The cryosphere is defined as the frozen part of atmosphere, hydrosphere, biosphere and lithosphere. This includes ice sheets, ice shelves, ice caps and glaciers, sea ice, seasonal snow cover, lake and river ice and seasonally frozen ground and permafrost. The importance of the cryosphere in the global climate system is related to the significant seasonal change of snow and ice cover, which affects the amount of energy absorbed at the surface dramatically. Studies have shown that the cryosphere is very sensitive to global change so that the change of cryosphere is considered as an indicator of global change. Global warming can cause a significant shrinkage in cryosphere extent and volume, therefore, impacting greatly on human living. Global warming will also cause a positive feedback between snow and ice albedo and air temperature, and change permafrost area from carbon sink to carbon source. These processes will have great feedback on climate system (IPCC, 1990; IPCC, 1992; Fitzharris, 1995; Cheng, 1996 and Nelson, F.E., Lachenbruch, A.H. et al., 1993. Permafrost and changing climate. In: Proceedings Volume 2 of Sixth International Conference on Permafrost, Yellowknife, Canada. Nordicana Quebec, South China University of Technology Press, Wushan, Guangzhou, China, pp. 987–1005.Nelson et al., 1993).

 

China has a vast expanse of cryosphere which contains a large portion of the world's middle- and low-latitude mountain glaciers. China's permafrost area ranks third in the world and is first in terms of the middle- and high-altitude permafrost area. In particular, the Qinghai–Tibet Plateau plays a very important role in global change. Therefore, the Lanzhou Institute of Glaciology and Geocryology, Chinese Academy of Sciences (LIGG) had made efforts to establish a geographic information system (GIS) of the Chinese cryosphere (Li et al., 1997 and Li, 1998), namely, the Chinese ryosphere Information System (CCIS). The objectives of CCIS are as follows:

 To make a detailed design of the CCIS, formulating the system standards.

To build up a geographic information system integrated closely with cryospheric models.

To analyze the spatial and temporal change of Chinese cryosphere using GIS technologies.

To develop some application models of cryosphere response to global change

The Chinese Cryospheric Information System (CCIS) is an integrated geographic information system (GIS) for storing, managing and analyzing the cryospheric data within China. Three regions were selected as the case study areas of CCIS. They are the Qinghai–Tibet Plateau, the regions along the Qinghai–Tibet Highway and the Urumqi River Basin of Tianshan Mountain. A draft geo-classification system that can express the logical hierarchy of cryospheric data was established. Based on this, CCIS stored large volumes of data, including maps of glacier, frozen ground and other environmental elements, digital elevation data, observation data of meteorological stations, hydrological gauges and permafrost boreholes and remote sensing data. CCIS is managed by ARC/INFO and can export data to other GIS environments easily, since data exchange interfaces were paid particular attention in the system. Based on CCIS, several GIS-based models about cryospheric processes and cryospheric response to global change have been developed. The models introduced are the following: a response model of high-altitude permafrost to global change, an evaluation model of engineering properties in permafrost regions along the Qinghai–Tibet Highway and a model of glacier mass balance estimation. The modeling results showed that the permafrost and glaciers in Chinese cryosphere will have significant changes under climatic warming.