Advances in Geosciences www.adv-geosci.net 1680-7340 1680-7359 18 Advances and visions in large-scale hydrological modelling 2008 10.5194/adgeo-18-25-2008 http://www.adv-geosci.net/18/25/2008/ http://www.adv-geosci.net/18/25/2008/adgeo-18-25-2008.html http://www.adv-geosci.net/18/25/2008/adgeo-18-25-2008.pdf 25 30 2008-06-20 Assessment of ecologically relevant hydrological change in China due to water use and reservoirs J. Zhang jizhang@stud.uni-frankfurt.de P. Döll Institute of Physical Geography, University of Frankfurt, Germany As China's economy booms, increasing water use has significantly affected hydro-geomorphic processes and thus the ecology of surface waters. A large variety of hydrological changes arising from human activities such as reservoir construction and management, water abstraction, water diversion and agricultural land expansion have been sustained throughout China. Using the global scale hydrological and water use model WaterGAP, natural and anthropogenically altered flow conditions are calculated, taking into account flow alterations due to human water consumption and 580 large reservoirs. The impacts resulting from water consumption and reservoirs have been analyzed separately. A modified "Indicators of Hydrologic Alteration" approach is used to describe the human pressures on aquatic ecosystems due to anthropogenic alterations in river flow regimes. The changes in long-term average river discharge, average monthly mean discharge and coefficients of variation of monthly river discharges under natural and impacted conditions are compared and analyzed. The indicators show very significant alterations of natural river flow regimes in a large part of northern China and only minor alterations in most of southern China. The detected large alterations in long-term average river discharge, the seasonality of flows and the inter-annual variability in the northern half of China are very likely to have caused significant ecological impacts. Alcamo, J., Döll, P., Henrichs, T., Kaspar, F., Lehner, B., Rösch, T., and Siebert, S.: Development and testing of the WaterGAP 2 global model of water use and availability, Hydrol. Sci. J., 48(3), 317–338, 2003. Arthington, A. H. and Pusey, B. J.: In-stream flow management in Australia: methods, deficiencies and future directions, Australian Biology, 6, 52–60, 1993. Black, A. R., Rowan, J. S., Duck, R. W., Bragg, O. M., and Clelland, B. E.: DHRAM: a method for classifying river flow regime alterations for the EC Water Framework Directive, Aquatic Conservation: Marine and freshwater Ecosystems, 15, 427–446, 2005. Clausen, B. and Biggs, B. J. F.: Flow variables for ecological studies in temperate streams: groupings based on covariance, J. Hydrol., 237, 184–197, 2000. Döll, P., Kaspar, F., and Lehner, B.: A global hydrological model for deriving water availability indicators: model tuning and validation, J. Hydrol., 270(1–2), 105–134, 2003. Government of China: White Paper on China's Strategy for Population, Environment and Development in the 21st Century, chapter 14, http://www.acca21.org.cn/ca21pa.html, 1994. Hunger, M. and Döll, P.: Value of river discharge data for global-scale hydrological modeling, Hydrol. Earth Syst. Sci. Discuss., 4, 4125–4173, 2007. Lehner, B. and Döll, P.: Development and validation of a global database of lakes, reservoir and wetlands, J. Hydrol., 296(1–4), 1–22, 2004. Poff, N. L., Allan, D. J., Brain, M. B., Karr, J. R., Prestegaard, K. L., Richter, B. D., Sparks, R. E., and Stromberg, J. C.: The natural flow regime: a paradigm for river conservation and restoration. BioScience, 47(11), 769–784, 1997. Poff, N. L. and Ward, J. V.: Implications of stream flow variability and predictability for lotic community structure: a regional analysis of stream flow patterns, Can. J. Fish. Aquat. Sci., 46, 1805–1818, 1989. Puckridge, J. T., Sheldon, F., Walker, K. F., and Boulton, A. J.: Flow variability and the ecology of large rivers. Mar. Freshwater Res., 49, 55–72, 1998. Richter, B. D., Baumgartner, J. V., Powell, J., and Braun, D. P.: A method for assessing hydrologic alteration within ecosystems, Conservation Biology, 10(4), 1163–1174, 1996. Richter, B. D., Baumgartner, J. V. Wigington, R., and Braun, D. P.: How much water does a river need?, Freshwater Biology, 37, 231–249, 1997.