| More than 40% of the territory of the Republic of Sakha(Yakutia)is located in the Arctic Circle.The winter is cold and long,and permafrost is widely distributed,making it a typical cold zone in the world.Based on the analysis of the natural background(location,topography,meteorology and frozen soil)of the Republic of Sakha(Yakutia),the concept of groundwater icings and the influence factors of groundwater icings,the ice of Russia's historical atlas and topographic maps are used.The data database and Landsat satellite images have investigated the distribution and characteristics of groundwater icings in the Republic of Sakha(Yakutia),and selected the largest groundwater icings point in the Republic of Sakha(Yakutia),Ulakhan-Tallinn.It is a typical research area.The hydrometeorology,topography and geomorphology,geological conditions,and chemical changes of groundwater in the typical research area are investigated and analyzed,and the following conclusions are drawn:(1)The territory of the Republic of Sakha(Yakutia)mainly belongs to the two largest structures-the Siberian region and the Mesozoic fold Upper Yansk-Chukotka region.The atmospheric circulation process over the sky depends on the overall circulation of the earth's atmosphere,but it also has a great influence on the local natural geographical conditions.Most areas are continental and arid,with long winters,cold,and little snow,while summers are short.The temperature is higher.Permafrost is widely distributed.In most areas,the permafrost is a continuous area.Usually,permafrost is found under large lakes and rivers,or continuous permafrost is formed due to the influence of groundwater.In the southwest of the region,there are discrete islands of permafrost in some places.(2)According to the cadastral data,the total area of the icings in the Republic of Sakha(Yakutia)is 1.6 times that of the Landsat satellite,and the ice with a total area of1253.9km2 is determined,and the size and height of the icing area is irregular.There is no obvious latitude division in the distribution of icing in the Sakha(Yakutia)Republic.In the Sakha(Yakutia)Republic,the area where groundwater icings is relatively more distributed is parts of the southeast,southern and central parts of the Sakha(Yakutia)Republic,where the piedmont valley topography is distinct from other places.Contrast;most of the icings in the Republic of Sakha(Yakutia)is at a height of 1100?1300m.The Spearman rank correlation coefficients between the average height of the watershed and the ice body are 0.71 and 0.77,respectively.Judging from the interannual change of ice accumulation,the area of groundwater icings accumulation has been decreasing in recent years.(3)The valley where Ulakhan-Tallinn is located is an erosion area of the Indigirka River.The river washed away the right slope of the valley and formed a 26 m high eroded steep slope.Its typical piedmont valley terrain provides a driving force for the formation of groundwater icings;the Ulakhan-Tallinn geological soil types are from top to bottom.From top to bottom,turf,sandy soil,silty soil,loose fine sediment sand layer(active seasonal freezing and thawing),sand layer containing various crystals(aquifer),permafrost layer(weakly permeable)are formed from top to bottom.Layer),which constitutes the water passage and replenishment source of groundwater icings;temperature changes are inversely related to changes in ice accretion volume.The lower the temperature,the greater the volume of groundwater icings;the upper permafrost in Ulakhan-Tallinn The aquifer is open in the interval of 422?502m,the groundwater salinity of this horizontal line is 3.9g/L,and the composition of sodium carbonate chloride is 230mg/L hydrogen sulfide.This indirectly proves that the groundwater of this horizontal line may have participated in the formation of the spring water in the small river valley.According to the water chemistry sampling data,the total mineralization value averaged 200?220mg/L,the maximum e value was observed in March,and the groundwater icings body reached the maximum in March. |
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