Agricultural Irrigation Water Use in a Closed Basin and the Impacts on Water Productivity: The Case of the Guadalquivir River Basin (Southern Spain)

Abstract

This paper analyses the agricultural irrigation water use in a closed basin and the impacts on water productivity, and examines how they have affected the 'closure' process of the Guadalquivir river basin observed in recent decades. Following a period of expansion in irrigation, an administrative moratorium was declared on new irrigated areas in 2005. Since then, the main policy measure has been aimed at the modernisation of irrigated agriculture and the implementation of water conservation technologies. The analysis carried out in this paper shows a significant increase in mean irrigation water productivity in the pre-moratorium period (1989)(1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005), driven by the creation of new irrigated areas devoted to high value crops and with a dominant use of deficit irrigation strategies, while a second phase (2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012) is characterised by slower growth in terms of the mean productivity of irrigation water, primarily as a result of a significant reduction in water use per area. Findings show that productivity gains seem to have reached a ceiling in this river basin, since technological innovations (such as new crops, deficit irrigation, and water-saving and conservation technologies) have reached the limits of their capacity to create new value.

Sustainability Implications of Deficit Irrigation in a Mature Water Economy: A Case Study in Southern Spain

“…The process whereby water resource development and use come to exceed available resources has been observed in many parts of the world and has been widely documented in the literature [12][13][14]. According to Randall [1], a water economy enters a 'mature phase' when the following characteristics occur: (1) inelastic water supply with increasing marginal supply costs (aquifers are already heavily exploited, the best dam locations have been taken and other rivers are protected); (2) high and growing demand (with increasing conflicts among water users); (3) an aging infrastructure which requires expensive renovation; (4) increasing negative externalities; and (5) a rising social cost of subsidising water use.…”

The Economic Analysis of Water Use in the Water Framework Directive Based on the System of Environmental-Economic Accounting for Water: A Case Study of the Guadalquivir River Basin

“…Carrasco et al [49] studied changes in irrigated crop water productivity for the Guadalquivir basin between 1989 and 2005 using statistical data at a regional and crop level, indicating that the irrigated crop water productivity was (in 2005 prices) 0.12 EUR/m 3 in 1989 and increased to 0.50 EUR/m 3 for 2005 (9% annual growth). Exposito and Berbel [50] continue this analysis finding that irrigation water productivity in the basin has stagnated between 2005 and 2012. Berbel et al [51] also studied water productivity ratios, producing a similar figure for 2005.…”

Cost-Benefit Analysis of the Managed Aquifer Recharge System for Irrigation under Climate Change Conditions in Southern Spain

“…According to Almansa and Martínez-Paz [35], the most favourable profitability from an economic and social point of view would be one that takes into account the environmental benefits, as the WDF establishes. Perhaps the decline in the irrigation area, along with recent public and private investments in irrigation modernization to improve water efficiency, will help mitigate the effects of drought and climate change and ensure environmental sustainability [52]. In order not to affect the benefits of agricultural crop production, the scenario of an artificial recharge with future demand equal to the current one could be the most feasible solution in any of the emission scenarios that occur (i.e., SC2-RCP4.5-0 or SC2-RCP8.5-0), because the values of NPV and IRR are very similar.…”