Canal Water Research Articles

Avaliação de risco ecológico em potencial avaliação de metal tóxico (chumbo) em prados contaminados nas proximidades da cidade suburbana: solo x forragens x gado

Heavy metal toxicity is becoming an increasing concern for environmental, human and animal health. The current research analyzed the lead (Pb) contamination in the food chain under three different irrigation sources (ground, canal, and wastewater). Soil, plant and animal samples were collected from the Jhang district of Pakistan and processed with an atomic absorption spectrophotometer. Lead concentration varied in the samples as: 5.22-10.73 mg/kg in soil, 2.46-10.34 mg/kg in forages and 0.736-2.45 mg/kg in animal samples. The observed lead concentration in forage and animal blood samples was higher than the standard limits. The pollution load index (0.640-1.32) in soil showed that lead contamination mainly took place at the wastewater irrigating sites. Bio-concentration factor values (0.313-1.15) were lower than one in all samples except Zea mays, showing that lead metal was actively taken up by Zea mays tissues from the soil. Enrichment factor values ranged from 0.849-3.12, showing a moderate level of lead enrichment. Daily intake and health risk index varied between 0.004-0.020 mg/kg/day and 0.906-4.99, respectively. All the samples showed maximum lead concentration at the wastewater irrigating site compared to the ground or canal water application sites. These results recommended that consistent application of wastewater for forage irrigation must be avoided to prevent health hazards associated with lead in the animal and human food chain. Government must implement adequate strategies to protect the animal and human health from the harms of toxic heavy metals.

Switching Model Predictive Control of canals characterized by large operating conditions

This paper presents a switched linear system representation of water canal dynamics to incorporate different operating modes, which arise due to the occurrence of extreme weather phenomena such as flooding and drought episodes. To guarantee the stability during mode switching, a proper analysis on permanence regions–given by a collection of equilibrium states–for the switched linear system is presented. The permanence region is computed within a compact set, which depends on an adequate level region for the canals. A suitable algorithm is used to formulate an asymptotic stable Model Predictive Control (MPC) that steers and maintains the states of the system inside the target region indefinitely in a feasible manner. This strategy is successfully tested in a simulation using a realistic model of a canal.

Heavy Metal Accumulation in Goosefoot (Chenopodium album L.) Irrigated With Wastewater

Wastewater sources contain enormous amounts of nutrients for plant growth. This study aimed to define the metal accumulation in the goosefoot plant (Chenopodium album L.) of wastewater use in agricultural irrigation and to evaluate the risks of this accumulation to human health. The present research was performed in field conditions in Khushab, Pakistan. The Cd, Cu, Cr, Fe, Zn, Ni, and Mn concentrations were determined with the analysis performed using Atomic Absorption Spectrophotometer-AAS. Heavy metal concentrations in goosefoot samples irrigated with groundwater (GWI), canal water (CWI) and sugar mill water (MWI) ranged from 0.84 to 1.08, 0.55 to 0.78, 0.23 to 0.70, 2.09 to 5.56, 2.84 to 13.53, 0.53 to 1.13 and 0.32 to 0.39 mg/kg for Cd, Cr, Cu, Fe, Ni, Zn, and Mn, respectively. According to the statistical analyses, wastewater applications had a non-significant effect on Cr, Cu, and Zn concentrations in C. album samples collected from three sites, and a significant effect on Cd, Fe, Mn, and Ni concentrations (p>0.05). The results also showed that the health risk index value of cadmium was higher than 1. According to these results, long-term consumption of C. album samples grown in the study area may cause an accumulation of Cd in the human body and diseases in many tissues and organs.

The Impact of the Surrounding Land Uses on Water Quality of Some Selected Cascade and Perennial Tanks in Anuradhapura District, Sri Lanka

The present study was conducted to evaluate the water quality of the inlet, irrigation outlet, and edges linked to Nuwarawewa reservoir, Mahakanadarawa reservoir, Hurulu wewa reservoir, Sangilikandarawa reservoir, and Nachchaduwa perennial reservoir in Anuradhapura, Sri Lanka. Water samples were taken from a designated position of each inlet, irrigation output, and edges in the second inter-monsoon, northeast monsoon, and first inter-monsoon seasons. Water quality indicators such as pH, electrical conductivity (EC), total dissolved solids (TDS), Na, K, Ca, Mg, Sodium Adsorption Ratio (SAR), NO3- -N, NH4+-N, dissolved reactive phosphorus (DRP), and heavy metals (Cd, As, Pb, and Hg) concentrations were measured in each water sample. Data was analyzed using SPSS statistica software. Considerable temporal fluctuations in water quality indicators were detected in inlets, irrigation outflows, and edges over the research period. The findings revealed that NO3- -N, NH4+-N, and DRP in Sangilikandarawa reservoir during the northeast monsoon were close but not above the FAO (1985) maximum levels guidelines for irrigation water. pH, EC, TDS, and heavy metals (Cd, As, Pb, and Hg) in all the other tanks were within permitted values according to WHO drinking water quality standards and FAO (1985) guidelines for irrigation water. This finding further demonstrated that the consequences of surrounding land use on water pollution in inlet water canals linked to Sangilikandarawa and Nuwarawewa are greater. It could be concluded that a pollution management plan needs to be implemented in order to stop further pollution.

Canal water distribution optimization model based on water supply conditions

The optimization of canal water distribution is vital in irrigation areas because a reasonable distribution is required to improve the water distribution efficiency and maximize the benefits of water resources. In this paper, under the condition that the total volume and flow rate of water supply in the primary canal have been determined, the water supply is compared with crop water demand, and three optimal models of canal water distribution are established. In situation 1, the total volume of water supply is sufficient to meet the crop water demand during the growing period. In situation 2, the water supply is insufficient to meet crop water demand during their growth period; however, this problem is resolved by extending the water supply period. In situation 3, the water supply cannot meet the crop water demands during the growth period, even after adjusting the water supply period. Because the proposed water distribution optimization model is based on water supply conditions in irrigation areas, the irrigation area managers can easily develop their operation water distribution schemes. The model was validated using the Bojili irrigation area. Results showed that the model’s calculated variation trend of the main-canal flow rate was similar to the actual flow rate, and irrigation area managers could meet the model requirements with a small adjustment in the actual flow rate. The model also considered canal leakage loss, timely water distribution, water distribution fairness, and other goals, potentially improving agricultural water efficiency and water distribution satisfaction as well as promoting sustainable agricultural development. The model presented here is universal and can be used in other irrigation areas.

A selective and sensitive colorimetric method for semi-automated solid-phase extraction of atrazine in environmental water samples

A selective and sensitive procedure for the trace analysis of atrazine (ATZ) in surface water samples was developed using the semi-automated solid-phase extraction (SPE) coupled with a colorimetric method. In this work, we developed Konig’s reaction using p-anisidine as a new coupling agent to form a red-colored dye product having λmax 500 nm and tuned the reaction conditions to occur at 40 °C. The possible structure of the orange-red dye product was proposed based on HPLC-UV and UPLC-MS analyses. Under the optimized conditions, the method provided linearity range of 10–30 µg/L with a good coefficient of determination (R2 > 0.99) in different sample matrices. The limit of detection and limit of quantification were 2.49 and 7.54 µg/L, respectively. The method validity was evaluated by analyzing the ATZ spiked samples collected from paddy fields, fish farms, and natural canal waters with a recovery range of 104–119 %, and the results were in good agreement with those obtained using HPLC-UV. The developed method was able to reduce the requirement of high heating temperature for the conventional Konig’s reaction and was expected to be used for the practical analysis of ATZ at the ppb levels in natural water.

Pemberdayaan Tim “Jumantik” (Juru Pemantau Jentik) di SD 14 dan 15 Koto Lalang pada Masa Pandemi

Schools, apart from functioning as places of learning, can also be a threat of disease transmission if they are not appropriately managed. School age for children is also a period prone to various diseases, such as diarrhoea, infectious diseases, dengue fever, etc. In response to this problem, the formation and empowerment of the "Jumantik" Team at SDN 14 and 15 Koto Lalang. Based on realising a healthy school, this activity was carried out by forming and empowering a team of monitors for larvae, called Jumantik, in schools. Methods used were conducting a pretest and posttest, counselling, outreach to school members, and evaluation. Based on the author's observation, SDN 14 and 15 Koto Lalang has an open water canal in front of it. There was an increase in the proportion of students' knowledge level after being given counselling compared to before counselling. It is hoped that SDN 14 and SDN 15 Koto Lalang will further improve behaviour related to DHF, CTPS habits, and the implementation of health protocols during the Covid - 19 pandemic. It is hoped that school residents at SDN 14 and SDN 15 Koto Lalang can use the hand washing facilities, especially in face-to-face learning programs during the Covid-19 pandemic.

Reconnaissance a new Palaeolithic site at Al-Huwaidy in Ha’il region, northwest Saudi Arabia

Ha’il region in northwest Saudi Arabia is characterized by the presence of oases, flat plains, Paleo-lakes, and lava fields, which are some of the main landscape characteristics in which Palaeolithic sites have been found in the region. It is located on one of the routes of early hominin dispersal across Arabia. The ongoing archaeological research made by the Paleodeserts and Disperse projects have recorded several Acheulean and Middle Palaeolithic sites in such localities as Jubbah basin in the Nefud desert (Groucutt et al. 2021; Petraglia et al. 2015; 2019), yet large parts of the region are still unexplored.
 The ground archaeological survey conducted by the authors at Al-Huwaidy village, 70 km southwest of Ha’il town, has led to the discovery of a unique Palaeolithic site on the margin of a palaeo-oasis, close to a volcanic mountain. The archaeological site consists of an agglomeration spread of lithics covering an area of basaltic field and outcrops. Numerous handaxes have been documented on the surface and the profiles of current water canal shafts. The site setting and the quantity and quality of lithics from Large Cutting Tools (LCT), including typical handaxes, foliate handaxes, Acheulean cores and flakes, indicate that the site represents a new and interesting extension of Palaeolithic archaeology in the northwest of Arabia similar to Palaeolithic characteristics in the Jubbah basin. Thus, this discovery has a direct relevance in assessing the distribution of Palaeolithic sites in the Ha’il region, showing that they not only occur in the northern area (Nefud desert), but also in the different landscape (basaltic lava field) in the southern part of the region.

Management of presumed trematode-induced granulomatous intermediate uveitis.

To describe the surgical management of presumed trematode-induced granulomatous intermediate uveitis (PTIGIU) not responding to medical treatment in controlling the inflammation. A prospective, interventional, single-center study in which patients with a history of fresh canal water contact and PTIGIU were enrolled. All patients underwent lensectomy-pars plana vitrectomy (PPV) and post-operative control of inflammation, functional and anatomical outcomes were assessed. Fifteen eyes of 12 patients were included in the study with median age of 11.6 ± 4 yrs. Six months following lensectomy-PPV, inflammation was well controlled in all patients. The eyes were divided into two groups: Group A: 10 patients with an attached retina while Group B: 5 patients who were in the cicatricial stage with tractional retinal detachment. All patients in group A had CDVA of 20/40 or better, unlike patients in group B who failed to achieve a CDVA better than 20/70 throughout their follow-up. In group B, final anatomical success was achieved in only 40% with hypotony occurring in 20%. PTIGIU is associated with the presence of ciliary body granuloma which, if left untreated, can lead to drastic outcomes. Early lensectomy-PPV represents a viable management option in cases resistant to medical treatment, with a favorable outcome.

Enhanced coagulation process for removing dissolved organic matter, microplastics, and silver nanoparticles

Dissolved organic carbon (DOC), microplastics (MPs), and silver nanoparticles (AgNPs) in water are of major concern because of their direct and indirect toxic effects on aquatic organisms and human exposure via water. This work investigated the effect of poly aluminum chloride (PACl) coagulation for reducing DOC, MPs, and AgNPs. This work used water from a canal in Thailand with a DOC of 5.2 mg/L in the experiment. AgNPs of 5–20 mg/L were added to canal water to create synthetic water for the PACl coagulation. Polyethylene and polypropylene (PP) type MPs were identified in the raw water with Fourier transform infrared spectroscopy. Coagulation with 15 mg/L of PACl performed better in the PP removal. The PACl coagulation at dosages of 15, 40, and 70 mg/L removed DOC by 16–20%, 44–52%, and 46–63% and AgNPs by 34–90%, 53–93%, and 81–95%, respectively. The presence of AgNPs at high levels could inhibit the efficiency of DOC reduction by the PACl coagulation. The FESEM identified the adsorption of silver-containing nanoparticles onto the flocs with increased dosages of PACl. So, PACl is a coagulant in the removal of AgNPs that can reduce health hazards and eco-toxicological risks in water sources due to the release of silver.

Assessment of Variability of Rainfall and Canal Water under Telugu Ganga Project Command in Andhra Pradesh

The present study was conducted to make a detailed assessment of the variability and relationships of rainfall (mm) received, canal water (Mcum) supplied and the yield (kg/ha) of major crops viz., paddy, groundnut, sugarcane, sorghum and cotton crops attained under the Telugu Ganga Project (TGP) command area in Andhra Pradesh during 1997 to 2021. The crop productivity would always be influenced by the water resource available to a crop. Accordingly, linear and quadratic regression models of yield were calibrated to predict the yield of crops through canal water supplied in different years. The regression models were assessed based on the significance of coefficient of determination (R2) and magnitude of prediction error (PE) of the yield over years. The canal water released in different years was found to significantly influence the yield of paddy, groundnut, cotton and sugarcane crops under the TGP command area. The quadratic regression models gave higher and significant values of R2 compared to the linear regression models calibrated for different crops. The predictability of yield was found to be 0.725 under quadratic model compared to 0.605 under linear model for paddy, while it was 0.458 under quadratic model compared to 0.406 under linear model for groundnut. In case of sugarcane, the predictability of yield was found to be 0.488 under quadratic model compared to 0.431 under linear model. The models were found to be useful for prediction of yield of crops through varying levels of canal water released in different years. This will greatly help to efficiently utilize the canal water resources with regard to the quantity and frequency of water to be provided for irrigation of crops. Since the canal water released under TGP command area is highly assured,we recommend that the farmers could efficiently utilize the available canal water by growing less water requiring crops and attain maximum yield and profit by adopting the improved agricultural technologies of different crops grown under the TGP command area.

Feasibility Assessment of Rural Hybrid Microgrid Using Canal-Based Microhydel Resources: A Case Study of Renala Khurd Pakistan

Water canal networks that are widely used for irrigation are an equally good source of micropower generation to be fed to the nearby areas. A practical example of such a system is the micro-hydro generation at Renala Khurd Pakistan integrated with the national grid known as hydro–grid configuration. Apart from the rare Renala Khurd hydro generation example, solar photovoltaic generation integrated with a mainstream network, i.e., solar PV-Grid configuration, is widely used. The integrated operation of combinations of primary distributed generation sources has different operational attributes in terms of economics and reliability that are needed to be quantified before installation. So far, various combinations of primary distributed generation sources have been simulated and their accumulative impact on project economics and reliability have been reported. A detailed economic and reliability assessment of various configurations is needed for sustainable and cost-effective configuration selection. This study proposes a trigeneration combination of solar–hydro–grid with an optimal sizing scheme to reduce the solar system sizing and grid operational cost. A genetic algorithm based optimal sizing formulation is developed using fixed hydro and variable solar and grid systems with a number of pre-defined constraints. The hydro–grid, solar–grid, and grid–hydro–solar configurations are simulated in HOMER Pro software to analyze the economic impact, and to undertake reliability assessments under various configurations of the project. Finally, optimal values of the genetic algorithm are provided to the HOMER Pro software search space for simulating the grid–hydro–solar configuration. It was revealed that the net present cost (NPC) of hydro-to-grid configuration was 23% lower than the grid–hydro–solar configuration, whereas the NPC of grid–hydro–solar without optimal sizing was 40% lower than the solar–grid configuration, and the NPC of grid–solar–hydro with the genetic algorithm was 36% lower than the hydro–grid configuration, 50.90% lower than solar–grid–hydro without the genetic algorithm, and 17.1% lower than the grid–solar configuration, thus proving utilization of trigeneration sources integration to be a feasible solution for areas where canal hydropower is available.

Successive addition of rice straw biochar enhances carbon accumulation in soil irrigated with saline or non-saline water

Biochar has been evaluated globally to improve soil fertility and mitigate climate change. However, the long-term effects of successive biochar application on carbon (C) accumulation in soil irrigated with saline versus non-saline water (canal water) has not been investigated. A field experiment was conducted to study the effects of rice straw biochar addition rates (0, 2, 4, 8 Mg ha−1) on C storage in soil irrigated with water of different electrical conductivity [EC, dS m−1]; 0.3 (non-saline canal irrigation water; CIW), 5 (saline irrigation water; SIW5), 10 (SIW10), and 15 (SIW15) in a cotton-wheat system. Long-term irrigation with saline water of variable EC levels adversely affected soil functions, reducing above-ground biomass in cotton (12–48%) and wheat (5–27%). In contrast, plots irrigated with saline water but amended with rice straw biochar showed significant improvement in aboveground biomass (both in cotton and wheat), possibly due to its beneficial effects on soil properties such as soil EC, organic carbon, microbial population, water and nutrient availability, bulk density, soil aggregation, and proliferation of roots. Interestingly, the change in total organic C (TOC) stocks (8.5, 17, and 27.5 Mg C ha−1) after 5 years were found to be almost double the amount of biochar C added (4.3, 8.6, 17.2 Mg ha−1), indicating stabilization of belowground C inputs from the root biomass by the applied biochar and also possibly through its physical interaction with aggregates and minerals. Even though biochar application to saline water irrigated plots increased the contribution of plant-derived C to overall soil TOC stocks, it was still lower compared with canal water irrigated plots. The study conclusively established that the long-term stabilization of biogenic C through biochar has essential implications for mitigating climate change by accumulating additional C beyond the recalcitrant C contained in biochar.

Assessment of water quality and ecosystem health of a canal system during the lockdown period.

The impacts of the lockdown period on water quality and ecosystem health in an artificial canal water system were investigated from the rapidly growing Kozhikode City in India. The ecosystem health is measured in terms of water quality indicators such as pH, electrical conductivity (EC), dissolved oxygen (DO), biological oxygen demand (BOD) and Escherichia coli (E. coli) during the pre-lockdown and lockdown period. The study reveals the massive improvement of the ecosystem health of the canal in terms of DO, BOD, and E. coli during the lockdown period. DO values were improved from anoxic (0mg/L) to oxic (> 5mg/L), BOD reduced from 31 to 0.7mg/L as well as E. coli at major urban stretches were 800 MPN/100mL, which was observed to be absent during the lockdown period. Urban stretches of the canal implicitly proved that the lockdown period was not sufficient to recover the natural ecosystem condition of the canal system. Principal component analysis revealed that the ecosystem health of the canal majorly governs two factors, such as the weathering process and anthropogenic waste sources. The study advocates the policy makers that temporary pollution source control in a timely interval may heal the environment and is useful to the regulatory bodies for suggesting the pollution source control mechanism.

A comprehensive performance assessment system for diagnosis and decision-support to improve water and energy efficiency and its demonstration in Portuguese collective irrigation systems

In regions with a strong seasonal or interannual asymmetry in the distribution of precipitation and higher frequency of droughts, collective irrigation systems are vital infrastructures for agricultural activity. Although operating for decades, several systems have ageing infrastructures, with relevant water losses and pumping energy inefficiencies. Consequently, the systems are not adequately designed or operated to meet current and future water demand. Therefore, rehabilitation to improve water and energy efficiency while ensuring infrastructure, economic sustainability and service quality is crucial. In this sense, comprehensive approaches using performance assessment to support the planning process or benchmarking between water users associations play an essential role in improving efficiency in collective irrigation systems. However, few methodologies assess interdependencies between water losses, energy efficiency, infrastructure condition, service quality, economic and operational dimensions. Additionally, these approaches rarely were applied to the different stages of the planning process (diagnosis, planning, monitoring, and reviewing the impact of measures) and to different types of collective irrigation systems (gravity, pressurised, combined) for comparative analysis. This paper presents a comprehensive performance assessment system (PAS) for diagnosis and decision support about measures to improve water and energy efficiency in collective irrigation systems. Afterwards, the PAS is applied for diagnosis and prioritisation of alternatives to enhance the efficiency of a gravity system. The results indicate significant water losses due to the canal and intermediate reservoirs discharges and leakage in canals and low-pressure pipes, related to network ageing and insufficient flow monitoring and control for the gravity system. Ranking allowed identifying the gravity network area with high priority of intervention due to poor performance in non-revenue water, water losses due to discharges, energy efficiency of pumping stations and system energy in excess. Several alternatives were studied for this network area, and infrastructural solutions involving canal rehabilitation and water discharge control significantly impact global performance improvement besides the substantial investment associated. Subsequently, the PAS is used for comparing gravity and pressurised systems. In opposition to gravity, the pressurised system, with efficient use of water resources, presents a poor performance in pumping energy efficiency. Furthermore, the significant energy costs indicate the importance of energy improvement measures for the pressurised system. Besides assessing water and energy efficiency, the novel PAS may help managers and policymakers identify every system's best practices and weak points.

Health risk implications of iron in wastewater soil-food crops grown in the vicinity of peri urban areas of the District Sargodha

Irrigation using sewage water can be beneficial, as it can increase the productivity of crops but has negative consequences on crops, soil contamination, and human health. It contains a variety of toxins, such as chemicals and heavy metals, which damage the soil and crops. In this regard, the aim of the research was to assess the potential health hazards of iron (Fe) metal in food crops (leafy and root crops) treated with wastewater (T_1), canal water (T_2), and tube well water (T_3). Water, soil, and edible components of food crops were collected at random from three distinct locations. Fe concentration in samples was estimated using atomic absorption spectrophotometer, following wet digestion method. The Fe concentrations, ranged from 0.408 to 1.03 mg/l in water, 31.55 to 187.47 mgkg-1 in soil and 4.09 to 32.583 mgkg-1 in crop samples; which were within permissible limits of the World Health Organization (WHO). There was a positive correlation between soils and crops. The bioconcentration factor, enrichment factor (EF), daily intake of metals (DIM), health risk index (HRI), and target hazard quotient (THQ) all values were <1, except for a pollution load index >1, which indicated soil contamination, but there was no Fe toxicity in crops, no health risk, and no-carcinogenic risk for these food crops in humans. To prevent the excessive accumulation of Fe metal in the food chain, regular monitoring is needed.

Genetic Behavior of Tomato (Solanum lycopersicum L.) Germplasm Governing Heavy Metal Tolerance and Yield Traits under Wastewater Irrigation.

Wastewater irrigation is a substitute for surface water scarcity, but traces of heavy metals (HMs) result in deleterious implications for soil, crop productivity, and in humans. Crops presenting HMs tolerance in genetic behavior are important for producing tolerant genotypes cultivated under wastewater irrigation. In the first part of this experiment, the results obtained previously are re-assessed in a hydroponic system and similar patterns and concentrations of HMs are found in different tomato organs. Following this trial, the tomato's (Solanum lycopersicum L.) genetic basis of traits conferring HMs tolerance and yield are assessed when irrigated with waste or canal water. The North Carolina Mating II analysis illustrate the amount of gene action, nature, and inheritance pattern. Genetic components depict the involvement of non-additive, additive, and maternal genetic effects in HMs tolerance inheritance and yield. A noticeable increase in cumulative additive variance for the number of flowers (11,907.2) and the number of fruits (10,557.9) is recorded for tomato plants irrigated with wastewater, illustrating additive gene action. However, female and male (MSf/MSm) square ratios also show an association with cytoplasmic inheritance. For HMs tolerance, both additive and dominant variances appeared to be significant; cumulative dominance variance (4.83, 16.1, 4.69, 76.95, and 249.37) is higher compared to additive variance (0.18, 2.36, 0.19, -0.27, and 14.14) for nickel (Ni), chromium (Cr), lead (Pb), manganese (Mn), and zinc (Zn), respectively, indicating dominance gene action. The genotype RIOGRANDI accumulated and translocated fewer HMs to the aerial part of the plant compared to CLN-2418A and PB-017906, thus presenting a tolerant tomato genotype according to the hydroponic experiment. This also exhibited a differential pattern of gene action for HMs tolerance, suggesting that genotypes possess significant differences for HMs tolerance.

Concentration of some heavy metals in main irrigation and drainage canals water of Bakolori irrigation project, Zamfara state, north western Nigeria

Concentration of Some heavy metals in main irrigation and drainage canals water of Bakolori Irrigation Project (BIP) were investigated from March 2019 to February 2020. Four sampling stations were systematically & randomly selected from the two canals respectively. Water samples were collected monthly from the eight sampling stations and taken to the laboratory for analysis of Cadmium (Cd), Chromium (Cr), Copper (Cu), Iron (Fe), Manganese (Mn), Lead (Pb) and Zinc (Zn). The data collected were arranged on the bases of two seasons (dry & wet) and five sub-seasons, namely: Early dry (Oct - Dec); mid dry (Jan & Feb); late dry (March - May); Early rainy (June & July) and flood period (Aug & Sept), and subjected to T test (p

Modeling of Irrigation Water Demand for Sustaining Crop Yield in Saline Environment

Increasing the productivity of water and making safe use of poor quality water in agriculture will play a vital role in easing competition for scarce water resources prevention of environmental degradation and provision of food security. The purpose of this study is to cover the crop water demand and supply gap with the management strategies. The comparison of actual water supplies and demand, i.e. crop water demand has been calculated and found that demand is more than supply. The daily reference evapotranspiration for Bhutana distributory is estimated using pan-Montieth method in CROPWAT model and crop-water demand has also been calculated using CROPWAT model. The supply shortfall in total Rabi seasons is 329.5 mm in 2009-10 and 162.2 in 2010-11. This gap is met by pumping ground water. Different scenario is generated after canal supply gap analysis because supply is less and demand is more and at the same, ground water quality is not so good. In some places, there is a problem of salinity or sodicity. Twelve point have been selected for soil sample from different locations of Butanadistributory. The result revealed that EC, SAR, RSC varies from 1.5 g/kg, 2.7-20 (mmoles kg-1)0.5 , 0- 8.8 mg/l. The best management strategies such as growing salt tolerant crops varieties and proper irrigation scheduling with effective conjunctive use of multiquality irrigation water, and pre-sowing water management was suggested for various scenarios of deficit canal water supply, poor soil and ground water quality, and water logging conditions for growing more food with less water of good/poor quality. This study will be helpful for engineers, researchers and farmers in taking decision on utilization of ground water, which will minimize their yield losses in scarce water supply and marginal quality of ground water.

The effects of riverside cities on microplastics in river water: A case study on the Southern Jiangsu Canal, China

Microplastics, which are usually recognized as artificial polymer particles with a particle size <5 mm, have attracted much attention as new pollutants in recent years. Urban areas are a major contributor of microplastics to the environment, but their microplastic emission intensity and characteristics are not clear. In this paper, the microplastic abundances and characteristics in the Southern Jiangsu Canal were studied to reveal the effect of riverside cities on microplastics in river water. The results show that the microplastic abundance in the water body of the South Jiangsu Canal ranges from 3.41 to 19.07 particles L−1, with an average of 9.59 ± 3.95 particles L−1, which is at the same level as major urban agglomerations in the world. The top five polymers were polyethylene terephthalate (PET), polycarbonate (PC), polyethylene (PE), chlorinated polyethylene (CPE) and polyurethane (PU). Fragments accounted for the largest proportion (68.47 %), followed by beads and fibers. Most microplastics were <100 μm (83.87 %). Human life and industry in riverside cities contribute significantly to microplastics in the Southern Jiangsu Canal water. After flowing through the cities, the microplastic abundance in the canal water increased by 26 % ~ 211 %. The overall economic and social development of the city affects the occurrence characteristics of the canal water microplastics. The average abundance of microplastics was positively correlated with Regional Gross Domestic Product (GDP) per capita. Wastewater treatment plant effluent is an important point source of microplastics in canal water. The microplastic abundances downstream of WWTPs increased by 21.8 % ~ 64.6 % compared with those upstream.