved by the experiments of sand and sand-clay models and the inaccuracy of empirical generalization is analyzed quantitatively. The calculation results show that the inaccuracy through the method of experiential generalizing is so large that the designers should be awake to it.展开更多
文摘The amount of human-caused environmental impact can be evaluated by the degree of pollution. Active coastal marine environmental exploitation has given rise to another problem： marine litter. The period of time allowing to evaluate the change in the degree of the shore pollution with litter is that from 1999 till 2014. Litter can be classified both by qualitative and quantitative character. Regarding qualitative character litter is divided into organic substance （garbage, wood） and non-organic substance （glass, plastics, rubber, metal）. As to the size there are three categories： small, middle, large. As to small litter it is still predominating in the litter structure of the shoreline pollution but its average amount has been decreased significantly. As to the litter distribution, it is mostly concentrated within the beach zone. It is thus natural to assume the land-based origin of the litter, such as litter brought by holiday-makers or introduced by nearby enterprises.
文摘In most cases, the slope stability of reservoir bank is analyzed on the premise that the location of phreatic surface is obtained. But many designers generalize a line as the phreatie surface through their experience to analyze the stability, which is unsafe in the project. To find a solution of the phreatic surface which is convenient to put into use and in accordance with the practice, the article, based on Boussinesq equation, infers analytic solutions suitable to the water level at different ratios and achieves an analytic solution equation through fitting curves. The correctness of the equation is also proved by the experiments of sand and sand-clay models and the inaccuracy of empirical generalization is analyzed quantitatively. The calculation results show that the inaccuracy through the method of experiential generalizing is so large that the designers should be awake to it.
