Theoretical Background - Response of Flood Events to Land Use and Climate Change - page 23

precipitation was the result of research which was found in the Russian Federation
[ 52 ], China [ 53 ], Turkey [ 54 ], and Africa [ 55 , 56 ].
Heino et al. [ 57 ] have distinguished that there is an increasing trend in mini-
mum temperature almost everywhere and increasing trend in maximum and mean
temperature in northern and central Europe. Over the Russian Federation, Canada
[ 58 ] and in Australia and New Zealand an increasing trend in maximum and mean
temperature was also observed [ 49 ]. These results confirm the outcomes of
Smit et al.'s investigation [ 59 ] which indicate that mid-latitude regions such as the
mid-western USA, southern Europe and Asia are becoming warmer and drier,
whereas the lower latitudes are becoming warmer and wetter.
IPCC [ 38 - 40 ] reported that, during recent decades, precipitation has tended to
increase in mid-latitudes, decrease in the Northern Hemisphere subtropical zones,
and increase generally throughout the Southern Hemisphere. Lettenmaier et al.
[ 48 ], Türke [ 54 ], Zhang et al. [ 60 ], Gonzalez Hidalgo et al. [ 61 ], Gong et al. [ 62 ],
del Rio et al. [ 63 ], and Partal and Kahya [ 64 ] are some examples of the researchers
who have investigated recent rainfall trends and confirm the IPCC claim about
increasing and decreasing precipitation over the mentioned locations. Extreme
temperature series have also received increased attention during the last decades of
the twentieth century [ 65 , 66 ].
The research analysis on temperature records across the world indicates there
has been an increase in the mean global temperature of about 0.6 C since the start
of the twentieth century [ 67 - 69 ]. Mearns et al. [ 70 ] and Hansen et al. [ 71 ] con-
cluded that small change in the mean temperature could produce substantial
changes in the frequency of the extreme temperature. Increase in temperature trend
of the planet has been particularly observed since 1920s [ 72 ].
According to IPCC and recorded investigations of previous researches, many
regions over Europe are vulnerable to climate change impacts. The updated report
of European environment agency (EEA) and intergovernmental panel on climate
change (IPCC) confirms that the warming trend in Europe was above the global
average mentioned since pre-industrial times. During the twentieth century, most
of the Europe experienced increasing trend in average annual surface temperature
with the stronger warming in winter which was observed over most regions. The
1990s were the warmest in the instrumental record.
According to IPCC [ 38 - 40 ], there was a 10-40 % increasing trend in precipi-
tation in the twentieth century in northern Europe but, on the other hand, there was
up to a 20 % decreasing trend in the southern part of Europe. IPCC also realized a
global rising in temperature from 1.8 to 4.0 C (3.24-7.2 F) in the twentieth cen-
tury. This Projection over Europe also showed a 1.0 and 5.5 C (1/8-9.9 F)
increasing trend in temperature. This report also emphasized that there was more
frequent, intense, and increasing number of hot extremes and a decreasing number
of cold extremes over the past 50 years, and these trends are projected to continue.
According to updated information of Jones and Moberg [ 73 ] the warming trend
between 1901 and 2005 throughout Europe was established at +0.90 C and
precipitation trends were more spatially variable. Table 2.2 shows trend analysis
throughout Europe between 1977 and 2000.