All other Geographic fields of studies , Interdisciplinary
yagob Dinpazhouh
Abstract
The aim of this study is trend analysis of streamflows of east Azerbaijan using the non-parametric methods. For this purpose the information of consentration of water quality ions (Ca, Mg, Cl, Na, HCo3, pH, So4, TDS, EC, SAR, Total Cations, Total Anions and Na%) of ten hydrometric stations (1983-2008) ...
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The aim of this study is trend analysis of streamflows of east Azerbaijan using the non-parametric methods. For this purpose the information of consentration of water quality ions (Ca, Mg, Cl, Na, HCo3, pH, So4, TDS, EC, SAR, Total Cations, Total Anions and Na%) of ten hydrometric stations (1983-2008) were used. To test trends the Mann-Kendal scheme after removing all significant autocorrelation effects from the data were used. To estimate trend line slope the non-parametric Sen´s estimator method was used. Results showed that trends of positive ions and EC were upward for most of the stations. Those stations which had negative trend in streamflow also exhibited positive trend in concentration of chemical elements of surface water. Furthermore, investigation of streamflow water quality using the Wilcox on method showed that the quality of water declined comparing the last decades. The reason of such declination attributed to the decreasing trend of streamflow and conveying pollutant materials into the rivers.
Yagoub Dinpazhooh; Faege Niazi; Hamed Mofid
Volume 19, Issue 51 , April 2015, , Pages 145-169
Abstract
The aim of this study is trend analysis of meteorological parameter including mean wind speed, min, max and mean air temperature, difference between the min and max temperature, pan evaporation, average relative humidity, sunshine hours, total precipitation, the number of days with precipitation more ...
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The aim of this study is trend analysis of meteorological parameter including mean wind speed, min, max and mean air temperature, difference between the min and max temperature, pan evaporation, average relative humidity, sunshine hours, total precipitation, the number of days with precipitation more than 1, 5 and 10 mm, the number of days with dust, number of the days with snow and the number of days with visibility less than 2Km, degree days based on 18 and 21 oC at Tabriz station during 1970-2005 in three time scales, monthly, seasonal and annually using the non-parametric Mann-Kendall (MK) method. Trend analysis was conducted using two methods, which are conventional MK (for series having insignificant autocorrelation coefficients) and modified MK (for other series) in three significant levels, 1%, 5% and 10%. Trend slopes were calculated using Sen’s estimator. Results showed that in annual time scale, pan evaporation, min, max and mean temperature and degree days based on 18 and 210C have significant increasing trends at 5% level but precipitation, number of the days with precipitation more than 1 and 5 mm and degree days based on 180C have decreasing trend (at 5% level). Other parameters did not show significant trend in annual time scale. Trend slope of annual precipitation was -2.28 mm/year and trend slopes of all three elements, average, max and min temperature were 0.06 0C/year. Observed trends in studying parameters indicate climate change in Tabriz.
