Water Scarcity in the Serbian Danube: Agricultural Land Use Change and Irrigation

Climate change is driving water scarcity in the Middle and Lower Danube River Basins. As growing season precipitation decreases and becomes more unpredictable, farmers have difficult decisions to make. They can invest in irrigation to sustain yields or transition to less water-intensive crops. Water exploitation will exacerbate scarcity, and could result in a race to the bottom for irrigation access. In Serbia, this process plays out across 630,000 farms that employ 21% of the working population. Meanwhile, thirty years removed from the breakup of Yugoslavia and subsequent regional conflict, Serbia is negotiating accession into the European Union (EU). Their integration into the EU single market is increasing agricultural exports and altering domestic agricultural policy. The interactions of market integration, climate change, and increasing water scarcity are uncertain, but they are drivers of agricultural land use change in the region, and understanding the feedback between them is critical.

The goal of this proposed research is to quantify how climate, water scarcity, and changing markets drive farmer decision-making and resulting land use change. The specific objectives are to: (1) map annual cropland and crop water use (2) estimate water availability and exploitation as a function of agricultural use (irrigation) and green and blue water, (3) identify mechanisms driving agricultural change with conditional crop choice and irrigation investment models, and (4) identify potential alternative futures of agricultural land use and water scarcity in response to climate and market shifts. We will link remote sensing of cropland, irrigated extent, and evapotranspiration from 1990-2019 to socioeconomic and hydrological models. The core remote sensing assets we will use are Landsat Collection 1 supplemented with Sentinel-1, 2, and MODIS. Annual cropland and crop water use maps will be created using deep learning (Objective 1). Remotely-sensed products will be coupled with climatic data to feed a hydrological/crop model to quantify water exploitation, availability, and provisioning of green and blue water (Objective 2). Crop maps, water availability, and commodity prices will inform the conditional crop choice and irrigation adoption socioeconomic models to identify the drivers of agricultural land use change (Objective 3). Finally, the models developed in Objective 3 and Objective 4 will be forced with climate change and commodity price scenarios (Objective 4).

This research fulfills the NASA LCLUC program goals by linking socioeconomic factors (farmer choices, market access, and prices) and climate change/water scarcity to land use change. In addition, it supports multiple LCLUC Program Science Themes: Food Security, Water and Energy Cycle Impacts, and Climate Variability and Change. By focusing on Serbia, we will integrate into the NASA GOFC-GOLD South, Central and East European Regional Information Network (SCERIN).