Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia

~~Holocene grassland vegetation, climate and human impact in central eastern Inner Mongolia1.Ye,D.Z.,Chou,J.E,Liu,J.Y.et al.,Causes of sand-stormy weather in northern China and control measures,Acta Geographica Sinica(in Chinese),2000,55(5):513-520. 2.Qiu,X.E,Zeng,Y.,Miao,Q.L.,Temporal spatial distribution as well as tracks and source areas of sand dust storms in China,Acta Geographica Sinica(in Chinese),2001,56(3):316-322. 3.Cui,H.T,Kong,Z.C,Preliminary analysis on the cli…     

内蒙古额济纳旗苏泊淖尔石制品的发现及当时的环境特征

在进行地质环境调查过程中,在内蒙古额济纳旗苏泊淖尔Ⅰ级湖积阶地面上发现古人类遗存的石制品,包括石砧、石斧、石片、石核等,大致应属于全新世的遗存。天鹅湖剖面距地表70.5cm深处14C测年结果为4930a±152a,表明该剖面主要形成于全新世,与苏泊淖尔石器的时代相同,其中的记录可反映古人类活动时期的气候特征。据孢粉组合变化可以确定,该区气候总体处于干旱—半干旱状态。剖面下部在相对干旱的背景下显示出一定程度的温湿气候环境,剖面中部则为干旱稳定发展期,成为全剖面干旱程度最强、温度较低的时期,而剖面上部又表现出温度和湿度略有升高的趋势。     

SEDIMENT CONTROL MEASURES IN SERIOUS SOIL EROSION REGION IN CHINA

I.INTRODUCTIONSoilerosionareasinChinasearchto3.67millionkm'whichoccupies38.2%OfthewholeareainChina.Thesoilerosionregionisspreadingovertheti)holecountry.Amongthat,soilerosionbyrainfallistermedas"watererosion"whichisdistributedinmountainsandhillarea.soilerosionbywindistermedas"winderosion",mainlydistributedinareasalongtheGreatWall,soilerosionbyfreezeandmeltistermedas"freezeerosion",mainlydistributedinhighmountainarea.Inthepastfortyyears,manyintegrateharnessmeasureshavebeenaPPliedindiffer…     

IPCC第二次气候变化科学评估报告的主要科学成果和问题

介绍了政府间气候变化委员会(IPCC)最近出版的第二次气候变化科学评估报告中的主要科学成果,并说明了今后3～4年中IPCC从科学上主要关注的问题。     

主要人类工程活动与地质环境相互作用图的编制

该图通过区域地质环境条件差异和主要人类工程活动引起的地质灾害，来反映主要人类工程活动与地质环境相互作用的规律。从而，圈划出主要人类工程活动与地质环境相互作用强列地区，它们是沪宁杭地区、湘中南桂东地区、攀西一六盘水地区。     

Responses of soil nutrient to driving mechanism in Taihu Lake basin in last 20 years

1 IntroductionPopulation growth and economic development aggrandizes day by day pressure on land resources, which results in serious land degradation and environmental pollution[1]. The status and management of land resources has become one of the highlights of global soil study[2]. Human-induced soil changes and their effects on human lives and eco-environments have received extensive attention[3-7]. Improving soil quality is one of the most important factors for sustaining the global biosphe…     

水文科学的基本问题及当代前沿

回顾了新中国70年来水文科学的发展历程。阐述了水文科学的基本问题及其当代前沿：水圈及其与地球其他圈层的界面过程；水文循环及人类活动对水文循环的扰动；水文学研究的特点及其方法论；水文知识的应用等。提出了划分水文科学分支学科的科学基础，建议将水文科学划分为普通水文学、水文气象学、陆地水文学、生态水文学和应用水文学5个分支学科。     

ON THE REDUCTION OF WATER AND SEDIMENT YIELD OF THE YELLOW RIVER IN LATE YEARS

ＯＮＴＨＥＲＥＤＵＣＴＩＯＮＯＦＷＡＴＥＲＡＮＤＳＥＤＩＭＥＮＴＹＩＥＬＤＯＦＴＨＥＹＥＬＬＯＷＲＩＶＥＲＩＮＬＡＴＥＹＥＡＲＳＧＵＷｅｎｓｈｕＡｂｓｔｒａｃｔ：ＴｈｅｒｅｃｏｒｄｅｄｈｙｄｒｏｌｏｇｉｃｄａｔａｏｆｔｈｅＹｅｌｌｏｗＲｉｖｅｒｉｎｄ...     

Temporal variations of fossil Cladocera in the sediments of Lake Orta (N. Italy) over the last 400 years

We use Cladocera remains in the sediments to reconstruct the longterm history of Lake Orta, a lake which experienced severe pollution from copper and ammonium sulphate, and started to recover during the last 15 years. Both human and natural impacts were detected over almost 400 years. Pollution was manifested by a dramatic decrease in the number of remains, in the planktonic/littoral (P/L) ratio, and in chydorid species diversity. Most species, even those most tolerant to stress, disappeared. The recolonization of biota was initially sustained by one species of chydorid,Chydorus sphaericus, which had a three-fold increase at the beginning of the 1980s, when studies on plankton recorded the development of a pelagic population. This fact, and the appearance in the sediments ofAlona quadrangularis, attest to the development of filamentous algae which was reported in studies on the plankton. The colonization of the lake by pelagic species came only in the last twelve years and was manifested also as a stabilization of the P/L ratio. Two other periods of disturbance were detected in the sediments: the first, at the end of the 19th century, was related to the introduction of exotic fish species; the second occurred during the second half of the 17th century. This event probably cannot be ascribed to human impact, but may be related to a decrease in temperature in that period (the Maunder Minimum).     

松江的地质人文旅游资源

上海郊县松江是一个古城,文物古迹甚多,其第四纪全新形地层发育,属典型软土,从而引发了诸多与建筑学有关的奇异地质事件,吸引着地质旅游者前去探秘,成为尚待开发的富有潜力的地质旋游资源。