14 Flood Potential of Polish Rivers
279
flood potential and also floods are less frequent than in the mountains. Important
for flood risk management is the observation that major rivers like Odra and Vistula
transfer the high flood potential from their upper catchement tributaries to the middle
reach. This is a feature that is relevant in flood protection designs for instance in case
of City of Warsaw. The major floods in Warsaw have been created by the high
runoff at the Vistula river mountain tributaries draining foot slopes of the Carpathian
mountains. The flood wave propagates down the middle and lower reach of the
Vistula river and it can lower its peak flow only by the flood transformation due to
natural river valley storage.
Lowland rivers like for example Bug and Narew (major tributaries of the Vistula
river) have a run-off regime controlled by the snow melt [20]. This makes the difference between flood index calculated for rainfall induced floods (years 1958 and 1970)
where k < 2 and snowmelt induced flood (year 1979) with k > 2. This is important
feature especially in the context of expected climate change. If in the winter time
there will be more rains than snow-falls the flood potential will be lower. The catastrophic flood of 1979 was induced by rapid melting of accumulated large masses of
snow. This sudden release of water accumulated in the snow-cover set an absolute
maximum of discharge at many lowland rivers in Poland. Rainfall induced floods will
be dominating at the mountains while lowland catchments will react less abruptly
due to their natural storage capacity, higher than in the case of mountain catchments.
14.5 Recommendations
This study has shown spatial difference in flood potential index on the territory of
Poland. This measure could be applied also for other geographical areas and could be
useful metric to compare for example EU countries. In case of Poland map of flood
potential index was used in the preparation of flood risk management plans for the
Vistula river. It has been shown that floods generated in the Carpathian mountains
propagate down the middle reach of the Vistula river. It means that the Vistula’s
river a middle course can propagate the floods with the magnitude characteristic
for mountain tributaries. To get a consistent results it is recommended to use the
common length of maximum discharge records for all analyzed hydrological gauges.
Presented method of flood index calculation can be used for making plans of flood
risk management. Index is showing in a quantitative way of the catchment’s potential
to produce maximum discharge at the flood peak.
279
flood potential and also floods are less frequent than in the mountains. Important
for flood risk management is the observation that major rivers like Odra and Vistula
transfer the high flood potential from their upper catchement tributaries to the middle
reach. This is a feature that is relevant in flood protection designs for instance in case
of City of Warsaw. The major floods in Warsaw have been created by the high
runoff at the Vistula river mountain tributaries draining foot slopes of the Carpathian
mountains. The flood wave propagates down the middle and lower reach of the
Vistula river and it can lower its peak flow only by the flood transformation due to
natural river valley storage.
Lowland rivers like for example Bug and Narew (major tributaries of the Vistula
river) have a run-off regime controlled by the snow melt [20]. This makes the difference between flood index calculated for rainfall induced floods (years 1958 and 1970)
where k < 2 and snowmelt induced flood (year 1979) with k > 2. This is important
feature especially in the context of expected climate change. If in the winter time
there will be more rains than snow-falls the flood potential will be lower. The catastrophic flood of 1979 was induced by rapid melting of accumulated large masses of
snow. This sudden release of water accumulated in the snow-cover set an absolute
maximum of discharge at many lowland rivers in Poland. Rainfall induced floods will
be dominating at the mountains while lowland catchments will react less abruptly
due to their natural storage capacity, higher than in the case of mountain catchments.
14.5 Recommendations
This study has shown spatial difference in flood potential index on the territory of
Poland. This measure could be applied also for other geographical areas and could be
useful metric to compare for example EU countries. In case of Poland map of flood
potential index was used in the preparation of flood risk management plans for the
Vistula river. It has been shown that floods generated in the Carpathian mountains
propagate down the middle reach of the Vistula river. It means that the Vistula’s
river a middle course can propagate the floods with the magnitude characteristic
for mountain tributaries. To get a consistent results it is recommended to use the
common length of maximum discharge records for all analyzed hydrological gauges.
Presented method of flood index calculation can be used for making plans of flood
risk management. Index is showing in a quantitative way of the catchment’s potential
to produce maximum discharge at the flood peak.