Indicator water

Mean flow

Mean runoff defines the amount of water discharged on average during a year or season. It naturally depends on the precipitation that has fallen in the catchment and how much is lost from it through evaporation or long-term storage (e.g. in glaciers). It can also be affected by human activity such as water management intervention (e.g. irrigation, diversions, retention in reservoirs or lake regulation). Runoff and its seasonal distribution are important parameters for water ecology and management (hydropower, drinking water use, irrigation, navigation). Long-term discharge time series indicate how the water balance is changing due to these influences.

Assessment of the state
impossible to evaluate impossible to evaluate
Assessment of the trend
impossible to evaluate impossible to evaluate
Mean winter flow 2018: 129 Mean winter flow 2017: 118 Mean winter flow 2016: 115 Mean winter flow 2015: 133 Mean winter flow 2014: 126 Mean winter flow 2013: 140 Mean winter flow 2012: 134 Mean winter flow 2011: 122 Mean winter flow 2010: 134 Mean winter flow 2009: 108 Mean winter flow 2008: 117 Mean winter flow 2007: 119 Mean winter flow 2006: 116 Mean winter flow 2005: 112 Mean winter flow 2004: 119 Mean winter flow 2003: 125 Mean winter flow 2002: 124 Mean winter flow 2001: 134 Mean winter flow 2000: 145 Mean winter flow 1999: 133 Mean winter flow 1998: 127 Mean winter flow 1997: 131 Mean winter flow 1996: 113 Mean winter flow 1995: 139 Mean winter flow 1994: 143 Mean winter flow 1993: 142 Mean winter flow 1992: 132 Mean winter flow 1991: 126 Mean winter flow 1990: 126 Mean winter flow 1989: 111 Mean winter flow 1988: 147 Mean winter flow 1987: 125 Mean winter flow 1986: 116 Mean winter flow 1985: 132 Mean winter flow 1984: 117 Mean winter flow 1983: 128 Mean winter flow 1982: 133 Mean winter flow 1981: 144 Mean winter flow 1980: 137 Mean winter flow 1979: 129 Mean winter flow 1978: 123 Mean winter flow 1977: 127 Mean winter flow 1976: 102 Mean winter flow 1975: 112 Mean winter flow 1974: 102 Mean winter flow 1973: 100 Mean winter flow 1972: 99 Mean winter flow 1971: 104 Mean winter flow 1970: 116 Mean winter flow 1969: 111 Mean winter flow 1968: 112 Mean winter flow 1967: 113 Mean winter flow 1966: 115 Mean winter flow 1965: 97 Mean winter flow 1964: 90 Mean winter flow 1963: 88 Mean winter flow 1962: 100 Mean winter flow 1961: 109 Mean winter flow 1960: 103 Mean winter flow 1959: 87 Mean winter flow 1958: 93 Mean winter flow 1957: 76 Mean winter flow 1956: 67 Mean winter flow 1955: 89 Mean winter flow 1954: 74 Mean winter flow 1953: 84 Mean winter flow 1952: 93 Mean winter flow 1951: 77 Mean winter flow 1950: 75 Mean winter flow 1949: 59 Mean winter flow 1948: 75 Mean winter flow 1947: 67 Mean winter flow 1946: 71 Mean winter flow 1945: 82 Mean winter flow 1944: 85 Mean winter flow 1943: 61 Mean winter flow 1942: 70 Mean winter flow 1941: 72 Mean winter flow 1940: 93 Mean winter flow 1939: 88 Mean winter flow 1938: 66 Mean winter flow 1937: 69 Mean winter flow 1936: 82 Mean winter flow 1935: 82 Mean winter flow 1934: 59 Mean winter flow 1933: 64 Mean winter flow 1932: 64 Mean winter flow 1931: 72 Mean winter flow 1930: 99 Mean winter flow 1929: 66 Mean winter flow 1928: 87 Mean winter flow 1927: 67 Mean winter flow 1926: 77 Mean winter flow 1925: 56 Mean winter flow 1924: 72 Mean winter flow 1923: 76 Mean winter flow 1922: 68 Mean winter flow 1921: 60 Mean winter flow 1920: 82 Mean winter flow 1919: 79 Mean winter flow 1918: 73 Mean winter flow 1917: 75 Mean winter flow 1916: 76 Mean winter flow 1915: 72 Mean winter flow 1914: 75 Mean winter flow 1913: 54 Mean winter flow 1912: 60 Mean winter flow 1911: 59 Mean winter flow 1910: 75 Mean winter flow 1909: 53 Mean winter flow 1908: 48 Mean winter flow 1907: 68 Mean winter flow 1906: 61 Mean winter flow 1905: 56 Mean summer flow 2018: 288 Mean summer flow 2017: 197 Mean summer flow 2016: 242 Mean summer flow 2015: 258 Mean summer flow 2014: 211 Mean summer flow 2013: 257 Mean summer flow 2012: 256 Mean summer flow 2011: 177 Mean summer flow 2010: 219 Mean summer flow 2009: 256 Mean summer flow 2008: 251 Mean summer flow 2007: 256 Mean summer flow 2006: 233 Mean summer flow 2005: 209 Mean summer flow 2004: 212 Mean summer flow 2003: 262 Mean summer flow 2002: 238 Mean summer flow 2001: 291 Mean summer flow 2000: 229 Mean summer flow 1999: 320 Mean summer flow 1998: 213 Mean summer flow 1997: 237 Mean summer flow 1996: 181 Mean summer flow 1995: 293 Mean summer flow 1994: 287 Mean summer flow 1993: 239 Mean summer flow 1992: 229 Mean summer flow 1991: 228 Mean summer flow 1990: 233 Mean summer flow 1989: 217 Mean summer flow 1988: 275 Mean summer flow 1987: 279 Mean summer flow 1986: 277 Mean summer flow 1985: 251 Mean summer flow 1984: 218 Mean summer flow 1983: 291 Mean summer flow 1982: 308 Mean summer flow 1981: 281 Mean summer flow 1980: 277 Mean summer flow 1979: 239 Mean summer flow 1978: 257 Mean summer flow 1977: 263 Mean summer flow 1976: 152 Mean summer flow 1975: 261 Mean summer flow 1974: 186 Mean summer flow 1973: 226 Mean summer flow 1972: 167 Mean summer flow 1971: 200 Mean summer flow 1970: 297 Mean summer flow 1969: 227 Mean summer flow 1968: 220 Mean summer flow 1967: 258 Mean summer flow 1966: 274 Mean summer flow 1965: 225 Mean summer flow 1964: 190 Mean summer flow 1963: 261 Mean summer flow 1962: 250 Mean summer flow 1961: 253 Mean summer flow 1960: 252 Mean summer flow 1959: 236 Mean summer flow 1958: 292 Mean summer flow 1957: 228 Mean summer flow 1956: 257 Mean summer flow 1955: 294 Mean summer flow 1954: 230 Mean summer flow 1953: 293 Mean summer flow 1952: 302 Mean summer flow 1951: 339 Mean summer flow 1950: 308 Mean summer flow 1949: 240 Mean summer flow 1948: 266 Mean summer flow 1947: 301 Mean summer flow 1946: 313 Mean summer flow 1945: 346 Mean summer flow 1944: 272 Mean summer flow 1943: 280 Mean summer flow 1942: 270 Mean summer flow 1941: 290 Mean summer flow 1940: 292 Mean summer flow 1939: 266 Mean summer flow 1938: 250 Mean summer flow 1937: 333 Mean summer flow 1936: 336 Mean summer flow 1935: 328 Mean summer flow 1934: 256 Mean summer flow 1933: 243 Mean summer flow 1932: 279 Mean summer flow 1931: 341 Mean summer flow 1930: 297 Mean summer flow 1929: 322 Mean summer flow 1928: 324 Mean summer flow 1927: 329 Mean summer flow 1926: 312 Mean summer flow 1925: 227 Mean summer flow 1924: 300 Mean summer flow 1923: 266 Mean summer flow 1922: 326 Mean summer flow 1921: 245 Mean summer flow 1920: 330 Mean summer flow 1919: 288 Mean summer flow 1918: 272 Mean summer flow 1917: 313 Mean summer flow 1916: 293 Mean summer flow 1915: 313 Mean summer flow 1914: 324 Mean summer flow 1913: 226 Mean summer flow 1912: 240 Mean summer flow 1911: 299 Mean summer flow 1910: 262 Mean summer flow 1909: 213 Mean summer flow 1908: 259 Mean summer flow 1907: 276 Mean summer flow 1906: 275 Mean summer flow 1905: 292 Mean annual flow 2018: 209 Mean annual flow 2017: 158 Mean annual flow 2016: 178 Mean annual flow 2015: 196 Mean annual flow 2014: 168 Mean annual flow 2013: 199 Mean annual flow 2012: 195 Mean annual flow 2011: 150 Mean annual flow 2010: 176 Mean annual flow 2009: 182 Mean annual flow 2008: 184 Mean annual flow 2007: 188 Mean annual flow 2006: 175 Mean annual flow 2005: 161 Mean annual flow 2004: 166 Mean annual flow 2003: 194 Mean annual flow 2002: 181 Mean annual flow 2001: 213 Mean annual flow 2000: 187 Mean annual flow 1999: 227 Mean annual flow 1998: 170 Mean annual flow 1997: 184 Mean annual flow 1996: 147 Mean annual flow 1995: 216 Mean annual flow 1994: 216 Mean annual flow 1993: 191 Mean annual flow 1992: 180 Mean annual flow 1991: 177 Mean annual flow 1990: 179 Mean annual flow 1989: 164 Mean annual flow 1988: 211 Mean annual flow 1987: 202 Mean annual flow 1986: 197 Mean annual flow 1985: 191 Mean annual flow 1984: 167 Mean annual flow 1983: 210 Mean annual flow 1982: 220 Mean annual flow 1981: 213 Mean annual flow 1980: 207 Mean annual flow 1979: 184 Mean annual flow 1978: 190 Mean annual flow 1977: 195 Mean annual flow 1976: 127 Mean annual flow 1975: 187 Mean annual flow 1974: 144 Mean annual flow 1973: 163 Mean annual flow 1972: 133 Mean annual flow 1971: 152 Mean annual flow 1970: 207 Mean annual flow 1969: 169 Mean annual flow 1968: 166 Mean annual flow 1967: 186 Mean annual flow 1966: 195 Mean annual flow 1965: 161 Mean annual flow 1964: 140 Mean annual flow 1963: 175 Mean annual flow 1962: 175 Mean annual flow 1961: 181 Mean annual flow 1960: 178 Mean annual flow 1959: 162 Mean annual flow 1958: 193 Mean annual flow 1957: 152 Mean annual flow 1956: 162 Mean annual flow 1955: 192 Mean annual flow 1954: 152 Mean annual flow 1953: 189 Mean annual flow 1952: 197 Mean annual flow 1951: 209 Mean annual flow 1950: 192 Mean annual flow 1949: 150 Mean annual flow 1948: 170 Mean annual flow 1947: 185 Mean annual flow 1946: 192 Mean annual flow 1945: 214 Mean annual flow 1944: 178 Mean annual flow 1943: 171 Mean annual flow 1942: 170 Mean annual flow 1941: 182 Mean annual flow 1940: 192 Mean annual flow 1939: 177 Mean annual flow 1938: 158 Mean annual flow 1937: 202 Mean annual flow 1936: 209 Mean annual flow 1935: 205 Mean annual flow 1934: 158 Mean annual flow 1933: 153 Mean annual flow 1932: 172 Mean annual flow 1931: 207 Mean annual flow 1930: 198 Mean annual flow 1929: 195 Mean annual flow 1928: 205 Mean annual flow 1927: 198 Mean annual flow 1926: 195 Mean annual flow 1925: 142 Mean annual flow 1924: 186 Mean annual flow 1923: 171 Mean annual flow 1922: 198 Mean annual flow 1921: 153 Mean annual flow 1920: 206 Mean annual flow 1919: 184 Mean annual flow 1918: 173 Mean annual flow 1917: 194 Mean annual flow 1916: 185 Mean annual flow 1915: 193 Mean annual flow 1914: 200 Mean annual flow 1913: 140 Mean annual flow 1912: 150 Mean annual flow 1911: 179 Mean annual flow 1910: 169 Mean annual flow 1909: 133 Mean annual flow 1908: 154 Mean annual flow 1907: 172 Mean annual flow 1906: 168 Mean annual flow 1905: 174
Mean annual and seasonal flow for the station Rhône-Porte du Scex

Data for the graph: Excel
Source: Bundesamt für Umwelt
Mean winter flow 2018: 945 Mean winter flow 2017: 840 Mean winter flow 2016: 813 Mean winter flow 2015: 759 Mean winter flow 2014: 829 Mean winter flow 2013: 1013 Mean winter flow 2012: 1153 Mean winter flow 2011: 767 Mean winter flow 2010: 850 Mean winter flow 2009: 761 Mean winter flow 2008: 771 Mean winter flow 2007: 868 Mean winter flow 2006: 743 Mean winter flow 2005: 636 Mean winter flow 2004: 802 Mean winter flow 2003: 784 Mean winter flow 2002: 1231 Mean winter flow 2001: 1036 Mean winter flow 2000: 1005 Mean winter flow 1999: 1092 Mean winter flow 1998: 934 Mean winter flow 1997: 728 Mean winter flow 1996: 843 Mean winter flow 1995: 1051 Mean winter flow 1994: 931 Mean winter flow 1993: 883 Mean winter flow 1992: 996 Mean winter flow 1991: 787 Mean winter flow 1990: 844 Mean winter flow 1989: 663 Mean winter flow 1988: 1017 Mean winter flow 1987: 836 Mean winter flow 1986: 704 Mean winter flow 1985: 644 Mean winter flow 1984: 862 Mean winter flow 1983: 827 Mean winter flow 1982: 1139 Mean winter flow 1981: 1305 Mean winter flow 1980: 962 Mean winter flow 1979: 1113 Mean winter flow 1978: 904 Mean winter flow 1977: 971 Mean winter flow 1976: 674 Mean winter flow 1975: 841 Mean winter flow 1974: 1018 Mean winter flow 1973: 703 Mean winter flow 1972: 652 Mean winter flow 1971: 517 Mean winter flow 1970: 1004 Mean winter flow 1969: 644 Mean winter flow 1968: 920 Mean winter flow 1967: 871 Mean winter flow 1966: 1022 Mean winter flow 1965: 919 Mean winter flow 1964: 626 Mean winter flow 1963: 690 Mean winter flow 1962: 673 Mean winter flow 1961: 713 Mean winter flow 1960: 966 Mean winter flow 1959: 672 Mean winter flow 1958: 955 Mean winter flow 1957: 759 Mean winter flow 1956: 825 Mean winter flow 1955: 955 Mean winter flow 1954: 825 Mean winter flow 1953: 632 Mean winter flow 1952: 1176 Mean winter flow 1951: 866 Mean winter flow 1950: 795 Mean winter flow 1949: 481 Mean winter flow 1948: 809 Mean winter flow 1947: 680 Mean winter flow 1946: 716 Mean winter flow 1945: 872 Mean winter flow 1944: 1011 Mean winter flow 1943: 569 Mean winter flow 1942: 719 Mean winter flow 1941: 850 Mean winter flow 1940: 1021 Mean winter flow 1939: 1148 Mean winter flow 1938: 675 Mean winter flow 1937: 881 Mean winter flow 1936: 1051 Mean winter flow 1935: 1011 Mean winter flow 1934: 625 Mean winter flow 1933: 628 Mean winter flow 1932: 688 Mean winter flow 1931: 879 Mean winter flow 1930: 965 Mean winter flow 1929: 602 Mean winter flow 1928: 876 Mean winter flow 1927: 826 Mean winter flow 1926: 825 Mean winter flow 1925: 617 Mean winter flow 1924: 721 Mean winter flow 1923: 1008 Mean winter flow 1922: 979 Mean winter flow 1921: 454 Mean winter flow 1920: 773 Mean winter flow 1919: 886 Mean winter flow 1918: 760 Mean winter flow 1917: 868 Mean winter flow 1916: 1006 Mean winter flow 1915: 836 Mean winter flow 1914: 869 Mean winter flow 1913: 784 Mean winter flow 1912: 847 Mean winter flow 1911: 686 Mean winter flow 1910: 1109 Mean winter flow 1909: 623 Mean winter flow 1908: 551 Mean winter flow 1907: 594 Mean winter flow 1906: 616 Mean winter flow 1905: 809 Mean winter flow 1904: 664 Mean winter flow 1903: 766 Mean winter flow 1902: 724 Mean winter flow 1901: 643 Mean summer flow 2018: 910 Mean summer flow 2017: 1002 Mean summer flow 2016: 1469 Mean summer flow 2015: 1151 Mean summer flow 2014: 1207 Mean summer flow 2013: 1365 Mean summer flow 2012: 1235 Mean summer flow 2011: 872 Mean summer flow 2010: 1272 Mean summer flow 2009: 1164 Mean summer flow 2008: 1294 Mean summer flow 2007: 1289 Mean summer flow 2006: 1394 Mean summer flow 2005: 1199 Mean summer flow 2004: 1107 Mean summer flow 2003: 802 Mean summer flow 2002: 1282 Mean summer flow 2001: 1568 Mean summer flow 2000: 1279 Mean summer flow 1999: 1772 Mean summer flow 1998: 955 Mean summer flow 1997: 1162 Mean summer flow 1996: 970 Mean summer flow 1995: 1515 Mean summer flow 1994: 1354 Mean summer flow 1993: 1167 Mean summer flow 1992: 1099 Mean summer flow 1991: 1028 Mean summer flow 1990: 1019 Mean summer flow 1989: 1024 Mean summer flow 1988: 1376 Mean summer flow 1987: 1718 Mean summer flow 1986: 1461 Mean summer flow 1985: 1274 Mean summer flow 1984: 1218 Mean summer flow 1983: 1350 Mean summer flow 1982: 1415 Mean summer flow 1981: 1329 Mean summer flow 1980: 1462 Mean summer flow 1979: 1182 Mean summer flow 1978: 1458 Mean summer flow 1977: 1458 Mean summer flow 1976: 821 Mean summer flow 1975: 1505 Mean summer flow 1974: 1068 Mean summer flow 1973: 1158 Mean summer flow 1972: 893 Mean summer flow 1971: 928 Mean summer flow 1970: 1750 Mean summer flow 1969: 1284 Mean summer flow 1968: 1450 Mean summer flow 1967: 1379 Mean summer flow 1966: 1546 Mean summer flow 1965: 1743 Mean summer flow 1964: 897 Mean summer flow 1963: 1309 Mean summer flow 1962: 1144 Mean summer flow 1961: 1178 Mean summer flow 1960: 1255 Mean summer flow 1959: 977 Mean summer flow 1958: 1297 Mean summer flow 1957: 1227 Mean summer flow 1956: 1438 Mean summer flow 1955: 1414 Mean summer flow 1954: 1321 Mean summer flow 1953: 1312 Mean summer flow 1952: 1103 Mean summer flow 1951: 1382 Mean summer flow 1950: 1030 Mean summer flow 1949: 804 Mean summer flow 1948: 1320 Mean summer flow 1947: 851 Mean summer flow 1946: 1306 Mean summer flow 1945: 1275 Mean summer flow 1944: 1174 Mean summer flow 1943: 952 Mean summer flow 1942: 1095 Mean summer flow 1941: 1305 Mean summer flow 1940: 1554 Mean summer flow 1939: 1540 Mean summer flow 1938: 1239 Mean summer flow 1937: 1490 Mean summer flow 1936: 1528 Mean summer flow 1935: 1389 Mean summer flow 1934: 991 Mean summer flow 1933: 1196 Mean summer flow 1932: 1302 Mean summer flow 1931: 1619 Mean summer flow 1930: 1458 Mean summer flow 1929: 1080 Mean summer flow 1928: 1056 Mean summer flow 1927: 1691 Mean summer flow 1926: 1499 Mean summer flow 1925: 1014 Mean summer flow 1924: 1635 Mean summer flow 1923: 1187 Mean summer flow 1922: 1626 Mean summer flow 1921: 758 Mean summer flow 1920: 1309 Mean summer flow 1919: 1334 Mean summer flow 1918: 1080 Mean summer flow 1917: 1376 Mean summer flow 1916: 1503 Mean summer flow 1915: 1456 Mean summer flow 1914: 1692 Mean summer flow 1913: 1314 Mean summer flow 1912: 1415 Mean summer flow 1911: 1049 Mean summer flow 1910: 1767 Mean summer flow 1909: 1175 Mean summer flow 1908: 1330 Mean summer flow 1907: 1390 Mean summer flow 1906: 1320 Mean summer flow 1905: 1440 Mean summer flow 1904: 1269 Mean summer flow 1903: 1225 Mean summer flow 1902: 1378 Mean summer flow 1901: 1458 Mean annual flow 2018: 927 Mean annual flow 2017: 921 Mean annual flow 2016: 1141 Mean annual flow 2015: 956 Mean annual flow 2014: 1018 Mean annual flow 2013: 1189 Mean annual flow 2012: 1194 Mean annual flow 2011: 819 Mean annual flow 2010: 1061 Mean annual flow 2009: 963 Mean annual flow 2008: 1033 Mean annual flow 2007: 1079 Mean annual flow 2006: 1070 Mean annual flow 2005: 918 Mean annual flow 2004: 954 Mean annual flow 2003: 793 Mean annual flow 2002: 1257 Mean annual flow 2001: 1303 Mean annual flow 2000: 1142 Mean annual flow 1999: 1433 Mean annual flow 1998: 944 Mean annual flow 1997: 945 Mean annual flow 1996: 906 Mean annual flow 1995: 1283 Mean annual flow 1994: 1143 Mean annual flow 1993: 1025 Mean annual flow 1992: 1047 Mean annual flow 1991: 908 Mean annual flow 1990: 932 Mean annual flow 1989: 844 Mean annual flow 1988: 1197 Mean annual flow 1987: 1278 Mean annual flow 1986: 1084 Mean annual flow 1985: 960 Mean annual flow 1984: 1040 Mean annual flow 1983: 1089 Mean annual flow 1982: 1278 Mean annual flow 1981: 1317 Mean annual flow 1980: 1212 Mean annual flow 1979: 1148 Mean annual flow 1978: 1182 Mean annual flow 1977: 1215 Mean annual flow 1976: 747 Mean annual flow 1975: 1174 Mean annual flow 1974: 1043 Mean annual flow 1973: 931 Mean annual flow 1972: 773 Mean annual flow 1971: 723 Mean annual flow 1970: 1378 Mean annual flow 1969: 965 Mean annual flow 1968: 1185 Mean annual flow 1967: 1126 Mean annual flow 1966: 1285 Mean annual flow 1965: 1332 Mean annual flow 1964: 762 Mean annual flow 1963: 1000 Mean annual flow 1962: 909 Mean annual flow 1961: 946 Mean annual flow 1960: 1111 Mean annual flow 1959: 825 Mean annual flow 1958: 1127 Mean annual flow 1957: 994 Mean annual flow 1956: 1132 Mean annual flow 1955: 1185 Mean annual flow 1954: 1074 Mean annual flow 1953: 973 Mean annual flow 1952: 1139 Mean annual flow 1951: 1125 Mean annual flow 1950: 913 Mean annual flow 1949: 643 Mean annual flow 1948: 1065 Mean annual flow 1947: 766 Mean annual flow 1946: 1012 Mean annual flow 1945: 1074 Mean annual flow 1944: 1093 Mean annual flow 1943: 761 Mean annual flow 1942: 908 Mean annual flow 1941: 1078 Mean annual flow 1940: 1287 Mean annual flow 1939: 1344 Mean annual flow 1938: 958 Mean annual flow 1937: 1186 Mean annual flow 1936: 1289 Mean annual flow 1935: 1200 Mean annual flow 1934: 809 Mean annual flow 1933: 913 Mean annual flow 1932: 995 Mean annual flow 1931: 1250 Mean annual flow 1930: 1212 Mean annual flow 1929: 842 Mean annual flow 1928: 966 Mean annual flow 1927: 1260 Mean annual flow 1926: 1163 Mean annual flow 1925: 816 Mean annual flow 1924: 1178 Mean annual flow 1923: 1098 Mean annual flow 1922: 1304 Mean annual flow 1921: 606 Mean annual flow 1920: 1041 Mean annual flow 1919: 1110 Mean annual flow 1918: 920 Mean annual flow 1917: 1123 Mean annual flow 1916: 1254 Mean annual flow 1915: 1147 Mean annual flow 1914: 1281 Mean annual flow 1913: 1050 Mean annual flow 1912: 1131 Mean annual flow 1911: 868 Mean annual flow 1910: 1439 Mean annual flow 1909: 899 Mean annual flow 1908: 941 Mean annual flow 1907: 993 Mean annual flow 1906: 969 Mean annual flow 1905: 1125 Mean annual flow 1904: 966 Mean annual flow 1903: 996 Mean annual flow 1902: 1052 Mean annual flow 1901: 1051
Mean annual and seasonal flow for the station Rhein-Basel

Data for the graph: Excel
Source: Bundesamt für Umwelt
Comment

Individual annual flows are subject to very wide variations. No clear trends are apparent from a study of the 20th century as a whole for either the Rhein-Basel or the Rhône-Porte du Scex. If the two halves of the year are compared, it is apparent that mean flow tends to rise in winter and fall in summer.

Runoff reacts sensitively to climate change: The rise in air temperatures observed since the 19th century promotes glacier melt and increases evaporation. Winter flows increase because in an increasingly warm climate more precipitation falls as rain in the winter and less is temporarily stored as snow or ice. This means that some of the water which fills the reservoirs in summer as the snow and ice melt is lost, and summer flows tend to decline. The impact of this on nature, water quality and water management can be both positive (e.g. higher hydropower production in winter) and negative (e.g. drought and water shortages in summer). This makes an evaluation difficult.

 

 

International comparison

Projections of the regional flow and its seasonal variations for the period 2071–2100 are computed in the EEA European Indicator System. An international comparison is not appropriate because modelled values rather than measured data are used internationally for the indicator.

Method

The flow for the two major river basins studied, the Rhine and the Rhone, is based on data measured at federal flow monitoring stations. The mean values for anual flows, summer flows (April to September) and winter flows (October to March) are shown.

 
Last updated on: 17.06.2019

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