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Jlassi W.,National Agronomic Institute of Tunisia INAT | Nadal-Romero E.,University of Zaragoza | Garcia-Ruiz J.M.,CSIC - Pyrenean Institute of Ecology
Cuadernos de Investigacion Geografica | Year: 2016

Large rainfed, dryland areas were transformed into irrigated land in northeast Spain, where rivers from the Pyrenees Range ensure the availability of abundant water resources. The transformation of the Riegos del Alto Aragón area (RAA), mainly during the second half of the 20th century, was subject to major problems during the 1960s and 1970s, including monoculture of poorly productive winter cereals, water wastage, and soil degradation. Since the 1990s the RAA has been affected by modernization involving: (i) a change in the mode of irrigation, from gravity to sprinkler systems; (ii) the concentration of plots to enlarge the size of irrigated fields; and (iii) the introduction of more productive and highly water-consuming crops (corn, lucerne, vegetables). These changes coincided with enlargement of the irrigated area, increasing water demand at a time of increasing water scarcity because of restriction on the construction of new large reservoirs and declining water resources, because of climate and land use changes. Addressing this major problem has required new strategies, specifically the construction of small reservoirs and water ponds within the irrigated area. The ponds increase water reserves and facilitate sprinkling irrigation by adding pressure to the system. However, this has involved a huge rise in electricity consumption, which has increased the cost of production. © Universidad de La Rioja. Source

Etteieb S.,National Agronomic Institute of Tunisia INAT | Kawachi A.,University of Tsukuba | Elayni F.,Leader Technologies | Han J.,University of Tsukuba | And 2 more authors.
Desalination and Water Treatment | Year: 2014

Water resources associated with the Mediterranean arid to semiarid environment in Tunisia are at risk of degradation in terms of quantity and quality, especially due to groundwater overexploitation. Therefore, the reuse of treated wastewater (TWW) for the artificial recharge of groundwater has been implemented as an alternative, particularly in Korba coastal area of Tunisia. The aim of the current study was to assess the environmental risk of the groundwater quality as well as the reuse of TWW for Korba local aquifer recharge. On one hand, results showed high levels of chloride, ammonia, and sodium adsorption ratio (SAR) in the TWW and high electrical conductivity, nitrate, chloride concentrations, and SAR in groundwater. Heavy metal concentrations were commonly under the detection limit. On the other hand, groundwater was contaminated with pesticides. Environmental risk monitoring of TWW is fundamental to assess its safety reuse on the aquifer recharge and in presenting a coastal barrier against seawater intrusion. Also, it will allow for more effective allocation of resources in future monitoring programs and it can contribute to the environmental management of the treatment plant. © 2013 Balaban Desalination Publications. All rights reserved. Source

Barbouchi M.,National Agronomic Institute of Tunisia INAT | Barbouchi M.,COSIM Laboratory | Abdelfattah R.,COSIM Laboratory | Abdelfattah R.,Telecom Bretagne | And 4 more authors.
IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing | Year: 2015

The phenomenon of soil salinization in semi-arid regions is getting amplified and accentuated by both anthropogenic practices and climate change. Land salinization mapping and monitoring using conventional strategies are insufficient and difficult. Our work aims to study the potential of synthetic aperture radar (SAR) for mapping and monitoring of the spatio-temporal dynamics of soil salinity using interferometry. Our contribution in this paper consists of a statistical relationship that we establish between field salinity measurement and InSAR coherence based on an empirical analysis. For experimental validation, two sites were selected: 1) the region of Mahdia (central Tunisia) and 2) the plain of Tadla (central Morocco). Both sites underwent three ground campaigns simultaneously with three Radarsat-2 SAR image acquisitions. The results show that it is possible to estimate the temporal change in soil electrical conductivity (EC) from SAR images through the InSAR technique. It has been shown that the radar signal is more sensitive to soil salinity in HH polarization using a small incidence angle. However, for the HV polarization, a large angle of incidence is more suitable. This is, under considering the minimal influence of roughness and moisture surfaces, for a given InSAR coherence. © 2008-2012 IEEE. Source

Rjeibi M.,University of Tunis | Ezzedine-Najai S.,National Institute of Marine science and Technologies INSTM | Chemmam B.,National Institute of Marine science and Technologies INSTM | Missaoui H.,National Agronomic Institute of Tunisia INAT
Malacologia | Year: 2013

The reproductive biology of Eledone cirrhosa (Lamarck, 1798) was studied for the first time in the northern and eastern region of Tunisia. Monthly samples were provided from surveys carried out on board the Tunisian oceanographic vessel "Hannibal" and from commercial catches of bottom-trawl operating in this area from October 2005 to September 2006. Although specimens have been collected at a wide depth range, E. cirrhosa shows the greatest abundance between 100 and 300 m. The sex ratio was estimated at 0.94 with no significant difference (P > 0.05). Length-weight relationships calculated for each sex and the whole sample showed negative allometric growth (b < 3). The allometric coefficient in immature individuals revealed an allometric growth (b < 3) and isometric growth (b = 3) in maturing and mature individuals. A three-stage maturity scale was intended to distinguish between immature, maturing and fully mature animals. The reproductive season for females extended from April to August, with a spawning peak from June to August, and for males from January to August with a peak from April to August. The dorsal mantle length (DML) at maturity, corresponding to the size class when 50% of individuals were mature, was estimated at 6.88 cm in males, and 8.80 cm in females. The juveniles were mainly found in between 100 and 200 m where a nursery area for the species is probably present, while mature individuals were mostly fished at a depth greater than 200 m, which represents the spawning area of Eledone cirrhosa. Potential fecundity, estimated from 37 mature females, was 4171 ± 1216 oocytes. The number of spermatophores ranged from 42 to 121, with a mean length of 51.34 ± 4.86 mm. Source

Etteieb S.,National Agronomic Institute of Tunisia INAT | Kawachi A.,University of Tsukuba | Han J.,University of Tsukuba | Tarhouni J.,National Agronomic Institute of Tunisia INAT | Isoda H.,University of Tsukuba
Clean - Soil, Air, Water | Year: 2015

Pollution of river systems in Tunisia by endocrine disrupting compounds (EDCs) is due to anthropogenic impacts through non-treated industrial wastewater and municipal-treated wastewater discharge. The aim of this study was to assess the estrogenic activity of environmental matrices involving raw industrial wastewater (WW), surface water (SW), and treated wastewater (TWW). A modified E-screen assay was used to evaluate estrogenic activity of the samples in MCF-7 breast cancer cells. Western blotting and real-time PCR molecular approaches were applied to investigate the mechanism of EDC-induced MCF-7 breast cancer cell proliferation which interferes with estrogen receptor alpha (ERα) and c-Jun. Our results revealed a dose-dependent estrogenic activity reaching an optimal level at a concentration of 0.01% for industrial WW and SW and 10% for TWW. Monitoring ERα protein and c-Jun gene expression levels after 1, 6, 24, and 48h of treatment showed a correlation in the overexpression of ERα and c-Jun most of the time. In fact, ERα and c-Jun correlated up-regulation began after 1h of treatment for industrial WW, TWW, and one SW sample. For the other SW samples, this correlated up-regulation started after 6-24h of treatment. Results emphasized the estrogen-like effect of our contaminated samples on MCF-7 cells which facilitate a cross-talk between ERα and c-Jun factor, thereby directly regulating the expression of estrogen-induced genes to mediate breast cancer cell growth. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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