Retrieval of key eco-hydrological parameters for cold and arid regions

Retrieval of eco-hydrological variables/parameters from the world's cold and arid regions using remote sensing is more challenging compared to other regions, and less research work on quantitative remote sensing has been carried out in these specific regions. This is because: (1) Cold and arid regions are most likely to be located in the world's remote and relatively under-developed areas, where conventional in situ observations are more scarce and more difficult to be carried out so that the validation of remote sensing is more difficult. (2) Terrain in cold and arid regions is usually more complex and landscape is more fragmented and heterogeneous. The special issue aims to address these challenges.

The papers appeared in this special issue use two regions as the case study areas. Both of them are located in west China, where one of most diverse and fragile environments exists in the world, with the Qinghai-Tibetan plateau elevated in the south and high mountains, plateaus, deserts, and oases interspersed in the north. The first case study area is the Qinghai-Tibetan plateau (QTP), the so-called world's third pole. QTP is a cold area, where the cryosphere dominates the natural environment and changes rapidly in recent years. Another case study area is the Heihe river basin, the second largest and a very typical inland river basin (endorheic basin) in northwest China, where mountain cryosphere and the world's driest area coexist. Environmental change in China's inland river basins is controlled by water resource availability, which is further influenced by both climate change and human activities such as farming and grazing.