THE GLACIER MONITORING COMPONENT OF THE USGS AFGHANISTAN PROJECT

As part of a nationwide investigation of the water resources of Afghanistan, an assessment of the recent behavior of Afghan glaciers is being conducted using remotely sensed data. The investigation consists of both a synoptic evaluation of each glacier-covered region and detailed examinations of selected individual glaciers. Nearly 40 VNIR (visible and near-infrared) digital images, encompassing all of the glacier-covered areas of Afghanistan, are the primary data set being analyzed. The imagery was collected between 2001 and 2004 by the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument on the Terra spacecraft. These images have also been processed using a supervised classification to determine the distribution of snow, debris-free glacier ice, debris-covered glacier ice, ice-marginal and supraglacial lakes, vegetation, and bare bedrock and soils. Visual imagery analysis results are being compared and contrasted with the supervised classification imagery data, stereo topographic information, historic maps, and terminus position data to determine glacier change and recent landscape feature development. Landsat TM data is used for selected locations to augment interpretations.

Among the glaciers and areas that have received detailed investigations are the large debris-covered, retreating North and South Issik and Zemestan Glaciers of the central Wakhan Pamir; the small retreating cirque and valley glaciers of the Koh-I-Baba range located west of Kabul; the retreating, debris-covered Keshnikhan Glacier and adjacent small debris-covered glaciers at the western end of the Wakhan panhandle; and the retreating, debris-covered valley glaciers of the Panshir Valley region. Ultimately, all of Afghanistan's other glacier-covered areas will be investigated in similar detail. Many recently ice-free cirques have been observed in every area of the country.

Soviet era topographic map data and published glacier extent and distribution data, especially that of University of Nebraska at Omaha researchers, are the basis for decadal scale terminus position comparisons. An additional component of this investigation is the determination of the location and size of ice-marginal and supra-glacial lakes that may pose a threat to outburst flooding and landslide generation.