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Chinampas are island plots (500-1000 m²) constructed of soil scooped from the bottom of the lake and surrounded by canals. Over 40 agricultural species, including vegetables, cereals, and flowers, are produced on chinampas and consumed by approximately 100,000 people. This agro-ecosystem, once one of the most diverse and productive, at present is at risk of disappearing, mainly as a consequence of the severe pollution of the irrigation water. To evaluate the relationship between the accumulation of metals and physical soil properties, total trace metals Fe, Cu, Mn and Zn and total heavy metals Pb, Ni, and Cr in soils were determined by Particle Induced X-Ray Emission (PIXE). This method provides a very suitable technique for treating a large number of samples because sample preparation is simple and determination of a large number of elements is simultaneous. Three sites were chosen because of their long history of pollution: Xochimilco, San Luis Tlaxialtemalco and Mixquic in Mexico City. Soil properties were determined by conventional analytical methods. Soils were found to be high in organic matter content, high in sodicity and salinity, and with an alkaline pH. The metals present in the samples are in the following order of abundance: Fe>Mn>Cr>Zn>Cu>Pb.

PIXE was adopted for analysis of trace elements in otoliths of Masu salmon Oncorhynchus masou masou to examine relationship between trace elements and environmental salinity. The otoliths were removed from salmon juveniles reared in four values of salinity and wild ones. The otolith Sr concentrations of reared individuals are positively related to salinity and there is significant difference between freshwater and seawater. The otoliths of smolts contain more Sr than those of parrs. It seems that the Sr concentrations in otoliths of Masu salmon reflect salinity where they had stayed and show the migration pattern.

In this paper, an improved integrated model of electromagnetic scattering for two dimensional fractal sea surface is built. Both geometrical fractal characteristic and permittivity characteristic of sea water are strictly considered, especially for the effects of salinity and temperature on the electromagnetic field scattered by sea water are added on. Finally, the calculated results from the new model are in accord with experimental results in terms of backscattering coefficient of sea water with no more than 2 dB error, which present higher precision than those traditional models. Thus, by using this model, the whole electromagnetic scattering characteristics of sea surface are obtained.

In this work, we demonstrate the sensing principle to simultaneously detect the salinity and temperature of seawater using a 1D-defective photonic crystal structure. We designed a one-dimensional defective mode photonic crystal based on the well-known transfer matrix method (TMM) for detecting the seawater salinity and temperature. Our proposed optical sensor is based on the following concept. Since the concentration of the salinity in the seawater changes the refractive index of the seawater, the sensitivity can be calculated by a peak wavelength shift happening in the output transmission spectrum for its variation of different concentration of samples. By adjusting the design parameters of our proposed structure such as the thickness of the defect layer, the temperature and the salinity, we investigated the corresponding optical properties response where the resulted transmittance peak can be turned over the considered range.

In this Letter, we propose and experimentally demonstrate a simple method to provide additional information on the electro-mechanical properties of soils by electrical conductivity measurements. The AC electrical conductance of the soil is measured while it is exposed to a periodic vibration. The vibration-induced density fluctuation implies a corresponding conductivity fluctuation that can be seen as combination frequency components, the sum and the difference of the mean AC frequency and the double of vibration frequency, in the current response. The method is demonstrated by measurements on clayey and sandy soils.

Soil bulk density is a physical property of soils that affects water storage, water and nutrient movement, and plant root activity in the soil profile. The ability to quantify soil bulk density using vibration-induced conductivity fluctuation was investigated with possible field applications in the future. The AC electrical conductance of soil was measured using a pair of blade-like electrodes while exposing to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. This normalized index was expected to provide data independent from the vibration strength, and to reduce the effect of soil salinity and water content. Simulations on a simplified resistor lattice indicate that the ratio of transversal and longitudinal fluctuation decreases as soil bulk density increases. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four compaction levels. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Dry sand measurements showed an inverse correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal fluctuation. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not associated with bulk density changes. This lack of sensitivity might be attributed to the heavy electrodes and/or the specific vibration method used. The effects of electrode material, vibration method and soil properties on the experiment need further study.

This paper quantifies the impacts of inundation risk and soil salinization on the family structure and income of coastal households in Bangladesh. The analysis is based on a household decision model that relates spatial deployment of working-age, migration-capable members to inundation and salinization threats. The empirical analysis uses appropriate estimation techniques, including adjustments for spatial autocorrelation. The findings are consistent with a model that treats urban migration of working-age family members as both an income source and the only feasible form of disaster insurance for coastal households. Greater inundation risk unambiguously decreases the rural household share of working-age members, while the direction of the salinity effect depends on households’ income elasticity of demand for disaster insurance. The econometric results suggest that this elasticity is significantly greater than one, yielding higher rural household shares of working-age members in areas with higher salinity (ceteris paribus). Both increased inundation risk and greater salinity increase the incidence of extreme poverty among coastal households. However, powerful poverty reduction results for market access indicate that road improvements would provide an important countervailing force. The benefits of increased market access for coastal households are present with or without inundation and salinization threats, making such investments an attractive no-regret option.

This paper presents the modification occurred to the dielectric strength feature of low density polyethylene compounded with nano magnesia (LDPE/MgO). MgO nanoparticles were prepared using sol–gel technique, MgO filler surface was functionalized to improve the interfacial bonding. Specimen’s groups of composites with different filler concentrations were fabricated by mix blend method. Samples exposed to various salinity media by immersion, dielectric strength test was applied on each set according to relevant ASTM standard with identical testing technique. The results were statistically processed then compared to the pristine material. Tests results utilized to learn Artificial Neural Network in order to acquire the value of dielectric strength of compounds having similar composition but containing different doping amounts or influenced with various salinity level media. The dielectric strength is enhanced by the addition of MgO nanofiller. From the investigation of the obtained results, it is concluded that additives of 1.4% filler concentration by weight is the optimum MgO content for LDPE/MgO nanofiller material. We think that this paper may promote a good researching methodology that gather both empirical work and numerical tools in this field.

Exploitation of alternative water sources is expected to grow in the decades to come in water-stressed countries with fast population growth, especially in regions where a further decline of natural freshwater availability is expected due to climate change. Increasing utilization of non-freshwater usually leads to salinity build-up in fields and water sources as well as accumulation of various pollutants — both having a considerable impact on the suitability of non-freshwater for irrigation due to constraints associated with crop salinity tolerance and food safety regulations. We developed a linked Computable General Equilibrium (CGE) — farm-level model of a water economy with representation for multiple water types characterized by different qualities. We employ the model to assess the impact of water shortage on the Israeli economy, where steadily growing water scarcity leads to an increasing utilization of alternative water sources. We simulate water shortage scenarios based on the Long Term National Master Plan for The Water Economy developed by the Israeli Water Authority (IWA). The linked CGE — farm-level model provides a mechanism for estimating the Constant Elasticity of Substitution (CES) rates between different irrigation water types used in agriculture. This mechanism accounts for the effects of salinity on yields and takes into consideration food safety regulations for irrigating crops with treated wastewater. We demonstrate that, in contrast to previous studies, CES rates between different water types are not identical. The CES rates obtained in our study have relatively low values, which can be attributed to the constraints associated with crop salinity tolerance and food safety regulations. Our results reveal that water shortage can lead to a significant decline of Israel’s GDP, where a considerable part of the decline is attributed to the decrease in agricultural outputs. The magnitude of the impact depends on the underlying assumptions regarding future desalination capacity. To further study the effect of desalination, we run simulations under various desalination levels and examine its impact on the GDP. We also examine the extent to which the impact of water shortage is sensitive to CES rates between different irrigation water types.

Using an environmentally adjusted performance measurement the study evaluates the tradeoffs between the benefits derived from irrigated cotton enterprises and its associated environmental damages. Deep drainage, which adds to the aquifer recharge and thereby contributes to salinization, is treated as an environmentally detrimental output. The analysis includes data collected from a sample of 53 observations in the Mooki Catchment located in northern New South Wales, Australia. Environmentally adjusted efficiency of cotton enterprises is estimated using the environmental performance index (EPI) and relative efficiency rankings are determined for each of the considered cotton areas in the catchment. The findings reveal that environmentally adjusted efficiency of irrigated cotton is within an acceptable range (more than 60% of observations have an EPI efficiency score of greater than 5). The efficiency variation among the observations based on hydrological response units (HRUs) can be attributed to a number of reasons including physical factors (i.e., soil quality, topography), type of irrigation technology used, and other environmental factors. For instance, the overall efficiencies of downstream HRUs are higher than that of upstream HRUs. Therefore, biophysical characteristics of an area need to be incorporated in the efficiency model. With the identification of the most and least efficient cotton irrigation areas in the region, policymakers can construct a relative ranking to best determine policy directions in order to take a more targeted approach towards salinity mitigation.

Irrigators in the Murray–Darling Basin (MDB) of Australia face a salinity triple threat, namely: dryland salinity, surface-water, and groundwater salinity. Water trading has now been adopted to the point where it is a common adaptation tool used by the majority of irrigators in the Basin. This study uses a number of unique water market and spatial databases to investigate the association between the severity and extent of areas which suffer from salinity and permanent trade over time, holding other regional characteristics constant. It was found that larger volumes of permanent water were likely to be sold from areas suffering from higher dryland salinity. In addition, increases in the concentration of groundwater salinity was found to decrease volumes of surface-water entitlements sold, providing evidence that groundwater entitlements (where they are viable substitutes) have been increasingly used as substitutes for surface-water entitlements in recent years. Other key influences on water sales included water market prices and net rainfall.

Monitoring affordability of drinking water services is constrained by data gaps from traditional approaches that rely on cross-sectional data from infrequent, nationally representative surveys. Estimates of income or expenditure ratios spent on accessing a main source of drinking water are poorly equipped to reflect affordability in rural contexts where poor people often resort to multiple sources of varying costs, quality and distance to cope with unreliable or absent water supplies. Here, we present findings from an 18-week water diary study that documented daily water choices and expenditures of a stratified sample of 120 households in coastal Bangladesh. This intensive, longitudinal monitoring is supported by household surveys, water infrastructure mapping, hydrogeological analysis of salinity, automated rainfall measurements and interviews with diary participants. We identify five water expenditure typologies, ranging from those who always rely on unpaid and often poor-quality sources like shallow tubewells, pond sand filters and rainwater, to those who purchase vended water for drinking and cooking all year-round, spending 3–7% of total household expenditure. These behavioral dynamics are shaped by environmental, infrastructure and cultural factors, with household wealth being a weak indicator of behavior. We conclude that affordability measures should recognize the quality of service available and chosen by users across seasons, rather than being fixated on income or expenditure ratios for a main source. Measuring the latter without considering the former impedes the design of service delivery models appropriate for providing safe and reliable water supplies, at costs that users and society are willing to bear and sustain.

This study aimed to assess the relationship between species-specific salinity tolerance and physiological parameters in three genotypes of Triticum aestivum L.: Pak-81 (tolerant), Lu-26 (medium tolerant), and Pasban-90 (sensitive). The objectives were to investigate changes in water and osmotic potential, stomatal resistance, chlorophyll fluorescence (relative fluorescence decreased ratio [Rfd] values), accumulation of Na+ ions, and proline content of leaves under salinity stress. To assess the effects of NaCl, three experiments were conducted. The first experiment involved collecting plant and soil samples from saline fields with varying salinity levels. The second experiment induced salinity in potted plants grown under natural conditions by applying NaCl either at the vegetative phase (three-leaf stage) or at the ear formation phase. The third experiment evaluated the effect of applying NaCl at different concentrations to plants grown under controlled conditions in the growth chamber. Results revealed that increasing concentrations of NaCl had significant detrimental effects on stomatal conductance, fresh and dry weight of shoots, and Rfd in Pasban-90 and Lu-26, which also showed decreased accumulation of Na and Cl at high NaCl concentrations. The tolerant lines exhibited greater Na+ and Cl contents than the sensitive ones, higher osmotic potential, less decrease in water potential, less stomatal resistance, and higher Rfd. In conclusion, a relationship exists between genotype-specific salinity tolerances and the putative role of proline and Cl in osmotic adjustment due to higher uptake of sodium.

The Chinese mitten crab (Eriocheir sinensis) is one of the most aggressive invasive species globally, and it has spread widely in Asia and Europe. Its unique morphological and physiological characteristics enable it to survive in high-temperature and hypersaline environments. The invasion of the Chinese mitten crab can damage the local aquatic ecology, including flora and fauna, necessitating the implementation of monitoring and control measures. Consuming the invasive crab is a potential strategy to prevent its further spread worldwide. This chapter documents the success of transforming this invasive species into a valuable food source in China. Notably, there is a significant demand for Chinese mitten crabs in China, with potential markets in several other Asian countries. However, natural Chinese mitten crabs often grow in polluted water, accumulating undesirable substances (e.g., pathogens and heavy metals). These substances could pose significant health hazards when consumed by humans. Therefore, adhering to proper cultivation techniques is essential to ensuring the safety of the crabs for human consumption.

The productivity of an aquatic system is often measured in terms of Chlorophyll-a, which is supplemented by the nutrients like nitrogen and phosphorous. An excess amount of Chlorophyll-a is often caused as a consequence of nutrient enrichment, termed as eutrophication. However, the measurement of Chlorophyll-a is not included in the monitoring programs of the Pollution Control Board (Central and State) and hence assessing the eutrophication status of an estuary is difficult. This necessitates the prediction of Chlorophyll-a from its influential parameters that are monitored regularly. In this study, the possible influence of salinity on Chlorophyll-a was studied and an Artificial Neural Network (ANN) model for prediction of Chlorophyll-a using parameters like Total Phosphorous (TP), Turbidity and Salinity was developed based on data from Pollution Control Board (PCB). The proposed model was tested using the field data from Ashtamudi estuary and a hydrodynamically and geographically different estuarine system, the Chikugo estuary Japan. From the study, it was found that salinity has an influence on Chl-a. Also, the prediction model needs to be modified according to the unique characteristics of estuaries for better prediction. The developed model is envisaged to support monitoring agencies, planning agencies and decision makers in the assessment of eutrophication status of estuarine systems.

In order to further explore the effective water treatment technology and the characteristics of water quality with high carbon dioxide for low-ultra low permeability oil fields in the peripheral part of Daqing, a series of experiments are used to evaluate the effect of aeration process for removing the CO2 from oily wastewater and investigate the oil-water separation property by a small simulation test system. The results show that the properties of CO2 flooding produced water, such as salinity and corrosion rate, may be affected due to the increasing carbon dioxide content. The aeration is an effective method for reducing the acidity and the corrosion products of the CO2 flooding produced water.