Monitoring of snowline altitude at the end of melting season in Tianshan Mountains from 1991 to 2021

Subjects: Geosciences >> Cartography submitted time 2022-12-20 Cooperative journals: 《干旱区研究》

王靖文 唐志光 邓 刚 胡国杰 桑国庆

Abstract：

The study of snowline altitude changes at the end of the melting season is helpful to predict future trends of snow systems in order to understand the regional and global climate changes. The remote sensing extraction method of region snowline altitude was developed based on the Google Earth Engine and Landsat satellite data. From 1991 to 2021, the snowline altitude at the end of the melting season in the four basins of the Tianshan Mountains was extracted. The variation characteristics of snowline altitude and its relationship with meteorological factors were carefully and accurately estimated. The results were as follows: (1) the extended snowline altitude at the end of the melting season correlated well with the snow cover extent (minimum) at end of the melting season, which was extracted by Sentinel-2. The overall accuracy was 91.6%, and the Kappa coefficient was higher than 0.9. The regional snowline altitude at the end of the melting season was accurately obtained with this model. (2) Generally, the snowline altitude at the end of the melting season in the study area showed an obvious increasing trend over the last 30 years. The increase rate was between 2.7 m·a-1 and 6.4 m·a-1 . The rise rate of the snowline altitude in the Manas River Basin was the fastest (6.4 m·a-1 ), while the rise rate of the snowline altitude in the Akeyazi River Basin was the slowest (2.7 m·a-1 ). (3) The summer temperature was the main factor that affected the change in the snowline altitude at the end of the melting season in the study area (P < 0.05), while the effect of precipitation was relatively weak.

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基于栅格的关中平原城市群人居环境质量综合评价

Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-11 Cooperative journals: 《干旱区地理》

魏献花 白永平 车磊 王栋 效瑞 张文娴

Abstract：基于自然与人文多重栅格数据，构建人居环境质量综合指数评价模型，分析2015年关中平原城市群人居环境的空间分异格局，并对人口分布与人居环境质量的协同性进行探讨。结果表明：(1)人居自然环境呈现出自东向西，由山地、高原向平原、谷地依次递减的空间分布格局，受地形影响最为明显，地形起伏度与人居自然环境呈负相关关系。(2)人居人文环境表现出平原低、山区高，城镇高于乡村的空间分布格局，受城市行政层级影响显著。(3)关中平原城市群人居环境综合质量指数介于0.216～0.716之间，呈现出以关中平原、汾河谷地向外梯级递减的带状空间分布格局。(4)关中平原城市群人口密度与人居环境质量空间分布显著一致，总体呈现出平原高于山地，城市高于乡村的空间分布规律，人居环境质量越高，人口密度越大，土地利用也越充分。

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