Regional techniques for extreme rainfall and runoff prediction

Ce papier présente une technique régionale pour les précipitations extrêmes et la prévision des écoulements. La méthode utilise cinq abaques où sont associées les caractéristiques des crues et des averses ; ces abaques permettent de déduire la pointe de la crue de projet et son volume, une fois que la période de retour, la durée de l'averse et sa hauteur ont été déterminées. Les problèmes de non linéarité des bassins n'affectent pas la méthode qui se montre précise, rapide et simple. Ces qualités rendent la méthode utile pour les applications d'ingénierie et de recherche, spécialement dans le cas des bassins non jaugés. (Résumé d'auteur

Technical Note: Determination of the SCS initial abstraction ratio in an experimental watershed in Greece

International audienceThe present study was conducted in an experimental watershed in Attica, Greece, using observed rainfall/runoff events. The objective of the study was the determination of the initial abstraction ratio of the watershed. The average ratio (Ia/S) of the entire watershed was equal to 0.014. The corresponding ratio at a subwatershed was 0.037. The difference was attributed to the different spatial distribution of landuses and geological formations at the extent of the watershed. Both of the determined ratios are close to the ratio value of 0.05 that has been suggested from many studies for the improvement of the SCS-CN method

Vertical zonation of testate amoebae in the Elatia Mires, northern Greece : palaeoecological evidence for a wetland response to recent climate change or autogenic processes?

The Elatia Mires of northern Greece are unique ecosystems of high conservation value. The mires are climatically marginal and may be sensitive to changing hydroclimate, while northern Greece has experienced a significant increase in aridity since the late twentieth century. To investigate the impact of recent climatic change on the hydrology of the mires, the palaeoecological record was investigated from three near-surface monoliths extracted from two sites. Testate amoebae were analysed as sensitive indicators of hydrology. Results were interpreted using transfer function models to provide quantitative reconstructions of changing water table depth and pH. AMS radiocarbon dates and 210Pb suggest the peats were deposited within the last c. 50 years, but do not allow a secure chronology to be established. Results from all three profiles show a distinct shift towards a more xerophilic community particularly noted by increases in Euglypha species. Transfer function results infer a distinct lowering of water tables in this period. A hydrological response to recent climate change is a tenable hypothesis to explain this change; however other possible explanations include selective test decay, vertical zonation of living amoebae, ombrotrophication and local hydrological change. It is suggested that a peatland response to climatic change is the most probable hypothesis, showing the sensitivity of marginal peatlands to recent climatic change

How can climate change be incorporated in river basin management plans under the WFD? Report from the EurAqua conference 2008

This report is based on the EurAqua conference 2008: "How can climate change be incorporated in river basin management plans under the WFD?". The conference focused on recent development in relevant EU policy, on challenges for WFD-based water management, and on the science-to-policy interface regarding adaptations to climate change impacts. This report provides recommendations for incorporating climate change considerations into river basin management plans, and identifies relevant research needs with emphasis on ecology, modelling and uncertainty.NIV

Derivation and verification of empirical catchment response time equations for medium to large catchments in South Africa

Published ArticleDespite uncertainties and errors in measurement, observed peak discharges are the best estimate of the true peak discharge from a catchment. However, in ungauged catchments, the catchment response time is a fundamental input to all methods of estimating peak discharges; hence, errors in estimated catchment response time directly impact on estimated peak discharges. In South Africa, this is particularly the case in ungauged medium to large catchments where practitioners are limited to use empirical methods that were calibrated on small catchments not located in South Africa. The time to peak (TP), time of concentration (TC) and lag time (TL) are internationally the most frequently used catchment response time parameters and are normally estimated using either hydraulic or empirical methods. Almost 95% of all the time parameter estimation methods developed internationally are empirically based. This paper presents the derivation and verification of empirical TP equations in a pilot scale study using 74 catchments located in four climatologically different regions of South Africa, with catchment areas ranging from 20 km2 to 35 000 km2. The objective is to develop unique relationships between observed TP values and key climatological and geomorphological catchment predictor variables in order to estimate catchment TP values at ungauged catchments. The results show that the derived empirical TP equation(s) meet the requirement of consistency and ease of application. Independent verification tests confirmed the consistency, while the statistically significant independent predictor variables included in the regressions provide a good estimation of catchment response times and are also easy to determine by practitioners when required for future applications in ungauged catchments. It is recommended that the methodology used in this study should be expanded to other catchments to enable the development of a regional approach to improve estimation of time parameters on a national-scale. However, such a national-scale application would not only increase the confidence in using the suggested methodology and equation(s) in South Africa, but also highlights that a similar approach could be adopted internationally

Hidrología de zonas áridas y semiáridas

[ES] La hidrología de cuencas de zonas áridas y semiáridas es de suma importancia para el desarrollo y manejo de los recursos hidráulicos. En este artículo se describen características climáticas, hidrológicas, y geomorfológicas propias de dichas zonas; modelos matemáticos de las componentes principales del ciclo hidrológico tales como la precipitación, infiltración y escorrentía; modelos matemáticos de cuencas, y el efecto de cambios climáticos en el análisis y síntesis de datos hidrológicos en zonas áridas y semiáridas. Este artículo es una version modificada de la conferencia magistral dada por el autor con motivo de la II Conferencia Internacional sobre “Hidrología Mediterránea” realizada en Valencia, España, Nov. 27-28, 1996.El autor agradece al profesor J.A. Ramirez y a la estudiante de doctorado Rosalia Rojas-Sanchez de Colorado State University por haber revisado el borrador de este artículo. Tambien agradece la colaboración de los profesores E. Wohl, F. Smith, y T. McKee, y del Dr. L. Ahuja, ARS-USDA, por haber sugerido y proporcionado material necesario para la preparación de la conferencia y del artículo.Asimismo, se agradece a la U.S. National Science Foundation y a la Colorado Agricultural Experiment Station por financiar investigaciones realizadas por el autor relacionadas a la hidrología de zonas áridas y semiáridas.Salas, JD. (2000). Hidrología de zonas áridas y semiáridas. Ingeniería del Agua. 7(4):409-429. https://doi.org/10.4995/ia.2000.2855SWORD40942974Chin, E.H. (1977). Modeling daily precipitation ocurrence process with a Markov chain . Water Resour. Res. 13(6), 949-956.Chebaane, M., Salas, J.D., y Boes, D.C. (1992). Modeling of monthly intermittent streamflow processes. Water Resources Papers, 105, Colorado State University, Fort Collins, Colorado.Chebaane, M., Salas, J.D., y Boes, D.C. (1995). Product periodic autoregressive processes for modeling intermittent monthly streamflows. Water Resour. Res., 31(6), 1513-1518.Dubayah, R. y Wood, E.F. (1996). Multiscaling analysis in distributed modeling and remote sensing: an application using soil moisture. En From Scale in Remote Sensing and GIS, Editado por D.A. Quattrochi y M.F. Goodchild, CRC/Lewis Publ., Boca Raton, Florida.Eagleson, P.S. (1978). Climate, soil and vegetation: 2. The distribution of annual precipitation derived from observed storm sequences. Water Resour. Res., 14(5), 713-721.El-Ashry M.T. y Gibbons, D.C. (1988). New water policies for the west. En Water and Arid Lands of the Western United States, editado por M.T. El-Ashry y D.C. Gibbons, Cambridge University Press, Cambridge.Eltahir, E.A. (1996). El Niño and the natural variability in the flow of the Nile River. Water Resour. Res., 32(1), 131-137.Entekhabi, D., Rodriguez-Iturbe, I., y Eagleson, P.S. (1989). Proabilistic representation of the temporal rainfall process by a modified Neyman-Scott rectangular pulse model: parameter estimation validation. Water Resour. Res., 25(2), 295-302.Frances, F. (1991). Utilizacion de la informacion historica en el analisis regional de las avenidas, tesis doctoral, Universidad Politecnica de Valencia, Valencia, España.Graf, W.L. (1990). Definition of flood plains along arid-region rivers. En Flood Geomorphology, editado por V.R. Baker y otros, J. Wiley, N. York.Greenholtz, D.E., Yeh, T.C.J., Nash, M.S.B., y Wierenga, P.J. (1988). Geostatistical analysis of soil hydrologic properties in a field plot. Jour. Contaminant Hydrology, 3, 227-250.Grove, A.T. (1977). The geography of semi-arid lands, Phil. Trans. R. Soc. London, B, 278, 457-475.Hirschboeck, K.K. (1990). Flood hidroclimatology. En Flood Geomorphology, editado por V.R. Baker, R.C. Kochel, y P.C. Patton, Wiley, N. York.Heathcote, R.L. (1983). The arid lands: their use and abuse, Longman, London.Hoogmoed W.B. and Stroosnijder, L. (1984). Crust formation of sandy soils in the Sahel. I. rainfall and infiltration. Soil Tillage Res.,4, 5-23.Islam, S., Bras, R.L, y Rodriguez-Iturbe, I. (1988). Multidimensional modeling of cumulative rainfall: parameter estimation and model adequacy through a continuum of scales. Water Resour. Res.24(7), 985-992.Kavvas, M.L. and Delleur, J.W. (1981). A stochastic cluster model of daily rainfall sequences. Water Resour. Res.,17(4), 1151-1160.Katz, R.W. and Parlange, M.B. (1995). Generalizations of chain-dependent processes: application to hourly precipitation. Water Resour. Res. 31(5), 1331-1341.Klemes, V. (1987). Empirical and causal models in hydrologic reliability analysis. En Engineering Reliability and Risk in Water Resources, editado por L. Duckstein y E.J. Plate, NATO ASI Series E, N. 124, Martinus Nijhoff Publ., Dordrecht.Koepsell, R.W. and Valdes, J.B. (1991). Multidimensional rainfall parameter estimation from a sparse network. ASCE J. Hydraul. Eng., 117(7), 832-850.Lacewell, R.D. y Lee, J.G. (1988). Land and water management issues: Texas High Planes. En Water and Arid Lands of the Western United States, editado por M.E. El-Ashry y D.C. Gibbons, Cambridge University Press, Cambridge.Leavesley, G.H., Litchy, R.W., Troutman, B.M., y Saindon, L.G. (1983). Precipitation-runoff modeling system: users manual, U.S. Geological Survey Water Resources Investigations, Report 83-4238, 207 p.Linsley, R.K., Kohler, M.A., y Paulhus, J.L.H. (1982). Hydrology for engineers, McGraw-Hill Book Company, N. York.Loague, K. y Gander, G.A. (1990). R-5 revisited 1. Spatial variability of infiltration on a small rangeland catchment. Water Resour. Res., 26(5), 957-971.Lorenz, E.N. (1990). Can chaos and intransitivity lead to interannual variability?. Tellus, 42A, 378-389.Marco, J.B. (1995). Hydrometeorological and hydraulic factors and problems related to floods in arid regions of Spain. US-Italy Research Workshop on the Hydrome-teorology, Impacts, and Management of Extreme Floods, Perugia, Italia, Nov. 13-17.Matthai, H.F. (1990). Floods. En Surface Water Hydrology, editado por M.G. Wolman y H.C. Riggs, The Geology of North America, Vol. 0-1, The Geological Society of America, Boulder, Colorado.McMahon, T.A. (1979). Hydrological characteristics of arid zones. En The Hydrology of Areas of Low Precipitation, Proc. del Simposio de Camberra, IAHS, Publ. N. 128, p. 105-123.Meigs, P. (1952). Arid and semiarid climatic types of the world. Proceedings, VIII General Assembly and XVII International Congress, International Geographical Union, Washington D.C., p.135-138.Meigs, P. (1953). World distribution of arid and semiarid homoclimates. En Arid Zone Hydrology, UNESCO Arid Zone Research Series, 1: 203-209.Meng, H., Ramirez, J.A., Salas, J.D., y Ahuja, L.R. (1996). On the scaling characteristics of infiltration process. American Geophysical Union, Abstract, Fall Meeting en San Francisco.Mimikou, M. (1983). Daily precipitation occurrences modeling with Markov chain of seasonal order. Hydrol. Sci. J., 28(2), 221-232.Mualen Y. y Assouline, S. (1996). Soil sealing, infiltration and runoff. En Runoff, Infiltration and Subsurface low in Arid and Semi-arid Regions, Editado por A.S. Issar y S.D. Resnick, Kluwer Academic Publ., Boston.Nielsen, D.R., Biggar, J.W., y Erb, K.T. (1973). Spatial variability of field-measured soil-water properties. Hilgardia, 42(7), 215-259.Obeysekera, J.T.B., Tabios, G., and Salas, J.D. (1987). On parameter estimation of temporal rainfall models. Water Resour. Res.23(10), 1837-1850.Osterkamp, W.R. y otros (1987). Great plains. En Geomorphic Systems of North America, editado por W.L. Graf, Centenial Special Vol. 2, Geological Society of America, Boulder, Colorado.Page, J. (1984). Arid lands, Time-Life Books, Virginia.Piechota, T.C. y Dracup, J.A. (1996). Drought and regional hydrologic variation in the United States: association with the El Niño-Southern oscillation. Water Resour. Res., 32(5), 1359-1373.Philip, J.R. (1957). Evaporation and moisture and heat fields in the soil. J. Meteorology, 14, 354-366.Ramirez, J.A. y Bras, R.L. (1985). Conditional distributions of Neyman-Scott models for storm arrivals and their use in irrigation control. Water Resour. Res., 21(3),317-330.Rawls, W.J., Ahuja, L.R., Brakensiek, D.L., y Shirmohammadi, A. (1993). Infiltration and soil water movement. En Handbook of Hydrology, edited by D.R. Maidment, Mc-Graw Hill Book Company, N. York.Redmond, K.T. y Koch, R.W. (1991). Surface climate and streamflow variability in the Western United States and their relationship to large-scale circulation indices. Water Resour. Res.,27(9), 2381-2399.Riggs, H.C. y Harvey, K.D. (1990). Temporal and spatial variability of streamflow. En Surface Water Hydrology, editado por M.G. Wolman y H.C. Riggs, The Geology of North America, Vol. 0-1, The Geology Society of America Inc., Boulder, Colorado.Robinson, T.W. (1952). Phreatophytes and their relation to water in Western United States. Trans. Am. Geophys. Union, 33, 57-61.Rodriguez-Iturbe I., Gupta, V.K., y Waymire, E. (1984). Scale consideration in the modeling of temporal rainfall. Water Resour. Res., 20(11), 1611-1619.Rodriguez-Iturbe, I. (1986). Scale of fluctuations of rainfall models. Water Resour. Res., 22(9), 15S-37S.Rodriguez-Iturbe, I., Vogel, G.K., Rigon, R., Entekhabi, D., Castelli, F. y Rinaldo, A. (1995). On the spatial organization of soil moisture fields. Geoph. Res. Letters, 22(20), 2757-2760.Roesner, L.A. and Yevjevich, V. (1966). Mathematical models for time series of monthly precipitation and monthly runoff. Hydrology Paper 15, Colorado State University, Fort Collins, Colorado.Roldan, J. and Woolhiser, D.A. (1982). Stochastic daily precipitation models. Water Resour. Res., 18(5), 1451-1459.Rovey, E.W., Woolhiser, D.A., y Smith, R.E. (1977). A distributed kinematic model of upland watersheds. Hydrology Paper 93, Colorado State University, Fort Collins, Colorado.Salas, J.D. y Boes, D.C. (1980). Shifting level modelling of hydrologic series. Advances in Water Resources, 3, 59-63.Salas, J.D., Saada, N., y Chung, C.H. (1995). Stochastic modeling and simulation of the Nile River system monthly flows. Computing Hydrology Laboratory, Tech. Report 5, ERC, Colorado State University.SCS (Soil Conservation Service) (1972). SCS national engineering handbook, Sec. 4, hydrology. US Department of Agriculture (USDA).Schick, A.P. (1990). Hydrologic aspects of floods in extreme arid environments. En Flood Geomorphology, editado por V.R. Baker y otros, J. Wiley, N. York.Shantz, H.L. (1956). History and problems of arid lands development. En The Future of Arid Lands, editado por G. F. White, Amer. Soc. Adv. Science, Publ. 43, Washington.Slatyer, R.O. (1961). Methodology of a water balance study conducted on a desert woodland (Acacia Aneura F. Muell) community in Central Australia. UNESCO Proc. Madrid Symp. on Plant-Water Relations in Arid and Semiarid Conditions, p.15-26.Slatyer, R.O. y Mabbutt, J.A. (1964). Hydrology of arid and semiarid regions. En Handbook of Applied Hydrology, editado por V.T. Chow, McGraw-Hill BookCompany, N. York.Smith, R.E. and Schreiber, H.A. (1974). Point process of seasonal thunderstorm rainfall: 2. rainfall depth probabilities. Water Resour. Res., 10(3), 418-426.Smith, R.E. y Hebbert, R.H.B. (1979). A MonteCarlo analysis of the hydrologic effects of spatial variability of infiltration. Water Resour. Res., 15(2), 419-429.Stiling, P.D. (1996). Ecology: Theories and Applications, Second Edition, Prentice Hall, N. Jersey.Thomas, D.S.G. (1989). The nature of arid environments. En Arid Zone Geomorphology, Halsted press, N. York.Thornthwaite, C.W. (1948). An approach toward a rational classification of climate. Geog. Rev., Vol.38, 55-94.Trewartha, G.T. (1968). An introduction to climate, McGraw-Hill Book Company, N. York.Weiss, G. (1977). Shot noise models for the generation of synthetic streamflow data. Water Resour. Res., 13(1).Williams, M.A.J. y Balling, R.C. (1996). Interactions of desertification and climate. Prepared for WMO United Nations Environmental Programme, Arnold, N. York.Woolhiser, D.A., Smith, R.E., y Goodrich, D.C. (1990).KI-NEROS, a kinematic runoff and erosion model: documentation and user manual. U.S. Agriculture Research Service, ARS-77.Woolhiser, D.A., Smith, R.E., y Giraldez, J.V. (1996). Effects of spatial variability of saturated hydraulic conductivity on Hortonian overland flow. Water Resour. Res.,32(3), 671-678.UNEP (United nations Environment Programme) (1992). World atlas of desertification, E. Arnold, London.UNESCO (1979). Map of the world distribution of arid regions, MAB Technical Notes 7, UNESCO, Paris.Yevjevich, V. (1967). An objective approach to definitions and investigations of continental hydrologic droughts. Hydrology Paper 23, Colorado State University, Fort Collins, Colorado.Yevjevich, V. (1972). Probability and statistics in hydrology, Water Resources Publications, Littleton, Colorado

Regional relationships between basin size and runoff characteristics / Relations regionales entre la surface du bassin et les caracteristiques de l'ecoulement

ABSTRACT The effect of basin size on runoff characteristics is investigated. The maximum observed floodflow, the maximum annual constant loss, the lag time and the unitgraph peak for a certain storm duration of basins in the western and northwestern regions of Greece are increasing power functions of the basin size. These functions explain significantly the variation in the runoff characteristics. For both regions single relationships are derived for the latter two characteristics, whereas for the two former ones they vary regionally in accordance to the climatic conditions. Thus, care is needed in transferring such relationships outside the location of their derivation; besides, the transferability of the values of their parameters is doubtful. The derivation of the relationships in th