Modelling Model Parameter Unit Minimum Maximum Runoff Volume Deficit and constant loss Initial deficit MM 0 500 Maximum deficit MM 0 500 Constant rate MM/HR 0.1 5 Direct runoff transformation Snyder’s UH Lag time HR 0.1 500 Peaking coefficient - 0.1 0.1 Base flow Exponential Recession Initial base flow m3/s 0 100000 Recession factor   0.000011 - Flow to peak flow ratio   0 1

Table 2: Area size and weather stations of each catchment in upper blue Nile river basin.