Pan evaporative changes are one of the key components of water resources management of a river basin under changing climate and anthropogenic-induced warming. The present study was undertaken for transboundary Godavari River basin (India) to identify the trends in pan evaporation (E_pan) by non-parametric Mann–Kendall (MK) test in annual, seasonal and monthly time scales. The Pettitt test, a non-parametric test, was also used in this study to detect abrupt changes in the mean of the distribution of the E_pan in the Godavari basin. Furthermore, the stepwise regression analysis was performed to find out the cause of the observed E_pan changes in the basin. On seasonal (monthly) time scales, statistically significant decreasing trends in E_pan were witnessed in the pre-monsoon season (in the months of March, April and May) in all the seven sites of the Godavari River basin. On the other hand, four sites witnessed statistically significant increasing trends in minimum temperature (maximum temperature) in the month of July (December) and in the monsoon (post-monsoon) season in the Godavari River basin. Statistically significant decreasing (increasing) trends in wind speed (relative humidity) in the pre-monsoon season and in the month of March at these seven sites support the observed decline in the evaporative demand in the basin leading to possible enhancement in the total yield of the Godavari River basin. Results of stepwise regression analysis showed that wind speed followed by relative humidity was found to be two main causative parameters of the observed decline in the E_pan under the warmer environments in the Godavari River basin. Pettitt’s test shows year 1991–1992 to be the probable year of change in the E_pan in the Godavari River basin.

泛蒸发变化是气候变化和人为变暖下流域水资源管理的关键组成部分之一。本研究是针对跨界戈达瓦里河流域（印度）进行的，目的是通过非参数 Mann-Kendall (MK) 检验在年度、季节性和每月时间尺度上确定泛蒸发 (E _pan )的趋势。Pettitt 检验是一种非参数检验，在本研究中也用于检测Godavari 盆地中E _pan分布平均值的突然变化。此外，进行逐步回归分析以找出观察到的盆地E_盘变化的原因。在季节性（每月）时间尺度上，E _{pan 的}统计显着下降趋势在季风季节（3 月、4 月和 5 月）在戈达瓦里河流域的所有七个地点都目睹了这一现象。另一方面，在戈达瓦里河流域的 7 月（12 月）和季风（季风后）季节，四个地点的最低温度（最高温度）出现统计上显着的上升趋势。季风前季节和 3 月份这七个地点的风速（相对湿度）在统计上显着下降（增加）趋势支持观察到的流域蒸发需求下降，导致总产量可能增加戈达瓦里河流域。逐步回归分析的结果表明，风速和相对湿度是观测到的 E 下降的两个主要成因参数。在戈达瓦里河流域较温暖的环境下_平底锅。佩蒂特的检验表明，1991-1992 年可能是戈达瓦里河流域E_盘发生变化的年份。