Assessing the effect of climate change on mean annual runoff

Summary From published runoff measurements in catchments with a wide range of climatic conditions it is found that long-term mean annual runoff ( R ) can be closely fitted ( r 2  = 0.94) to measured climatic data by R  =  P  * exp(-PET/ P ), where P is the mean annual precipitation and PET is the mean annual potential evapotranspiration (in mm) calculated via the Holland equation, PET = 1.2 × 10 10  * exp(−4620/Tk), which is solely a function of the mean annual temperature in Kelvin, Tk. Application of the chain rule for partial differentiation to the combined equations gives the following equation for estimating the change in runoff due to changes in P and Tk: d R = exp ( - PET / P ) * [ 1 + PET / P ] * d P - [ 5544 × 10 10 * exp ( - PET / P ) * exp ( - 4620 / Tk ) * Tk - 2 ] * dTk By setting d R equal to zero, this equation can be used to estimate the increase in P required to maintain constant runoff for a small increase in T . It can also be used to estimate the decrease in runoff in a scenario with constant precipitation and increased temperature. It is shown herein that predictions of annual runoff changes for various climate change scenarios based on this simple model compare favorably with those based on more complex, calibrated hydrological models, as well as with those based on long-term historical observations of runoff and climate change. Application of the equation above also indicates that the IPCC projections for climate change under the A1B emissions scenario may underestimate the area of North America that is likely to suffer decreases in runoff.

[1]  A. Sankarasubramanian,et al.  Hydroclimatology of the continental United States , 2003 .

[2]  D. B. Boorman,et al.  A regional investigation of climate change impacts on UK streamflows , 1997 .

[3]  J. B. Burford,et al.  Hydrologic data for experimental agricultural watersheds in the United States, 1971. , 2018 .

[4]  Corinne Le Quéré,et al.  Climate Change 2013: The Physical Science Basis , 2013 .

[5]  D. Yates.  WatBal: an integrated water balance model for climate impact assessment of river basin runoff , 1996 .

[6]  X. Chen,et al.  Comparison of hydrological impacts of climate change simulated by six hydrological models in the Dongjiang Basin, South China , 2007 .

[7]  Wilfried Brutsaert,et al.  Evaporation into the atmosphere : theory, history, and applications , 1982 .

[8]  S. Charles,et al.  A two‐parameter climate elasticity of streamflow index to assess climate change effects on annual streamflow , 2007 .

[9]  H. D. Holland.  The chemistry of the atmosphere and oceans , 1978 .

[10]  V. Malmstrom.  A New Approach To The Classification Of Climate , 1969 .

[11]  C. W. Thornthwaite.  THE WATER BALANCE , 1955 .

[12]  A. Becker,et al.  Assessment of land use and climate change impacts on the mesoscale , 2001 .

[13]  P. E. Waggoner,et al.  From climate to flow. , 1990 .

[14]  Francis Chiew Hock Soon.  Estimating groundwater recharge using an integrated surface and groundwater model , 1990 .

[15]  Francis H. S. Chiew,et al.  Simulation of the impacts of climate change on runoff and soil moisture in Australian catchments , 1995 .

[16]  K. Beven,et al.  Testing a physically-based flood forecasting model (TOPMODEL) for three U.K. catchments , 1984 .

[17]  J. Niemann,et al.  Sensitivity of regional hydrology to climate changes, with application to the Illinois River basin , 2005 .

[18]  J. Klaus,et al.  Recent climate trends and implications for water resources in the Catskill Mountain region, New York, USA , 2007 .

[19]  B. Lofgren.  GLOBAL WARMING EFFECTS ON GREAT LAKES WATER: MORE PRECIPITATION BUT LESS WATER? , 2004 .

[20]  Dingfang Li,et al.  A macro-scale and semi-distributed monthly water balance model to predict climate change impacts in China , 2002 .

[21]  Vijay P. Singh,et al.  Historical temporal trends of hydro-climatic variables and runoff response to climate variability and their relevance in water resource management in the Hanjiang basin , 2007 .

[22]  Vincent R. Gray.  Climate Change 2007: The Physical Science Basis Summary for Policymakers , 2007 .

[23]  William M. Alley,et al.  On the Treatment of Evapotranspiration, Soil Moisture Accounting, and Aquifer Recharge in Monthly Water Balance Models , 1984 .

[24]  P. Waggoner.  Climate change and US water resources. , 1990 .

[25]  Richard M. Vogel,et al.  REGIONAL REGRESSION MODELS OF ANNUAL STREAMFLOW FOR THE UNITED STATES , 1999 .

[26]  L. B. Leopold,et al.  Water In Environmental Planning , 1978 .

[27]  A. Sankarasubramanian,et al.  Climate elasticity of streamflow in the United States , 2001 .

[28]  Chong-Yu Xu,et al.  Methodology and comparative study of monthly water balance models in Belgium, China and Burma , 1992 .

[29]  L. Boorman.  Salt marshes – present functioning and future change , 1999 .

[30]  S. Steele‐Dunne,et al.  The impacts of climate change on hydrology in Ireland , 2008 .

[31]  Heinz G. Stefan,et al.  Stream flow in Minnesota : Indicator of climate change , 2007 .

[32]  F. Chiew,et al.  Estimation of rainfall elasticity of streamflow in Australia , 2006 .

[33]  Shenglian Guo,et al.  A two-parameter monthly water balance model and its application , 1999 .