Long-term changes in flood event patterns due to changes in hydrological distribution parameters in a rural―urban catchment, Shikoku, Japan

Abstract This article describes the principal control parameters of flood events and precipitation and the relationships between corresponding hydrologic and climatologic parameters. The long-term generation of runoff and associated processes is important in understanding floods and droughts under changes in climate and land use. This study presents detailed analyses of flood events in a coastal amphitheatre catchment with a total area of 445 km 2 in western Japan, followed by analyses of flood events in both urban and forest areas. Using long-term (1962 to 2002) hydrological and climatological data from the Ministry of Land, Infrastructure and Transport, Japan, the contributions of precipitation, river discharge, temperature, and relative humidity to flood events were analysed. Flood events could be divided into three types with respect to hydrologic and climatologic principal control parameters: the long-term tendency; medium-term changes as revealed by hydrographs and hyetographs of high-intensity events such as the relative precipitation, river discharge, and temperature; and large events, as shown by the flow–duration curve, with each cluster having particular characteristics. River discharge showed a decreasing tendency of flow quantity during small rainfall events of less than 100 mm/event from the 1980s to the present. An approximately 7% decrease from 44.8 to 37.3% occurred in the percentage of river water supplied by precipitation in the years after the 1980s. For the medium-term changes, no marked change occurred in the flow quantity of the peak point over time in event hydrographs. However, flow quantities before and after the peak tended to decrease by 1 to 2 m 3 /s after the 1980s. Theoretical considerations with regard to the influence of hydrologic and climatologic parameters on flood discharge are discussed and examined in terms of observational data. These findings provide a sound foundation for use in hydrological catchment modelling.

[1]  T. McVicar,et al.  Wind speed climatology and trends for Australia, 1975–2006: Capturing the stilling phenomenon and comparison with near‐surface reanalysis output , 2008 .

[2]  Marco Borga,et al.  Controls on event runoff coefficients in the eastern Italian Alps. , 2009 .

[3]  Felix Naef,et al.  A decision scheme to indicate dominant hydrological flow processes on temperate grassland , 2003 .

[4]  B. Fu,et al.  The effect of land uses and rainfall regimes on runoff and soil erosion in the semi-arid loess hilly area, China , 2007 .

[5]  Lilia Bocheva,et al.  Variability and trends of extreme precipitation events over Bulgaria (1961–2005) , 2009 .

[6]  Taikan Oki,et al.  Modelling the catchment-scale environmental impacts of wastewater treatment in an urban sewage system for CO₂ emission assessment. , 2010, Water science and technology : a journal of the International Association on Water Pollution Research.

[7]  B. Arheimer,et al.  A systematic review of sensitivities in the Swedish flood-forecasting system , 2011 .

[8]  Rolf Weingartner,et al.  Distribution of peak flow derived from a distribution of rainfall volume and runoff coefficient, and a unit hydrograph , 1998 .

[9]  Malcolm G. Anderson,et al.  Process studies in hillslope hydrology. , 1993 .

[10]  P. Pesice,et al.  A comparison of the flood precipitation episode in August 2002 with historic extreme precipitation events on the Czech territory , 2005 .

[11]  David A. Woolhiser,et al.  EFFECT OF STORM RAINFALL INTENSITY PATTERNS ON SURFACE RUNOFF , 1988 .

[12]  Marco Borga,et al.  USE OF DIGITAL ELEVATION MODEL DATA FOR THE DERIVATION OF THE GEOMORPHOLOGICAL INSTANTANEOUS UNIT HYDROGRAPH , 1997 .

[13]  Xixi Lu,et al.  Hydrological responses to precipitation variation and diverse human activities in a mountainous tributary of the lower Xijiang, China , 2009 .

[14]  Eric Gaume,et al.  Hydrological analysis of a flash flood across a climatic and geologic gradient: The September 18, 2007 event in Western Slovenia , 2010 .

[15]  Surfaces saturees, surfaces contributives: localisation et extension dans l'espace du bassin versant / Saturated and contributing areas: location and spatial extent in a catchment , 1996 .

[16]  Z. Sokol,et al.  Extremeness of meteorological variables as an indicator of extreme precipitation events , 2009 .

[17]  K. Pandžić,et al.  Principal component analysis of a river basin discharge and precipitation anomaly fields associated with the global circulation , 1992 .

[18]  R. Batalla,et al.  Hydrological response of a small Mediterranean agricultural catchment. , 2010 .

[19]  M. Mosley.  Delimitation of New Zealand hydrologic regions , 1981 .

[20]  B. Merz,et al.  Trends in flood magnitude, frequency and seasonality in Germany in the period 1951–2002 , 2009 .

[21]  P. Germann,et al.  Investigations on the runoff generation at the profile and plot scales, Swiss Emmental , 2006 .

[22]  S. Uhlenbrook,et al.  Hydrograph separations in a mesoscale mountainous basin at event and seasonal timescales , 2002 .

[23]  Günter Blöschl,et al.  Regionalisation of catchment model parameters , 2004 .

[24]  R. P. Collins,et al.  A GIS Framework for Medelling Nitrogen Leaching from Agricultural Areas in the Middle Hills, Nepal , 1998, Int. J. Geogr. Inf. Sci..

[25]  R. Weingartner,et al.  Rainfall-runoff events in a middle mountain catchment of Nepal , 2006 .

[26]  Vazken Andréassian,et al.  Waters and forests: from historical controversy to scientific debate [review article] , 2004 .

[27]  M. Mosley.  Streamflow generation in a forested watershed, New Zealand , 1979 .

[28]  Y. Onda,et al.  Runoff generation mechanisms in high-relief mountainous watersheds with different underlying geology , 2006 .

[29]  Murugesu Sivapalan,et al.  Linking flood frequency to long‐term water balance: Incorporating effects of seasonality , 2005 .

[30]  M. Bonell,et al.  The generation of storm runoff in a forested clayey drainage basin in Luxembourg , 1984 .

[31]  Felix Naef,et al.  An experimental tracer study of the role of macropores in infiltration in grassland soils , 2003 .

[32]  Olivier Cerdan,et al.  Scale effect on runoff from experimental plots to catchments in agricultural areas in Normandy , 2004 .

[33]  A. Pearce,et al.  Storm runoff generation in humid headwater catchments 1 , 1986 .

[34]  Trevor Dickinson.  Rainfall intensity-frequency relationships from monthly extremes , 1977 .

[35]  L. Pfister,et al.  Spatial variability of trends in hydrological extremes induced by orographically enhanced rainfall events due to westerly atmospheric circulations. , 2005, Water science and technology : a journal of the International Association on Water Pollution Research.

[36]  Andrew W. Western,et al.  A review of paired catchment studies for determining changes in water yield resulting from alterations in vegetation , 2005 .

[37]  Larry Boersma,et al.  Effect of antecedent rainfall on runoff during low-intensity rainfall , 1986 .

[38]  T. Oki,et al.  Investigating the roles of climate seasonality and landscape characteristics on mean annual and monthly water balances , 2008 .

[39]  D. Bae,et al.  Climatic variability of soil water in the American Midwest: Part 2. Spatio-temporal analysis , 1994 .

[40]  Felix Naef,et al.  A process based assessment of the potential to reduce flood runoff by land use change , 2002 .

[41]  L. Gardner,et al.  Assessing the effect of climate change on mean annual runoff , 2009 .

[42]  A. Iroumé,et al.  Variability of annual rainfall partitioning for different sites and forest covers in Chile , 2001 .

[43]  R. Clark,et al.  Rainfall stormflow analysis to investigate spatial and temporal variability of excess rainfall generation , 1980 .

[45]  Francesc Gallart,et al.  Seasonal dynamics of runoff-contributing areas in a small mediterranean research catchment (Vallcebre, Eastern Pyrenees) , 2007 .

[46]  K. Beven,et al.  Throughflow and solute transport in an isolated sloping soil block in a forested catchment , 1991 .