3 Renewable water resources under the changing climate

Key messages

Overall, annual renewable freshwater resources per capita is above 1 700 m3 in EaP countries (no data available for Ukraine) indicating no actual water stress. However, due to irrigation practices and high water losses in the conveyance systems, Armenia and Azerbaijan face severe water-scarcity conditions.

In absolute terms, the available data indicate that renewable freshwater resources in Azerbaijan fell by 27 % between 2000-2017, whereas renewable freshwater increased in Armenia, Belarus, Georgia and Moldova. Further analyses are needed to justify this mixed trend across EaP countries.

Available studies suggest prolonged droughts in summer seasons are associated with increasing water stress conditions in EaP countries in the near future.

Changing natural hydrological conditions associated with greater socio-economic demand for water may exacerbate competition and tensions between upstream and downstream water users in the region. Strengthening monitoring programmes, regionally harmonised data and effective exchange of data and information at the regional level may facilitate informed policy dialogue among EaP countries.

Water is a cross-cutting area in the context of climate change impacts. There is growing evidence that climatic changes in recent decades have already affected the global hydrological cycle, for example, through changes in seasonal river flows (EEA, 2017). In addition, human and economic activities exacerbate the impacts of climate change, and climate change poses an additional threat to the flow regime of water ecosystems (EEA, 2012a). According to projections, annual average land temperature across Europe will rise in the range of 1.0 °C to 4.5 °C by the end of this century (2071-2100 compared to 1971-2000) (EEA, 2019). Projections indicate that water availability will continue to decline, particularly in southern Europe, under the scenario of 1.5-2 oC global warming according to pre-industrial levels (Bisselink et al., 2020).

According to recent assessments, the soil-moisture conditions in the Dinester Basin might change because of rising temperatures, especially in the winter months. This trend would be associated with increasing temporal variations of drought and heavy precipitation at the seasonal scale (Krakovskaya et al., 2012).

Available studies indicate rising precipitation and humidity in the highlands of the Caucasus, whereas the frequency and magnitude of drought and warmer summers in the lowlands, such as southern Armenia, central Azerbaijan and eastern Georgia, are increasing (Rucevska, 2017; Elizbarashvili et al., 2017; Toropov et al., 2019). This trend will be exacerbated by the drastic melting of glaciers in the Caucasus due to rising temperatures, thereby causing a reduction in the area of glaciation of up to 0.69 % per year (Toropov et al., 2019).

The EU's recent policy initiative, the European Green Deal, addresses climate change and water stress in the context of moving to a circular economy and becoming climate neutral (EC, 2019b). It should be underlined that the EU Water Diplomacy initiative promotes sustainable and IWRM as a response to climate change adaptation and resilience of the environment (EC, 2018).

Renewable water resources are generated and replenished by precipitation and the inflow of surface and groundwater from neighbouring countries throughout the hydrological year. Net precipitation (internal flow as the difference between precipitation and actual evapotranspiration) replenishes surface run-off to rivers, lakes and recharge groundwater aquifers. Surface waters and groundwater flowing from neighbouring countries (external inflow or inflow from upstream countries) is an important part of renewable water resources (UNECE, 2020a).