In this research, De Martonne’s index of aridity (IDM), Pinna combinative aridity index (IP), and UNEP aridity index (AI) were used for the drought analysis in the Sirvan river basin, Iran, during the period 2002–2018. Spatiotemporal analysis of aridity indices on each station was determined by calculating the Z statistic value of the nonparametric Mann–Kendall (MK) method of time series on the index values, and the slope of trend lines was calculated by Sen’s slope estimator method. The percentage change (tv%) in the amount of indicators was obtained during the studied period for each station. The results showed that eight stations out of 10 studied stations had a downward trend and the other stations had an upward trend (close to zero and nonsignificant) for the IDM on an annual scale, and one station (Janevareh, Z = −1.66) was statistically significant at the level of 10%. In the IP method, five stations had a downward trend, and the station (Janevareh, Z = −1.93) was statistically significant at the level of 10%. Also, in the AI method, nine stations had a downward trend, and the station of Janevareh (Z = −1.93) was statistically significant at the level of 10%. Among the stations that have experienced the highest amount of drying, Sarcheshmeh station in IDM with a slope of −0.45, Janevareh station in IP with a slope of −0.22, and Sarcheshmeh and Janevareh stations in AI index with a slope of −0.01 and more have tended toward drying, respectively. In general, it can be concluded that the climate of most of the studied stations in the Sirvan river basin has become significantly drier and warmer.

在本研究中，De Martonne 的干旱指数（IDM）、Pinna 组合干旱指数（IP）和 UNEP 干旱指数（AI）被用于伊朗锡尔万河流域 2002-2018 年期间的干旱分析。各站干旱指数的时空分析采用非参数Mann-Kendall(MK)法对指标值时间序列的Z统计值进行计算，趋势线的斜率采用Sen斜率估计法计算。在每个站点的研究期间获得了指标数量的百分比变化（tv%）。结果表明，10个研究站中有8个站呈下降趋势，其他站IDM在年尺度上呈上升趋势（接近于零且不显着），1个站（Janevareh，Z= -1.66) 在 10% 的水平上具有统计学意义。IP法中，有5个台站呈下降趋势，台站（Janevareh，Z = -1.93 ）在10%的水平上具有统计显着性。另外，在AI方法中，9个站有下降趋势，Janevareh站（Z= -1.93) 在 10% 的水平上具有统计学意义。在经历最大干燥量的站点中，IDM的Sarcheshmeh站的斜率为-0.45，IP的Janevareh站的斜率为-0.22，以及AI指数的Sarcheshmeh和Janevareh站的斜率为-0.01以上分别趋于干燥。总的来说，可以得出结论，Sirvan 河流域中大多数研究站点的气候已经变得明显干燥和变暖。