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Perception of water regime in connection to present and past human influence
Buchtele, Josef ; Slámová, Romana ; Chlumecký, M.
The variability of the water regime is ascertained as being influenced by the frequent natural evolutions in the span of decades and also by some abrupt changes in the recent periods, including the damages or grows of vegetation cover or human influence in the historical decades. Analysis of such natural or man-made impacts in the context of historical evolution could clarify uncertainties and oscillations in basin water regime. The events as changes in vegetation cover, resp. evapotranspiration, land-use changes, building of new reservoirs and disappearing the old ones, effect of water management changing the condition of the water supply should be evaluated taking into account the influencing of the natural water regime. The modeling of rainfall-runoff process could be used to identify such impacts, especially for the cases when the long term complex monitoring is missing. The difference between observed and simulated streams flow appears as the helpful tool for the assessments of the resulting water regime.
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Evaluation of Changes in Water Regime Caused by Long-term Development of Vegetation Cover
Chlumecký, M. ; Tesař, Miroslav ; Buchtele, Josef
Long monitoring of air temperature and precipitation for three catchments with up to 100 years series has been used as the input for the modelling of rainfall-runoff process and for the re-assessments of the evapotranspiration demand (ET.sub.demand./sub.). The resulting oscillations and the random changes of vegetation cover have been pursued as the indication of fluctuations also in the evapotranspiration. The intention is to appraise this complicated time series as the long-term process. The modified implementation of the conceptual model SAC-SMA enables the quicker simulation and facilitates also the conditions for automatic calibration of parameters in the used model; separately for individual, i.e. partial time intervals, namely with the diverse expected evapotranspiration. That process is to be identified simultaneously with the optimal parameters of the mode; the resulting actual evapotranspiration (ET.sub.act./sub.) is then represented as the modelling outputs, as such values could be hardly gained as measured or computed values, e. g. from other meteo-observations.
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Flash floods as theme for the summer periods in next decades
Buchtele, Josef ; Tesař, Miroslav ; Chlumecký, M. ; Fořtová, Magda
The variability of water regime in the annual cycle is influenced not only by the annual development of the vegetation cover, but also by its increases in the span of several decades. In the actual year it has been twelve years ago when the disastrous floods appeared in the Labe River, and more than fifteen years from destructive inundations in the Morava River basin, and so it is reasonable to remind those situations in the context with the recent flood. The modeling of rainfall-runoff process is the tool for the evaluation of the possible changes in the water regime in the mentioned landscape development.
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Influence of the development of vegetation cover in the basin on the regime of surface water and groundwater resources
Buchtele, Josef ; Tesař, Miroslav
Variability of water regime is influenced usually not only by the changes of vegetation cover in the annual cycle, but also by the vegetation development in the span even of several decades. The resulting evapotranspiration requirement depends on actual climatic conditions; moreover the needs of soil moisture and the oscillation of solar radiation are also significant. The simulations of rainfall–runoff process have been used with the intention to follow the role of the developing vegetation cover and long-term climatic fluctuations. The differences between monitored and simulated runoff in the relatively long periods are the possible tool for the appraisal of changes in the water regime, which are influenced also by the changes of evapotranspiration need.
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Variability of water regime in forested experimental basis
Buchtele, Josef ; Tesař, Miroslav
Climatic conditions represent a significant factor for water regime of a watershed. They form conditions both for the vegetation cover development in the annual cycle and also its changes in the span of decades of years. Land-use changes can be a reason of variability and/or tendencies in the evapotranspiration process affecting water balance in both short-term and long-term temporal scales. The present contribution deals with simulations of the rainfall-runoff process with the help of SAC-SMA (Sacramento Soil Moisture Accounting) a BROOK´90 models. The time course of differences between observed and simulated runoff represents a possible tool for the evaluation of tendency and/or variability of water regime of a basin. The used approach makes possible to assess a result of long-term development of the vegetation cover in a catchment and consequent evapotranspiration changes.
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