1976-2017年青藏高原可可西里盐湖面积动态变化及成因分析

青藏高原湖泊是全球气候变化的敏感指示器。近56年来，可可西里地区气候呈显著暖湿化趋势，其中气温上升速率为0.33℃·（10a）^-1（R=0.746，P<0.01），降水增加速率为23.4mm·（10a）^-1（R=0.422，P<0.01）。近40年来，盐湖面积总体呈增大趋势，其中，1976-2011年溃堤前盐湖面积以1.63 km²·a^-1的速率扩大，溃堤后以8.51 km²·a^-1的速率持续扩大。总体来看，近40多年来，盐湖面积先后经历了缓慢增大（1976-2011年）→急剧增大（2012-2013年）→稳定增大（2014-2017年）三个阶段。盐湖面积前期缓慢扩大的主要原因是可可西里地区气候暖湿化的结果，而后期面积急剧扩大的主要原因是因为2011年9月15日盐湖上游的卓乃湖溃堤，导致下游的3个湖泊（库赛湖、海丁诺尔湖和盐湖）串连成一体；冰川和冻土融水可能是引起可可西里盐湖面积扩张的原因，但并非主要原因。后期盐湖面积还将呈稳定增大趋势。盐湖面积扩大导致盐湖湖水淡化，周边草地受到淹没破坏的面积不断扩大，这种变化不仅对其周边草地生态环境产生破坏，还可能对可可西里周边重大工程设施产生不利影响。鉴于盐湖面积今后还将持续增大，并对其周边重大工程设施产生不利影响。因此，应用多源卫星资料对盐湖进行长期持续的跟踪观测仍将是相关政府部门关注的重点。

Dynamic change and cause analysis of Salt Lake area in Hoh Xil on Qinghai-Tibet Plateau during 1976-2017

Lakes on the Tibetan Plateau are sensitive indicators of global climate change. In the last 55 years, the climate of the Hoh Xil region showed a significant warm and wet trend, in which the temperature rise rate was 0.33℃·(10a)^-1 (R=0.746, P<0.01), and the increasing rate of precipitation was 23.4 mm·(10a)^-1 (R=0.422, P<0.01). Over the past 40 years, the area of salt lake has shown an increasing trend. Among them, the area of Salt Lake before dike burst increased by 1.63 km²· a^-1 from 1976 to 2011, and after dike burst it continued to expand at the rate of 8.51 km²·a^-1. On the whole, in the past 40 years, the area of Salt Lake has experienced three stages:slowly increasing (1976-2011)→sharply increasing (2012-2013)→steadily increasing (2014-2017). The main reason for the early expansion of the Salt Lake area was the warm and wet of the climate in the Hoh Xil region. The reason for the sharp increase in the area in the later period was due to the dike burst of the Zonag Lake in the upper branches of the Salt Lake on September 15, 2011, resulting in three lakes downstream (Lake Kosei, Lake Dinard Noir), and Salt Lake are connected in a row; glacial and frozen water melting may be the cause of the expansion of the Hoh Xil Salt Lake area, but it is not the main reason. In the later period, the area of Saline Lake will also show a steady increase trend. The expansion of the Salt Lake area has led to the desalinization of Salt Lake, and the area where the surrounding grassland has been submerged and destroyed continues to expand. Which not only damages the ecological environment surrounding grassland, but may also have an adverse effects on major engineering facilities around Hoh Xil. In view of the fact that the area of Salt Lake will continue to increase in the future, it will adversely affect the major engineering facilities around it. Therefore, long-term and continuous tracking and observation of Salt Lake Lake using multi-source satellite data will remain the focus of relevant government departments.