Department Systems Analysis, Integrated Assessment and Modelling

Modeling the water-food-environment-trade nexus in the context of agricultural intensification

With continuing population growth, increasing affluence and economic development, and diet change towards more meat consumption, the demand for food will also increase. Given that only very limited expansion of crop land is possible in most parts of the world, agricultural intensification on the existing crop land will play the main role in providing additional capacity to meet this demand. This also means that more water will be used for irrigation and that there will be higher risks of environmental impacts and soil degradation, e.g., water scarcity (WS), soil organic carbon losses (SOCL), and nutrient losses (NL). Food is not only produced for local consumption, but also traded in large quantity internationally. The trade of food induces virtual water flows and environmental externality. 

This project aims to advance the understanding of the water-food-environment-trade nexus on the global scale. The concrete tasks include:

  1. apply a Python-based EPIC (PEPIC) model for simulating global crop growth related processes and investigate the impacts of different evapotranspiration (ET) calculation algorithms on Y and ET estimation;
  2. assess global-scale environmental impacts of crop production using the PEPIC model and identify hotspots of these impacts on the scale of river basins;
  3. investigate the potential impacts of agricultural intensification on Y, CWP, SOCL and NL in the context of  irrigation area expansion and different fertilizer application strategies with reference to the projected future food demand across the world;
  4. assess the positive and negative environmental externalities of international food trade with respect to the water-food-environment-trade nexus. We focus on the trade between China and its major trading partners because of China’s important role in the international food market.

The results of this project are expected to provide useful information for water and land resources management to meet the increasing demand for food while mitigating environmental impacts.


Liu, W.F., Yang, H., Folberth, C., Wang, X.Y., Luo, Q.Y., Schulin, R., Global investigation of impacts of PET methods on crop-water relation of maize. Agricultural and Forest Meteorology (in review).

Liu, W.F., Yang, H., Liu, J.G., Azevedo, L, Wang, X.Y., Folberth, C.,  Balkovič, J., Skalský, R., Schulin, R., Global concentrated nitrogen losses in major crop fields. To be submitted to ES&T.