Altered precipitation characteristics in two Polish Carpathian basins, with implications for water resources

2017

Water

This study analyzes changes in long-term patterns of precipitation and river flow, as well as changes in their variability over the most recent 60 years . The study area is situated in the mountain basin of the Dunajec River, encompassing streams draining the Tatra Mountains in southern Poland. The focus of the study was to evaluate how regional warming translates into precipitation changes in the studied mountain region, and how changes in climate affect sub-regional hydrology. Monthly time series of precipitation measured at several sites were compared for two 30-year periods (1986-2015 versus 1956-1985). The significance of the difference between the periods in question was evaluated by means of the Wilcoxon signed rank test with the Bonferroni correction. The identified shifts in precipitation for 6 months are statistically significant and largely consistent with the revealed changes in river flow patterns. Moreover, significant differences in precipitation variability were noted in the study area, resulting in a significant decrease in the repeatability of precipitation over the most recent 30 years . Changes in the variability of the river flow studied were less visible in this particular mountain region (while significant for two months); however, the overall repeatability of river flow decreased significantly at the same rate as for precipitation.

Section: Discussionsupporting

confidence: 79%

Altered Precipitation and Flow Patterns in the Dunajec River Basin

2017

Water

“…Increasing trends in spring Tw are in line with results obtained for a 30-km 2 catchment in Scotland over the period 1968-1997 [40]. Moreover, increasing summer Tw can also be associated with diminished summer river flow in the Raba catchment for 1985-2014 [41]. If these tendencies continue, the created thermal conditions will likely be unsuitable for native, coldwater fish (e.g.…”

Section: Discussionsupporting

confidence: 70%

Long-term trends in river water temperature: a case study of the Raba River (Polish Carpathians)

2017

E3S Web Conf.

Abstract. This study analyses potential trends in river water temperature (Tw) over a period of 50 years . The study area is located in the Raba catchment in the Polish Carpathians. The aim of the study was to evaluate long-term trends in daily Tw for each season of the year as well as to compare the direction of these trends for sites located some distance upstream and downstream from the Dobczyce Reservoir (DR), built in 1986 on the Raba River. For autumn and winter, increases in mean, median, and minimum Tw are significant for the downstream site (39 km from the DR), with a rate of change of 0.18-0.26 °C per decade. Contrasting results were obtained for the spring and summer seasons; significant increases (0.22-0.47 °C per decade) in mean, median, and maximum Tw were found for the upstream site, in concordance with seasonal air temperature trends, but a significant decrease in maximum Tw (-0.42 and -0.35 °C per decade, respectively) was identified for the downstream site. The revealed discrepancies in the direction of seasonal trends for the upstream and downstream sites studied suggest an anthropogenic impact on Tw downstream from the DR. Overall, a significant increase in summer Tw suggest the need for appropriate flowing water management that would mitigate adverse effects of climate warming on the fluvial environment.

“…4) for the downstream site only, which is accompanied by a decreasing trend in P (minimum values of P at Oświęcim). On the other hand, summer is the only season when all remaining trends in Q and P (Table 4 and 5, respectively) show a decreasing, yet statistically insignificant, tendency consistent with revealed, significant decreases in summer Q and P for the mentioned nearby catchments [27,43]. No trend in autumn Q was identified, while increasing trends in autumn precipitation were found (at Lipowa and Kocierz Moszczanicki).…”

Section: E3s Web Of Conferences 19 02012 (2017) Doi: 101051/e3sconfmentioning

confidence: 75%

“…An increasing trend in winter Q (at Żywiec) is consistent with a similar trend in winter P (mean, minimum, and maximum values of P at a nearby site, Lipowa). An increasing trend in spring Q can be associated with increased spring precipitation regionally, especially for March and May, as revealed for the neighbouring catchments of the Skawa, Raba, and Dunajec rivers [27,43]; moreover, it corresponds with an increase in spring P found at Kocierz Moszczanicki. However, such an increasing tendency in spring Q is absent for the downstream site (28 km downstream from the CR dam), and even a decreasing tendency is present (minimum values, Fig.…”

Section: E3s Web Of Conferences 19 02012 (2017) Doi: 101051/e3sconfmentioning

confidence: 99%

Long-term trends in river flow: a case study of the Soła River (Polish Carpathians)

2017

E3S Web Conf.

Abstract. This study analyses potential trends in river flow for the most recent 60 years . The study area is situated in the Soła catchment in the Polish Carpathians. The focus of the study was to evaluate long-term trends in mean monthly river flow for each season of the year as well as to compare the direction of these trends for sites located a distance upstream and downstream from a cascade of three dams built on the Soła River. Moreover, potential long-term trends in seasonal precipitation were also studied. The data indicate a significant increase in minimum discharge during the winter for the upstream site. Increases in mean and maximum discharge are significant for spring at that site as well. In contrast, a significant decrease in minimum discharge was identified for the downstream site during the spring. Moreover, significant decreases in mean and minimum discharge were noted for the summer season at the downstream site only. No trends in discharge were identified for the autumn at either site. Significant trends in precipitation were noted for each season of the year, with increases during the winter, spring, and autumn (3.6-9.8 mm per decade) in the vicinity of the upstream site, but a decrease in minimum summer precipitation (-5.0 mm per decade) at the downstream site. The revealed differences in the direction of seasonal trends for the upstream and downstream sites studied suggest an anthropogenic impact on river flow downstream from the cascade of dams. Overall, the identified decrease in summer discharge at the downstream site, accompanied by a decrease in summer precipitation, indicate the need for adaptive water management in the studied catchment to ensure water availability for the summer season.