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Within the last two decades, modelling of rainfall-runoff has become an important topic in water resources assessment due to increasing water demand and energy, particularly in the determination of hydropower potential. In addition to remote sensing (RS) and geographical information systems (GIS), with the development on satellite technologies, it becomes possible to asses rapid and economic solutions to determine a practical rainfall-runoff relation, particularly poorly gauged or ungauged basins. In this paper, Solakli Watershed which is located in Eastern Black Sea Region of Turkey is selected as the study area. To determine the hydroelectric water potential in a poorly gauged basin, basin boundary and area, minimum 3758 H. Gonca Coskun et al. maximum and mean elevation, slope information of the basin have been derived from the digital elevation model (DEM) using remote sensing (RS) and geographical information systems (GIS) techniques. IRS P5 stereo satellite data with 2.5-m spatial resolution has been used for deriving the DEM. This DEM is used to produce the flow direction and flow accumulation maps of the basin. Afterward, synthetic drainage network is obtained with the analysis of these maps. Using topographical data such as area, mean basin elevation and limited point observations of rainfall data; a regression model was derived for the whole watershed. This regression model was validated on a sub-basin with satisfactory results using mean areal rainfall which was calculated isohyetal map produced by kriging method. Suggested hydropower station points are also determined.

The estimation of the monthly mean flow is a critical issue in many water resource development projects. However, in practice the mean flow is not easily determined in ungauged and poorly gauged basins. Therefore, in the literature, various flow estimation methods have been developed recently for mountainous regions which are generally ungauged or poorly gauged basins. In this study a fuzzy logic model based on the Mamdani approach was developed to estimate the flow for poorly gauged mountainous basins. This model was applied to the Solakli Basin which is located in the Eastern Black Sea Region of Turkey. Limited rainfall and flow data are available for this basin. In addition to these variables, the stream and time coefficients were introduced and used as variables for modeling. The data was divided into training and testing phases. The model results were compared with the measured data. The comparison depends on seven statistical characteristics, four different error modes and the contour map method. It was observed that the fuzzy model developed in this study yielded reliable results.

Sediment transport in a meandering channel is measured in a laboratory flume. The measurements are evaluated and compared with previous studies. The values of the calculated sediment transport rates using previous formulas are generally overestimated. Under these circumstances, in this research, it is noticed that the sediment transport rates as measured in the laboratory, and sediment transport capacities computed with the Einstein's approach, behave in a quite similar way, seemingly closely related to the varying bottom shear velocity or stress. Einstein's approach for bed load comparison is chosen in this experimental research because it has been tested to some extent.

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