Reference alternative

The reference alternative is the scenario in which the NbS will not be implemented. Intensive agricultural practises, in which the land is kept free from flooding as much as possible through levees and grey infrastructure, and employing a model with three rice crops annually, are continued, both at the project level and at the basin level. The reference alternative assumes that no incremental investment costs are required to sustain the current systems, yet it is acknowledged that over time agricultural production is not sustainable and hence production may stall or decline, and costs of production increase substantially, mainly due to more fertiliser and pesticide use.^[1] In the long run, a possible scenario is a severe decline in agricultural production of the Mekong Delta due to the sinking of soils below sea level and reducing soil fertility. However, this would be beyond the current project horizon.

_{[1] See Tran, D. D., van Halsema, G., Hellegers, P. J., Ludwig, F., & Wyatt, A. (2018). Questioning triple rice intensification on the Vietnamese mekong delta floodplains: An environmental and economic analysis of current land-use trends and alternatives. Journal of environmental management, 217, 429-441.}