Recent progress of glaciological studies in China

Glacier inventory compilation during the past 20 years and modifications ofthat for the Eastern Pamir and Banggong Lake indicate that there are 46,342 modern glaciers with atotal area and volume of 59415 km^2 and 5601 km^3 respectively in China. These glaciers can beclassified into maritime and continental (including sub-continental and extremely continental)types. Researches show that glaciers in China have been retreating since the Little Ice Age and themass wastage was accelerated during the past 30 to 40 years. Being an important part ofglaciological studies in China, ice core climatic and environmental studies on Tibetan Plateau andin the Antarctica have provided abundant, high resolution information about past climatic andenvironmental evolution over the Tibetan Plateau and Antarctica. Except for different parametersrecorded in ice cores relating to climate and environment changes on Tibetan Plateau, records fromice cores extracted from different glaciers show that the discrepancies in climatic andenvironmental changes on the north and south parts of the plateau may be the consequence ofdifferent influencing effects from terrestrial and solar sources. Glaciological and meteorologicalphenomena imply that Lambert Glacier valley is an important boundary of climate in the eastAntarctica, which is thought to be connected with cyclonic activities and Circum-polar Waves overthe Antarctica.

Evidence for cold events in the early Holocene from the Guliya ice core, Tibetan Plateau,China

Evidence for the '8.2 ka cold event' has been provided mostly from the circum-North Atlantic area. However, whether this cold event occurred in other places is a key to understanding its cause. Here, we provide the evidence for the '8.2 ka cold event' from the Guliya ice core in the northwest Tibetan Plateau, and it was found that the peak cooling (-8.3-8.2 ka) in this ice core was about 7.8-10°C, which was larger than the cooling in the North Atlantic region. The primary causes for this episode were diminished solar activity and weakened thermohaline circulation. Moreover, another weak cold event, centered about 9.4 ka, was also recorded in the Guliya ice core record. These two cold events were concurrent with the ice-rafting episodes in the North Atlantic during the early Holocene, which implies that the millennial-scale climatic cyclicity might exist in the Tibetan Plateau as well as in the North Atlantic.

Paleosandstorm characteristics and lake evolution history deduced from investigation on lacustrine sediments——The case of Hongjiannao Lake, Shaanxi Province

Sediment cores from desert lakes serve as good records of the frequency and intensity of sandstorms in his- tory. By multi-proxy analysis of grain-size, magnetic suscep- tibility, TOC and Rb/Sr ratio, the paleosandstorm character- istics and lake evolution history in Yulin Area for the past 80 years. are discussed in this article. It is revealed that Hong- jiannao Lake formed in about 1928 A.D. and in its initial stage sandstorms were prevalent with three extremes taking place in 1936 A.D., 1939 A.D. and 1941 A.D.. During the ex- pansion period of 1952―1960 A.D., inflow waters to the lake increased sharply and a lot more weathered materials were carried into the lake. The frequency and intensity of sand- storms have reduced a lot since 1960s and the “double peaks” feature of the grain-size frequency curve has changed into the “single peak” feature. Study on the catchment ecol- ogy of the lake shows that the occurrence of sandstorms has been effectively restrained by the forest plantation and water and soil conservation.

Ecological Environment Change in North Slope of Qilianshan Mountains

Based on meteorological,hydrological, forest,and grassland data collected by location observation,remote sensing,field surveys and relevant literature during 1956 to 2009,the ecological environment change in northern slope of the Qilianshan Mountains was analyzed synthetically using regression and correlation analyses.The results showed that the temperature had an annual variation rate of 0.033 4℃·a-1 in northern slope of the Qilianshan Mountains since 1960,and exhibited a raising trend,especially since 1987.The annual variation rate of annual precipitation was 0.570 2 mm·a-1,indicating that the precipitation tended to increase.The climate had changed from arid to humid in this region since 1976.From 1956 to 2006,the glacier area of six inland river basin（Shiyanghe river,Heihe river, Beidahe river,Shulehe river,Danghe river and Halternhe river） and Datonghe river basin in northern slope of Qilianshan mountains decreased by 17.7%. Thickness of the glacier reduced about 5-20 m,and the snow line rose about 100-140 m.The Glacier ice reserves in inland river basin of Hexi decreased by 11.4%.From 1972 to 2007,27 glaciers in the eastern section of the Qilianshan Mountains disappeared.From 1956 to 2009,the runoff change in the northern slope of the Qilianshan Mountains was different in different regions.The runoff was reduced significantly in Shiyanghe river basin, increased slightly in Heihe river basin,and increased obviously in Shulehe river basin.From 1958 to 1988, the area of deforestation and farming was more than 10.0 million ha,and the forest area was reduced 0.6 million ha.Since the Qilianshan Mountain Nature Reserve was established in 1989, the forest was restoring gradually because of continual protection and cultivating,and the forest area was increased 9.4 million ha from 1989 to 2008. Due to human interference,especially over-grazing impact,the quality of the wood-land,shrub-land and grass-land in northern slope of the Qilianshan Mountains were in a degraded condition,which resulted in serious harm of forest pests,decrease of shrubbery snow and water-retention capacity and exacerbation of soil erosion.The ecological environment in northern slope of the Qilianshan Mountains was improved in certain regions,but deteriorated in overall region,and the protection and management are needed to be strengthened.