Web-ET: A Web Enabled Tool for Computing Evapotranspiration

Hydroinformatics supports the water resources engineers by utilising the modern Information and Communication Technology (ICT). For decades numerical modelling has been the core activity for hydroinformatics. With the popularity of World Wide Web (WWW), web enabled applications are gaining popularity in almost all spheres of our life. The adoption of WWW technology to hydrology is an important application of hydroinformatics. This opens a new potential for joint modelling in distributed environments and to set up and apply net based hydrological information systems. The web enabled applications offer hydrologists the opportunity to give a larger audience access to their products in a more structured manner and, at the same time, allows them to benefit from the achievements of others.

Agriculture and urban landscape water management planning and regional water balance studies need computation of evapotranspiration (ET) very frequently. Numerous ET equations are used by practitioners according to availability of data. As an initiation in the direction of development of web based application, a web enabled software (Web-ET) has been developed. Web-ET provides standardised calculations of reference evapotranspiration for six common methods and equations that are currently in use. These include FAO Penman-Monteith equations, Hargreaves equations, Blaney-Criddle equation, Turc method, Thornthwaite method and temperature based method. The calculations are based on the weather data measurements provided by the user. When installed on a website, the users can use it with the help of a web browser, without actually having to install the software on their computer. The paper summarises the available innovative technologies of WWW and also demonstrates their application in hydroinformatics for ET computation using Web-ET.