Snow Cover Mapping Over the Region of Hindu Kush Himalaya (HKH) for 2008–2018 Using Cloud Mitigated Moderate Resolution Spectroradiometer (MODIS) Snow Cover Data

Abstract

AbstractAs we know that in the HKH region snow cover is an essential component because it not only balances the earth’s ecosystem but also provides the freshwater to 240 million people who live in this region. Monitoring and mapping of snow cover estimation is necessary because snow cover estimations work as an input for various Hydrological Models. We know that generation of snow cover maps using in-situ observations is an arduous task, so we use an approach of remote sensing not only for the generation of snow cover maps but also for the calculation or estimation of different parameters of snow. The present study uses the MOD10C2 and MYD10C2 MODIS 8 day snow cover products. These MODIS snow cover products (MOD10C2 and MYD10C2) are freely available at spatial resolution of 0.05° × 0.05° but the main problem in the available imagery is the availability of cloud coverage. For this, we mitigate the cloud cover using three Spatio-temporal filters. The first step (Terra and Aqua Combination) removes approximately 51.044% of the total existing cloud. This first Terra-Aqua combination filter was an effective filter for cloud mitigation. The second step (short-term temporal filter) removes approximately 36.157% clouds. 87.201% of clouds are removed by these two filters. For removing the remaining clouds, we use the nearest neighborhood filter which removes approximately 12.528% of clouds. Remaining 0.271% cloud cover exists in the imagery. For the accuracy assessment of snow products, we comprise the 8-day MODIS snow cover product with Landsat-7 ETM+ and Landsat-8 OLI snow cover products. The validation showed a strong agreement with Landsat imagery and provides an accuracy of 94%. We analyzed the total 506 images of 8-day MODIS snow products and estimated the area of snow cover, i.e., SCA. It is found that the maximum SCA is in February 2, 2008 which is equal to 1.03945 million sq. km. The minimum snow cover area is found in July 28, 2013 and which is equal to 0.293775 million sq. km. Our study estimates the SCA with the 8-day MODIS snow cover product 2008 to 2018 and found that the average snow-covered area is equal to 0.652 million sq.km. This enhanced product of snow cover can be used for further estimation of different snow cover studies and works as an input for different Hydrological Models.KeywordsMODISCloud mitigationSnow cover mappingThe Hindu Kush Himalayan region