TRANSFER OF HYDROLOGIC INFORMATION ALONG RIVERS PARTIALLY FED BY KARSTIFIED LIMESTONES

Abstract
Two types of measures are used to find how much information can be transferred between the runoff series along the river and how much information the linear and non - linear (power - function non - linearity) regression analyses actually transfer. In the former case the relative measures of transferability are based on the entropy theory, and in the latter case the classical correlation coefficients for measuring the transferred information among the river flows are used. The Esencay River basin in Turkey is used as a demonstration case of complex composition of karstic and non - karstic formations feeding water to a river. It was found that the non - linear correlation always transfers more information than the linear correlation. The transferable information is nearly always greater than the transferred information of non - linear case, especially in summer/fall months of flow recession. Due to differences in responses of karstified and non - karstic subbasins to precipitation, it is likely that a search for the other non - linear relationships and the use of the multiple lag cross correlation and regression analysis, would significantly reduce the differences between the transferable and actually transferred information. The correlation and regression analysis of flows of upstream and downstream stations is basically a spurious correlation since all upstream flows pass through the downstream stations, regardless of some transformation and delay due to travel of discharge hydrographs. The analysis of relationships between the upstream stations flows and the contributing (intermediate) flows between the upstream and downstream stations avoids this spurious correlation which results from the redundant information. The measures of transferability and actually transferred information may serve as tools to identify the characteristics of flow yields from karstified and non - karstic subbasins.
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N. Harmancioglu & V. YevCharacteristics of rivers partially fed by karstified limestones. Rivers partially fed by karstified limestones have basins characterized by a significant degree of heterogeneity with regard to their geology, topography, climate and hydrology. The diversity of areal and temporal distributions of such characteristics requires the concept of information transfer for runoff along the rivers to be investigated by far more advanced methods than the classical ones. River basins, especially those in karstic regions, are composed of pervious, semi pervious and impervious geologic subbasins, each with different level of porosity. The variety in geological characteristics results in different forms of transformation of the input (precipitation) into the output (runoff) in each subbasin. Impervious surfaces show a fast response to effective rainfall input whereas low - permeability but high - porosity aquifers react very slowly with prolonged responses to infiltrated water. Karstic subbasins generally have medium, rapid - to - slow responses of complex character. In most cases, the drainage system transforms the excess precipitation into direct flow via retention which results in delay of runoff. Thus, subbasins with varying geological structures reflect different types of responses and different percentages of runoff due to precipitation. Basins of rivers partially fed by karstified limestones not only have heterogeneous geology, but often are characterized by rugged topography which, in parallel, leads to rapidly varying climatic factors. Therefore, the terrains of karstic river basins are, in general, topographically and climatically specific, with a very variable distribution of water resources both in the and space. All three factors, geology, topography and climate, finally result in subbasins with different hydrologie response characteristics. The effects of complex karstified and non - karstified subbasins on runoff characteristics basically result in three different forms of input - output relations. The response hydrographs of steep impervious surfaces to effective rainfall have a sharp, large peak, a relatively short time - to - peak and a rapid recession. The response hydrographs of low permeability high-porosity aquifers have a relatively very small peak,a longtime -to -peak and very long but low recession outflows. The karstic formations often have medium, rapid - to - slow responses between these two extremes. In complex river basins, the response hydrographs are composed of several individual hydrographs of various characteristics, each reflecting the response of particular types of karstic and non - karstic formations (Yejevich, 1976). The hydrologie evaluation of such responses becomes much more complicated when outputs have significant but different autodependence correlograms. Consequently, subbasins with areally and temporally varying geology, topography and climate, and thereby with different types of response hydrographs require specific investigative methods, especially in terms of hydrologie information transfer along rivers. This paper then treats the differences in transferable and/or transferred information between subbasins of these complex basins. Methods of information transfer for runoff along rivers. The classical method of information transfer for runoff to points along the rivers has been the correlation and regression analysis between the observations at upstream and downstream gauging stations. The main objective