Innovative Trend Analysis of Reference Crop Evapotranspiration in Peninsular Malaysia

<jats:title>Abstract</jats:title>
<jats:p>The inconsistencies in reference crop evapotranspiration (ET<jats:sub>0</jats:sub>) trends due to the occurrence of climate change have been detected over the world. This has substantially affected both the local and global water resources. The objective of this study is to investigate the historical trend of ET<jats:sub>0</jats:sub> and its meteorological variables in Peninsular Malaysia. The meteorological data in daily scale, such as minimum, maximum and mean air temperature, relative humidity, wind speed and solar radiation covering the 2000-2019 period were obtained from Malaysian Meteorological Department and used to compute the ET<jats:sub>0</jats:sub> estimation using FAO-56 Penman Monteith model. Then, innovative trend analysis was employed to detect the variations trends in ET<jats:sub>0</jats:sub> and its meteorological variables. In the study area, the results showed that significant positive ET<jats:sub>0</jats:sub> trends were found at Ipoh (8.09), Kuantan (15.10) and Subang (12.7620) stations respectively and no significant negative ET<jats:sub>0</jats:sub> trend can be found. The finding of the study can be used to achieve support and improvement in the efficiency of irrigation regions and optimal water resources planning and utilization.</jats:p>