1990～2015年青海省湖泊时空变化及其对气候变化的响应分析

Spatial-Temporal Variations of Lakes in Qinghai Province and Its Responses to Climatic Change Analysis from 1990 to 2015

湖泊作为陆地水圈重要组成部分,是揭示全球气候变化与区域响应的重要信息载体。利用遥感技术获取青海省1990~2015年湖泊时空变化特征,并结合近25 a青海省气温和降雨量的时空变化特征以探究湖泊对气候的响应。结果表明:近25 a,青海省湖泊面积从12 757 km^2增加到15 167 km^2,湖泊数量由241个增加到286个。不同区域湖泊时空变化存在差异,主要包括3个区域:东部地区(Ⅰ)、西北地区(Ⅱ)和西南地区(Ⅲ)。其中,降雨量的增加促进了Ⅰ区域湖泊面积和数量的增加,湖泊面积由7 173 km^2增加到8 474 km^2,湖泊数量增加19个。Ⅱ区域湖泊面积由1 369 km^2增加到1 542 km^2,湖泊数量增加7个。该区域主要地形为柴达木盆地,是我国干旱区之一,干燥少雨,湖泊面积较少且变化剧烈。其湖泊扩张主要是因为降雨量增加,而较强的蒸散发极易导致湖泊萎缩。Ⅲ区域湖泊面积由4 215 km^2增加到5 152 km^2,湖泊数量增加19个。湖泊扩张的主要原因为降雨量的增加和蒸发的减少。研究为青海省湖泊科学利用与水资源合理配置提供了基础数据。

As an important part of the terrestrial hydrosphere, lake is an essential information carrier for revealing global climate change and regional response. Spatiotemporal variation characteristics of lakes in Qinghai Province from 1990 to 2015 were obtained by using remote sensing technology,and the responses of lakes to climate change were explored based on the spatiotemporal variation characteristics of temperature and rainfall in Qinghai Province in recent 25 years. Results show that the lake area has increased from 12 757 km^2 to 15 167 km^2 and that the number of lakes has increased from 241 to 286 in Qinghai Province over the past 25 years. The spatiotemporal variations of lakes are very different in different regions,including Eastern region（ Ⅰ）,northwest region（ Ⅱ） and southwest region（ Ⅲ）. Precipitation enhancement promoted the increase of lake area and quantity in the area Ⅰ where lake area increased from 7 173 km^2 to 8 474 km^2 and where number of lakes increased by 19. In the area Ⅱ,lake area increased from 1 369 km^2 to 1 542 km^2,and number of lakes increased by 7. The area Ⅱ is located in the Qaidam Basin,which is one of the arid areas in china with dry and rainless climate and small lake area. The main factor for lake expansion is the increase of rainfall and main factor for lake shrinking is lake evaporation. Lake area of the area Ⅲ increased from 4 215 km^2 to 5 152 km^2,and number of lakes increased by 19. The lake expansion in the area Ⅲ is due to the increase of rainfall and decrease of evaporation. The basic data for scientific utilization of lake and rational allocation of water resources in Qinghai Province were provided in this study.