Geographia Polonica (1998) vol. 71

Abstract

The assumption of stationarity made in flood frequency analysis has been relaxed by introducing the possibility of the existence of a tread in the first two moments of a probability distribution function. The problem of the estimation of the time-variable moments and probability distribution function has been analysed. The basic assump-tions and structure of the IDT (Identification of Distribution and Trend) soft package as well as a plan for its further development have been presented and discussed. The maximum likelihood method is used to estimate model parameters from a time series and the Akaike Information Criterion goodness-of-fit test to identify an optimum model, i.e. of distribution and trend functions. Preliminary results of a flood frequency analysis for Polish rivers obtained with the IDT package are described briefly.

Keywords: Time series, trends, annual flood peaks, probability distribution, time variable parameters, time-dependent moments, likelihood function, Akaike Infor-mation Criterion

Abstract

The paper contains some remarks on detecting climate variability or climate change in river discharge processes. The selection of adequate non-parametric statistical tests is discussed as well as the conditions which should be fulfilled by data records of the considered processes. After statistical analysis had been carried out on the basis of more than 150 long-term river-discharge time series, using non-parametric tests at the 5% significance level, it was found that the stationary hypothesis could not be rejected in most cases. Moreover, no conclusion could be drawn as to an regional pattern of trends in runoff characteristics: in some cases, neighboring river catchments show trends in the opposite direction.

Keywords: climate, non-parametric tests, non-stationarity

Henryk T. Mitosek, Institute of Geophysics, Polish Academy of Sciences ul. Księcia Janusza 64, 01-452 Warszawa, Poland

Abstract

In the first part of the paper various approaches to the formulation of regional climate scenarios are described. In the second part an example of a climate scenario for Poland based on results from the ECHAM1/LSG general circulation transient model is presented. Two perturbed runs of the model are considered: A — "business as usual" and D — "accelerated policies". The hydrological regime of Polish catchments in changed climate conditions is evaluated using the CLIRUN 31 watershed model. Some of the results are discussed.

Keywords: regional climate scenarios, general circulation models, global climate change, downscaling, water balance model, hydrological impact assessment

Małgorzata Liszewska, Institute of Geophysics, Polish Academy of Sciences Księcia Janusza 64, 01-452 Warszawa, Poland
Marzena Osuch, Institute of Geophysics, Polish Academy of Sciences Księcia Janusza 64, 01-452 Warszawa, Poland

Keywords: weather generator, general circulation model (GCM), climate change scenario, climate variability

Anna Olecka, Climate Protection Center, Institute of Environmental Protection ul. Kolektorska 4, 01-692 Warszawa, Poland

Keywords: hydrology, climate change, water resources

Zdzisław Kaczmarek, Institute of Geophysics, Polish Academy of Sciences ul. lisięcia Janusza 64, 01-452 Warszawa, Poland

Abstract

Will the hydrological regime of rivers be transformed as a result of global climatic :hange, assuming physico-geographical properties of catchments to be permanent? An answer to this question was sought by way of comparison of the behaviour patterns of a river (its discharge structure in the normal yearly cycle) in real conditions defined on the basis of an observation series from the years 1961-1990 (scenario 0), and in the conditions of the assumed climatic change (GFDL and GISS scenarios). The assessment of changes in the regine was made in quantitative and qualitative terms.The Rega, the Utrata and the Soła, three rivers, whose catchments lie in different physico-geographical regions of Poland were chosen for the analysis, in order to gain an insight iito the direction and intensity of changes at a regional scale also.The -esults obtained corroborate the impact of global climatic change on the rivers, both at the rmso-scale of Poland and the regional scale. The total annual discharge may change significantly, either by going up, according to the GISS scenario, or going down, according to the G?DL scenario. The transformation of the discharge rhythm may manifest itself in a shift ii the stages of discharge while seasonality is maintained, and in a change in its magnitude in particular seasons (e.g., the lowering of the level of base flows and their lengthering, mainly in mountain and lowland streams, as well as restricted and greatly reduced neltwater floods).

Keywords: hydrological regime of rivers, effect of global climatic change

Małgorzata Gutry-Korycka, Faculty of Geography and Regional Studies, University of Warsaw Krakowskie Przedmieście 30, 00-927 Warszawa, Poland
Jadwiga Rotnicka, Institute of Physical Geography, Adam Mickiewicz University ul. Fredry 10, 60-701 Poznań, Poland

Abstract

If properly situated in the landscape mosaic, ecotonal land-water vegeta-tion can reduce effect of catchment degradation on freshwaters. The development of ecotones positively depends on temperature, rain and water level. If long dry period appear due to climate changes, vegetation in ecotone zones may decline so during heavy rains the surface flow may cause high external nutrient load to freshwaters. Internal load may also be intensified because of acceleration of organic matter mineralization due to higher microorganisms and phosphataze activity and also higher rate of organ-isms excretion.At elevated temperatures primary production will be higher. Consequently, accel-eration of phytoplankton succession, and extension of the period of blue-green algae (cyanophyta) blooms is probable. During periods when the temperature is above 18°C winds intensity may regulate blooms appearance. Long periods of epilimnion stability intensify cyanophyta blooming, contrary strong winds may be an inhibitor of blooms appearance. In elevated temperatures toxicity of blue-green algae tends to be higher.Zooplankton communities regulate phytoplankton density, if not reduced by zoo-planktivorous fish. Due to higher energy needs with increasing temperature, pressure of fish on zooplankton will result in zooplankton number reduction. At temperatures above 15° (data for Daphnia sp.) zooplankton body size is reduced because smaller specimen posses energetic and behavioral advantages. Lower number of large filtrators may reduce filtering ability of zooplankton and intensify phytoplankton growth.Freshwaters biota is mostly composed of polikilothermie organisms (zooplankton, fish). The temperature dependent physiological processes have been characterised by right skewed parabolic function. In consequence, water temperature increase may seriously modify (mostly accelerate) rates of energy flow and matter cycling in temper-ature freshwaters.Concerning the above processes, especially shallow, eutrophic reservoirs will re-spond to climate changes by intensification of biological processes. To prevent intensi-fication of eutrophication symptoms it is necessary to consider environmentaly sound management of the catchment and tributaries and control of internal hydrological and biological processes in the reservoir.

Keywords: eutrophic ecosystem, global climate changes impact, nutrient dynamics

Maciej Zalewski, Department of Applie d Ecology, University of Łódź ul. Banacha 12/16, 90-237 Łódź, Poland
Iwona Wagner, Department of Applie d Ecology, University of Łódź ul. Banacha 12/16, 90-237 Łódź, Poland

Abstract

This paper investigates the possible impact of climate change on physical and biological processes in storage reservoirs supplying water for domestic use and industry. As a case study the water temperature and evaporation in Sulejów Reservoir, Central Poland, will be simulated for a number of climate scenarios. An energy balance model for a non-stratified (or weakly-stratified) lake was applied. Reservoir tempera-ture is shown to be highly sensitive to changes in air temperature. Further research is needed to reduce the level of uncertainty in freshwater ecosystem impact assessments, focusing mainly on developing more credible climate scenarios.

Keywords: temperature of water, reservoirs, climate impact

Danuta Jurak, Institute of Meteorology and Water Management ul. Podleśna 61, 01-673 Warszawa, Poland

Keywords: thermal balance, carp ponds

Krystyna Pianko-Kluczyńska, Institute of Meteorology and Water Management ul. Podleśna 61, 01-673 Warszawa, Poland

Abstract

The forecast climatic warming will cause hydrological changes on Earth which will be accompanied by changes to the chemism and quality of waters. On account of their wide-spread occurrence and permanence, it is heavy metals in the bottom sediments of surface waters which pose the greatest endangering to the natural environment. Once introduced into it, they cannot be removed, and can in suitable conditions (i.a. of reduced pH, changed redox potential, increased salinity, increased content of organic compounds) be released from bottom sediments and give rise to secondary pollution of waters in their soluble forms. It is for that reason that heavy metals have been termed "chemical time bombs".

Keywords: climate change, aquatic sediments, metal mobility in sediments, "chemical time bombs"

Teresa Rudzirska-Zapaśnik, Polish Geological Institute ul. Rakowiecka 4, 00-975 Warszawa, Poland

Abstract

Water management is choice in face of bounded uncertainty (Shackle 1961). Uncertainty may be limited (e.g. by improving scenarios for climate change), but the hope that it might be eliminated is an illusion. However, as a failure to take account of uncertainty leads to social, economic and ecological damage, there is a need for full use to be made of appropriate theories and the measures of uncertainty based on them. The paper thus presents some theories, as well as three principles of uncertainty, namely: of the minimum and maximum of uncertainty and of its immutability. Exam-ples are cited of the undesirable consequences of a failure to heed these principles. Methods of rational decisionmaking in conditions of uncertainty are presented, while methodological considerations are supported by examples of applications in water management.

Keywords: uncertainty, water management, decisionmaking, risk

Janusz Żelaziński, Institute of Meteorology and Water Management ul. Podleśna 61, 01-673 Warszawa, Poland

Keywords: greenhouse gas emission (GHG) and sink, GHG reduction options and strategies, GHG impacts on economy and society

Edward Radwański, Polish Foundation for Energy Efficiency ul. Brodzińskiego 21, 01-557 Warszawa, Poland

Abstract

Possible future growth in Poland's demand for irrigation water is analyzed in relatim to possible climate change by comparing demand for 1951-1990, estimated on the basis of hydrometeorological data, with that for 1991-2050 determined on the basis of hydrometeorological variables (precipitation, potential évapotranspiration) forecasted according to the Global Circulation Model with the GFDL (Geophysical Fluid Dynamic Laboratory, Princetown) scenario of doubled CO2 content by the year 2080. The analysis was performed for the catchment of the Warta (c. 60,000 km2) and the Wieprz ((. 15,000 km2 ) rivers, with areas of future irrigation determined in relation to possible technical and agronomic factors. Use is made of results from the project entitled "Countrj Study-Poland, SE-12. Strategy for Poland's Water Resources Management in the Face of Climatic Change" (Kaczmarek et al. 1995).

Keywords: Irrigation of agricultural land, water demand, climate change

Czesław Somorowski, Faculty o:' Land Reclamation and Environmental Engineering, Warsaw Agricultural University ul. Nowoursynowska 166, 02-766 Warszawa, Poland

Keywords: multireservoir system, water management, climate change, reliability criteria

Jarosław J. Napiórkowski, Institute of Geophysics, Polish Academy of Sciences ul. Księcia Janusza 64, 01-452 Warszawa, Poland
Tomasz Terlikowski, Institute of Geophysics, Polish Academy of Sciences ul. Księcia Janusza 64, 01-452 Warszawa, Poland

Zdzisław Kaczmarek, Institute of Geophysics, Polish Academy of Sciences ul. lisięcia Janusza 64, 01-452 Warszawa, Poland