We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
联合 Sentinel-3 雷达测高和光学影像的青藏高原 典型湖泊水量变化估算.
- Authors
陈军; 高婧潇; 汪永丰; 金璐
- Abstract
Lakes in the Qinghai-Tibet Plateau are highly sensitive to climate fluctuations, and dynamic monitoring of the lakes'changes provides crucial evidences for regional and even global climate research. Most of the lakes had little field observation record due to traffic inaccessibility in the Plateau. Some academic comments on the changes of lakes in the Plateau were based on remote sensing; data such as lake water level and area generally referred to mutiple satellites, and there was remarkable temporal deviation between the data, for example, temporal disagreement between measured water levels and lake areas. In this study, Sentinel-3 SRAL (SAR Radar Altimeter) radar altimetry data and Sentinel-3 SLSTR (Sea and Land Surface Temperature Radiometer) optical images collected by the same satellite were used to detect the water level and area changes of four large lakes, i. e. the Ayakkumu Lake, the Selinco Lake, the Qinghai Lake and the Namco Lake in the Qinghai-Tibet Plateau from April 2016 to September 2022. By comparison in-situ water level measurements with DAHITI data (Database for Hydrological Time Series of Inland Waters), it confirmed that Sentinel-3 radar altimetry could accurately capture weekly and monthly lake level fluctuations. (1) A consistent annual rise in water levels took place during the monitoring period at the four lakes, rising by 3.01 m, 2.04 m, 1.62 m, and 0.28 m, respectively. Seasonal changes in the area and water level of the four lakes were generally characterized by a significant increase in the lake surface during summer monsoon periods and a gradual decrease during non-monsoon periods. (2) Lake levels were the lowest in the second quarter and rose to peak levels at the end of the third and beginning of the fourth quarter. The water volumes of the four lakes displayed different increases during the monitoring period, among which the Qinghai Lake got the largest rise of 7. 381 km³ but the Namco Lake changed the least at only 0. 072 km³. (3) Comparing the linear trend of water volumes fitted by DEM estimation and obtained by empirical formula, respectively, it justified the accuracy of lake water volume estimation based on Sentinel-3 data. (4) Further, taking the Lake Ayakkumu as an example, it was demonstrated that there was correspondence between the weekly change of its water level and the daily change of precipitation, proving that precipitation was the main influencing factor on the change of water level in the lake. Based on the advantages of Sentinel-3, which produced a synchrony of optical images and radar altimetry data, i. e., exact consistency between extraction of lake water level/area and time, it avoided result uncertainty caused by time delay of using multiple satellite data combinations, and provided a unique data resource for in-depth analysis of water resources balance in the Qinghai-Tibetan Plateau.
- Publication
Mountain Research (10082786), 2023, Vol 41, Issue 6, p926
- ISSN
1008-2786
- Publication type
Article
- DOI
10.16089/j.cnki.1008-2786.000798