Spatio-temporal Analysis of Temperature and Precipitation Trends in Tashk-Bakhtegan Watershed

Document Type : Research Article

Authors

1 Department of environment engineering-water resources, faculty of environment, College of Engineering, University of Tehran.

2 The Head of Surface Water Group, Water Research Institute

3 Professor, Water Resource Engineering Group, Faculty of Agriculture, Tarbiat Modares University, Tehran, Iran

4 Head of Department of Water Resources Studies and Research

Abstract

In the present era, Climate change and its impact on available water resources are one of the main challenges. In this regard, temporal and spatial analysis of temperature and precipitation, which are important parameters in determining the status of water resources, can be used to assess the hydro-climatological conditions of the watershed and appropriate management policies. In this research, the trend in precipitation and temperature distribution over 30 years testing period of 1981-2010 was investigated using non-parametric tests such as Man-Kendal, Spearman, Sen’s Slope, and Pettit. Afterward, interpolation techniques, such as IDW, LPI, GPI, and RBF were used to detect spatially trends at the watershed. The results showed that precipitation decreased by 14.3% during the period 1981-2010 and the temperature increased by 3.5%, with changes in precipitation and temperature occurring in 2004 and 1985, respectively. However, the negative trend in precipitation was not significant in contrast to the positive temperature trend during the study period. A comparative analysis of interpolation techniques shows that Ordinary Kriging and Radial Basis Functions with least error are the best methods for spatial analysis of precipitation and temperature, respectively

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