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Long-term ecological interactions between nutrient and phytoplankton community in the Changjiang estuary 被引量:9
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作者 江涛 俞志明 +2 位作者 宋秀贤 曹西华 袁涌铨 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2010年第4期887-898,共12页
Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in ... Both nitrate((NO_3)^-) and soluble reactive phosphate((PO_4)^(3-)) concentration in the freshwater end-member at the mouth of the Changjiang River have increased dramatically since the 1960s.Within the same period in the sea area,with surface salinity>30,(NO_3)^-concentration has shown an obvious increase,(PO_4)^(3-) has not changed greatly and dissolved reactive silica((SiO_3)^(2-)) has deceased dramatically.An examination of the elemental ratio of(NO_3)^-to(PO_4)^(3-) at the mouth of the Changjiang River did not show a systematic trend from the 1960s to 2000s largely because both nutrients increased simultaneously.In comparison,the elemental ratio of dissolved inorganic nitrogen(DIN) to(PO_4)^(3-) in surface seawater,with salinity>22,has shown a clearly increasing trend.Furthermore,an overall historical change of the(SiO_3)^(2-):(PO_4)^(3-) ratio has undergone a reverse trend in this area.Based on the changes of(SiO_3)^(2-):(PO_4)^(3-) and DIN:(PO_4)^(3-) ratios,we can conclude that an overall historical change of(SiO_3)^(2-):DIN ratio has decreased in this area from the 1950-1960s to 2000s.The argument that phytoplankton productivity in the Changjiang estuary has been enhanced by increasing nutrient input from the riverine transport was supported by these results.A comparative study analyzing the shift of phytoplankton composition from the mid-1980s to 2000s was also made.The results indicated that the average yearly percentage of diatom species in the Changjiang estuary has decreased from 84.6% during 1985-1986 to 69.8% during 2004-2005.Furthermore,the average yearly percentage of diatom abundance in the Changjiang estuary decreased from 99.5% during to 75.5% over the same time period,while the abundance of dinoflagellates has increased dramatically,from 0.7% to 25.4%. 展开更多
关键词 EUTROPHICATION NUTRIENTS phytoplankton community Changjiang estuary
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PROJECTION BASED STATISTICAL FEATURE EXTRACTION WITH MULTISPECTRAL IMAGES AND ITS APPLICATIONS ON THE YELLOW RIVER MAINSTREAM LINE DETECTION 被引量:1
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作者 Zhang Yanning Zhang Haichao +2 位作者 Duan Feng Liu Xuegong Han Lin 《Journal of Electronics(China)》 2009年第3期359-365,共7页
Mainstream line is significant for the Yellow River situation forecasting and flood control.An effective statistical feature extraction method is proposed in this paper.In this method, a between-class scattering matri... Mainstream line is significant for the Yellow River situation forecasting and flood control.An effective statistical feature extraction method is proposed in this paper.In this method, a between-class scattering matrix based projection algorithm is performed to maximize between-class differences, obtaining effective component for classification;then high-order statistics are utilized as the features to describe the mainstream line in the principal component obtained.Experiments are performed to verify the applicability of the algorithm.The results both on synthesized and real scenes indicate that this approach could extract the mainstream line of the Yellow River automatically, and has a high precision in mainstream line detection. 展开更多
关键词 Mainstream line PROJECTION Between-class scatter matrix High-order statistics SKEWNESS
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Impact of Climate Change on Regional Hydroclimate Projection in Peninsular Malaysia
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作者 Mohd Ekhwan Toriman Mazlin Bin Mokhtar +3 位作者 Rahmah E1-fithri NorAzlina Abdul Aziz Md.Pauzi Abdullah Muhamad Barzani Gasim 《Journal of Environmental Science and Engineering(A)》 2012年第1期41-45,共5页
For the assessment of the impact of future climate change on the hydrologic regime and water resources of Peninsular Malaysia, it is necessary to downscale the climate change simulations of a coarse scale General Circ... For the assessment of the impact of future climate change on the hydrologic regime and water resources of Peninsular Malaysia, it is necessary to downscale the climate change simulations of a coarse scale General Circulation Model to the region of Peninsular Malaysia at fine grid resolution. This paper presents a desktop review of the state of climate change parameters, namely rainfall and river flow over the Peninsular Malaysia for the 2041-2050 projection period. Analysis of the results from the models shows there will be a substantial increase in mean monthly precipitation over the North East Coastal region from historical 259.5 mm to 281.5 mm, from 289.0 mm to 299.0 mm and 221.8 mm to 239.5 mm over Terengganu and Kelantan, respectively. Meanwhile, for river flow projection, it will be an expected increase in interannual and intraseasonal variability with increased hydrologic extremes (higher high flows, and lower low flows) at Kelantan, Pahang, Terengganu, and Kedah watersheds in the future. 展开更多
关键词 Climate change peninsular Malaysia RAINFALL river flow.
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Projection and Historical Analysis of Hydrological Circulation in Sittaung River Basin, Myanmar
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作者 Takao Yamashita Htay Aung 《Journal of Civil Engineering and Architecture》 2016年第6期736-742,共7页
Based on the comparison between several model outputs from CMIP5 (Coupled Model Intercomparison Project Phase-5) and the satellite rainfall mapping data of GSMaP (global satellite mapping of precipitation), This p... Based on the comparison between several model outputs from CMIP5 (Coupled Model Intercomparison Project Phase-5) and the satellite rainfall mapping data of GSMaP (global satellite mapping of precipitation), This paper selected MIROC4h as a future projection of rainfall in the Sittaung River basin, Myanmar, with the fine spatial resolution of 0.5°. At first, MIROC4h projection towards 2035 was corrected by using the error trend (GSMaP-MIROC4h) for nine years over-rapping of both outputs from 2006 to 2014. Assuming the seasonal autoregressive processes, future error trend at each grid point was estimated by the time series forecast of SARMAP processes using the nine years training data. Then future projection correction was done by M1ROC4h output plus error trend at each grid point to obtain the corrected MIROC4h precipitation. As a historical analysis, using the corrected precipitation in the Sittaung River basin and observed river discharge at the outlet of the river, the hydrological model (HSPF (Hydrological Simulation Program Fortran)) calibration was carried out with consideration of the water utilization data for darn/reservoir and irrigation. As a projection analysis, future simulation of hourly discharge at the outlet of Sittaung River from 2015 to 2035 was conducted by using the corrected MIROC4h precipitation. The results of projection analysis show that high risks of flood will appear in 2023 and 2028 and the risks of draught will be expected in 2019-2021. 展开更多
关键词 Hydrological simulation HSPF CMIP5 MIROC4h TRMM GSMaP.
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A Health Evaluation Method for Mountainous River Systems 被引量:1
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作者 王丽萍 郑江涛 +1 位作者 周婷 周晓蔚 《Journal of Resources and Ecology》 CSCD 2010年第3期221+216-220,共6页
本文通过对山区河流的基本特征研究,从生态功能和人类服务功能两大角度建立了山区河流健康评价系统,并基于投影寻踪理论构建了山区河流健康评估指标体系。以中国西南地区某典型山区河流为研究对象,本文对该河流水电开发前后的健康状况... 本文通过对山区河流的基本特征研究,从生态功能和人类服务功能两大角度建立了山区河流健康评价系统,并基于投影寻踪理论构建了山区河流健康评估指标体系。以中国西南地区某典型山区河流为研究对象,本文对该河流水电开发前后的健康状况进行了研究。结果显示水电开发后河流综合健康状况较现状有显著提高。在此基础上,本文进一步通过对投影指标体系的结构特征分析,提出了维持河流健康的对策。 展开更多
关键词 COUNTERMEASURES evaluation index mountainous river projection pursuit system health
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十八岁(长篇小说)
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作者 周岂衣 《作品》 2019年第6期22-99,共78页
1.讣告高考过后,我们'状元班'的群再无动静,形同虚设。大家各奔东西,不再有联系,有的甚至下落不明。忽然有一天,'状元班'的群里出现了这么一条消息:各位同学:告诉大家一个很不幸的消息,失踪的老马已经被警方找到,死在... 1.讣告高考过后,我们'状元班'的群再无动静,形同虚设。大家各奔东西,不再有联系,有的甚至下落不明。忽然有一天,'状元班'的群里出现了这么一条消息:各位同学:告诉大家一个很不幸的消息,失踪的老马已经被警方找到,死在离他家不远的那条河道里。是投河自杀。老马已经永远离开了我们。 展开更多
关键词 群里 大家 消息 各奔东西 状元 投河 老马
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