Timely information to the agricultural sector
Pedro, 34 years old, is an agricultural engineer working for an irrigators association in the Segura river basin, Murcia (Spain), a drought prone Mediterranean river basin. Droughts are periods with a temporary decrease of the average water availability. Rainfall deficiency is the main trigger of a drought period but the severity, duration and intensity of a drought depends on how it is managed and how it propagates to the hydrological and agricultural productive system.
The challenge for Pedro
A major threat to the agricultural sector in Europe is an increased occurrence of droughts, affecting the local and regional food security and economies. The agricultural sector needs timely information on droughts to anticipate and take mitigation or emergency actions to reduce associated impacts (socio-economical, environmental, etc.).
Part of the water demand of the Segura basin is met with water from the Upper Tagus basin in Central Spain through a channel infrastructure of about 300 km long (see Fig. 1). This Tajo-Segura Water Transfer (TSWT), which connects the Upper Tagus basin with the Upper Segura basin, provides more than one-third of the total water demand for irrigation from the upper Tagus river basin – in total about 80,000 ha. Pedro’s organisation is a consortium of irrigation associations, located in Alicante and Murcia, as well as the eastern part of Almeria, that rely fully or partly on the Tajo-Segura water transfer.
The main mission of Pedro’s organisation is to ensure water transfers for the member irrigation associations. The organisation also allocates the available water among its members and collects the water fees for this. These allocation decisions influence not only the planning of the cropping season but also the implementation of mitigation or emergency measures during drought periods, such as the use of alternative sources as groundwater emergency wells or desalinated water.
The decisions on the amount of water to be transferred from the TSWT basin take place periodically, depending on the water availability in the two storage reservoirs located in Buendía and Entrepeñas (Upper Tagus). The water transfer decisions depend on the reservoir inflow for the forthcoming months. Currently, there is an established procedure that allows for Pedro to foresee up to six months of inflows to the upper Tagus storage reservoirs, on the basis of statistical forecasts based on river discharge from preceding months. Pedro’s main duty is to then process those estimations and provide decision-makers with the most accurate available information, so the best decisions can be taken.
Obviously, agriculture production depends on water availability and a lack of irrigation water can have multiple impacts. For example, the drought period of 1990 – 1995 led to production losses in the Segura river basin amounting to 120 million euros. This period also led to an 11-19% reduction of production and a 14% reduction of irrigated areas compared to the average. This reflects the direct economic effects of long-lasting drought periods in the region, but of the same significance are the effects on other socio-economic factors, in particular direct employment as well as induced employment in other sectors. Likewise, environmental issues arise, such as the overexploitation of groundwater aquifers.
Solving the challenge with IMPREX
Pedro’s goal is to optimise decision-making by providing more reliable information to the steering committee of the irrigators association, who create and put into practice, decisions for better management of water resources. Model-based seasonal hydrologic forecasting (CM-SHF) systems, such as the solutions being explored within IMPREX, can provide enhanced forecasts that reduce the uncertainty of water availability.
Reliability on climate services has great potential to increase if such products are proven to demonstrate better skill than our current practices. People like Pedro are anticipating the uptake of these technologies as their work would be made more effective if they had easier access to more reliable information. This would also translate into better management and planning of resources, leading to economic profits from increased agricultural productivity and related employment, better informed decisions on water transfers and more adequate mitigation or emergency actions, as well as environmental benefits from the sustainable use of groundwater resources.