TY JOUR TI EVALUATION OF CORRELATION BETWEEN NDVI VEGETATION INDEX AND NDMI HUMIDITY INDEX ACCORDING TO SENTINEL-2 SATELLITE KW humidity index KW vegetation index KW NDMI KW NDVI KW SAGA GIS KW correlation KW Spearman's ratio JO INTERNATIONAL AGRICULTURAL JOURNAL AU Zver'kov, M.S. PY 2026 IS 9 PB Electronic science