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This study evaluated the technical efficiency and irrigation water use efficiency of olive farms in Tunisia, using Data Envelopment Analysis. In order to calibrate and validate the findings, data related to area, water use, water quality, cultivar, input, and yield were collected based on interviews from 45 irrigated olive farms in Kairouan Governorate. The results show that average input-oriented water use efficiency under the CRS and VRS specifications is 17.2% and 36.3%, respectively, indicating that the sampled olive farms could reduce the use of water by an average of 82.8% and 63.7% by improving the performance of irrigation systems. Also, it was found that there are large differences in irrigation water use efficiency between the CRS and VRS specifications. Consequently, this indicates that a number of olive farms can enhance overall efficiency by improving the scale of operation. In practical terms, this study provides significant insights for the olive growers in this study regarding the importance of removing scale inefficiency. Specifically, they need to consider the effects of water and soil quality on irrigated fields to improve the efficiency of irrigation water use.

The sustainability and efficiency of flood risk management depends on the assessment of flood hazards and on the quantification of flood damage. Under the conditions of climate change and rapid urbanization, the evaluation of flood risk can lead to the success of adaptation strategies. The main objectives of this study are the estimation of future direct flood damage in two urban watersheds: The Pasig–Marikina–San Juan River in Metro Manila, Philippines, and the Ciliwung River in Jakarta, Indonesia, as well as the determination of the relation between factors that drive floods and flood damage. A spatial analysis approach based on the integration of several parameters, such as flood hazard, climate, and property value, was applied using a Geographic Information System (GIS). The flood depth-damage function generated from the field surveys was employed for the analysis to identify the spatial distribution of flood loss. The findings showed that, under future scenarios (target year: 2030), the total flood damage will increase by 212% and 80% in the target areas of Manila and Jakarta, respectively, compared to the current scenarios. This growth is due to the higher level of extreme rainfall events and to the degree of urbanization in the future. A comparative analysis of the two study areas highlighted the significant effects of the level of water depth and the inundated areas on flood damage, depending on the sites. This study is useful for local decision makers to implement suitable strategies for urban planning and flood control.

Water scarcity and water quality degradation are important problems that can affect human well-being. Population growth, unplanned urbanization, land-cover change, and the intensification of agricultural and industrial activities are the main reasons for water resource issues. The main aim of this work was to evaluate the effect of land-cover change on groundwater quality in the Chiba watershed, Nabeul, Tunisia. A remote-sensing technique was used to identify the principal transitions in land cover between 1998 and 2018. Additionally, four water quality indicators (electrical conductivity, chloride concentration, nitrate concentration, and sodium absorption ratio) were utilized to investigate variations in water quality in the study area. It was found that most of the watershed was covered with agricultural land in 1998 (87.5%) and 2018 (88.6%). Based on a comparison of these two periods, various types of land-cover transitions were observed. Moreover, the water quality indicators revealed that the salinity hazard and nitrate contamination in the watershed were high. The spatial relationship between water contamination level and land-cover transition category indicated that barren land to built-up land transitions had the strongest negative effect on water quality among all of the main land-cover transitions. Demonstrating the impact of land-cover change on water quality should encourage local decision makers and water managers to implement strategies for sustainable urban planning and periurban agriculture.

Tunisia olive production fluctuates yearly because it is highly dependent on annual precipitation, and growers need to enhance productivity and efficiency by introducing irrigation. Investigating how irrigation affects the technical efficiency of olive production may contribute to improvement in productivity. This study employs the Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA) methods to estimate non-parametric and parametric frontiers for a sample of Tunisian olive orchards. It identifies factors which determine variations in technical and scale efficiencies among orchards. The DEA results show that average output-oriented technical efficiency under constant returns to scale (CRS) and variable returns to scale (VRS) is 8.9 and 17.8%, respectively. The SFA results show that average technical efficiency of the half-normal model with constant returns to scale is estimated at 81.2%, indicating Tunisian olive growers can raise output by an average of 18.8% by improving technology and using fewer inputs. Average technical efficiency in irrigated orchards under the DEA approach was higher than in irrigated ones while irrigated orchards under the SFA approach was less technically efficient than non-irrigated ones. However, the test results of mean difference indicate that average VRS technical and scale efficiencies in irrigated orchards under the DEA approach were not significantly higher than in non-irrigated ones. On the other hand, technical rather than scale inefficiency is the major source of overall inefficiency in irrigated orchards because room for improvement in technical efficiency was larger than in scale efficiency. These results suggest that Tunisian olive growers should raise output and efficiency by introducing more advanced technologies for improving the performance of irrigation systems. Key words: Olive orchards, technical efficiency, scale efficiency, irrigation, Tunisia.

The design, development, and operation of current and future urban water infrastructure in many parts of the world increasingly rely on and apply the principles of sustainable development. However, this approach suffers from a lack of the necessary knowledge, skills, and practice of how sustainable development can be attained and promoted in a given city. This paper presents the framework of an integrated systems approach analysis that deals with the abovementioned issues. The “Water and Urban Initiative” project, which was implemented by the United Nations University’s Institute for the Advanced Study of Sustainability, focused on urban water and wastewater systems, floods, and their related health risk assessment, and the economics of water quality improvements. A team of researchers has investigated issues confronting cities in the developing countries of Southeast Asia, in relation to sustainable urban water management in the face of such ongoing changes as rapid population growth, economic development, and climate change; they have also run future scenarios and proposed policy recommendations for decision-makers in selected countries in Southeast Asia. The results, lessons, and practical recommendations of this project could contribute to the ongoing policy debates and decision-making processes in these countries.

Modeling insecurity under future climate change and socio-economic development is indispensable for adaptive planning and sustainable management of water resources. This case study strives to assess the water quality and quantity status for both the present and the near future in the Ciliwung River basin inside the Jakarta Province under different scenarios using population growth with planned additional wastewater management infrastructure by 2030 as mentioned in the local master plan, and comparing the above conditions with the addition of the effects of climate change. Biochemical oxygen demand (BOD), chemical oxygen demand (COD) and nitrate (NO3), the three important indicators of aquatic ecosystem health, were simulated to assess river pollution. Simulation results suggest that water quality in year 2030 will further deteriorate compared to the base year 2000 due to population growth and climate change, even considering the planned wastewater management infrastructure. The magnitude of impact from population growth is far greater than that from climate change. Simulated values of NO3, BOD and COD ranged from 6.07 to 13.34 mg/L, 7.65 to 11.41 mg/L, and 20.16 to 51.01 mg/L, respectively. Almost all of the water quality parameters exceeded the safe limit suitable for a healthy aquatic system, especially for the year 2030. The situation of water quality is worse for the downstream sampling location because of the cumulative effect of transport of untreated pollutants coming from upstream, as well as local dumping. This result will be useful for local policy makers and stakeholders involved in the water sector to formulate strategic and adaptive policies and plan for the future. One of the potential policy interventions is to implement a national integrated sewerage and septage management program on a priority basis, considering various factors like population density and growth, and global changes for both short- and long-term measures.

L’employabilite est un concept mobilise par des auteurs de differentes disciplines telles que l’economie (Gazier, 1989 ; Outin, 1990), la psychologie (Bernston, 2008), les sciences sociales (Leduc Browne, 1999), les sciences de gestion (Dietrich, 2010 ; Baruel Bencherqui, 2005). Cette recherche s’interesse, plus particulierement, a l’intention de developper son employabilite (Hategekimana et Roger, 2000, 2002) chez les jeunes salaries de 18 a 30 ans. Ainsi des analyses quantitatives, portant sur un echantillon de 160 jeunes salaries, ont ete menees afin d’examiner quels sont les facteurs pouvant intervenir sur cette intention de developper son employabilite. Les resultats de notre etude montrent une difference dans l’intention de developper son employabilite entre hommes et femmes et ils mettent en exergue l’importance accordee, par les jeunes salaries, a la satisfaction dans la vie professionnelle et au role des reseaux (sociaux, intra et inter-organisationnels) sur l’intention de developper leur employabilite.

Since Horton in 1965, many authors have sought to aggregate different variables characterizing the state of water into a single value called Water Quality Index ( W Q I ). This index is intended to facilitate the operational management of water resources and their allocation for different uses. Detailed and operational description of the main W Q I calculations are here reviewed. The review contains: (1) an historical analysis of the evolution of W Q I calculation methods by looking both at the choice of variables, the methods of weighting and aggregating these variables into a final single value, (2) an illustration of the contradictions observed in the final result when, on the same database, the W Q I is calculated by different methods, (3) the significant progress possible via fuzzy logic to define a W Q I adapted to specific water use.

In spite of water scarcity problem in Tunisia, irrigation strategy was adopted and supported by the government. In addition, the introduction of the irrigation in olive sector was also encouraged because it will be the way for maintaining the production of this strategic product. Therefore, the main objective of this work is to detect irrigated and non-irrigated olive growing farms using remote sensing techniques which can be useful to establish efficient and sustainable strategy of water resource management. This study was conducted in olive growing farms of 04 regions (Bouhajla, Nasrallah, Chebika and Oueslatia) in Kairouan prefecture. To monitor the irrigated olive growing farms, we used multi-temporal Landsat 8 imagery from June to September 2015 which were processed to obtain specific vegetation indices such as RVI (ratio vegetation index) and NDVI (Normalized Difference Vegetation Index). Moreover, LST (Land Surface Temperature) and BT (Brightness Temperature) are produced to assess temperature. To drought monitoring, VCI (Vegetation Condition Index), TCI (Temperature Condition Index), and VHI (Vegetation Health Index) were applied as indicators. The validation approach was based on the field survey and data collection. The main results of the study are the detection of irrigated and rainfed olive growing farms using specific vegetation indexes and indicators. The findings are validated by the field observations for checking the accuracy of the results. This study can be useful for stakeholders to detect the olive growing farms which can be helpful to estimate the olive production.

Soil erosion by water is a common environmental problem which can affect the sustainable development and the agriculture of developing countries especially. Therefore, several countries, threatened by this phenomenon, adopt different measures to preserve and protect their natural resources. The main purpose of this study was to identify vulnerable areas to establish a soil erosion risk map in Tunisia. In order to do so, an approach based on a combination of the Revised Universal Soil Loss Equation (RUSLE) as an erosion model, Geographic Information System (GIS) and Remote Sensing was applied. RUSLE, which is a model to predict soil loss, is composed of five factors. Erosivity factor (R factor), erodibility factor (K factor), topography factor (LS factor), crop management factor (C factor), and supporting practices factor (P factor). Furthermore, in order to get the most accurate C factor for each land use, times series Moderate Resolution Imaging Spectroradiometer Enhanced Vegetation index (MODIS-EVI) were used. MODIS-EVI time series was helpful for distinguishing vegetation dynamics with taking into account phenological variation of the crops. The results indicated that Tunisia has a serious risk of soil erosion. Indeed, about 24.57% of our study area had a soil loss rate more than 30 t/ha. In these areas, suitable and urgent measures and treatments should be required. Finally, this approach which is based on remote sensing techniques, GIS and erosion model can be useful for planning appropriate environmental decision-making policy in a global scale.

Soil erosion by water is a serious environmental problem which affects particularly the agriculture of developing countries. Due to specific factors, such as high rainfall intensity, steep slopes and vegetation scarcity, Tunisia is prone to soil erosion. Taking this into account, the main objective of this study was to estimate the soil erosion risk in the Batta watershed in Tunisia using qualitative and quantitative erosion model with remote sensing data and geographic information system (GIS). Moreover, a developed method that deals with evaluating the impact of vegetation on soil erosion by water is also applied. This method used multi-temporal satellite images with seasonal variability and the transformed soil adjusted vegetation index (TSAVI) which is appropriate in arid and semi-arid areas. For both erosion models, the results show that a large area of the Batta watershed is seriously affected by erosion. This potentially high risk is due especially to severe slopes, poor vegetation coverage and high soil erodibility in this watershed. Furthermore, the use of multi-temporal satellite images and vegetation index show that the effect of vegetation is a significant factor to protect the soil against erosion. The risk is especially serious in the summer season, but it decreases with the growth of vegetation cover in spring. Erosion model, combined with a GIS and remote sensing, is an adequate method to evaluate the soil erosion risk by water. The findings can be used by decision makers as a guideline to plan appropriate strategies for soil and water conservation practices.