A MODIS (Moderate Resolution Imaging Spectroradiometer) receiver and acquisition system installed on the premises of the International Centre for Integrated Mountain Development (ICIMOD) is feeding key environmental data to ICIMOD's regional member countries. The Department of Hydro-Met Services in Bhutan, which is receiving automated snow cover maps, is among the first beneficiaries.
Climate change has affected snow precipitation pattern in the Hindu Kush Himalayas, and glaciers are shrinking. Officials in Bhutan need timely, accurate snow cover mapping to manage the country's hydropower sector* and develop appropriate infrastructure. They requested access to the MODIS data for up-to-date date snow cover mapping.
“Glacier melt being one of the major sources of water, information on snow cover mapping will be used to forecast river flow and subsequent hydropower generation," said Chhimi Dorji from the Department of Hydro-Mets Services in Thimphu, Bhutan. "Availability of good snow cover data would thus aid hydropower operators for appropriate planning by ensuring that they run the plants optimally during snow melt and only do optional maintenance during forecasted low flows.”
The MODIS station was procured with Norwegian funding and installed in early 2013 at the ICIMOD campus in Kathmandu, Nepal. It receives real-time data captured in snapshots when NASA's (National Aeronautics and Space Administration) Terra and Aqua satellites pass over the region. There is a MODIS sensor on board each of these satellites. Datasets received from these sensors are automatically customized for the end user. For instance, in the case of snow cover maps for Bhutan, the system automatically selects snow covered areas and removes the rest before transferring the data to Bhutan’s file transfer protocol (FTP) in the format of their choice.
Long-term data on snow cover mapping can provide information on snowfall patterns. For instance, it can help one distinguish areas permanently covered by snow from areas of seasonal snow cover. Datasets collected over time can be used for developing river flow models, which enable effective hydropower planning. This also allows officials to disseminate evidence-based information to inform agricultural practices. Agriculture is the main source of livelihood in the major areas of the Hindu Kush Himalayan region.
However, there is still need for improvement. For example, some of the MODIS datasets show snow pixels at low altitudes where snowfall is not possible, such errors need to be filtered out. Also, snow cover mapping only shows the range of snow cover area and not the depth of snow. These are some of the areas for which ICIMOD is gathering information from additional sources.
Other ICIMOD/SERVIR-Himalaya MODIS products and services include aerosols, clouds, enhanced vegetation index, land surface temperature (LST), and normalized difference vegetation index (NDVI), all freely available at the ICIMOD FTP site. Kathmandu University is also using some of these MODIS products for their student projects.
To familiarize its national partners with MODIS products and services, ICIMOD held a consultative workshop as part of the SERVIR-Himalaya initiative on 10-11 April 2014. Professionals from Nepal, Pakistan, Bhutan, and Bangladesh deliberated extensively on MODIS products and services for regional environmental applications and automated forest cover.
*The hydropower sector constitutes 12% of Bhutan’s Gross Domestic Product and 45% of government revenue. As of 2013, Bhutan has four large-scale hydropower plants, according to the Department of Hydropower and Power System.