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Wujiashan, China

Darn-Horng H.,National Kaohsiung University of Applied Sciences | Anh-Vu P.-T.,National Kaohsiung University of Applied Sciences | Tung-Chin K.G.,National Cheng Kung University | Chieh-Jui L.,Bureau of Water Resources
Disaster Advances

This study presents an experimental investigation on subsurface displacements evaluated by means of boreholes, rainfall, groundwater level, inclinometer system and ERT technique in Chaishan area, Kaohsiung, Taiwan. From 2003, the local government provided financial funding support for the geotechnical program with expectancy to understand and reduce the damage due to the deformation and landslide. The boreholes were bored in 2004 and 2013 to detect the strata of geological condition. In the meanwhile, an inclinometer system was installed, consisting in fifteen positions to measure the movement of subsurface from 2005 to 2012. To facilitate understanding more geological strata, the Electrical Resistivity Topography technique was employed to obtain continued geological cross-sections and to complement the results of borehole technique. Results showed that strata are composed of limestone, silty clay and mudstone distributed with different depths in the survey area. ERT elucidated that surface is found by heterogeneous layers, including not only limestone but also limestone interbedded with silty clay. Inclinometers revealed that movement of subsurface gradually increases with increasing observation time, especially for rainy reason. Close to Taiwan Strait had a displacement rate of subsurface more than 10 mm per year, the movements were mainly towards South-West direction. In addition, a combination of steep terrain, weak geology and rainfall is main reason for the landslide and deformation of the subsurface in the study area. Finally, factor of safety against landslide obtained from STABL6 software indicated that some places of this area are in critical equilibrium in the range of 0.9 and 1.93 and the risk of damage is thus predicted to continuously occur in the future. Source

Li P.,Wuhan University | Lu W.-B.,Wuhan University | Qiao X.-M.,Bureau of Water Resources | Chen M.,Wuhan University | Yan P.,Wuhan University
Meitan Xuebao/Journal of the China Coal Society

Multiple disturbing components of the vibration data measured during the blasting excavation of a high slope were eliminated through the pre-processing and filtering. And then the vibration data from different monitoring points were analyzed by different predicting formulas and different filtering schemes. Finally through comparing the analysis results, the blasting vibration response law was obtained. The results indicate that the vibration characteristics of surface monitoring points are different from those of internal monitoring points, and analyzing only with the surface monitoring points is more reasonable. The formula derived from the dimension analysis is more accurate to reflect the effect of elevation on the blasting vibration of the high slope. The filtering scheme of high pass 15 Hz can effectively eliminate the disturbing signals of measured vibration data and further improve the precision of blasting vibration prediction. Source

Yin C.,CAS Research Center for Eco Environmental Sciences | Su S.,Bureau of Water Resources | Zhang R.,Water Affairs Investment Co. | Wang W.,CAS Research Center for Eco Environmental Sciences | And 3 more authors.
Huanjing Kexue Xuebao/Acta Scientiae Circumstantiae

JX City, located in the Yangtze River delta, takes drinking water from a stream network. In recent years, the water quality has declined rapidly because of the economic development in upstream areas. Stream networks have many pollution sources and complicated hydrodynamics that are difficult to control and threaten regional water safety. The JX City built an "ecological water purification wetland" in front of the water plant as the final barrier. The wetland has an area of 110 hm2, including a pretreatment zone, root-channel purification zone, water level rising and aeration zone, and deep purification zone. The wetland significantly improves water quality, and the removal rate of ammonia nitrogen was 32.5%. This wetland system has other functions of ecological service, such as water storage buffering, urban air refreshing, habitats for wildlife and recreation site for the residents. Source

Yuan S.-X.,South China Normal University | Wang M.,South China Normal University | Chen W.-Y.,South China Normal University | Chena Z.-H.,South China Normal University | And 3 more authors.
Journal of Freshwater Ecology

We tested the effects of the floating plant Eichhornia crassipes (water hyacinth) and nonwoven filter for contaminant removal from eutrophic water. Four microcosms were designed for this purpose- (i) water hyacinth plus nonwoven filter; (ii) water hyacinth only; (iii) nonwoven filter only; and, (iv) control with neither water hyacinth nor nonwoven filter. The complex microcosm of water hyacinth and filter had significantly higher percentage removal of total phosphorus (TP) and chemical oxygen demand than found in the treatments without water hyacinth (P < 6.01 or P < 0.05). The complex treatment of water hyacinth and filter maintained a neutral water pH, while pH values in the treatments without E. crassipes reached 10 or even higher within three-five days. The filter treatment eliminated about 60-80% of ammonium nitrogen, nitrate nitrogen, TP, soluble phosphorus, and biochemical oxygen demand in three-six days. The complex treatment of water hyacinth and filter generally had higher removal rates than either the water hyacinth treatment or the filter treatment. These results suggest that interaction between floating plants and filter in the complex wetland can improve contaminant removal capacity. Source

Zhao. J.-G.,South China Normal University | Zhao. J.-G.,Jinan University | He. F.-F.,South China Normal University | Chen Z.-H.,South China Normal University | And 3 more authors.
Journal of Freshwater Ecology

The effects of culture and extract solutions of six macrophytes on the growth of three common phytoplankton were investigated under laboratory conditions. Culture solutions were taken from a Hoagland nutrient solution that contained live plants growing for 7 days and the extract solution was made from a solution with fresh plant pieces immersed in Hoagland nutrient solution for 48 h. The algae were grown in the culture or extract solution for 15 days and the algal density was determined every 2 days. The results showed that the culture solution of the macrophytes both inhibited and stimulated algae growth depending on the macrophytes and the algae. All extract solutions of the macrophytes exhibited a stimulatory effect on the growth of the algae that also varied with the macrophytes and the phytoplankton. The results indicated that culture solutions of macrophytes may be more suitable for the control of algal blooms in eutrophic waters than their extract solutions © 2012 Taylor & Francis. Source

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