Abstract
Karst rivers in Croatia have been heavily dammed in the past. However, long-term impacts of dams, water diversion and climate change on karst rivers in Croatia have rarely been examined. This study analyzes long-term trends of hydrological and temperature conditions, prior to closure of new large dam, in five connected karst rivers of central Croatia: the sinking rivers Gornja Dobra and Zagorska Mrežnica that have underground connections with the Gojačka Dobra, Tounjčica and Mrežnica Rivers. It was established that hydrological conditions of these rivers have been greatly changed after the Gojak HPP, located at spring of Gojačka Dobra, became operational in 1959. Water diversion from the reservoirs on Zagorska Mrežnica and Gornja Dobra to the Gojak HPP has increased mean annual discharge (52–106%), causing great subdaily fluctuations and overall modification of natural flow regime along the whole course of Gojačka Dobra. By cutting the connection between Zagorska Mrežnica and Tounjčica, water diversion has caused a reduction of mean annual discharges of the Tounjčica (−60%) and Mrežnica (−29%) Rivers. Analyses of long-term trends in water temperature over the last 50 years have revealed significant positive trends in average annual temperature at three gauging stations on three rivers with increase of 0.17, 0.44 and 0.48°C per decade and climate change as the primary cause. The highest significant increasing trend was established at the lower course of Mrežnica where discharge was reduced by water diversion. Mitigation measures for the improvement of hydrological conditions of affected rivers and underground systems are proposed and discussed.
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References
Allan, J. D. (1996). Stream ecology. Structure and function of running waters (1st ed.). London: Chapman & Hall.
Allan, J. D., & Flecker, A. S. (1993). Biodiversity conservation in running waters. Identifying the major factors that threaten destruction of riverine species and ecosystems. BioScience, 43(1), 32–43.
Arthington, A. H., Bunn, S. E., Poff, N. L., & Naiman, R. J. (2006). The challenge of providing environmental flow rules to sustain river ecosystems. Ecological Applications, 16(4), 1311–1318.
Arthington, A. H., Naiman, R. J., Mcclain, M. E., & Nilsson, C. (2010). Preserving the biodiversity and ecological services of rivers: new challenges and research opportunities. Freshwater Biology, 55, 1–16.
Bahun, S. (1968). Geologic basis of hydrogeologic relations of the karst area between Slunj and Vrbovsko (Croatia). Geološki Vjesnik, 21(4), 19–82.
Bonacci, O. (1987). Karst hydrology with special references to the Dinaric karst. Berlin: Springer.
Bonacci, O., & Andrić, I. (2010). Impact of an inter-basin water transfer and reservoir operation on a karst open streamflow hydrological regime: an example from the Dinaric karst (Croatia). Hydrological Processes, 24, 3852–3863.
Bonacci, O., & Roje-Bonacci, T. (2003). The influence of hydroelectrical development on the flow regime of the karstic river Cetina. Hydrological Processes, 17, 1–15.
Bonacci, O., Trninić, D., & Roje-Bonacci, T. (2008). Analysis of the water temperature regime of the Danube and its tributaries in Croatia. Hydrological Processes, 22, 1014–1021.
Bonacci, O., Gottstein, S., & Roje-Bonacci, T. (2009). Negative impacts of grouting on the underground karst environment. Ecohydrology, 2, 492–502.
Bunn, S. E., & Arthington, A. H. (2002). Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity. Environmental Management, 30(4), 492–507.
Cox, D. R., & Stuart, A. (1955). Some quick sign tests for trend in location and dispersion. Biometrika, 42, 80–95.
Dudgeon, D., Arthington, A. H., Gessner, M. O., Kawabata, Z.-I., Knowler, D. J., Lévêque, C., et al. (2006). Freshwater biodiversity: importance, threats, status and conservation challenges. Biological Reviews, 81, 163–182.
Emeis, K. C., Richnow, H. H., & Kempe, S. (1987). Travertine formation in Plitvice National Park, Yugoslavia: chemical versus biological control. Sedimentology, 34, 595–609.
Friedl, G., & Wüest, A. (2002). Disrupting biogeochemical cycles—consequences of damming. Aquatic Science, 64, 55–65.
Gottstein Matočec, S., Bakran-Petricioli, T., Bedek, J., Bukovec, D., Buzjak, S., Franičević, M., et al. (2001). Croatia. In C. Juberthie & V. Decu (Eds.), Encyclopaedia biospeologica III (pp. 2237–2287). Moulis: Société de Biospéologie.
Hamed, K. H., & Rao, A. R. (1998). A modified Mann–Kendall trend test for autocorrelated data. Journal of Hydrology, 204(182), 196.
Horvatinčić, N., & Srdoč, D. (1990). Kemijske i izotopne karakteristike krških voda s posebnim osvrtom na Plitvička jezera. Plitvički Bilten, 3–4, 7–17.
http://www.mathworks.fr/matlabcentral/fileexchange/25533-mann-kendall-modified-test. Accessed 20 August 2011.
IPCC (Intergovernmental Panel on Climate Change). (2007). Climate change 2007. Synthesis report. A contribution of Working Groups I, II, and III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge: Cambridge University Press.
Kaushal, S. S., Likens, G. E., Jaworski, N. A., Pace, M. L., Sides, A. M., Seekell, D., et al. (2010). Rising stream and river temperatures in the United States. Frontiers in Ecology and the Environment, 8, 461–466.
Malez, M. (1954). Đula sinkhole in Ogulin (General speleological description; in Croatian). Geološki Vjesnik, 8–9, 153–173.
Malmqvist, B., & Rundle, S. (2002). Threats to the running water ecosystems of the world. Environmental Conservation, 29(2), 134–153.
Matzinger, A., Schmid, M., Veljanoska-Sarafiloska, E., Patceva, S., Guseska, D., Wagner, B., et al. (2007). Eutrophication of ancient Lake Ohrid: global warming amplifies detrimental effects of increased nutrient inputs. Limnology and Oceanography, 52(1), 338–353.
MEPPPC (Ministry of Environmental Protection Physical Planning and Construction) (2010). Fifth National Communication of the Republic of Croatia under the United Nation Framework Convention on the Climate Change. (Vol. 308, pp. 1–215). Zagreb.
Nilsson, C., Reidy, C. A., Dynesius, M., & Revenga, C. (2005). Fragmentation and flow regulation of the world’s large river systems. Science, 308, 405–408.
Pepeonik, Z. (2000). The Mrežnica River. Pearl of the Croatian karst (1st ed.). Zagreb: Croatian Geographical Society.
Poff, N. L., & Zimmerman, J. K. H. (2010). Ecological responses to altered flow regimes: a literature review to inform the science and management of environmental flows. Freshwater Biology, 55, 194–205.
Poff, N. L., Allan, J. D., Bain, M. B., Karr, J. R., Prestegaard, K. L., Richter, B. D., et al. (1997). The natural flow regime: a paradigm for river conservation and restoration. BioScience, 47, 769–784.
Richter, B. D., Baumgartner, J. V., Powell, J., & Braun, D. P. (1996). A method for assessing hydrological alternation within ecosystems. Conservation Biology, 10(4), 1163–1174.
Richter, B. D., Baumgartner, J. V., Wigington, R., & Braun, D. P. (1997). How much water does a river need? Freshwater Biology, 37, 231–249.
Richter, B. D., Braun, D. P., Mendelson, M. A., & Master, L. L. (1997). Treats to imperiled freshwater fauna. Conservation Biology, 11(5), 1081–1093.
Richter, B. D., Jeffrey, V. B., David, P., & Braun, J. P. (1998). A spatial assessment of hydrological alternation within a river network. Regulated Rivers: Research & Management, 14, 329–340.
Richter, B. D., Mathews, R., Harrison, D. L., & Wigington, R. (2003). Ecologically sustainable water management: managing river flows for ecological integrity. Ecological Applications, 13(1), 206–224.
Richter, B. D., Warner, A. T., Meyer, J. L., & Lutz, K. (2006). A collaborative and adaptive process for developing environmental flow recommendations. River Research and Applications, 22, 297–318.
Salmi, T., Määttä, A., Anttila, P., Ruoho-Airola, T., Amnell, T. (2002). Detecting trends of annual values of atmospheric pollutants by the Mann–Kendall test and Sen’s slope estimates—the Excel template application MAKESENS. Publication on air quality No. 31 (pp. 1–35). Helsinki, Finnish Meteorological Institute.
Stanford, J. A., & Ward, J. V. (1984). The effects of regulation on the limnology of the Gannison River: A North American case history. In A. Lillehammer & S. J. Saltveit (Eds.), Regulated rivers (pp. 467–478). Oslo: Universitetsforlaget AS.
Strayer, D. L. (2006). Challenges for freshwater invertebrate conservation. Journal of North American Benthological Society, 25(2), 271–287.
Vaughn, C. C., & Taylor, C. M. (1999). Impoundments and the decline of freshwater mussels: a case study of an extinction gradient. Conservation Biology, 13(4), 912–920.
Webb, B. W. (1996). Trends in stream and river temperature. Hydrological Processes, 10, 205–226.
Webb, B. W., & Nobilis, F. (1995). Long-term water temperature trends in Austrian rivers. Hydrological Sciences Journal, 40, 83–96.
Webb, B. W., & Nobilis, F. (2007). Long-term changes in river temperature and the influence of climatic and hydrological factors. Hydrological Sciences Journal, 52(1), 74–85.
Webb, B. W., & Walling, D. E. (1992). Long term water temperature behaviour and trends in a Devon, UK, river system. Hydrological Sciences Journal, 37, 567–580.
World Commission on Dams. (2000). Dams and development. A new framework for decision-making (Vol. 3). London: Earthscan.
Acknowledgments
The data used for the analyses were obtained from the Croatian Meteorological and Hydrological Service who made temperature and discharge data available for this study. Tomislav Devčić is thanked for help on programming macros for Excel and help with MATLAB, Nika Galić for discussions on trend analyses tools and Petra Đurić is thanked for linguistic improvements on an earlier version of the manuscript.
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Žganec, K. The effects of water diversion and climate change on hydrological alteration and temperature regime of karst rivers in central Croatia. Environ Monit Assess 184, 5705–5723 (2012). https://doi.org/10.1007/s10661-011-2375-1
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DOI: https://doi.org/10.1007/s10661-011-2375-1