Impact of agricultural development on evapotranspiration trends in the irrigated districts of Pakistan: evidence from 1981 to 2012

Understanding time-series evapotranspiration trends is critical for water-balance assessments and sustainable water management in arid regions. In this paper, an approach is presented to understand time-series evapotranspiration trends by combining remote sensing-based evapotranspiration and agricultural statistics data and applying them to understand district-level water-use trends in the Indus basin irrigation system of Pakistan. The evapotranspiration of most districts in the Punjab increased over the period, whereas in Sindh it generally remained about the same or decreased. The trends in Punjab suggests that the already unsustainable groundwater use in some areas may become more unsustainable.