HR: 1340h
AN: A13B-0110    [Abstracts]
TI: Assessment, Changes, and Prediction of Water Cycle Components in Central Asian Alpine Basins
AU: * Aizen, E
EM: eaizen@uidaho.edu
AF: University of Idaho, Department of Geography, College of Science, Mines Bld., P.O Box 443025, Moscow, ID 83844-3025 United States
AU: Aizen, V
EM: aizen@uidaho.edu
AF: University of Idaho, Department of Geography, College of Science, Mines Bld., P.O Box 443025, Moscow, ID 83844-3025 United States
AU: Kuzmichenok, V
EM: alex@continent.kg
AF: Institute of Water Problems and Hydro Power, 533 Frunze Str., Bishkek, 720033 Kyrgyzstan
AB: To estimate the modern condition of river runoff in Tien Shan alpine basins and to forecast its variability in relation to global and regional climate changes, means of the major water cycle characteristics (air temperature, precipitation, evapotranspiration and river runoff) have been simulated using data from 212 hydro-meteorological stations and 304 precipitation gauges. The mean evapotranspiration was calculated using data on air temperature, precipitation, and the topography aspects (including type of vegetation). Findings were simulated over the Tien Shan relief using rectangular coordinates of the equivalent cone projection with standard parallels 1:500 000 scale 100 m grid resolution Digital Elevation Model covering 800 000 knotted points. Applicable GIS-based distributed River Runoff Model was implemented for regional conditions and tested in three different Tien Shan basins, taking into account snow and glacial melt, forest, grassland and irrigated areas. Simulations of glacier river runoff accounts for glacier recession by using geodetic and terrestrial photogrammetry data (1869, 1932, 1956), aerial photography (1943, 1977), GPS survey (2002), ASTER images (2003), and Shuttle Topography Radar Mission data (2000). The parameterization between measured and simulated runoff occurred by least squares method with discrepancy approximation using linear functions with multiple parameters: annual precipitation, snow and glacial runoff and first-derivative of previous year river runoff. The mean square discrepancy between measured and simulated runoff is in accordance with the root-mean-square error of measured runoff, ranging from 8% to 12%. The rank of calculated evapotranspiration revealed the same level as the river runoff. Hypothetical climate-change scenarios in Tien Shan modeled as a stepwise progression predict an increase in air temperature of $1.8\deg$C - $4.4\deg$C (i.e., on average $3\deg$¥) and precipitation at 0.94 to 1.54 times (1.2 times) during the XXI Century, leading to a reduction of river runoff by only 0.008 times. If we assume that precipitation remains constant and air temperature increases by $5\deg$¥, river runoff in Tien Shan and Central Asia can decrease two-fold due to increased evapotranspiration.
UR: http://www.uidaho.edu/~aizen
DE: 1655 Water cycles (1836)
DE: 1719 Hydrology
DE: 1818 Evapotranspiration
DE: 1833 Hydroclimatology
DE: 1640 Remote sensing
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting