AAssessment of the spatial-temporal eutrophic character in the Lake Dianchi

Water-quality deterioration and eutrophication of the Lake Dianchi have acquired more and more attention in the last few decades. In this paper, the spatial and temporal eutrophication status of the Lake Dianchi was assessed. The comprehensive trophic state index was chosen to assess the trophic status of the Lake Dianchi in the past 13 years. The result reveals that the trophic condition of Caohai is more serious than that of Waihai. Most of time Caohai was in extremely hypereutrophic state from 1988 to 2000. The trophic condition of Waihai had a worsening tendency from 1988 to 2000. Waihai was in eutrophic state before 1995, but it got in a hypereutrophic state after 1995. It was pointed out that TN and TP were the two biggest contributors of CTSIM in both Caohai and Waihai.     

Human settlements in the Ordos Plateau since the Neolithic Age

Settlements are excellent spatiotemporal indicators for studying historical human activities and environmental change. This paper discusses the spatial and temporal changes of sites on the Ordos Plateau in China since the Neolithic Age, based on an analysis of spatiotemporal distribution characteristics of the human settlements. The frequency of human settlements on the Ordos Plateau presented a phased fluctuation process, and the sizes were mainly small and medium. The spatial distribution of h...     

G-WADI—the first decade

The G-WADI network by UNESCO promotes the global capacity for management of water resources in arid and semi-arid areas. The primary aim has been to build a comprehensive global network to promote regional and international cooperation so as to increase knowledge and improve management practices through the sharing of information. The G-WADI objectives and achievements of the past 10 years are reviewed. A number of key initiatives have been implemented––the formation of five regional networks, the creation of a central G-WADI web site, promotion of near-real-time rainfall distribution software enhanced by the inclusion of satellite based precipitation estimations, as well as workshop and web-based activities on chemical and isotopic tracers and on rain water harvesting. Two workshops on surface and on groundwater modeling, supported by publications have been held in India and China. The Asian G-WADI network remains very active, but activities in the other three regions are developing (Africa, Arab Region, Latin America and the Caribbean).     

An Important Forum for the Future of the World＇s Rivers： The 8th International Riversymposium in Brisbane

The 8th Intemational Riversymposium was held in Brisbane, Australia on 6-9 September 2005. The Intemational Riversymposium is an integral part of Brisbane＇s annual broadbased cultural event. The Queensland Government is a foundation partner of the Intemational River Foundation, formed to secure the future of the Intemational and National Thiess Riverprize. The theme of symposium in this year is “Water and Food Security- Rivers in a Global Context” （ www.riversymposium.com ）. The Riversymposium provides a global forum which aims to make a difference to the declining state of rivers and waterways globally. Its strength lies in the breadth of its challenging program content of important keynote presentations and case studies of rivers in crisis, attracting a diverse range of national and intemational delegates. Some 450 scientists from 38 countries attended this conference, and about 100 papers were presented on the symposium in 2005.     

Variations and trends of the freezing and thaw- ing index along the Qinghai-Xizang Railway for 1966?2004

Annual freezing and thawing index of 7 meteorological stations along the Qing-hai-Xizang Railway were calculated based on daily maximum and minimum temperature records for 1966?2004. Trends of annual freezing and thawing index were analyzed using the Mann-Kendall test and a simple linear regression method. The results show that: 1) The mean annual freezing indices range from 95 to 2300℃·d and the mean annual thawing indi-ces range from 630 to 3250℃·d. The mean annual freezing index of the 7 stations exhibited decreasing trends with decreasing rate of ?16.6– ?59.1℃·d /10a. The mean annual thawing index of these 7 stations showed increasing trends with the related decreasing rate is 19.83–45.6℃·d /10a. 2) The MK trend test indicated the significant decreasing trends (sig-nificant at < 0.05 significant level) in the annual freezing index for most stations except for Golmud. The significant increasing trends can be observed in the annual thawing index for 4 stations except Golmud and Tuotuohe. Golmud was the only station with no trends in both annual freezing and annual thawing index.     

The δ~(18)O in the Guliya shallow ice core during the prevailing summer monsoons and sea-air interactions

1 Introduction The Tibetan Plateau is gigantic in extent and has the highest elevation and the most complex topography in the world. Its existence is of important significance for the formation of atmospheric circulation, weather and climate in China, much of Asia and even of the globe. Therefore, great attention is given to it. The analyses show that the influencing range of the Tibetan Plateau is the widest during the summer[1]. The powerful updrafts from the plateau warm low flow towar…     

Study on the distribution,abundance and growth condition of Antarctic Krill(Euphausia superba)in the Prydz Bay region,Antarctica during the Austral summer of 1999/2000

Antarctic krill (Euphausia superba) were collected from the Prydz Bay region during the austral summer of 1999/2000. The sample - collection was made at 15 sites in 3 longitudinal transects. Although krill were encountered at 14 sites, the abundance was comparatively low in general. The main component of the krill population was of post -larval stages. The mean numerical and weight density of krill integrated for all sampling stations in the survey area were 16. 17 ind. 1000 m -3and 12.02 g 1000 m -3 , respectively. In the survey area, stations with larger krill density are mainly located in the slope zone, except that the largest sample was collected in the open sea zone. No krill occurred in the only station of the shelf zone during our investigation. Krill collected from the slope zone were under better growth condition than those from the open sea zone, but when the survey area is considered as a whole, the growth condition is normal. The results of the comprehensive analysis of the environmental fa     

The spatial—temporal dynamic characteristics of the marsh in the Sanjianlg Plain

Using the methods of combining landscape ecology with GIS spatial analysis,this paper analyses the dynamics of the marsh landscape stucture of the Sanjing Plain in the past 20 years,furthermore,taking Fujin County,located in the north of the plain,as an example,analyzes the conversion between marsh and other land use types.It is shown that the marsh in the Sanjiang Plain decreased greatly in the past 20 years,but the trend has begun to reverse,The marsh area decreased by 51.33% from 1980 to 1996,whereas it decreased by 4.19% from 1996 to 2000.The fragmentation of the marsh increased;the number of the patches increased by 326 from 1986 to 1996,whereas it only increased by 18 patches from 1996 to 2000,It is obvious that the speed of patches number diminished and the marsh fragmentation decreased,which shows that the reclamation of the marsh converted from the fragmentation to the brim in a large area of the marsh.The reclaimed marsh has mainly converted to paddy field and dry land .Large area of the marsh.The reclaimed marsh has mainly converted to paddy fiedld and dry land.Large-scale reclamation in the Sanjiang Plain influences its natural environment directly:the climate of the region turns from cold and wet to warm and dry,which makes the marsh both in the low-temperature northern part and in the deeply stagnant eastern part suitable for further agricultural development.     

Engineering Geological Map of the Sakha （Yakutia） Republic

The Engineering Geological Map of the Sakha（Yakutia） Republic covers about 3 million kilometers which is one-fifth of the territory of Russia.The map displays ground and geocryological conditions and active faults.Seismic intensity,schemes of zoning by factors of engineering geological conditions,and the general scheme of engineering geological zoning of the Sakha（Yakutia） Republic or the SR（Y）,are shown on the inset maps.The map is required to provide information for planning,construction and exploitation of engineering structures in the SR（Y）.A distinguishing feature of the map is the indication of almost blanket distribution of the frozen ground class.Types of the frozen ground class are separated by lithology,while ground varieties are separated by temperature.Fresh and ultra-fresh suprapermafrost water is predominant within the territory.The compiled map indicates parts of the Arctic-Asian and Baikalo-Stanovoi planetary seismic belts that make engineering geological conditions more complicated.     

SR-XRF analysis of Polytrichum in the Fildes Peninsula,Antarctica

In order to study the element contents and distribution of various mosses collected in the Antarctica, we analyzed the heavy elements of 3 species of Polytri-chum in the Fildes Peninsula, P. alpinum, P. juniperinum and P. alpestre, by synchrotron radiation X-ray fluorescence ( SR-XRF). The result shows that the elements, such as K, Ca, Mn, Fe, Cu, Zn and Sr, are nearly the same in Potytrichum. The peak intensity of K is higher than that of Ca, and the peak intensity of Ca is higher than that of Fe in P. alpinum. In P. juniperinum, the peak intensity of K is higher than that of Ca, and the peak intensity of Ca is close to that of Fe. The peak intensity of K is nearly equal to those of Ca and Fe in P. alpestre. Therefore, the habitats of 3 species of Polytrichum are similar in the Fildes Peninsula. By XRF analyzing of different parts of P. alpestre, we found that the peak intensities of relative concentration of elements are obviously different. The peak intensity of K in apical-bud is the highest in orga     

Impact of the shrinking winter wheat sown area on agricultural water consumption in the Hebei Plain简

This study firstly analyzed the shrinkage of winter wheat and the changes of crop- ping systems in the Hebei Plain from 1998 to 2010 based on the agricultural statistic data of 11 cities and meteorological data, including daily temperature, precipitation, water vapor, wind speed and minimum relative humidity data from 22 meteorological stations, and then calcu- lated the water deficit and irrigation water resources required by different cropping systems, as well as the irrigation water resources conserved as a result of cropping system changes, using crop coefficient method and every ten-day effective precipitation estimation method. The results are as follows. 1） The sown areas of winter wheat in the 11 cities in the Hebei Plain all shrunk during the study period. The shrinkage rate was 16.07% and the total shrinkage area amounted to 49.62×10^4 ha. The shrinkage was most serious in the Bei- jing-Tianjin-Tangshan metropolitan agglomerate, with a shrinkage rate of 47.23%. 2） The precipitation fill rate of winter wheat was only 20%-30%, while those of spring maize and summer maize both exceeded 50%. The irrigation water resources demanded by the winter wheat-summer maize double cropping system ranged from 400 mm to 530 mm, while those demanded by the spring maize single cropping system ranged only from 160 mm to 210 ram. 3） The water resources conserved as a result of the winter wheat sown area shrinkage during the study period were about 15.96×10^8 m^3/a, accounting for 27.85% of those provided for Beijing, Tianjin and Hebei by the first phase of the Mid-Route of the South-to-North Water Diversion Project.     

Dynamics of the global semiconductor trade and its dependencies

The semiconductor industry typifies the international division of labor and exhibits significant structural differences in global trade in key product segments. The evolution of cross-border trade flows and dependency relationships, as well as trade organization patterns of manufactured products, equipment and materials for manufacturing, are investigated by constructing a global semiconductor trade relationship matrix and using the Gini coefficient and trade dependency index. It was found that:...     

Understanding the spatial heterogeneity of grazing pressure in the Three-River-Source Region on the Tibetan Plateau

Elucidating the distribution of the grazing pressure requires an understanding of the grazing activities. In this study, we analyzed the grazing behavior of yaks in Three-RiverSource Region(TRSR) and identified the main factors influencing the distribution of grazing intensity(GI) using trajectory data and remote sensing datasets. Our results revealed that a semi-resident transhumance strategy is employed in this region. The average grazing time(GT) of four GPS collars over the year was 11.84 h/...     

Progress in China’s climate change study in the 20th century

IPCC (2001) pointed out that the earth's climate was undergoing a remarkable change with characteristics of global warming over the past 100 years. The latest research showed that the global mean surface temperature has increased by about 0.6 oC since 1861. It is very likely that the last 20 years in the 20th century was the warmest decades. The Northern Hemisphere temperatures in the 20th century appeared to have been unprecedented during the past millennium. The research also indicates th…     

Regional disparity in the changes of agricultura land use intensity in China during 1980-2002

Based on the cost-benefit data （1980-2002） of farm products and China Agriculture Yearbooks, this paper studies the regional disparity in the changes of the agricultural land use in China during the period 1980-2002 from three aspects such as the degree of intensity, the sown area and the abandoned farmland. The results show that： （1） The degree of intensity of land use in the westena region during 1980-2000 has a strong uptrend, but in the eastern and central regions the degree of intensity descends obviously and has shown a continuous downtrend since 1997. （2） The total sown area shrinks notably in the eastern region, while it enlarges constantly in the western region. （3） The sown area in the eastern, central and western regions has gone through a similar cyclic process： down （1980-1985）-up （1985-1991）-down （1991-1994）-up （1994-1999）-down （1999-2002）. However, there are obvious differences in amplitude variation and tendency among them. The sown area has shrunk in the eastern region and expanded in the central and western regions especially before 1999. （4） The most cases of abandoned farmland are reported in the central region, the second in the eastern region and the least in the western region. The abandonment phenomena chiefly occurred during 1992-1995 in the eastern region, and during 1998-2002 in the central region.     

Human sedentism and use of animal resources on the prehistoric Tibetan Plateau

The transition of human societies from high mobility to sedentary lifestyles had a profound impact on subsistence, technology, and the origin of civilization. Sedentism was influenced by various factors such as climate change, population growth, resource pressure,and technological innovation. The Tibetan Plateau, due to its alpine and hypoxic conditions, is an ideal region to study human adaptation to extreme environments. However, the prehistoric process of sedentism on the Tibetan Plateau is u...     

Glacial changes in the Gangdisê Mountains from 1970 to 2016

Based on the revised First Chinese Glacier Inventory(FCGI), the Second Chinese Glacier Inventory(SCGI) and Landsat OLI images for 2015–2016, we analyzed the spatial-temporal variation characteristics of glaciers in the Gangdisê Mountains from 1970 to 2016. The results showed that there were 3953 glaciers with a total area of 1306.45 km~2 and ice volume of ～58.16 km~3 in the Gangdisê Mountains in 2015–2016. Glaciers with sizes of 0.1–5 km~2 and 0.5 km~2 accounted for the largest area and the most amounts of glaciers in the Gangdisê Mountains, respectively. Over the past five decades, the area of glaciers in the Gangdisê Mountains decreased by 854.05 km~2(-1.09%·a~(-1)), accounting for 39.53% of the total glacier area in 1970. The increase in temperature during the ablation period was the most important cause for glacier retreat. Compared to other mountains in western China, the Gangdisê Mountains have experienced the strongest glacial retreat, and the rate of recession has increased in recent years. The decrease of glacier area was mainly concentrated at elevations of 5600–6100 m, and no change in glacier area was observed at elevations above 6500 m. The number and area of glaciers decreased in all orientations in the Gangdisê Mountains except for south-and southeast-oriented glaciers. Among them, north-oriented glaciers suffered the largest loss of glacier area, while glacier retreat saw the fastest in northwest-oriented glaciers. The rate of glacier retreat increased from west to east in the Gangdisê Mountains. The relative rate of glacier area change was the highest in the eastern section of the Gangdisê Mountains(-1.72%·a~(-1)), followed by the middle section(-1.67%·a~(-1)) and the western section(–0.83%·a~(-1)).     

Desert-steppe migration on the Loess Plateau at about 450 kaBP

According to the field investigation, observation by an electronic microscope and x-ray identification and chemical analysis, desert-steppe migration in the Loess Plateau at about 450 kaBP was studied. The data show that gypsum illuvial horizon indicating the desert-steppe environment developed in the early stage of the formation of the fifth layer loess in Shaoling tableland in Chang‘an and Bailu tableland in Xran of Shaanxi are situated in the southern Loess Plateau. This indicates that remarkable drying occurred, a large-scope migration of desert steppe took place toward south and the climate zone migrated 5 degrees in latitude to south which is the largest migration range indicated by geochemical indexes. The desert-steppe and more wild environment distributed widely on the Loess Plateau at that time. The development of gypsum also indicates that the climate changed at 450 kaBP from monsoon climate to nonmonsoon climate in the Loess Plateau, and the region was not affected by summer monsoon and was in the cold and dry environment of nonmonsoon climate. Annual mean nrecinitation was about 200 rnm. 400 mm less at that time than at oresent.     

Fourth International Symposium on the Harmonization of Quality Assurance Schemes for Analytical Laboratories

The IUPAC-ISO-AOAC Fourth Symposium onthe Harmonization of Quality AssuranceSchemes for Analytical Laboratories will be heldon 2 and 3 May 1991 at ISO Central Secretariat,1 rue de Varembé,Geneva,Switzerland.The aims of the Symposium are (1)using as a     

Dynamical variations in groundwater chemistry influenced by intermittent water delivery at the lower reaches of the Tarim River

The water of Bosten Lake was released to lower reaches of the Tarim River for 5 times from 2000 to 2002. The changes of total dissolved solid (TDS) and the major ions (SO4^2-, Cl^-, Na^-,Ca^2 , Mg^2- and HCO3^- ) were analyzed during this period. It was found out that TDS and the concentrations of the major ions initially and quickly increased and then decreased, but finally increased again. These changes were different at different distances from the river, which indicated that the groundwater changes relied on the distance from the river. In addition, the salt in groundwater was only diluted but not removed by the water. It was suggested that ecological measures should be sought to really promote the quality of the groundwater at the lower reaches of the Tarim River.