Nanjing Research Institute of Electronics Technology, Nanjing, 210000, China.
Information Center of Jiangsu Academy of Agricultural Sciences, Nanjing, 210000, China.
Sci Rep. 2022 Feb 14;12(1):2415. doi: 10.1038/s41598-022-06363-9.
China has a great wealth of lake resources over a great spatial extent and these lakes are highly sensitive to climate changes through their heat and water budgets. However, little is known about the changes in lake surface water temperature (LSWT) across China under the climate warming conditions over the past few decades. In this study, MODIS land surface temperature (LST) data were used to examine the spatial and temporal (diurnal, intra-annual, and inter-annual) variations in LSWT of China's lakes during 2001-2016. Our results indicated that 169 large lakes included in the study exhibited an overall increasing trend in LSWT, with an average rate of 0.26 °C/decade. The increasing rate of nighttime LSWT is 0.31 °C/decade, faster than that of daytime temperature (0.21 °C/decade). Overall, 121 (71.6%) lakes showed an increase in daytime temperature with a mean rate of 0.38 °C/decade, while the rest 48 (28.4%) lakes decreased in temperature with a mean rate of - 0.21 °C/decade. We also quantitatively analyzed the relationship of the lake surface temperature and diurnal temperature differences (DTDs) with geographical location, topography, and lake morphometry by utilizing multivariate regression analysis. Our analysis suggested that the geographical location (latitude and longitude) and topography (altitude) were primary driving factors in explaining the national lake water temperature variation (P < 0.001), which were also mediated by morphometric factors such as lake surface area and volume. Moreover, the diurnal lake temperature variations were significantly correlated with altitude, latitude, and lake surface area (R = 0.426, P < 0.001). Correlation analyses of LSWT trend and air temperature trend for each lake indicated that LSWT was positively correlated with air temperature in both daytime and nighttime for most lakes.
中国拥有丰富的湖泊资源，分布范围广泛。这些湖泊的热量和水分收支对气候变化非常敏感。然而，在过去几十年的气候变暖背景下，中国湖泊的湖面水温（LSWT）变化情况却鲜为人知。本研究利用 MODIS 地表温度（LST）数据，研究了 2001-2016 年期间中国湖泊 LSWT 的时空（昼夜、年内和年际）变化。结果表明，研究中包含的 169 个大湖泊的 LSWT 总体呈上升趋势，平均增长率为 0.26°C/decade。夜间 LSWT 的增长率为 0.31°C/decade，快于白天温度（0.21°C/decade）。总体而言，121 个（71.6%）湖泊的白天温度呈上升趋势，平均增长率为 0.38°C/decade，而其余 48 个（28.4%）湖泊的温度呈下降趋势，平均增长率为-0.21°C/decade。我们还通过多元回归分析，定量分析了湖泊表面温度和昼夜温差（DTDs）与地理位置、地形和湖泊形态的关系。分析表明，地理位置（纬度和经度）和地形（海拔）是解释全国湖泊水温变化的主要驱动因素（P<0.001），湖泊表面积和体积等形态因素也起到了中介作用。此外，昼夜湖泊温度变化与海拔、纬度和湖泊表面积呈显著相关（R=0.426，P<0.001）。对每个湖泊的 LSWT 趋势与气温趋势的相关分析表明，对于大多数湖泊，LSWT 在白天和夜间均与气温呈正相关。
