1986—2017年呼伦湖湖冰物候特征变化

湖冰冰情物候特征是气候变化的敏感指示器之一。论文以呼伦湖为研究对象,基于MODIS、Landsat、GF-1、HJ-1等多源遥感影像及气象数据,利用RS和GIS技术综合分析了1986—2017年呼伦湖冰情物候特征及其对区域气候的响应。结果表明：① 呼伦湖年均开始冻结时间在10月下旬至11月上旬,从结冰开始到完全封冻的时间平均只有6.4 d;开始融冰时间在次年的4月上旬,消融期平均为32 d左右,到5月初或5月上旬湖冰完全融化。② 1986—2017年,在整个研究期呼伦湖完全封冻期呈现显著缩短趋势,平均缩短18.5 d;完全结冰时间有一定延迟现象,平均延后8.4 d;冰全部融化时间呈现提前趋势,平均提前了11.2 d。③ 湖冰冻结消融空间特征表现不同,冻结时先从湖岸形态较复杂地区结冰,然后由东岸向西岸迅速封冻,消融时先从湖泊西北岸开始,逐渐向东岸融化。④ 在影响因素方面,呼伦湖冰情特征主要受到区域气温、风速、风向等因素的影响。

Change of ice phenology in the Hulun Lake from 1986 to 2017

Lake ice phenology is a sensitive indicator of climate change. This study examined lake ice phenology of the Hulun Lake in Inner Mongolia, China based on multi-source remote sensing imageries including MODIS, Landsat, GF-1, and HJ-1 and meteorological data. We used GIS technology to comprehensively analyze the phenological characteristics of ice in the Hulun Lake and its response to regional climate from 1986 to 2017. The results show that: 1) The average freezing time of the Hulun Lake began in late October to early November, and the average time from freezing to complete freezing was 6.4 days. The melting start was usually in early April of the following year, and the ablation period averaged about 32 days. At the beginning of early May, the lake ice completely melted. 2) From 1986 to 2017, the complete freezing period of the Hulun Lake showed a significant shortening trend, with an average shortening of 18.5 days. The complete freezing time showed some delay, with an average delay of 8.4 days. The complete ice melting time advanced, with an average advancement of 11.2 days. 3) The spatial characteristics of freezing and melting of lake ice are different. Freezing starts from the complex shoreline areas of the lake, then rapidly propagate from the east coast to the west coast, but melting starts from the northwest coast of the lake and gradually spread toward the east shore. 4) The characteristics of ice conditions in the Hulun Lake are mainly affected by regional air temperature, wind speed, wind direction, among other factors.