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

Alfonso Expósito,Julio Berbel

doi:10.3390/w9020136

Alfonso Expósito, Julio Berbel

Open Access

https://doi.org/10.3390/w9020136

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Journal: Water	Publication Date: Feb 20, 2017
Citations: 55	License type: CC BY 4.0

Affiliation: Universidad de Sevilla, University of Córdoba

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 (1989–2005), 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 (2005–2012) 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.

Highlights

Irrigated agriculture occupies about 15% of the total cultivated area in Spain but is responsible for60% of the total value of agricultural production; the average production per hectare of irrigated crops is 6.5 times greater than that of rain-fed agriculture
We have focused on water abstraction and irrigation rights as the variable that is determined by the water authority, and propose standard performance measures estimated as the ratio of gross value added (GVA) of irrigated area minus GVA of rain-fed area divided by irrigation water use
Since 2005, the main policy measure used in the Guadalquivir river basin (RB) has been aimed at modernising irrigated agriculture through the use of water-saving and conservation technologies (WCTs)

Summary

Introduction

Irrigated agriculture occupies about 15% of the total cultivated area in Spain but is responsible for60% of the total value of agricultural production; the average production per hectare of irrigated crops is 6.5 times greater than that of rain-fed agriculture. Farmers must adapt to water scarcity and a continued decline in farm incomes (falling 1.1% annually since the beginning of the 90s, according to Spanish Ministry of Agriculture and Environment (MARM) [1], which attributes this decrease to the increasing cost of inputs and lower commodity prices), and they have reacted by prioritising crops with greater value added per hectare and higher productivity per water input. Farmers facing growing resource scarcity and increasing water costs have responded by using the resource more efficiently; significant investments (public and private) have been made over the last decades to improve water-use efficiency as part of an initiative to modernise irrigated areas in southern Spain.

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Conclusion