A study on dam construction, hydrological changes, and the shift in dietary protein in the Lower Mekong River Basin

"An important ramification that could be linked to the accelerated dam construction in the Lower Mekong Basin (LMB) is a dietary shift from fish as a source of protein to land-animal- based protein. The proposed chain of events that lead to this conclusion starts with a disruption in the river's hydrodynamics from dams (e.g., flood-pulse, annual discharge, seasonality, water level), combined with physical barrier (i.e., a dam structure) lead to lower fish catch rates and reproduction from migratory impediment. A shift to a westernized diet by the developing country population of the LMB countries, can be observed as well. A relationship between fish catch and flooded area is developed to downscale fish catch to a 10 km grid in the study area, which enables the quantification of yearly distributed catch per capita. It is found that wet years yield higher catch per capita than dry years. Further, a statistical analysis on fish and meat production and consumption show an overall increase in local production of meat. The 2% cropland expansion is found to be largely attributed to an increase in meat production as most of the crops are grown for animal feed. Finally, a meat virtual water trade (VWT) network of is constructed between 1988 and 2016. Virtual water outflow is four to eight orders of magnitude larger than inflow from 1998 to 2003, when outflow drops significantly, and the direction of flow completely reverses. In fact, in 2011 the LMB countries' virtual water inflow reached similar values to that of past outflow (1998-2003). The abrupt virtual water flow change opens the door for a water savings analysis, where local and international production of meat is discussed to reach greater regional water savings (RWS) (i.e., minimizing water footprint)."--Page ii.