Abstract:

This study uses multi-source remote sensing data， field surveys， in-situ observations and other methods to analyze the spatial patterns of lake ice freezing and melting in the hinterland of the Badain Jaran Desert and the main influencing factors of their differences. The results of the study show that there are four different freezing-melting spatial patterns in the desert： lake ice spreads from the lake shore to the lake center， and the earlier freezing area melts later； the lake ice spreads from the lake shore to the lake center， and the earlier freezing area melts earlier； the ice spreads from one bank of the lake to the other bank， and the earlier freezing area melts later； the lake ice extends from one bank of the lake to the other bank， and the earlier freezing area melts earlier. The freezing-melting spatial pattern of most of the smaller lakes is： lake ice spreads from the lake shore to the lake center， and the earlier freezing area melts later. The difference between different freezing-melting spatial models reflects the replenishment of spring water and groundwater to the lake. The difference in phenological characteristics of twin lakes in the same basin or on both sides of the same sandy mountain is mainly affected by the morphological characteristics of the lake， lake’s TDS， and local climate. In areas with spring water and groundwater replenishment， low TDS， shallow water level， and low wind speed， the sooner the lake water freezes. The mixing of spring， groundwater and lake water reduces the TDS of lake water and makes it easier to freeze， this is the initial form of most lake ice in the Badain Jaran Desert， indicating that lake ice phenology is in a sense a direct reflection of lakes receiving regional deep groundwater replenishment.

Key words: Badain Jaran Desert, lake ice phenology, multi-source remote sensing, field observation, influencing factors, deep groundwater recharge