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31.
Yuchun WANG Jun ZHU Congqiang LIU 《中国地球化学学报》2006,25(B08):161-162
Damming is a common anthropogenic intervention along the course of rivers, which is defined as "artificial-lake effect", both in China and across the world. Today as many as 48000 dams and/or reservoirs are in operation in the Changjiang River (Yangtze River) drainage area, and more are being constructed. While damming is well known to affect riverbome nutrient loads, and thus the riverine ecosystems owing to removal of carbon fixation, and removal of particles in reservoir sediments, there is limited information on the detailed early diagenesis of sediments in reservoirs including the regeneration processes of nutrients deposited in sediments and exchange flux across the sediment-water interface, which is important for mass balance of riverbome nutrients. In the present study, two large-size reservoirs, Wujiangdu Reservoir (WJDR) and Dongfeng Reservoir (DFR), located on the main steam of the Wujiang River and with uniformity hydrography and discrepancy biogeochemical activity (e. g. primary production), were selected for a comparative study on the detailed processes of nutrient regeneration. Water, pore water and sediment were sampled from these two reservoirs and dissolved organic carbon (DOC), NH4^+, NO3^-, PO4^3-, dissolved silica (DSi) in the overlying water and pore water, and total organic matter in sediments were determined. The results of correlation analysis suggested that in these two reservoirs, processes of nutrient regeneration near the sediment-water interface were significantly different. As a result of rapid decomposition of algae-derived "labile" organic matter in upper sediments, nutrient regeneration processes and upward fluxes in WJDR are dramatically stronger than those of DFR. NH4^+ upward flux from sediment in WJDR was about 17 times higher than that in DFR. PO4^3- flux in WJDR is about 13 times above that in DFR. DOC flux in WJDR is larger that in DFR by 5 times, and DSi by 1 time. 相似文献
32.
城市河岸土地利用对河流廊道功能影响初探——以上海苏州河为例 总被引:1,自引:0,他引:1
城市河岸土地利用往往改变河岸的自然地理条件,对城市河流功能产生影响。通过总结城市河岸廊道功能以及国内外城市河岸规划土地利用的实践,分析了河岸土地利用对城市河流廊道功能的影响,并以上海苏州河为例进行了实证分析。结果表明,苏州河河岸规划土地利用方式提高了河岸开放带宽度,改善了河岸舒适性,控制了河岸建筑高度,有利于保护和开发苏州河河流的景观、遗产和经济廊道的功能。干流河岸在自然廊道功能方面,仍存在一定缺陷,与支流的部分河段相比仍有差距。 相似文献
33.
Siyue LI Quanfa ZHANG 《中国地球化学学报》2006,25(B08):274-274
As the diversion dike of the Middle Route of the South to North Water Transfer Project (MRSNWTP), the water quality and water quantity of Danjiangkou Reservoir is critical to the project. At present, the rates of industrial wastewater treatment and sewage discharge, which belongs to Chinese State Standard in the districts near the reservoir except Shiyan city, are less than 60% and 40% respectively. The point source pollutants will be controlled because of the project after some time, but the non-point source pollutants caused by vegetation degradation and water-soil erosion will not be controlled effectively in a long time. Water samples were collected from the Danjiangkou Reservoir during 2004 and 2005 and analyzed for trace metals, i.e., silver (Ag), aluminum (Al), arsenic (As), barium (Ba), bismuth (Bi), calcium (Ca), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), mercury (Hg), potassium (K), lithium (Li), magnesium (Mg), manganese (Mn), molybdenum (Mo), sodium (Na), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), silicon (Si), strontium (Sr), vanadium (V), zinc (Zn), chemicophysical parameters and nutrients, i.e., temperature (T), pH, dissolved oxygen (DO), turbidity, total suspended solid (TSS), nitrate/ammonia/ammonium-nitrogen (NO3^-/NH3/NH4^+-N), total nitrogen (TN), dissolved inorganic nitrogen (DIN), total phosphorus (TP), potassium permanganate index (IMn), biochemical oxygen demand (BOD), dissolved inorganic carbon (HCO3^-). Our results are water quality belongs to Chinese standard level II, trace metals are low, but they are accumulating, and many of which, i.e., As, Pb, will endanger reservoir water security. 相似文献
34.
《地理学报(英文版)》2006,16(4):512-512
Please mark your calendars and plan to attend this event! This event will bring together world experts - practitioners, lawyers and policy experts, scientists, sociologists, economists, and others representing project-based efforts, national perspectives, and global insight - to provide a holistic view of river management and environmental flows. It will showcase practices from throughout the world, provide opportunities for networking, and advance common knowledge related to the themes and sub-themes of this conference. 相似文献
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鄂尔多斯西缘前陆盆地上古生界沉积相特征研究 总被引:3,自引:0,他引:3
在层序地层学研究的基础上,对鄂尔多斯盆地西缘逆冲构造带上古生界进行了详细的沉积相研究.分析出该地发育了6种沉积相,分别为碳酸盐潮坪相、障壁砂坝-泻湖相、河口湾相、三角洲相、河流相、湖泊相.并按上古生界识别出的2个二级层序,推测出沉积相的平面展布特征,总结出鄂尔多斯盆地西缘地区,晚古生代沉积演化经历了拗拉槽再活动背景下的裂谷海湾充填、陆表海充填和内陆坳陷充填3个发展阶段.并结合构造、物源供给、海侵、古气候等条件分析了鄂尔多斯西缘前陆盆地上古生界沉积相演化的控制因素. 相似文献
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主要介绍北川河流域地下水的动态分布、赋存和补、径、排条件,并对该流域地下水资源量进行计算和评价. 相似文献
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