2013

Ochoa, C.; Fernald, A.; Guldan, S.; Tidwell, V.; Shukla, M.

http://ascelibrary.org/doi/pdf/10.1061/(ASCE)HE.1943-5584.0000718

Abstract: Irrigation percolation can be an important source of shallow aquifer replenishment in arid regions of the southwestern United States. Aquifer recharge derived from irrigation percolation can be more significant in fluvial valleys overlying shallow aquifers, where highly permeable soils allow rapid water infiltration and aquifer replenishment. This study used data from various irrigation experiments and data at the piezometric level to assess the irrigation percolation effects on the recharge of a shallow aquifer in an agricultural valley of northern New Mexico. The water balance method (WBM) and the water table fluctuation method (WTFM) were used to estimate aquifer recharge at the field scale (<1  ha<1  ha) and the WTFM was used to determine recharge at the entire valley scale (40  km240  km2). Also, the temporal and spatial distribution of aquifer response to irrigation percolation and canal seepage inputs was characterized. The results showed that for separate irrigation events at the field scale, aquifer recharge values ranged from 0 to 369 mm when using the WBM and from 0 to 230 mm when using the WTFM. For the cumulative irrigation season at the valley scale, recharge ranged from 1,044 to 1,350  mm year−11,350  mm year−1. A relatively rapid water table response with sharp water table rises and declines was observed in all but dryland location wells in response to canal seepage and irrigation percolation inputs. The results of this study add to the understanding of the mechanisms of shallow aquifer recharge and the interactions between surface water and groundwater in a floodplain agricultural valley of northern New Mexico.