Drought planning and management in the IP is framed under EU common water policy requirements (WFD) and specific policy option recommendations on WS&D. Although the spatial variability of droughts in the IP is significant, homogenous regions with similar temporal variability of droughts can be identified. As noted earlier, drought planning and management in the IP is mostly dependent on cooperation between Portugal and Spain, as the two countries five shared river basins area corresponds to 45 percent of IP territory. The required drought policy harmonization shall be in line with existing river basin management bilateral agreements. Although the two countries have been cooperating and working toward a declared joint management of the shared RBDs, they are currently at different stages concerning drought planning and management, with no agreement on a common or coordinated drought management framework.
In fact, Spain's drought management policy is based on a more proactive and planned approach whereas Portugal's drought policy still reflects a crisis management approach, with no DMP approved yet. In order to definitively shift to an effective and anticipated (since 2012) drought proactive management, Portugal will likely need to redefine the operational institutional framework for drought management (involving institutions that are currently under different ministries than in 2012) and the role of and/or coordination with the National Water Authority. It is also aimed and expected that both countries will contribute to and/or foster best practices on drought
Temporal evolution of the index of status and alert levels on Douro river basin considering (a) precipitation indicators established in the Albufeira Convention and (b) global operational indicators of the river basin. (Adapted from CHD, Actualizacion del Plan Especial de Sequias (Drought Management Plan Actualization), Anejo 13.1 del Plan Hidrologico de la Parte Espanola de la Demarcacion Hidrografica del Duero (2015-2021), 2016.) management policy (WMO 2012) framed on EU and regional bilateral agreements, as follows:
- • The implementation of effective drought monitoring and early warning systems, to anticipate and predict drought occurrence
- • The promotion of standard and common approaches in drought planning and management aimed at coordinated and possible joint drought planning and management of the shared RBDs, under the frame of the WFD and of the Albufeira Convention
- • The development of a sound common indicators system
In addition, although the current drought management measures have contributed to reduced vulnerability and impacts in agriculture and livestock sectors, and improved water management during critical drought periods, it is necessary to reinforce DMPs and indicators corresponding to environmental droughts. Environmental drought impacts have grown in the IP over the past two decades, in association with climatic warming processes over the entire Mediterranean. Droughts have affected forest growth and caused forest decline in large areas (Camarero et al. 2015; Carnicer et al. 2011) and contributed to land degradation processes (Vicente-Serrano et al. 2012). Nevertheless, the development of environmental drought indicators is difficult since the drought resistance and resilience of forests depends on the forest type and is also a function of the climate aridity conditions (Pasho et al. 2011), and further research and development on these relationships is necessary.