Архив метки: Selyaninov hydrothermal coefficient

ANALYSIS OF HYDROTHERMAL CONDITIONS IN THE ROSTOV REGION IN THE PERIOD 1960-2019

Arid Ecosystems

Gudko V.N., Usatov A.V.,  Azarin K.V. ANALYSIS OF HYDROTHERMAL CONDITIONS IN THE ROSTOV REGION IN THE PERIOD 1960-2019 // Arid ecosystems. 2021. V.27. № 4 (88). P. 25-31. | PDF

Based on data from six meteorological stations in the Rostov region in the period 1960-2019, the tendencies of changes in air temperature, precipitation, and hydrothermal conditions, expressed by the Selyaninov hydrothermal coefficient, were analyzed. For all meteorological stations, a significant trend was determined for the increase in the average annual air temperature and the sums of temperatures above 10 °C. The annual amount of precipitation had a significant upward trend only at the Chertkovo meteorological station, at the other five meteorological stations — an upward trend. On the background of an intensive increase in temperatures, a tendency for a decrease in the values of the Selyaninov hydrothermal coefficient for the Gigant, Rostov-on-Don, Taganrog and Tsimlyansk meteorological stations was noted. At the meteorological stations Chertkovo and Remontnoye, the increase in temperatures was compensated by an increase in the amount of precipitation; as a result, a tendency to an increase in the values of the Selyaninov hydrothermal coefficient was noted. Hydrothermal conditions at six meteorological stations in the period 1960-2019 were characterized as dry, and the mean annual value of HTC varies within 0.64 — 0.82. The driest conditions are typical for meteorological stations located in the east and north-east of the Rostov region. Based on the calculated trends, it can be concluded that in the period 1960-2019 for the meteorological stations Gigant, Rostov-on-Don, Taganrog and Tsimlyansk, arid warming is characteristic, while the meteorological stations Remontnoye and Chertkovo are characterized by humid warming.

Keywords: air temperature, precipitation amount, hydrothermal conditions, Selyaninov hydrothermal coefficient, arid warming, humid warming, Rostov region.

Financing. The work was carried out with the financial support of the Ministry of Science and Higher Education of the Russian Federation within the framework of the state assignment in the field of scientific activity (No. 0852-2020-0029).

DOI: 10.24412/1993-3916-2021-4-25-31

ASSESSMENT OF SPATIAL – TEMPORAL VARIABILITY OF ARID ECOSYSTEMS IN THE REPUBLIC OF BURYATIA

Arid Ecosystems

Garmaev E.Zh.,  Ayurzhanaev A.A.,  Tsydypov B.Z.,  Alymbaeva Zh.B.,  Sodnomov B.V., Andreev S.G.,  Zharnikova M.A.,  Batomunkuev V.S.,  Mandakh N., Salikhov T.K.,  Tulohonov А.К.  ASSESSMENT  OF  SPATIAL – TEMPORAL VARIABILITY OF ARID ECOSYSTEMS IN THE REPUBLIC OF BURYATIA // Arid ecosystems. 2020. V. 26. № 2 (83). P. 34-42. | PDF

Climate change and human activity on the territory of the Republic of Buryatia intensify the processes of desertification and land degradation. Zoning of the territory of Buryatia was carried out according to the aridity index using ENVIREM high spatial resolution climatic data. Based on the correlation analysis of the time series of the NDVI AVHRR vegetation index, meteorological series of the NCEP / NCAR reanalysis and field studies, a quantitative assessment of the long-term changes in vegetation cover in arid and humid zones was carried out. Maps of the spatial distribution of linear trends of NDVI and precipitation for 1982-2015 with the separation of wet (1982-1999) and dry periods (2000-2015) were obtained. During the wet period, positive NDVI trends are observed for almost the entire territory of the Republic, while the dry period is characterized by a significant increase in the negative trends of the vegetation index. The positive correlation between the Selyaninov hydrothermal coefficient and NDVI is observed for intermountain steppificated hollows, negative for forest landscapes. The dynamics of NDVI of steppe vegetation largely depends on precipitation, the dynamics of NDVI of forests — on temperature. Reforestation, post-pyrogenic succession, shrubbing of abandoned fields, etc., cause the increase of NDVI. Negative NDVI trends are typical for steppe ecosystems under conditions of decreasing precipitation, and for forest vegetation prone to cuttings and fires.

Keywords: Buryatia, arid zones, vegetation, NDVI, Selyaninov hydrothermal coefficient, precipitation, trend, reanalysis, dendrochronology.

DOI: 10.24411/1993-3916-2020-10093