Aminjafari Saeid, Brown Ian, Chalov Sergey, Simard Marc, Lane Charles R, Jarsjö Jerker, Darvishi Mehdi, Jaramillo Fernando
Department of Physical Geography and Bolin Centre for Climate Research, Stockholm University, Stockholm SE-106 91, Sweden.
Faculty of Geography, Lomonosov Moscow State University, Moscow 119991, Russia.
J Hydrol Reg Stud. 2021 Dec;38:1-18. doi: 10.1016/j.ejrh.2021.100945.
Selenga River Delta (SRD), Russia.
How is water occurrence changing in the SRD, and what are the hydroclimatic drivers behind these changes? The presence of water on the surface in river deltas is governed by land use, geomorphology, and the flux of water to and from the Delta. We trained an accurate image classification of the Landsat satellite imagery during the last 33 years to quantify surface water occurrence and its changes in the SRD. After comparing our estimations with global-scale datasets, we determined the hydrological drivers of these changes.
We find mild decreases in water occurrence in 51% of the SRD's surface area from 1987-2002 to 2003-2020. Water occurrence in the most affected areas decreased by 20% and in the most water-gaining areas increased by 10%. We find a significant relationship between water occurrence and runoff (R = 0.56) that does not exist between water occurrence and suspended sediment concentration (SSC), Lake Baikal's water level, and potential evapotranspiration. The time series of water occurrence follows the peaks in the runoff but not its long-term trend. However, the extremes in SSC do not influence surface water occurrence (R < 0.1), although their long-term trends are similar. Contrary to expected, we find that the Delta has a relatively stable long-term water availability for the time being.
俄罗斯色楞格河三角洲（SRD）。
色楞格河三角洲的地表水状况如何变化，以及这些变化背后的水文气候驱动因素是什么？河三角洲地表水体的存在受土地利用、地貌以及进出三角洲的水流通量控制。我们对过去33年的陆地卫星图像进行了精确的图像分类，以量化色楞格河三角洲地表水状况及其变化。在将我们的估算结果与全球尺度数据集进行比较之后，我们确定了这些变化的水文驱动因素。
我们发现，从1987 - 2002年到2003 - 2020年，色楞格河三角洲51%的表面积的地表水状况略有下降。受影响最严重地区的地表水状况下降了20%，而地表水增加最多的地区则增加了10%。我们发现地表水状况与径流之间存在显著关系（R = 0.56），而地表水状况与悬浮泥沙浓度（SSC）、贝加尔湖水位和潜在蒸散之间不存在这种关系。地表水状况的时间序列跟随径流的峰值，但不跟随其长期趋势。然而，尽管悬浮泥沙浓度的长期趋势相似，但其极值并不影响地表水状况（R < 0.1）。与预期相反，我们发现目前三角洲的长期可用水量相对稳定。
