30
K. Kubiak-Wójcicka
showed that the maximum daily precipitation for the summer half-year increased
at many stations in Poland and that the increases in the summer half-year are more
numerous than those in the winter half-year. In addition, there are increases in 5-day
and monthly precipitation totals at several stations. The number of days of intense
precipitation is increasing in north-western Poland in particular [42].
The course of air temperatures has also changed. Owczarek and Filipiak [9]
recorded downward trends in the annual number of frost days, and in the number
and duration of cold waves. The analysis revealed symptoms indicating systematic
and persistent warming. The growth rate varies from 0.18 °C to 0.34 °C per decade,
which indicates that the average annual air temperature in Poland has increased
by 1.1–2.2 °C since 1951. There has been a significant increase in average and
extreme air temperatures. The confirmed that in Poland, the frequency of heat waves
is increasing, mainly in July and August (maximum temperature ≥ 25 °C) [43, 44].
It is expected that these changes will adversely affect the size of water resources
and their temporal and spatial distribution, limiting access to and the availability of
surface and ground waters [6]. Examples of the variability of Polish river flows can
be found in detailed studies [24, 45–47] and reviews [48, 49].
One way to reduce excesses and deficits of water may be to undertake smallretention reservoir projects within agricultural catchments [18, 50–53] and in urban
areas [54, 55]. Such works have been implemented in Poland as part of a smallretention programme by Lasy Pa´ nstwowe (State Forest Holding) in mountainous
and lowland areas.
A separate problem related to the use of water resources is the level of water
intake and consumption by various sectors of the national economy. The reduction
of water consumption can be achieved in various ways. One of the simplest, but
also the most severe for all users, is to increase the price of water. However, the
most practical solution is to invest in the most modern water recovery and reuse
technology in industrial plants, agriculture, and newly built residential buildings.
Nowadays, technical solutions using rainwater in single-family houses are becoming
increasingly popular in Poland. This water is most often used for watering gardens.
However, there is little interest in the construction of purification and reuse systems
for previously used water (“grey water”), mainly due to high installation costs. Grey
water recycling or rainwater management not only significantly reduces operating
costs, but also has tangible environmental benefits.
2.7 Summary and Conclusions
Compared to other countries in the Baltic Sea basin and other European countries,
Poland’s water resources are small. Surface water resources depend on climate and
anthropopressure. In periods of low outflow, there is a lack of water, which may inhibit
economic development in some parts of Poland. Therefore, the proper management
of excess water and its use during shortages is very important.
K. Kubiak-Wójcicka
showed that the maximum daily precipitation for the summer half-year increased
at many stations in Poland and that the increases in the summer half-year are more
numerous than those in the winter half-year. In addition, there are increases in 5-day
and monthly precipitation totals at several stations. The number of days of intense
precipitation is increasing in north-western Poland in particular [42].
The course of air temperatures has also changed. Owczarek and Filipiak [9]
recorded downward trends in the annual number of frost days, and in the number
and duration of cold waves. The analysis revealed symptoms indicating systematic
and persistent warming. The growth rate varies from 0.18 °C to 0.34 °C per decade,
which indicates that the average annual air temperature in Poland has increased
by 1.1–2.2 °C since 1951. There has been a significant increase in average and
extreme air temperatures. The confirmed that in Poland, the frequency of heat waves
is increasing, mainly in July and August (maximum temperature ≥ 25 °C) [43, 44].
It is expected that these changes will adversely affect the size of water resources
and their temporal and spatial distribution, limiting access to and the availability of
surface and ground waters [6]. Examples of the variability of Polish river flows can
be found in detailed studies [24, 45–47] and reviews [48, 49].
One way to reduce excesses and deficits of water may be to undertake smallretention reservoir projects within agricultural catchments [18, 50–53] and in urban
areas [54, 55]. Such works have been implemented in Poland as part of a smallretention programme by Lasy Pa´ nstwowe (State Forest Holding) in mountainous
and lowland areas.
A separate problem related to the use of water resources is the level of water
intake and consumption by various sectors of the national economy. The reduction
of water consumption can be achieved in various ways. One of the simplest, but
also the most severe for all users, is to increase the price of water. However, the
most practical solution is to invest in the most modern water recovery and reuse
technology in industrial plants, agriculture, and newly built residential buildings.
Nowadays, technical solutions using rainwater in single-family houses are becoming
increasingly popular in Poland. This water is most often used for watering gardens.
However, there is little interest in the construction of purification and reuse systems
for previously used water (“grey water”), mainly due to high installation costs. Grey
water recycling or rainwater management not only significantly reduces operating
costs, but also has tangible environmental benefits.
2.7 Summary and Conclusions
Compared to other countries in the Baltic Sea basin and other European countries,
Poland’s water resources are small. Surface water resources depend on climate and
anthropopressure. In periods of low outflow, there is a lack of water, which may inhibit
economic development in some parts of Poland. Therefore, the proper management
of excess water and its use during shortages is very important.