Abstract

This paper presents an analysis of the effect of an irrigation network on the hydrology of an agricultural valley. The study area is the Peumo Valley, in Chile's VI Region. The main effect of this interaction is the stability of groundwater levels during the year. In the winter, with the irrigation divertion closed, the channel network works as a storm water drainage system, taking away the water from the flat areas where it normally would infiltrate to the groundwater system. In the summer, on the other hand, with the irrigation divertion open, infiltrations from the channel network recharge the groundwater system, compensating for losses due to evapotranspiration and base flow. At the farm scale, high-efficiency irrigation systems generate temporary agrochemical storage zones in the soil.