José Luis García-Aróstegui

Groundwater intensive use and mining in south-eastern peninsular Spain: Hydrogeological, economic and social aspects

Intensive groundwater development is a common circumstance in semiarid and arid areas. Often abstraction exceeds recharge, thus continuously depleting reserves. There is groundwater mining when the recovery of aquifer reserves needs more than 50years. The MASE project has been carried out to compile what is known about Spain and specifically about the south-eastern Iberian Peninsula and the Canary Islands. The objective was the synthetic analysis of available data on the hydrological, economic, managerial, social, and ethical aspects of groundwater mining. Since the mid-20th century, intensive use of groundwater in south-eastern Spain allowed extending and securing the areas with traditional surface water irrigation of cash crops and their extension to former dry lands, taking advantage of good soils and climate. This fostered a huge economic and social development. Intensive agriculture is a main activity, although tourism plays currently an increasing economic role in the coasts. Many aquifers are relatively high yielding small carbonate units where the total groundwater level drawdown may currently exceed 300m. Groundwater storage depletion is estimated about 15km(3). This volume is close to the total contribution of the Tagus-Segura water transfer, but without large investments paid for with public funds. Seawater desalination complements urban supply and part of cash crop cultivation. Reclaimed urban waste water is used for irrigation. Groundwater mining produces benefits but associated to sometimes serious economic, administrative, legal and environmental problems. The use of an exhaustible vital resource raises ethical concerns. It cannot continue under the current legal conditions. A progressive change of water use paradigm is the way out, but this is not in the mind of most water managers and politicians. The positive and negative results observed in south-eastern Spain may help to analyse other areas under similar hydrogeological conditions in a less advanced stage of water use evolution.

Object-Oriented Bayesian Networks for Participatory Water Management: Two Case Studies in Spain

Object-oriented Bayesian networks (OOBNs) have recently been introduced to model water systems that can be represented as repetitive patterns. This paper shows the way in which OOBNs can be used as a groundwater management decision support system in two Spanish case studies. The two areas, in the southern and eastern parts of inland Spain, are characterized by a semiarid climate, water scarcity, and frequent droughts; consequently, the agrarian economy in both cases depends on the provision of irrigation from groundwater sources. Both case studies are illustrative examples of conflict among various water actors, complexity, and uncertainty about the consequences of water management actions. Each study is approached from a different viewpoint: one from an agroeconomic and the other from a hydrogeological perspective. The sites display different degrees of aquifer overexploitation and agrarian profitability. This indicates that, in each case, the effects generated by water management interventions and the t...

Object-Oriented Modelling as a Decision-Making Tool in Agriculturally Overexploited Karstic Aquifers

Object-Oriented Bayesian Networks (OOBNs) utilise the power of Object-Oriented Programming (OOP) and offer a novel approach to the problems of integrated water management. This paper describes the building of an OOBN Decision Support System (DSS) that allows complex domains to be described in terms of inter-related objects. Thus, the DSS structure is able to represent an accurate reflection of a complex real-world water system made for an aquifer that has been used as an example of a successful application. In this research, conventional Bayesian Networks (BNs) are used to describe the probabilistic relationships between variables (objects) within each network. A network is a group of objects that can be described as a class. Different classes can possess similar sets of objects and be linked through other networks having common variables. Classes inherit commonly used states and behavior from other classes in a hierarchical way. This model of networks represents a participatory DSS for helping water managers.