Temporal changes in rainfall erosivity can be expected to occur with changing climate and because rainfall amounts areknown to bein pait of afunction of elevation erosivity can be expected to be influenced by elevatio...Temporal changes in rainfall erosivity can be expected to occur with changing climate and because rainfall amounts areknown to bein pait of afunction of elevation erosivity can be expected to be influenced by elevation as well.This is particularly truein mountainous regions such as are found over much of the westem United Stafes.The objective of this study was to identify temporal and elevation trends in rainfall erosivity on a 149km^(2)(58 miles)watershed in a semi-arid region of southeastem Arizona Data from 84 rain gages forthe years 19602012 at elevations ranging from 1231 to 1644 m(40385394 ft)were used in the analyses.The average annual erosivity over the watershed as a whole was 1104 MJ mm ha^(-1)h^(-1)yr^(-1)(65 hundreds of foot ton inch acrei h^(-1)yr^(-1)),and ranged from approximately 950 to 1225 MJ mm ha^(-1)h^(-1)yr^(-1)(56-72 hundreds of foot ton inch acre^(-1)h^(-1)yr^(-1)),with a statistical trend showing greater erosivity af the higher elevations No statistically significant temporal changes in annual or summer erosivities were found.This result stands in contrast to fecent modeling studies of runoff and erosion in the area based on downscaled GCM information that project significant levels of erosivity changes over coming decades.These results are consistent with known orographic rainfall effects,but contrast with recent studies that presented projections of significant trends of increasing erosivity in the future based on downscaled GCM outputs for the area The results illustiate the need for testing and developing improved techniques to evaluate future erosion scenarios for purposes of making targeted soil conservation decisions Production and Hosting by Elsevier B.V on behalf of International Research and Training Center on Erosion and Sedimentation and China Water and Power Press This is anopen access article under theCCBY-NC-ND licens(http://creativecommons.org/licenses/by-ncnd/4.0/).展开更多
文摘Temporal changes in rainfall erosivity can be expected to occur with changing climate and because rainfall amounts areknown to bein pait of afunction of elevation erosivity can be expected to be influenced by elevation as well.This is particularly truein mountainous regions such as are found over much of the westem United Stafes.The objective of this study was to identify temporal and elevation trends in rainfall erosivity on a 149km^(2)(58 miles)watershed in a semi-arid region of southeastem Arizona Data from 84 rain gages forthe years 19602012 at elevations ranging from 1231 to 1644 m(40385394 ft)were used in the analyses.The average annual erosivity over the watershed as a whole was 1104 MJ mm ha^(-1)h^(-1)yr^(-1)(65 hundreds of foot ton inch acrei h^(-1)yr^(-1)),and ranged from approximately 950 to 1225 MJ mm ha^(-1)h^(-1)yr^(-1)(56-72 hundreds of foot ton inch acre^(-1)h^(-1)yr^(-1)),with a statistical trend showing greater erosivity af the higher elevations No statistically significant temporal changes in annual or summer erosivities were found.This result stands in contrast to fecent modeling studies of runoff and erosion in the area based on downscaled GCM information that project significant levels of erosivity changes over coming decades.These results are consistent with known orographic rainfall effects,but contrast with recent studies that presented projections of significant trends of increasing erosivity in the future based on downscaled GCM outputs for the area The results illustiate the need for testing and developing improved techniques to evaluate future erosion scenarios for purposes of making targeted soil conservation decisions Production and Hosting by Elsevier B.V on behalf of International Research and Training Center on Erosion and Sedimentation and China Water and Power Press This is anopen access article under theCCBY-NC-ND licens(http://creativecommons.org/licenses/by-ncnd/4.0/).
