TY - JOUR AU - D. Dovhanenko AU - Т. Mokritskaya PY - 2017/12/19 Y2 - 2024/03/29 TI - Some aspects of analysis of landslides using series of Landsat images. JF - Journal of Geology, Geography and Geoecology JA - JGGG VL - 25 IS - 2 SE - DO - https://doi.org/10.15421/111719 UR - https://geology-dnu.dp.ua/index.php/GG/article/view/410 AB - The study devoted to problem of landslide dynamic in the territory of Dnipropetrovsk oblast. Study area covered right bank of Dnipro river, between Dnipro and Kamyanske cities. The territory characterized with hilly plain relief on loss soils. Specific combination of geomorphological and climate factors within the territory causes appearance the huge number of landslides. According to the highlighted problems the main aim of this study was to check the hypothesis about long-term dynamic and relation between activation of landslide processes and sunspot activity. The secondary aim was to determine stable diagnostic signs of landslides using satellite images. In accordance to aims the data base of Landsat images was created. The time series of images covered warm season during twenty years period (from 1988 till 2011 years). At the first stage of the study images were preprocessed and digital number was converted into reflectance values. Its allowed to investigate changes of surface type in long term dynamic. The surface changes were studied within locations of active and non-active landslides. There are all over 90 known locations where landslides took placed within this territory. The spectral analysis determined that most relevant signs of landslide are changes with vegetation and soil cover. According to this, the dynamic of surface type transformations was studied using normalized built-up and vegetation indexes (NDBI and NDVI). However, in the urban territory there were problems with recognition type of surface because of insufficient space resolution of Landsat images. This issue had medium influence on the statistical reliability of correlation value. Nevertheless, correlation and in-row statistical analysis showed cyclic and trend type of surface dynamic. More than half of locations characterized with cyclic dynamic, and the last part – with trend dynamic. The zero hypothesis about statistical homogeneity of extremum values NDVI and NDBI confirmed at significance level 0,5. General long-term tendency of NDBI and NDVI has opposite character to itch other: NDBI trend is descending, NDVI – is rising. It allowed to conclude about stabilization of landslides processes in the territory. However, the central hypothesis of the research was confirmed partially. The main part of landslide events took placed in the beginning and in the end of summer seasons of 1988, 2001 and 2007 years. The first pair of years matched with the highest sunspot activity.  ER -