A1 through A4 DESCRIPTION:
Global gridded fields of long-term average (1950-2000) water balance components. Fields are input to (ie., precipitation) or output (Ii.e., evapotranspiration, runoff, discharge) from the Water Balance Model (Vorosmarty et al., 1998) with improved interception function as recommended by Federer et al. (2003). Model climate inputs were from Mitchell et al. (2003). Monthly evapotranspiration computed using Shuttleworth and Wallace (1985) PET estimates (Vorosmarty et al, 1998) and limited by modeled soil moisture. River flow was computed as flow accumulated runoff along a 30-minute resolution digital river network (Fekete et al., 2001, Vörösmarty et al, 2000a,b). Blended river flow represents a composite of observed and modeled river flow. Land cover was represented by potential vegetation (Melillo et al., 1993) overlain with agricultural land cover (Ramankutty and Foley, 1999).
(A1) annual_precip_1950-2000.asc = long-term annual average precipitation (mm/yr) computed from monthly precipitation fields. Primary source: Mitchell et al. (2003).
(A2) annual_et_1950-2000.asc = long-term annual average evapotranspiration (mm/yr) computed from monthly evapotranspiration fields. Primary source: Fekete et al. (2002).
(A3) annual_runoff_1950-2000.asc = long-term annual average runoff (mm/yr) computed from monthly modeled runoff. Primary source: Fekete et al. (2002).
(A4) annual_blended_q.asc = long-term average river flow (km3/yr) representing a composite of observed and modeled river flow. Primary source: Fekete et al. (2002).
Federer, C. A., Vorosmarty, C. J., and B. Fekete. 2003. Sensitivity of annual evapotration to soil and root properties in two models of contrasting complexity, Journal of Hydrmeteorology, 4: 1276-1290.
Fekete, B. M., C. J. Vorosmarty, W. Grabs. 2002. High-resolution fields of global runoff combining observed river discharge and simulated water balances, Global Biogeochemical Cycles, 16 (3): 15-1 to 15-10.
Fekete, B. M., C. J. Vorosmarty, and R. B. Lammers. 2001. Scaling gridded river networks for macroscale hydrology: Development, analysis and control of error, Water Resources Research, 3 (77): 1955-1967.
Melillo, J. M., A. D. McGuire, D. W. Kickligher, B. Moore, C. J. Vorosmarty and A. L. Schloss. 1993. Global climate change and terrestrial net primary production, Nature, 363: 234-240.
Mitchell, T.D., Carter, T.R., Jones, P.D., Hulme,M., New, M., 2004. A comprehensive set of high resolution grids of monthly climate for Europe and the globe: the observed record (1901-2000) and 16 scenarios (2001-2100). Tyndall Centre Working Paper 55.
Ramankutty, N., and J. A. Foley. 1998. Characterizing patterns of global land use: An analysis of global croplands data. Global Biogeochemical Cycles 12(4):667-685.
Shuttleworth, J. W. and J. S. Wallace. 1985. Evapotranspiration from sparse crops: an energy combination theory, Quarterly J. R. Meteorol. Soc., 111: 839-855.
Vorosmarty, C. J., C. A. Federer, and A. L. Schloss. 1998. Potential evapotranspiration functions compared on US watersheds: Possible implications for global-scale water balance and terrestrial ecosystem modeling, Journal of Hydrology, 207: 147-169.
Vörösmarty, C.J., B. M. Fekete, M. Meybeck, and R. Lammers. 2000. Geomorphometric attributes of the global system of rivers at 30-minute spatial resolution (STN-30). Journal of Hydrology 237: 17-39.
Vörösmarty, C.J., B.M. Fekete, M. Meybeck, and R. Lammers. 2000. A simulated topological network representing the global system of rivers at 30-minute spatial resolution (STN-30). Global Biogeochemical Cycles 14: 599-621.