A few distributions compiled together for flood frequency analysis

Five different probability distributions, proposed particularly for flood frequency analysis, have been used to model observed annual flood peaks series, by properly compiling them in a computer program to compute many return period floods of exceedence probabilities between 0.99 and 0.0001. The distributions used are: two parameter log-normal (by moments), Gumbel (both by moments and by maximum likelihood), log-Gumbel (by moments), one-parameter log-Gamma (both by moments and by maximum likelihood), Smemax transformation, and log-Boughton. For standard normal probabilities, Abramowitz and Stegun's precise formula is used. Gumbel, Smemax, and log-Boughton distributions are exactly computed. Wilson-Hilferty approximation is applied to Gamma distribution to convert it to standard normal. To help differentiate the more suitable ones out of the eight models used, statistics of the classical goodness-of-fit tests also are computed. -from Autho

(A study on operation of two reservoirs in series on the Seyhan River during flood period). [Catalan ve Seyhan berajlarinin taskin durumunda isletilmesi uzerine bir calisma.]

A simple and efficient computer program is developed to compute and plot the outflow hydrograph routed from a reservoir. By applying this program to the at-building-stage Catalan Reservoir, just at upstream end of Seyhan Dam, and then to Seyhan Reservoir with various cases, the effect of Catalan Reservoir on reduction of outflow peaks from Seyhan Dam was studied. It was concluded that if both reservoirs faced serious floods with water levels at around their service spillway crest elevations considerable retention of floods was possible. If the initial water level in Catalan Reservoir is close to the project value of 118.60 m, however, some degree of minor flooding would still occur in the city of Adana and at Cukurova Plain. In case a huge flood which is double the 1980 flood occur, the reservoirs still would be able to pass it safely from their own stability standpoint, but severe flood damages downstream would result.-English summar

STORAGE YIELD RELATIONSHIPS FOR RESERVOIRS BY A SEQUENTIAL-OPERATION ALGORITHM AND COMPARISONS WITH GOULD PROBABILITY MATRIX-METHOD

WOS: A1989AH69500004

SUITABILITY OF 2-PARAMETER-GAMMA AND 3-PARAMETER-BETA DISTRIBUTIONS AS SYNTHETIC UNIT HYDROGRAPHS IN ANATOLIA

WOS: A1990CV58600003

Investigación experimental comparativa de vigas de hormigón reforzado con fibras de acero

Five different batches of class C20 concrete, containing Dramix-RC-80/60-BN steel fibers (SFs) as additives at doses of 0, 30, 40, 50 and 60 kg/m3, and six Ø 15x30 cm prisms were poured from each batch. Standard crushing tests were run on all the specimens and the respective load-displacement and stress-strain curves were plotted. Toughness, ultimate compressive strength and the modulus of elasticity were determined for all specimens. The compressive strength and modulus of elasticity declined in 30 kg/m3 steel-fiber-additive concrete (SFAC) by 9% and 7% compared to the reference C20 concrete without SFs, and the area under the load-deflection curve grew more than twofold. In concrete with a higher SF dosage, the differences in strength and elasticity were around I0% whilst toughness was about the same. Because toughness values were similar in 30, 40, 50 and 60 kg/m3 plain SF-additive concrete and the strength and modulus of elasticity were slightly better in the mixes with the smallest proportion of SF for reasons of economy, 30 kg/m3 was taken as the optimum dose of steel fiber to be added to the reinforced concrete used in a second phase of the study. Hence, of the six reinforced concrete (RC) beams made, all of equal size and with the same under-reinforced tensile reinforcement design, three were made with concrete containing the above-mentioned dose of SF. In addition to compressive strength, these beams were tested for flexural strength, which was found to be 18%) greater for the SFARC beams than the ordinary RC beams, and the upper arms of the load versus mid-span deflection curves prior to ultimate failure of the SFARC beams were considerably longer than the same arms on the curves for ordinary RC beams.Se han utilizado cinco lotes diferentes de hormigón clase C20 cuatro de ellos con fibras de acero (FA), identificadas como Dramix-CR-80/60-BN, en cuatro proporciones diferentes: 30, 40, 50 y 60 kg/m3 y el quinto exento de FA. De cada lote se elaboraron 6 probetas cilíndricas de Ø 15x30 cm. Se midió la resistencia a compresión de todas las probetas así como las relaciones carga-deformación. Se determinó la dureza, la resistencia a compresión y el módulo de elasticidad de las probetas. La resistencia a compresión y los módulos de elasticidad del hormigón con un contenido de 30 kg/m 3 de fibras (SFA) disminuyeron en un 9% y en un 7% respecto al hormigón de referencia (C20) sin FA, mientras que el área limitada por la curva carga deformación aumenta más del doble. Con los hormigones de mayor cantidad de FA esas proporciones están alrededor del 10% y el incremento de la dureza es casi la misma. Debido a que los valores de las durezas de los hormigones con 30, 40, 50 y 60 kg/m3 de FA están muy próximos y dado que tanto la resistencia como el módulo de elasticidad del primero son incluso ligeramente superiores a los del último, por razones de economía la dosis de 30 kg/m3 dé fibra de acero es la seleccionada como óptima para el hormigón armado (SFARC). Se fabricaron seis probetas de hormigón armado (RC) de iguales dimensiones, todas ellas con barras de acero de la misma capacidad de tensión, diseñadas para que alcanzaran un valor mínimo de rotura a compresión con la proporción de acero más baja. Tres de las probetas se elaboraron adicionando fibras de acero en una proporción de 30 kg/m3. Los ensayos de rotura a compresión de esas probetas se complementaron con ensayos de rotura a flexión: el resultado obtenido fue un 18% superior en el caso de las vigas SFACR que en el caso de las vigas RC, y la zona superior de la sección central de las curvas de carga-deformación antes de la última rotura de las SFARC, ha dado un valor considerablemente superior que el correspondiente a las vigas RC

Suitability of two-parameter gamma and three-parameter beta distributions as synthetic unit hydrographs in anatolia

The scale-adjusted probability density functions of the two-parameter gamma and the three-parameter beta distributions were shown to fit reasonably well to ten observed unit hydrographs in Anatolia, the gamma exhibiting slightly better fits. As a result, a method making use of this curve is suggested for the synthetic unit hydrograph. © 1990 Taylor and Francis Group, LLC

Comparison of hydraulic and hydrologic routing on three long reservoirs

Outflow hydrographs for three dams with long lakes in narrow valleys were computed by both hydrologic routing (level-pool routing) and hydraulic routing. They were compared with three inflow hydrographs of different peaks with three unregulated ogee spillways of different capacities. In all these cases, the difference between outflow hydrographs was greatest at the peak value, growing larger as the spillway capacity became smaller, relative to the magnitude of the inflow hydrograph. The peak outflow by hydraulic routing was smaller than that by hydrologic routing for all the routing combinations, the difference varying between 2 and 11%