Irrigation water use efficiency in collective irrigated schemes of Tunisia: determinants and potential irrigation cost reduction

This study aims first to measure the farm specific irrigation water use efficiency (IWUE), through non parametric DEA model; and second to evaluate the potential irrigation cost reductions and identify the main factors causing variations in IWUE among the sample farms. Cross sectional data collected from a sample of 75 farms participating in the WaDImena project in Nadhour region (northern Tunisia) was used for this aim. The results showed that the average level of IWUE across the farm sample was around 61.2% under variable returns to scale (VRS) assumption. However, the estimated mean irrigation water technical cost efficiency (ITCE) is much higher than IWUE. Farmers would be able to reduce their actual cost by 5% under VRS by adjusting irrigation water to its efficient level. This low level of cost reductions is consistent with the existing literature about IWUE in Tunisia. Moreover, education level of farmers, access to credit and agricultural extension service showed a positive relationship with the IWUE in our case study.Resource /Energy Economics and Policy,

Measuring factor substitution and technological change in the Tunisian agricultural sector, 1971 - 2000

The production structure of Tunisian agriculture over the last three decades is investigated using a translog variable cost function. Standard results of neoclassical duality theory are used to obtain measures of elasticities of substitution between inputs, price elasticities of factor demands and the rate of growth and bias of technological progress. Empirical results obtained from the joint estimation of parameters of the cost and share equations indicate an increasing trend in the degree of substitutability between labour and intermediate inputs. The own-price elasticities of labour and intermediate inputs are inelastic. While the labour price elasticity of demand has increased over time, the intermediate input price elasticity of demand has declined. Finally, technological progress occurred at an impressive and sustained annual growth rate of 3.8 percent.Factor substitution, technological change, Tunisian agriculture, Research and Development/Tech Change/Emerging Technologies,

Irrigation water pricing between governmental policies and farmers’ perception: Implications for green-houses horticultural production in Teboulba (Tunisia)

A positive mathematical programming model was constructed in this study to assess the effect of three water pricing scenarios on Teboulba’s agricultural production systems. The effects of these scenarios were estimated for three groups of farmers from three irrigated districts. Results show that water demand in group 1 remains inelastic until achieving the price of 0.20 TD. A price above this level decreases water consumption, farmer’s incomes as well as seasonal labor demand. For groups 2 and 3, the water demand curves remain highly inelastic even with a full cost recovery price. However, once reaching this last price, the model shows important income reductions reaching 20% of the current observed income. Moreover, a pricing policy aiming to recover operational and maintenance costs and which will be implemented independently from other economic, social and environmental measures can threaten the sustainability of the production systems in the region.Water pricing, positive mathematical programming, greenhouses, economic impact, Teboulba, Environmental Economics and Policy, Farm Management, Resource /Energy Economics and Policy, Q15, Q18,

Factors affecting farmers’ willingness to adopt salt-tolerant forage crops in south-eastern Tunisia

This paper analyzed the factors that affect farmers’ willingness to adopt salt-tolerant forage for livestock, using a Tobit model. The data used for the empirical analysis was obtained from a survey of 97 farmers in southeastern Tunisia. The results of this study show that variables related to age, education level, the salinity level of water and membership in a farmers’ association do not significantly influence the degree to which salt-tolerant forage production is adopted. It did, however, find a positive relationship between off-farm income availability and adoption. In addition, the flock size variable, expressed in Standard Livestock Units, has a significant and positive relationship with adoption. This indicates farmers’ need to cover their forage deficit. Agricultural extension services should ensure that the requisite forage species are made available, and work with farmers to encourage them to adopt salt-tolerant forage species and pass on their knowledge to other farmers.Farmers’ willingness to adopt, Salt-tolerant forage, Tobit model, Tunisia, Crop Production/Industries,

Effect of changes in the institutional structure of irrigation water property rights on the willingness to pay of farmers for water: case of Tunisia

This paper assesses the economic value of changes in the attributes of farmers’ irrigation water property rights in Tunisia. Changes on attributes generated by the transfer process of the property rights from the collective to the individual level in addition to changes in “constitutional” attributes were integrated into three scenarios. The valuation was conducted using the Contingent Valuation Method through the elicitation of individuals’ willingness to pay. Results show positive willingness to pay values for all scenarios. However, farmers of the studied region are shown willing to pay more for changes in the constitutional attributes. Furthermore their willingness to pay appears to be most affected by their perceptions concerning the organization and the functioning of the water users’ association to which they belong and by their productivity.Property rights, irrigation water, Contingent Valuation, Resource /Energy Economics and Policy,

PERFORMANCES AND EFFICIENCIES OF THE IRRIGATION WATER USERS’ ASSOCIATIONS IN TUNISIA

This article analyzes the efficiency of Water Users Associations (WUA) in the Cap Bon region (Tunisia) and studies its main determinants. The analysis is performed in two stages. First, the efficiency is measured via the nonparametric “Data Envelopment Analysis” (DEA) technique. The DEA models are constructed not only to assess the overall WUA efficiency but also to evaluate the management and engineering sub-vectors efficiencies separately through a mathematical modification in the initial DEA model. In a second stage critical determinants of efficiency are determined using a Tobit model. In this analysis the focus is on technical (characteristics of the irrigation area and network), organizational and administrative variables. Results show that on average 18.7% of the used inputs could be saved if the WUA would operate on the frontier. The average scale efficiency, which can be calculated as the ratio between Constant and Variable Returns to Scale efficiency measures was around 71%, indicating that many WUAs are not operating at an efficient scale. Subvectors efficiencies show that WUAs present better performances in maintenance activities than in management. The inefficiency found can furthermore be mainly attributed to the number of years of experience in operating a WUA in addition to the number of water pumping stations managed and the rate of the exploited area. The scale inefficiencies are mainly due to administrative and organizational variables.WUA, irrigation, efficiency, DEA method, Institutional and Behavioral Economics, Land Economics/Use,

Signal analysis of vibration measurements for condition monitoring of bearings

Rotating machinery is a common class of machinery in industry. The root cause of faults in rotating machinery is often faulty rolling element bearings. These rolling element bearings wear out easily due to the metal-metal contacts and create faults in the outer race, inner race, or balls. This study compares several techniques used for monitoring bearing condition. These techniques are based on the processing of vibrational data in the time-domain, frequency-domain, or time-frequency-domain. It was found that the discrete wavelet transform which is based on time-frequency analysis produces the best results

Design of differential resistive measuring system and its applications

Differential resistive systems are easily designed using potentiometric sensors. They usually contain two sensing resistances and a common movable terminal. This circuit can be used to sense a number of scenario; such as the liquid level in a tank, biomedical applications in determining the expansion and contraction of the muscles, the amount of bend in a bimetallic strip, the expansion and contraction in roads and railways, cracks in building for civil application, the penetration of signal in buildings for telecommunication and communication engineering applications, the voltage level in complex circuit. Since sensors with high sensitivity and good resolution are required for industrial applications, hence the need for this cheap and affordable sensor's design. Also, their output must have linear responses, that is, the output produced should be linearly proportional to the parameters of interest [1]. This chapter deals with the design of a differential resistive measuring sensor with low cost, low power consumption, with small size and improved overall performance of the circuit implanted in human body in order to generate voltage, current whose frequency, duty cycle is proportional to the physical parameters of interes

Building and Analyzing a Corpus of Contextualized Traces Collected during a Technology Enhanced Teaching Module

International audience—Sharing and analyzing data collected within Technology Enhanced Learning environments is an interesting issue for researchers to validate their models and systems. In this paper we present a corpus we built and analyzed in order to validate our proposed " Proxy approach " as an approach for sharing and analyzing learning data corpora