Javed Alam

A Spreadsheet Approach for Prediction of Rating Curve Parameters

Streamflow data is required for planning and design of various hydraulic structures and water resource projects such as bridges, culverts, flood plain zoning, flood protection works, flood warning systems, and assessment of water resources potential. A reliable and continuous record of streamflow data is, therefore, of utmost importance. However, it is very difficult to maintain a continuous record of discharge and sometimes even impractical during floods. A continuous record of elevation of water surface in a stream above some arbitrary datum or the stage of river is rather easy and accurate as compared to discharge. A functional relationship between stage and discharge at a site in a river is called the rating curve. The accuracy of discharge estimated from the rating curve depends on the accuracy of stage measurement and development of the rating curve. The conventional method of regression analysis for the development of the rating curve often fails to give stage–discharge relationship accurately. In the present study, a simple and quick Excel solver technique has been used for the development of the rating curve accurately. The results of the solver in Excel are compared with conventional method of regression analysis. The statistical parameters such as root mean square error, correlation coefficient, and Nash criteria were computed for assessment of the performance of these methods for the rating curve development. It has been found that the performance of the Excel solver is better than that of the conventional method.

Regional flood frequency analysis: comparison of L-moment and conventional approaches for an Indian catchment

Abstract A realistic estimation of flood magnitude for a given return period is essential for successful operation and economical design of pivotal hydraulic structures such as dams, reservoirs and spillways, bridges, small culverts, urban drainage systems, flood plain zoning, economic evaluation of flood protection projects, etc. The flood frequency analysis is generally used for flood estimation, entirely based on the assumption that the floods are random and the floods in future are supposed to bear similar statistical properties that have occurred in the past. If adequate data are available at-site flood frequency analysis is used, otherwise regional flood frequency analysis (RFFA) is preferred for flood estimation. The RFFA for various small and medium catchments of India with different approaches have been carried out and reported in the literature. The focus of the present study is to carry out the RFFA using different approaches i.e. conventional method and L-moment and comparing the results for the Krishna and Penner subzone 3(h) of India. It was found that the values of growth factors obtained by the conventional method are higher than those of L-moment methods, thus leading to conservative estimate of the peak floods.

SEEPAGE AND STRENGTH CHARACTERISTICS OF FLY-ASH SAND MIXTURES: AN EXPERIMENTAL STUDY

ABSTRACT The aim of the present study is to utilize favourably the situation where sand is available in abundance, for example in the adjoining areas of rivers/streams. Very often civil engineers have to construct works like Dikes, Guide bund, Detention dams and Debris dams etc. So if we can make a low permeable mass by utilizing available sand/coarse sand mixed with otherwise problematic materials such as fly-ash, we shall be able to be benefited in two ways one by utilizing the available/otherwise discarded materials and at the same time by saving the cost of structure. With this background in mind an effort has been made in this paper to produce a low permeable mass by mixing fly-ash and sand in different proportions. Present paper is an attempt to study the effect of fly-ash in reducing the permeability of sand beds. The sand beds are highly permeable as compared to fly-ash (Parua, P. K., 1996). As a case study fly- ash has been collected from Dadri thermal power station situated in U.P. In an attempt...