Luca Giraldo

An Integrated Assessment of the Impacts of Changing Climate Variability on Agricultural Productivity and Profitability in an Irrigated Mediterranean Catchment

Climate change is likely to have a profound effect on many agricultural variables, although the extent of its influence will vary over the course of the annual farm management cycle. Consequently, the effect of different and interconnected physical, technical and economic factors must be modeled in order to estimate the effects of climate change on agricultural productivity. Such modeling commonly makes use of indicators that summarize the among environmental factors that are considered when farmers plan their activities. This study uses net evapotranspiration (ETN), estimated using EPIC, as a proxy index for the physical factors considered by farmers when managing irrigation. Recent trends suggest that the probability distribution function of ETN may continue to change in the near future due to changes in the irrigation needs of crops. Also, water availability may continue to vary due to changes in the rainfall regime. The impacts of the uncertainties related to these changes on costs are evaluated using a Discrete Stochastic Programming model representing an irrigable Mediterranean area where limited water is supplied from a reservoir. In this context, adaptation to climate change can be best supported by improvements to the collective irrigation systems, rather than by measures aimed at individual farms such as those contained within the rural development policy.

The Cost of Irrigation Water Delivery: An Attempt to Reconcile the Concepts of Cost and Efficiency

This work discusses the conflict between two of the main objectives of the EU Water Framework Directive: cost recovery and economic efficiency in the use of irrigation water. In the Mediterranean region, this conflict is commonly embedded in a state of under-utilization of irrigation networks managed by Water User Associations (WUAs). This under-utilization arises from factors independent of farmers’ choice, such as water shortage, crises in the sector, and changes to the Common Agricultural Policy. This prevents the facilities from operating at the minimum average cost. This paper argues that farmers should not suffer this inefficiency, which results in them paying higher water prices to cover the costs of water supply. Indeed, the application of the Water Directive should be rethought, taking into account the specific problems related to irrigation in the Mediterranean region. Based on an econometric analysis of the costs of water distribution in a WUA in Sardinia (Italy), we propose a payment system based on two components. Primarily there is a fee related to the number of hectares under irrigation. In addition there is a fee that considers the intensity of irrigation: this component is to encourage farmers to save water. The results show that the proposed approach has some desirable effects, including higher rates of cost recovery and possibly a reduction in the use of groundwater. Finally, the proposed system is not overly expensive for the rest of the community, who must bear the costs of inefficiencies in the use of irrigation water that do not depend on choices of farmers.

Irrigation Water: Alternative Pricing Schemes Under Uncertain Climatic Conditions

The European Water Framework Directive (European Union, 2000; herein, WFD) aims to protect the environmental quality of water and encourage its efficient use. The EU member states are required to implement effective water-management systems and appropriate pricing methods that ensure the adequate recovery of water costs. These directive also relates to the pricing of water for agriculture. However, a general framework specific methodologies used by each country to establish water tariffs is not yet available.

Assessing the economic and productive impact of climate change in a Mediterranean irrigated agricultural area subject to water shortage

Climate changes in agriculture act on various climate variables (precipitation, temperature etc.) at different times of crop cycles. Many physical and technical relationships have to be represented even when analyzing a limited aspect of farm management. This work employs the net evapotranspiration (ETN) estimated with the EPIC model, as a synthetic index of the physical factors that the farmer considers in decisions on irrigation. The probability distribution of ETN is inserted into a territorial model of DSP that represents farm choices in conditions of uncertainty about water availability and irrigation requirements of crops. Recent trends of ETN suggest that the probability distribution of this variable may appreciably change in the near future. Also, water availabil- ity may become more variable due to changed rainfall. These modifications amplify uncertainty of management and, consequently, costs incurred by the farm typologies of the study area, which in many cases suffer an appreciable drop in income.

The coverage of the costs of providing water in agriculture and their variation during the irrigation season

The pricing of many public services varies with the change of use, often even during the day, as the level of cost is influenced by the timing of the activity. This linkage also comes out for the water provision operated by an irrigation Consortium in typical Mediterranean conditions. The relationship is verified by estimating a translog cost function of the water supply, which includes the standard Gini index for indicating whether the water provision is concentrated in a few months, or is distributed throughout the year. The results, which depend on the general condition of under-utilization of the water distribution structures, show that average costs are lowered when the irrigation activity, and water supply, is concentrated in time. This suggests changing the pricing for the irrigation service by increasing the payments outside the peak demand periods. This differentiation is related to the effects of management choices of the farms, which influence the timing of irrigation and, therefore, of the water provision. In this way, it would be consistent to the guidelines of the WFD (2000/60), which calls for attributing the costs to those who actually determine them.

Water distribution costs in the farm sector: an attempt to reconcile the concepts of cost and efficiency

The EU Water Framework Directive (WFD) copes with several problems related to the costs of water services, the protection of water and its efficient management. This paper focuses on some inconsistencies that may arise between the objectives of protecting the resource and of covering the costs of water services, and between the goal of full recovery of the costs and the efficiency in the use of water. This paper proposes a scheme for payment of irrigation water that does not ask farmers to pay for some of the inefficiencies arising in the water distribution service. These inefficiencies can be generated in the systems managed by Water Users Associations as a result of underutilization of the facilities. This payment scheme also provides an element that varies depending on the levels of water use. Thus, it encourages farmers to assess the effect of their production decisions on the costs of water distribution. The analysis applies this scheme to the case of an Italian Water User Association. This has been done taking into account the operational costs of the irrigation supply by means of an estimated translog cost function which is articulated according to the technological characteristics of the water distribution system.