The Multiple Benefits of River–Floodplain Connectivity for People and Biodiversity

Agricultural land-use dynamics in the floodplains of the Vietnamese Mekong Delta : hydrodynamic implications on flood regimes and adaptation options

“…Worldwide, delta floodplains are among the most favored areas for concentration of intensive agriculture, due to the ideal conditions that delta floodplains offer for cultivation, such as fertile soils and abundant water. However, agricultural intensification influences the land and water management strategies that can be adopted on delta floodplains (Opperman et al, 2013). To prevent flooding from damaging residential areas and infrastructure for intensive agriculture, hard structures are usually the preferred means of floodwater management (Käkönen, 2008).…”

“…In recent years, many studies have pointed to downsides of hard structures, while highlighting the benefits of soft measures in increasing floodwater retention capacity and conserving ecosystem services (Buijs, 2009(Buijs, , 2009Temmerman et al, 2013;Van Staveren et al, 2014). ecosystem services found in more natural river-floodplain systems (Opperman et al, 2013;Kousky and Walls, 2014). In environmental terms, floodplain soils and water may be degraded by overuse of agrochemicals and the loss of the erstwhile benefits of floodwaters, such as fertile sediment inflows and wild fish stocks (Tsujimoto et al, 2017).…”

“…Many countries have shifted their emphasis in flood protection from hard measures to soft measures geared toward maintaining natural ecosystems and increasing capacity to adapt to the impacts of global environmental change (Opperman et al, 2013;Bubeck et al, 2015). Indeed, due to the negative impacts of hard measures on the environment, soft measures have been strongly recommended in recent decades as a more effective approach to maintaining ecological systems (Samuels et al, 2006;Wesselink et al, 2015).…”

“…High dikes interrupt interactions between rivers and floodplains. Wetland ecosystems need this interaction to exploit natural benefits, such as deposition of fertile sediment and provision of wild fish stocks (Danh and Mushtaq, 2011;Opperman et al, 2013;Hung et al, 2014a;Manh et al, 2014). The quality of soils, in particular, sulphate acid soils, may be degraded as a result of triple-crop rice farming, combined as it typically is with excess pesticide and fertiliser use (Howie, 2011).…”

“…Reduced water retention capacity, furthermore, has led to diminished flows in the dry season, exacerbating saltwater intrusion into freshwater areas (Hoang et al, 2016). In addition, the high dikes have erected a barrier between the floodplains and rivers, interrupting ecosystem services (Opperman et al, 2013). On the local scale, the high dikes have prevented fertile sediments and wild fish from washing into and replenishing the rice fields (Käkönen, 2008;Danh and Mushtaq, 2011;Danh, 2011;Trung et al, 2013).…”