Analysis of Eastern Black Sea basin flow

Water has been an essential substance for both living organisms and non-living things, and it has drawn great attention throughout the history. Most of the civilizations settled and rose near water resources like rivers, lakes and wetlands to sustain their existence. While excess water can cause hazardous floods, water shortage can cause droughts and mass migrations. The demand for water is increasing continuously due to growing population and industrial facilities. Water can be transported from its sources to the places that lacks water, and stored in structures like reservoirs. However, learning from the past behavior of water to predict its future is the most efficient way of water management.Known time sequence of water quantity provides better understanding for the planning of water usage. For future planning purposes, the individuals and the companies that invest in hydrology, hydrometeorology, and water must know what kind of changes in water flow have occurred in the reservoirs. Annually, seasonally, monthly and daily historical data of river flows must be available, because planning of future investments in hydrology, hydrometeorology, and water requires these data.Time sequence of water quantity provides information to determine whether or not to invest. It also provides "what if scenarios" for the production phase.Quantity of water needed for energy production and irrigation can be accurately calculated by the use of time sequence of water. This calculations is based on historical data, and performed using statistical control methods. By this method, responsibilities of the potential investors can be identified in advance, and changes in water resources can be foreseen.It is important to analyze streams in water spring engineering. Flood and average stream rates are used for Project designing of flood constructions and the calculation of the storage capacity of barrages. So it is vital to analyze past stream records and find a trend compound of low stream and flood rates for water spring project planning. Moreover, calculating the trends of streams is significant for the optimum planning and operating of water supplies and planning hydro electrical station.In this thesis, 12 stream gauges, which is read in a timeline of East Black Sea Basin, is chosen. Annual and monthly average stream and flood graphs are drawn and interpreted. Since the stream data of 2215 stream gauges' is nonexistent in 1991, the graphs are completed by linear regression. Using monthly average stream rates, the Flow Sustainability Slope is found. The stream data is divided into precipitation area thus non-dimensional graphs are obtained. Worst case scenarios are also inserted in those graphs. (The lowest and highest precipitation cases from past to present)The flood rates are calculated for every station in intervals of 2, 5,10,25,50,100 and 200 years according to current data. The procedure for calculation is derived from the book Maximum Stream Frequency Analysis of Turkey's Drainage Basin belonging to EİE. The Normal, Log-Normal, Log- Normal with three parameters, Gumbel, GEV, Pearson Type III and Log-Pearson Type III distributions are used. The results are compared to the old rates in the book and interpreted. Mann-Kendall trend analysis is done to explore the increase and the decrease of data with time. The annual average flow and maximum stream graphs are drawn for each station and trend line is added to check the linearity. Flood graphs of all region is drawn according to maximum streams and precipitation areas in 200 year intervals and interpreted. Seasonality Analysis is conducted by relative frequency and angular seasonality analyzing procedures. All flood dates observed in the stations are examined monthly and frequency rates are analyzed thus regulated frequency value is found.Consequently, the data obtained from the State Water Supply Administration is filled in by linear regression method. Then the annual average stream, the highest stream rates of each stream gauges and the lowest stream rates are shown on the same graph. Generally the months with highest stream rates are April and May whereas the lowest are January and September.Flow Sustainability Slope is constructed using the monthly average streams of the stations. Q10 and Q90 flow rates of highest and lowest stream periods are shown according to this data. The data of low stream periods is analyzed. The fact that Q90 flow in stream gauges numbered 2202, 2215, 2218, 2233 and 2238 is flat in low stream region shows the base current is high. Since Q90 flow in stream gauges numbered 2213, 2228, 2232, 2239 2245 and 2247 is perpendicular in low stream region, the base current is low. Q90 low stream flow is high in stream gauges' numbered 2218 and 2232 but low in other stations. Unit stream is found by dividing monthly average stream rates into precipitation areas. Flow Sustainability Slope is drawn using the highest and lowest monthly values for each stream gauge through the year it has been evaluated. The worst case scenarios are created. These slopes are interpreted and it is clear that the maximum and the minimum stream vary much when the flood rate is lower than 40% but vary less when it gets over 40%. Using current data of stations and the probability distribution function of the State Water Supply Administration, the frequency analysis is done in intervals of 2, 5, 10, 25, 50, 100, and 200 and compared with the results of 1990's frequency analysis of the State Water Supply Administration. Although there is not much difference in stream gauges numbered 2201, 2202, 2215, 2233, the values of other stations differ. Two separate flood graphs are drawn according to highest streams of stations and flood data calculated in intervals of 200 years and a linear trend line is added. It is seen that two graphs yielded similar results. The flood graph of East Black Sea Basin is compared to that of Turkey and concluded that it has much lower rates. These graphs are significant in flood prediction. Mann-Kendall trend analysis is done in annual average and maximum stream rates of stations separately. As a result of annual average stream analysis, in stream gauges numbered 2232 and 2239 an increasing trend is observed. With the analysis of maximum stream, an increasing trend is found in stream gauges numbered 2201 and 2228 but a decreasing trend is discovered in stream gauges numbered 2213 and 2215. Although a trend is non-existent, there are stations with increasing or decreasing slopes in annual and maximum stream analysis. According to data of each station, Angular Seasonality Analysis is done and unit circles are drawn using flood rates.The highest similarity value belongs to stream gauge numbered 2215 with 0.94 whereas the lowest value belongs to stream gauge numbered 2228 with 0.24. The homogeneities of stream gauges numbered 2228, 2245 and 2247 are low but in general The East Black Sea Basin has a high homogeneity. Floods generally happen in spring. The reason is the precipitation and the melting of the snow.As a result of all the analysis, a hydrological map of East Black Sea Basin, which is rich in supply but poor in current data, is constructed. These results are going to provide convenience for business, design and project stages.