Page - 599 - in Book of Full Papers - Symposium Hydro Engineering

If there is an impact of climate change on annual sediment yield during the period 1961-2015 there should be a trend in the time series data. To check whether there is a trend Spearman’s Rank-Correlation Method was applied [2]. The results are summarized in Table 2. Table 2 Parameters for trend analysis calculation Parameter Value Spearman’s rank correlation coefficient; (𝑅 𝑠 𝑝 ) 0.60 For Student’s t distribution; (𝑡 𝑡 ) 5.48 Degree of freedom; 𝑣 (= 𝑛 − 2) 53 For significance level of 5% ; Upper level value from t distribution Lower level value from t distribution 2.01 -2.01 If there is no trend in the time series data the value of student’s distribution, 𝑡 𝑡 should be such that; -2.01 < 𝑡 𝑡 < 2.01. As this condition is not satisfied where the calculated value of 𝑡 𝑡 equals to 5.48 (Table 2) it can be concluded that annual total sediment yield from 1961 to 2015 has a strong increasing trend. Accordingly, sediment yield of the MRUB is influenced by climate change as rainfall and temperature are the only variables during modeling period (1961-2015). When sub basins are considered soil erosion has a spatial variation (Fig. 3). For finding exact reasons for this variation requires physical inspection of the Fig. 2 Annual total sediment yield of study area 599