Monitoring and analysis of snow cover change in an alpine mountainous area in the Tianshan Mountains, China

Abstract

Estimating the snow cover change in alpine mountainous areas (in which meteorological stations are typically lacking) is crucial for managing local water resources and constitutes the first step in evaluating the contribution of snowmelt to runoff and the water cycle. In this paper, taking the Jingou River Basin on the northern slope of the Tianshan Mountains, China as an example, we combined a new moderate-resolution imaging spectroradiometer (MODIS) snow cover extent product over China spanning from 2000 to 2020 with digital elevation model (DEM) data to study the change in snow cover and the hydrological response of runoff to snow cover change in the Jingou River Basin under the background of climate change through trend analysis, sensitivity analysis and other methods. The results indicate that from 2000 to 2020, the annual average temperature and annual precipitation in the study area increased and snow cover fraction (SCF) showed obvious signs of periodicity. Furthermore, there were significant regional differences in the spatial distribution of snow cover days (SCDs), which were numerous in the south of the basin and sparse in the central of the basin. Factors affecting the change in snow cover mainly included temperature, precipitation, elevation, slope and aspect. Compared to precipitation, temperature had a greater impact on SCF. The annual variation in SCF was limited above the elevation of 4200 m, but it fluctuated greatly below the elevation of 4200 m. These results can be used to establish prediction models of snowmelt and runoff for alpine mountainous areas with limited hydrological data, which can provide a scientific basis for the management and protection of water resources in alpine mountainous areas.

Study of snow cover/depth evolution characteristics in Tianshan region of China based on geographical partition

“…5 ). The evolution of snow cover is the most active in Low relief middle altitude mountain, and the evolution of snow cover is the most stable in Middle relief high altitude mountain, The same as the altitude distribution of SCP in the high altitude area of Tianshan region reported by Zhang 45 . There is also a strong correlation between the variation of snow cover and the slope gradient.…”

The spatiotemporal variability in precipitation gradients based on meteorological station observations in mountainous areas of Northwest China

“…Since the 1960s, precipitation in the Tianshan Mountains has been continuously increasing, and the increase has become more significant since the 1980s. The increase in summer precipitation is the largest, and mountainous precipitation shows a clear increasing trend Zhang, Liu, and Tang 2013). Based on the spatiotemporal distribution characteristics of different precipitation intensities in the Qilian Mountains and their relationship with altitude, previous studies have concluded that, apart from the influence of altitude, the height zone of maximum precipitation in the Qilian Mountains is likely to be closely related to the occurrence of maximum relative humidity centers at high and low altitudes and the corresponding centers of strong cold air activity .…”

Investigating the critical influencing factors of snowmelt runoff and development of a mid-long term snowmelt runoff forecasting

“…For snowmelt forecasting, it is important to understand first the relationship between the meteorological influencing factors and snowmelt runoff before identifying the critical influencing ones (Vasil Ev et al, 2013). Common methods used in previous studies include, for instance, by analyzing the correlation coefficient between each factor and snowmelt runoff (Nabi et al, 2011;Zhang et al, 2014), or applying a local sensitivity analysis of individual factors (Zhang et al, 2016;Stigter et al, 2017;Zhang et al, 2022). However, these methods often failed to consider the joint effects of multiple factors.…”