Technical principles and figures of agricultural drainage - From pipes to hydro-diplomacy

Abstract

This article reviews the state of the art of agricultural drainage and shows an evolution from rural engineering to remediation engineering, increasingly calling upon the disciplines of ecological engineering and territorial dialogue. Concerning remediation, solutions - necessarily complementary to a responsible use of agricultural inputs and aimed at improving the quality of drainage water - do exist and are presented in this issue. Some, such as artificial wetland buffer zones, have proven their efficiency and their recognized amenities (biodiversity, landscapes). Others, such as bioreactors or controlled drainage -applicable without investment or land consumption in our polders- require validation, or more precisely performance assessment, in our climatic context. It is therefore rather "at the end of the pipe" that the know-how on agricultural drainage needs to be consolidated, and in many areas. Another research issue is the place of agricultural drainage in a context of climate change, because it is necessary to know whether current structures that are known to be durable if properly taken care of should be maintained or adapted to future conditions.