SCIENCE CHINA Earth Sciences © Science China Press and Springer-Verlag Berlin Heidelberg 2014 earth.scichina.com link.springer.com *Corresponding author (email: xmcai@illinois.edu) SPECIAL TOPIC: Watershed Science January 2015 Vol.58 No.1: 16–24  PROGRESS  doi: 10.1007/s11430-014-5005-2 Decision support for integrated river basin management —Scientific research challenges CAI XiMing 1* , Landon MARSTON 1 & GE YingChun 2 1 Ven Te Chow Hydrosystems Laboratory, Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, Urbana, IL, USA; 2 Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China Received May 8, 2014; accepted October 10, 2014; published online November 4, 2014 Integrated River Basin Management (IRBM) has been a long discussed way to sustainably manage water and land resources; yet, very few examples of effective IRBM are found because there is a lack of sufficient scientific support, as well as institu- tional accommodation, to successfully implement it. This paper overviews the major challenges with IRBM, the promising scientific approaches for the implementation of IRBM, and the areas of needed research, with considerable issues and experi- ences from China. It is expected that novel research will draw together disparate disciplines into an integrated scientific framework, upon which better modeling tools, stakeholder involvement, and decision-making support can be built. Cut- ting-edge new technologies will bring ideas of IRBM forward to theory and finally to practice. The paper will prompt scientists to undertake research to fill in the gaps in the current IRBM knowledge base and provide practitioners guidance on how to in- corporate scientifically based information within the IRBM decision process. integrated river basin management, scientific framework, decision support, China Citation: Cai X M, Marston L, Ge Y C. 2015. Decision support for integrated river basin management—Scientific research challenges. Science China: Earth Sciences, 58: 16 – 24, doi: 10.1007/s11430-014-5005-2 The volume of water necessary to satisfy human and envi- ronmental requirements is approaching or exceeding locally available renewable water supplies in river basins through- out the world, leading to overcommitted basins that can experience frequent water stress (Molle et al., 2010). Solu- tions originating from researchers and practitioners of the 20th century primarily centered on the management of indi- vidual reservoirs, aquifers, and other water resource infra- structure. The inception of these large, insular management schemes was often met with great acclaim for the local ben- efits that they produced: irrigation, hydropower generation, domestic water supply, flood protection, and recreation, just to name a few. In recent years, however, many of these same projects are now criticized for the accompanying neg- ative socioeconomic and environmental impacts they have produced at the basin scale: unsustainable depletion of aq- uifers, damage to local and regional ecosystems, decreased downstream flow and impaired water quality, and dis- placement of local populations along with excessive immi- gration to surrounding areas. In the last few decades, a renewed emphasis has been placed on holistic planning and decision-making across the river basin in order to more equitably allocate resources, better incorporate stakeholder input, and give greater con- sideration to the complex interactions within the basin (Molle, 2009). Many researchers contend that an integrated assessment of all the components of the basin system (Fig- ure 1) (often called Integrated River Basin Management, IRBM), will yield fewer unforeseen detrimental side effects