{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T05:28:38Z","timestamp":1767850118899,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2020,10,19]],"date-time":"2020-10-19T00:00:00Z","timestamp":1603065600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Snow is one of the essential factors in hydrology, freshwater resources, irrigation, travel, pastimes, floods, avalanches, and vegetation. In this study, the snow cover of the northern and southern slopes of Alborz Mountains in Iran was investigated by considering two issues: (1) Estimating the snow cover area and the (2) effects of droughts on snow cover. The snow cover data were monitored by images obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. The meteorological data (including the precipitation, minimum and maximum temperature, global solar radiation, relative humidity, and wind velocity) were prepared by a combination of National Centers for Environmental Prediction-Climate Forecast System Reanalysis (NCEP-CFSR) points and meteorological stations. The data scale was monthly and belonged to the 2000\u20132014 period. In the first part of the study, snow cover estimation was conducted by Multiple Linear Regression (MLR), Least Square Support Vector Machine (LSSVM), Group Method of Data Handling (GMDH), Multilayer Perceptron (MLP), and MLP with Grey Wolf Optimization (MLP-GWO) models. The most accurate estimations were produced by the MLP-GWO and GMDH models. The models produced better snow cover estimations for the northern slope compared to the southern slope. The GWO improved the MLP\u2019s accuracy by 10.7%. In the second part, seven drought indices, including the Palmer Drought Severity Index (PDSI), Bahlme\u2013Mooley Drought Index (BMDI), Standardized Precipitation Index (SPI), Multivariate Standardized Precipitation Index (MSPI), Modified Standardized Precipitation Index (SPImod), Joint Deficit Index (JDI), and Standardized Precipitation-Evapotranspiration Index (SPEI) were calculated for both slopes. The results showed that the effects of a drought event on the snow cover area would remain up to 5 (or 6) months in the region. The highest impact of drought appears after two months in the snow cover area, and the drought index most related to snow cover variations is the 2\u2013month time window of SPI (SPI2). The results of both subjects were promising and the methods can be examined in other snowy areas of the world.<\/jats:p>","DOI":"10.3390\/rs12203437","type":"journal-article","created":{"date-parts":[[2020,10,19]],"date-time":"2020-10-19T20:44:41Z","timestamp":1603140281000},"page":"3437","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":33,"title":["Using the MODIS Sensor for Snow Cover Modeling and the Assessment of Drought Effects on Snow Cover in a Mountainous Area"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5640-865X","authenticated-orcid":false,"given":"Pouya","family":"Aghelpour","sequence":"first","affiliation":[{"name":"Agricultural Meteorology, Department of Water Engineering, Faculty of Agriculture, Bu-Ali Sina University, Hamedan 65178-38695, Iran"}]},{"given":"Yiqing","family":"Guan","sequence":"additional","affiliation":[{"name":"College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7621-8888","authenticated-orcid":false,"given":"Hadigheh","family":"Bahrami-Pichaghchi","sequence":"additional","affiliation":[{"name":"Agricultural Meteorology, Department of Water Engineering, Faculty of Agricultural Engineering, Sari Agricultural Sciences and Natural Resources University, Sari 48181-68984, Iran"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8427-5965","authenticated-orcid":false,"given":"Babak","family":"Mohammadi","sequence":"additional","affiliation":[{"name":"College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7847-5872","authenticated-orcid":false,"given":"Ozgur","family":"Kisi","sequence":"additional","affiliation":[{"name":"Department of Civil Engineering, Ilia State University, 0162 Tbilisi, Georgia"},{"name":"Institute of Research and Development, Duy Tan University, Da Nang 550000, Vietnam"}]},{"given":"Danrong","family":"Zhang","sequence":"additional","affiliation":[{"name":"College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China"}]}],"member":"1968","published-online":{"date-parts":[[2020,10,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Tsai, Y.L.S., Dietz, A., Oppelt, N., and Kuenzer, C. 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