Accountability and Transparency through Water-Energy-Food Nexus Accounting in Central Asia

In Central Asia, more than 90 % of annually renewable water resources are consumptively utilized in irrigation, and allocation conflicts between large-scale hydropower in the upstream and irrigation in the downstream occur regularly and mostly across complex international borders, especially during water scarce years and low storage conditions. With increasing attention on climate-neutral hydropower solutions, including on small-scale hydropower
(< 10MW), the water-energy-food-environment nexus is now under renewed focus in the region. In line with these developments, new nexus tradeoffs emerge that need to be yet acknowledged and quantified, also under the considering of a changing climate.

As part of the ongoing EU Horizon 2020 Project Hydro4U that demonstrates innovative and sustainable hydropower solutions targeting the unexplored small-scale hydropower potential in Central Asia, a new online nexus toolbox with an innovative monitoring and accounting methodology is developed. It assimilates data from different sources, including from remote sensing and through local monitoring, to monitor and predict water availability and energy production in the mountainous zones of runoff formation and irrigation water use in the downstream. Target user groups are Basin Irrigation System Administrations, private and public energy stakeholders, and Ministry of Water representatives in the two demonstration sites where small-scale hydropower plants are built as part of the project.

Irrigation water use is monitored using an innovative unsupervised machine learning technique for mapping crop-disaggregated irrigated areas at the catchment scale. State-of-the-art datasets on evapotranspiration and biomass production are used for the detailed analysis of crop water demands and irrigation efficiencies in conjunction with local scheme-level water use where available. All processing steps were implemented in Google Earth Engine (GEE), enabling to process large amounts of irrigated crop statistics at a high spatial resolution for the entire semi-arid Central Asia region, including Afghanistan.

In relation to water availability and renewable energy, hydropower production at the demonstration sites is modeled using hydrological modeling using the HBV model. Discharge is forecast at decadal (10-days) to monthly time scales using data from the NOAA NCEI Global Forecasting System product and information on the development of the catchment scale snow cover from the MODIS Snow Cover Daily Global 500m product in the zones of runoff formation.

The nexus toolbox is a web-based tool that can deliver unique and objective data and intelligence to local stakeholders and decision-makers, off-farm and on-farm alike. The advantage of such technology is that no local infrastructure, beyond a computer connected to the internet, is required to access these types of data and intelligence relevant for irrigation improvements is required. The software can be specifically tailored (through an iterative co-design approach) to the needs and wants of stakeholders at all levels, from farmers to Water User Associations on the consumer side and from service providers at district, Province, and National levels. It will also contribute to designing climate-proofed benefits sharing regimes considering uncertainties explicitly to ensure optimal and fair resource use and distribution across the different domains and countries and, therefore, contributing to regional cooperation and peace.