Ye Baisheng

Responses of various-sized alpine glaciers and runoff to climatic change

This paper presents a glacier ice-flow model that simulates changes to alpine glaciers of various sizes and their runoff response to climate change in the Yili river basin in the Tien Shall mountains, northwestern China. It is suggested that the sensitivity of glaciers to climatic change is determined by glacier size. The change in glacial runoff does not keep pace with climactic change. As climate warms and glaciers retreat, the glacier runoff tends to increase and then decrease. The runoff peak and its timing depend not only-on glacier size but also on the rate of air-temperature rise.

Different response of vegetation to permafrost change in semi-arid and semi-humid regions in Qinghai–Tibetan Plateau

The effects of the depth of the active layer of permafrost on aboveground vegetation in semi-arid and semi-humid regions of the Qinghai–Tibetan Plateau were studied. The depth of active permafrost was measured and aboveground vegetation recorded. Differences in correspondence between permafrost depth and aboveground vegetation in semi-arid and semi-humid regions were analyzed. Vegetation cover and biomass were well correlated with permafrost depth in both semi-arid and semi-humid regions, but the correlation coefficient in the semi-arid region was larger than in the semi-humid region. With the increase in permafrost depth, vegetation cover and biomass decreased in both regions. Species richness and diversity decreased with increasing depth of permafrost in the semi-arid region. In the semi-humid region, these at first increased and then decreased as permafrost depth increased. It seems likely that vegetation on the Qinghai–Tibetan Plateau will degenerate to different degrees due to permafrost depth increasing as a result of climatic warming. The influence would be especially remarkable in the semi-arid region.

Mass balance sensitivity to climate change: A case study of glacier No. 1 at urumqi riverhead, Tianshan Mountains, China

In this paper the degree-day mass balance model is applied to the sensitivity test of mass-balance/ELA (equilibrium line altitude) to climate change of Glacier No. 1 at Urumqi Riverhead, the Tianshan Mountains, China. The results demonstrate that the mass balance of Glacier No. 1, which is of continental type and accumulates in warm seasons, is less sensitive than that of a maritime glacier. On Glacier No. 1, air temperature rise of 1°C or precipitation increase by 20% can cause the ELA shift 81 m up or 31 m down respectively. Air temperature and precipitation play the different roles in the mass balance formation, in which the mass-balance hypsometry follows the temperature variations by the means of rotation against the elevation axis and it shifts in parallel with precipitation change. Assuming a future temperature rise of 2 °C the mass losing trend on Glacier No. 1 can not be radically alleviated even if there is a precipitation increase by 30%.

The application of remote sensing technology in the glacier change monitoring of Yulong Mountain

This study, based on remote sensing and GIS technologies, the glacier distribution map and related parameters in 1999 are obtained with some spatial data including remote sensing images, DEM, and so on. Compared to data in 1957, in 1999, there are only 15 glaciers in this area and 4 glaciers disappeared; the glacier area is 8.5, with the total reduction of 26.78% and the annual reduction of 0.64%; the average terminus altitude is 4649m, with the annual raise of 3.2m. In the period of 42 years, the glaciers in Mt. Yulong region have been retreated greatly. This mainly results from the temperature increasing in the background of global warming. Furthermore, there are some differences of glacier change in the spatial scale, and those are controlled by some topographical factors like aspect, terminus altitude. In addition, according to the observation data on Baishui Glacier No.1, it can be predicted that the glaciers in Mt. Yulong region will be further shrink with the enhanced global warming.

A model simulating the processes in responses of glacier and runoff to climatic change

This paper presents a dynamic glacier model that simulates the processes in response of Glacier No. 1 in headwaters of the Ürümqi River to various future climatic scenarios. The results indicate that the Glacier No. 1 will continue retreating if current climatic conditions prevail, until it reaches an equilibrium state of 1600 m in length after 700 to 800 years. If air temperature raise 1°C, the glacier would become a hanging glacier with a length of 300 m after 700 to 800 years. Due to its retreat, cooling function of the glacier would be weakened, resulting in the air temperature in glaciated area higher than that in ice-free areas. The results also indicate that the current glacier melt runoff is in higher value period in comparison with the runoff in the equilibrium state under the current climatic condition. If the air temperature continues increasing, however, the runoff would still increase to a new peak and then decrease rapidly.

Glaciers in China and Their Variations

This chapter summarizes recent glacier variations in China as investigated using remote-sensing methods. We find that glaciers in China have lost a tremendous amount of ice mass since the Little Ice Age maximum: area and ice volume have decreased by 26.7 and 24.5 % of the respective amounts of glaciers based on maps compiled during the late 1950s and 1980s. Chinese Glaciers have been in a general state of mass loss during recent decades as monitored by satellite remote-sensing methods over glaciers totaling one fifth of the glacier area in China. At present, the ability to monitor ice volume change and the surface velocity of glaciers by satellite is relatively new, but shows potential for glaciers having complex topographical conditions in the high mountains. This is an important research focus, in part because Chinese economic development is locally heavily impacted by changes in the glacier dynamical regime due to (1) glaciers’ role in supplying meltwater to most of the region and (2) potential for local glaciological hazards.

Study on runoff process of the glacier and permafrost in the headwaters of Urumqi River

Based on the fact that the climatic change impacts on the hydrological process in the alpine region in the headwaters of Urumqi River, the analysis that the runoff change of glaciers, snow and permafrost in the headwaters make a response to the change of temperature and precipitation is significant to understand the impact of the climatic change on the runoff change in cold and arid regions and the rational use of water resource. The date of spring runoff occurrence on May all postponed in both Glacier No.1 and dry cirque hydrological section, and runoff halt time is also a not significant on September, which indirectly present a delayed ablation season; on the other hand, the spring runoff since 2000 is more than that in 1980s, and the variation amplitude of runoff since 2000 is less than that in 1980s during the high ablation season, both summer runoff and runoff variation amplitude in dry cirque hydrological section all increase clearly, which mainly implied that precipitation high increase resulted in hillside runoff increase in alp permafrost.