The role of agriculture and climate change in the region
Intensive agriculture in the province of Almería together with the tourism are key for the regional economy, but their sustainability is being questioned due to the depletion of water resources and the increase of the impacts of climate change. Intensive agriculture in Almería is characterized by cultivation in greenhouses, which cover large areas of land. These greenhouses allow for the production of a wide variety of crops throughout the year getting several harvests a year. However, this agricultural model requires large amounts of water for irrigation, leading to unsustainable use of water resources.
In parallel, Almería is experiencing the impacts of climate change, including the increased variability in precipitation patterns and rising temperatures. These climate changes affect the water availability negatively. Future climate data anticipates a climate where droughts are expected to become more frequent and more widespread in the region with the consequent effects on the water availability as well as on the population. This projected increase of water stress due to climate change exacerbates the water scarcity situation in an economy highly dependent on the water resources. It is necessary to highlight that impacts on water resources due by climate change can be exacerbated when occurring in regions already presenting low water resource levels and frequent droughts, and that are subject to imbalances between water demands and availability of resources [1] as occurs in the case of Almería.
Aquifers are being overexploited, precipitation is reduced, and surface and groundwater resources are being depleted. This water scarcity not only affects the agricultural production but also the availability of water for domestic use and other economic sectors such as tourism. In this context of water scarcity, the installation of rainwater harvesting (RWH) systems for use in agricultural holdings can contribute to mitigate this problem although it is not a very widespread practice today [2].
Solutions and tools addressing the water challenge
To address the challenges of water scarcity due to the effects of climate change in the province of Almería, RethinkAction is developing a local integrated assessment model to evaluate the implications of land use as a driver to guide the implementation of land use-based adaptation and mitigation solutions. The water module included in the local system dynamics models will help to understand the current and future patterns of water consumption and could be used as a tool to take better decisions about resource management in the province. Based on the Almería case study, the module includes water cycle variables such as:
- Water availability in the region, including surface, storage and groundwater data.
- Water storage and water available for hydropower use (depending on the water availability in the region at the time).
- Current and future patterns (up to 2100) of precipitation and evaporation by different climate scenarios.
- Water consumption based on economic sectors (industry, services, urban…)
- Water consumption based on the type of crop and area it covers, as not all crops and production systems consume the same amount of water per hectare. In this way, if the cropping pattern changes, it will be possible to see the impact it has on the water use.
- Water storage by desalination. This process supplies in the case of Almería, a total of 250,000 citizens with potable water and irrigates 4,600 hectares of crops. The Campo de Dalias desalination plant can produce a total of 30 Hm3/year [3]. By the end of this year, the Mar de Arborán desalination plant I scheduled to be operational, with an estimated annual production capacity of 20Hm3 per year [4].
- Water available by transferring water from other rivers of Spain to the region when water is scarce. The Tajo – Segura water transfer is the most relevant in the region, with an annual capacity of 600 hm3, from the Tajo river basin to the Southeast of Spain [5].
The figure shows how the model is fed by exogenous variables like precipitation and evaporation (dependent on the regional climate and on future climate scenarios) and endogenous variables like desalination and water transfers (that depend on human manipulation to increase the availability of water resources in the region). These water resources are consumed according to the demand of the population, and economic drivers: industry, the tertiary sector (including tourism), agriculture (food sector, including food production) and hydropower production as long as the population is supplied. Based on the aforementioned variables, an evaluation of the surface, storage and groundwater resources could be obtained. This way, and by analysing their behaviour, adaptation and mitigation measures can be implemented.
Thanks to these local integrated assessment models, the RethinkAction project is developing an Integrated Assessment Platform where the users will have the opportunity to select the case study and deploy different analysis for the implementation of water resources management strategies based on land use, promote the sustainable use of water and the adoption of adaptation and mitigation measures to fight against climate change effects. A collaborative approach involving relevant stakeholders is necessary to effectively address the identified challenges and ensure a platform tailored to the real needs of the end users.
References [1] Estrela, T; Pérez-Martin, M.A.; Vargas, E. (2012). Impacts of climate change on water resources in Spain, Hydrological Sciences Journal, 57:6, 1154-1167, DOI: 10.1080/02626667.2012.702213
[2] López-Felices, B.; Velasco-Muñoz, J.F.; Aznar-Sánchez, J.A.; Román-Sánchez, J.M. (2023). AQUA - Water Infrastructure, Ecosystems & Society, 72 (2): 185–201. https://doi.org/10.2166/aqua.2023.205
[3] Water Technology. (2022). Bajo Almanzora Desalination Plant, Almeria. https://www.water-technology.net/
[4] iAgua. (2023). La desaladora Mar de Alborán, una nueva alternativa a la creciente demanda de agua en Almería. https://www.iagua.es/
[5] Ministerio para la Transición Ecológica y el Reto Demográfico. (n.d). Trasvase Tajo-Segura. https://www.miteco.gob.es/es/agua/temas/concesiones-y-autorizaciones/trasvase-tajo-segura.html