Estimation of Canal Seepage Losses in Irrigation District with Shallow Groundwater Table.

title: Estimation of canal seepage losses in irrigation district with shallow groundwater table

Abstract：Estimation of canal seepage losses from unlined irrigation canals in irrigation systems is important for optimizing allocation of deficit resource and improving the water use efficiency. The aim of this investigation is to estimate the canal seepage losses in an irrigation district with shallow groundwater table. Considering the influence of groundwater mound, the Green-Ampt model and an approximate analytical solution is developed in this investigation. Dataset from 2006-2013 about the two main canals in Jiefangzha sub-district (a sub-district with shallow aquifers in Inner Mongolia, China) were selected to calculate the canal seepage losses. More than 90% total water diverted days infiltration were under the influence of the groundwater mound. Comparison with experimental results in the irrigation district shows that the solution is feasible to estimate the canal seepage losses in shallow water table district. The canal seepage amount is very large and ignorable. This evaluation method will be valuable to accurately calculate the canal seepage losses in the shallow groundwater table district and useful to make reasonable water use policy.

Key words: Canal seepage losses; Green-Ampt model; analytical solution; shallow groundwater table