Altitudinal Gradient Characteristics of Spatial and Temporal Variations of Snowpack in the Changbai Mountain and Their Response to Climate Change

Yongming Chen,Xiaoyu Tang,Zehua Chang,Dongmei Liu,Shiguo Xu,Peng Qi,Yang Song

doi:10.3390/w13243580

Abstract

The variations in the snowpack in water towers of the world due to climate change have threatened the amount and timing of freshwater supplied downstream. However, it remains to be further investigated whether snowpack variation in water towers exhibits elevational heterogeneity at different altitude gradients and which climatic factors mainly influence these differences. Therefore, Changbai Mountain, a high-latitude water tower, was selected to analyze the changes in the snowpack by the methods of modified Mann–Kendall based on the daily meteorological data from the China Meteorological Data Service Centre. Meanwhile, the responses of snowpack change to climatic factors over recent decades were assessed and generalized using additive models. The results showed that the snow depth was greater in the higher altitude areas than in the lower elevation areas at different times. Areas with a snow depth of over 70 mm increased significantly in the 2010s. Increasing trends were shown at different altitudes from December to March of the next year during 1960~2018. However, a significant decreasing trend was shown in April, except for altitudes of 600–2378 m. The snow cover time at different altitudes showed a trend of first increasing and then decreasing during 1960~2018. The date of maximum snow depth appears to be more lagged as the altitude increases. In addition, the spring snowpack melted significantly faster in the 2010s than that in the 1960s. The snowpack variation in low-altitude regions is mainly influenced by ET and relative humidity. However, the mean temperature gradually became an important factor, affecting the snow depth variation with the increase in altitude. Therefore, the results of this study will be beneficial to the ecological protection and sustainable development of water towers.

Highlights

This research was conducted in the Changbai Mountains, which are the source of Second Songhua River (SSR), Tumen River (TR), and Yalu River (YR); the area is approximately
Snow depth in the Changbai Mountains was greater in the higher altitude areas than in the lower elevation areas at different times. It showed that snow distribution in the Changbai Mountains exhibits obvious altitude gradient characteristics
This study identified the recent decades and their driving factors in a high-latitude water tower

Summary

Introduction

Mountains are the water towers of the world and are important sources of freshwater; they supply a substantial proportion of both natural and anthropogenic water demands [1,2]. In these high-altitude regions, snow is the main component of the hydrological cycle, because changes in the snowpack have a great impact on streamflow, groundwater recharge, hydropower production [3], agricultural irrigation and ecosystem function [4]. Due to climate change over the past few decades, the duration, depth and cover of snowpacks in these mountain regions have all changed, which has threatened the amount and timing of the freshwater supply [5]. An increasing trend (>0.01 cm/year) in maximum and mean snow depth was found north of 40◦ N in

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