30多年来柴窝堡湖演化特征及其环境效应   总被引：1，自引：0，他引：1  

马龙  吴敬禄  吉力力·阿不都外力 《干旱区地理》2011,(4):649-653

在对柴窝堡地区多期陆地资源卫星、中巴资源卫星以及Modis遥感影像解译基础上,结合器测气象资料、地下水以及湖泊水深等数据,对柴窝堡湖面积变化及其环境效应进行了研究.结果表明:20世纪70年代以来湖泊总体呈下降趋势,但到20世纪末至21世纪初期受流域降水增加影响,湖泊面积出现一定程度的扩展,面积最高达到约29.5 km2...  相似文献   

内蒙古阴山雪玉成矿地质特征及成因探讨     

赵月明  张志祥  张有宽  王弢 《西部资源》2011,(5):42-43

阴山雪玉产于华北陆块北缘西段狼山一渣尔泰山裂陷槽沉积的中元古界渣尔泰山群阿古鲁沟组的碳质板岩中,形状各异、大小不等的断裂构造十分发育,火山活动时,富含挥发分高温粘稠的硅酸盐熔融体从火山口爆发或喷溢,晚期富含挥水分的二氧化硅溶液在构造裂隙中充填或交代围岩形成形态各异的玉髓（玛瑙）——阴山雪玉。它色泽美丽,质地坚韧、温润光...  相似文献   

中国湖泊的现状和开发途径   总被引：6，自引：0，他引：6  

戴雄武 《地域研究与开发》1989,8(2):4-7,29

湖泊是国土资源的重要组成部分,由于它具有供水、航运、水产、发电、灌溉、旅游、防洪以及调控环境等多项功能,近古时代,我们的祖先就已选择了这些地方,在其周围生息演进。  相似文献   

湖泊水生生物在人为富营养化因素影响下的变化     

张开翔 《海洋湖沼通报》1992,(2):90-98

一、前言在本世纪三十至四十年代,生物生产力和水域营养评价方面的研究,还只是少数湖泊学者和水生生物学者感兴趣的课题。湖泊营养评价的研究只是在渔业范围,或者是为了类型分类的需要而进行的。湖泊发展的历史表明:在湖泊演化期间通常发生营养水平的提高;水域由贫营养型转变至中营养型及富营养型。这个过程发展很缓慢,并且在每种具体情况下的发展速度又取决于湖泊的形态指标及其历史与地理特点。  相似文献   

柴北缘铅石山榴辉岩地质特征     

田承盛 《青海国土经略》2001,(1)

根据对铅石山榴辉岩岩石学、岩石化学、地球化学元素、变质岩相及变质作用等特征,该类岩石形成时代可能为中元古代后期,并经历了四堡期、晋宁期、加里东期三次快速折返及相应的退变质作用叠加,进一步证实了柴北缘地区高压变质带的存在。  相似文献   

Energy flow in Branchiura sowerbyi （Oligochaeta： tubificidae） in a shallow macrophyte-dominated lake, Biandantang Lake     

闫云君  梁彦龄 《中国海洋湖沼学报》2004,22(4):403-407

The energy flow of Branchiura sowerbyi was studied for the first time in China in a shallow macrophytic lake, Biandantang Lake, Hubei Province. The energy flow was calculated from the measurement of flesh production (12.5241kJ/m^2a), egestion (517.7302kJ/m^2a), metabolism (38.3273 kJ/m^2a), and excretion (4.3798kJ/m^2a). The net growth efficiency of the species is about 22.7%, which accords well with the generally reported value for oligochaetes. In addition, the relationship between starvation respiration (R, mgO2/ind‘d), wet weight (Ww, mg) and temperature (T, ℃) were also measured, with the regression function being R=0.008 Ww^0.736 e^0.050T.  相似文献   

RELATIVE BRIGHTNESS INDEX AND IT‘S CLIMATIC SIGNIFICANCE FROM LACUSTRINE SEDIMENT OF NAPAHAI LAKE，NORTHWESTERN YUNNAN PLATEAU，CHINA     

YINYong  FANGNian－qiao 《中国地理科学(英文版)》2002,12(3):249-253

Information on the palaeoenvironment from Late Pleistocene to Holocene in northwestern Yannan Plateau has been deduced from a study of a 28.81m-long core taken from Napahai Lake.The results from Relative Brightness In-dex(RBI) as well as those from the lithological analyses of bulk sediments,total organic carbon and granulometric analy-ses have been used to reconstruct the environmental and climatic evolution of the area.The ages were provided by three ^14C datings.The record suggested a climate fluctuation between warm-dry and cool-wet from ca.57 to 32ka B.P.which led a shallowing and swamping of the lake.The water level again increased quickly at ca.32ka B.P.,reached itˊs peak during LGM(Last Glacial Maximum,ca.18-20kaB.P.)and remained relative high until ca.15kaB.P.The high wa-ter level at LGM is attributed to cold-wet conditions.The area experienced an abrupt and unstable climatic changes dur-ing the transition period form 15 to 10ka B.P.with a dominated littoral environment.Awarm-dry climate led to the contrac-tion of the lake during the Holocene and reed-swamps became dominant..After a minor wet-cool pulse during the Late Holocene,the modern climate became to be established.  相似文献   

洱海的营养状态发展趋势的灰色预测   总被引：1，自引：0，他引：1  

倪长健 《成都信息工程学院学报》2001,16(2):117-118

根据洱海多年（1990－1998）的几个主要富营养化指标的普适卡森指标TSIG值，建立了TSIG指数的灰色GM（1，1）预测模型，应用该模型对洱海1999－2004年的营养状态发展趋势进行了预测，此预测结果可为今后的治理提供一定的依据。  相似文献   

Turbulence and Fossil Turbulence in Oceans and Lakes     

Pak-TaoLeung CarlH.Gibson 《中国海洋湖沼学报》2004,22(1):1-23

Turbulence is defined as an eddy-like state of fluid motion where the inertial-vortex forces of the eddies are larger than any of the other forces that tend to damp the eddies out. Energy cascades of irrotational flows from large scales to small are non-turbulent, even if they supply energy to turbulence. Turbulent flows are rotational and cascade from small scales to large, with feedback. Viscous forces limit the smallest turbulent eddy size to the Kolmogorov scale. In stratified fluids, buoyancy forces limit large vertical overturns to the Ozmidov scale and convert the largest turbulent eddies into a unique class of saturated, non-propagating, internal waves, termed fossil-vorticity-turbulence. These waves have the same energy but different properties and spectral forms than the original turbulence patch. The Gibson (1980, 1986) theory of fossil turbulence applies universal similarity theories of turbulence and turbulent mixing to the vertical evolution of an isolated patch of turbulence in a stratified fluid as its growth is constrained and fossilized by buoyancy forces. Quantitative hydrodynamic-phase-diagrams (HPDs) from the theory are used to classify microstructure patches according to their hydrodynamic states. When analyzed in HPD space, previously published oceanic datasets showed their dominant microstructure patches are fossilized at large scales in all layers. Laboratory and field measurements suggested phytoplankton species with different swimming abilities adjust their growth strategies by pattern recognition of tur-bulence-fossil-turbulence dissipation and persistence times that predict survival-relevant surface layer sea changes. New data collected near a Honolulu waste-water outfall showed the small-to-large evolution of oceanic turbulence microstructure from active to fossil states, and revealed the ability of fossil-density-turbulence patches to absorb, and vertically radiate, internal wave energy, information, and enhanced turbulent-mixing-rates toward the sea surface so that the submerged waste-field could be detected from a space satellite (Bondur and Filatov, 2003).  相似文献   

失色的陆地明珠--中国湖泊状况的思考   总被引：1，自引：0，他引：1  

吴岗 《国土资源》2002,(10):18-21

湖泊:陆地上较封闭的天然洼地中蓄积着停滞的或流动缓慢的水体。 湖泊有“天然水库” 的美誉。它不仅为江河大川调节洪枯,而且蕴藏着丰富的淡水资源。在全球约8万立方千米的淡水储量中,湖泊占据了0.26％。  相似文献