Flooded Fields Research Articles

Pore-scale experiments on the synergistic EOR mechanisms between the main components of LASP (lipopeptide-alkali-surfactant-polymer) system

To improve the oil recovery efficiency of ASP (alkali-surfactant-polymer) flooding, lipopeptide surfactant was added into ASP to form a new system (LASP). Core flooding experiments and field pilots suggested that LASP can achieve better oil recovery with lower costs. To determine the synergistic effects of the LASP system, a series of pore-scale flooding experiments were performed to quantify the displacement and sweep efficiencies of the LASP system and its main components independently. The results suggested that the petroleum sulfonate tends to improve displacement efficiency (by 21.1%) and the polymer tends to widen the effective sweep area (by 14.2%). While lipopeptide improved both oil displacement efficiency (31.2%) and sweep efficiency (10.2%) depending on the oil emulsification. Their mixture, that is; LASP, reached a higher displacement (42.1%) and sweep efficiency (12.9%) that depended on synergistic effects between the components. For instance, the bio- and chemical surfactants and the polymer synergistically improved the stability and deformability of oil emulsion, which reduce flow resistance and then improve displacement efficiency. However, the throat-blocking mechanism, which expanded sweep area during lipopeptide flooding, no longer existed in the LASP system. Nevertheless, the LASP system can depend on high viscosity of polymer to effectively expand sweep area. Oil recovery in the LASP system is more than the sum of the mechanism of each component.

A framework for assessment of flood vulnerabilities – case of Narmada River Basin, India

The aim of this study is to lay a framework for evaluating flood vulnerabilities. Specifically, it applies the proposed methodology to evaluate flood vulnerability index (FVI) across 21 districts comprising a significantly large part (drainage area of 85 859 km2) of Narmada River basin in the central Indian state of Madhya Pradesh. The study assesses sensitivity, adaptive capacity indices, and the exposure risk over a chosen set of 22 climatic, demographic, social and economic parameters, and applies principal component analysis to evolve a composite FVI. The results rank various districts for their vulnerabilities to floods. The analysis indicates that, in the study area, around a third of the vulnerability is accounted by two factors: a lack of adaptive capacity of the community and heightened sensitivity to floods. There exists significant scope to modify these two factors by appropriate policy interventions at the social and economic levels. It is expected that the framework would be of use to stakeholders such as planners, policymakers, flood management authorities, field engineers, district administration and local non-governmental organisations who strive to make the community less vulnerable to floods.

Impact of sewage water irrigation on agricultural soil

The rapidly increasing population growth and the steady increase in water requirements for agricultural and industrial development have placed severe stress on the water resources available and the long term use of sewage water for irrigation highly affects soil properties. In this study soil samples were collected from a cauliflower field prior and after sewage water irrigation, and the impact of sewage water irrigation on physical, chemical, and biological properties of soil was compared. For this, tested were pH, Electrical Conductivity (EC), Organic Carbon, available Nitrogen, Phosphorus, Potassium, Calcium, Magnesium, Zinc, Iron, Copper, Manganese, and microbial activity. Soil microbial biomass carbon, basal soil respiration, total viable count of bacteria, coliform population, Pseudomonas species, and Azotobacter significantly increased after sewage water irrigation as compared to prior to irrigation. Nevertheless, the bulk density and Rhizobium species of the soil flooded with sewage water was decreased relative to the same characteristics prior to irrigation. Cauliflower yield was significantly increased when sewage water flooded field as compared to the tube well water flooded field (i.e., water delivered via an iron pipe). Escherichia coli contamination was greater in sewage water and groundwater that can pose health risks for the nearby communities, to farmers and consumer of farm products. Hence, the efficient use of sewage and municipal wastewater successfully increase water resource for irrigation and may help in expanding agricultural production. But excessive use of sewage water may also affect the soil flora and fertility.

Novel Bayesian Additive Regression Tree Methodology for Flood Susceptibility Modeling

Identifying areas prone to flooding is a key step in flood risk management. The purpose of this study is to develop and present a novel flood susceptibility model based on Bayesian Additive Regression Tree (BART) methodology. The predictive performance of the new model is assessed via comparison with the Naïve Bayes (NB) and Random Forest (RF) based methods that were previously published in the literature. All models were tested on a real case study based in the Kan watershed in Iran. The following fifteen climatic and geo-environmental variables were used as inputs into all flood susceptibility models: altitude, aspect, slope, plan curvature, profile curvature, drainage density, distance from river distance from road, stream power index (SPI), topographic wetness index (TPI), topographic position index (TPI), curve number (CN), land use, lithology and rainfall. Based on the existing flood field survey and other information available for the analyzed area, a total of 118 flood locations were identified as potentially prone to flooding. The data available were divided into two groups with 70% used for training and 30% for validation of all models. The receiver operating characteristic (ROC) curve parameters were used to evaluate the predictive accuracy of the new and existing models. Based on the area under curve (AUC) the new BART (86%) model outperformed the NB (80%) and RF (85%) models. Regarding the importance of input variables, the results obtained showed that the location’s altitude and distance from the river are the most important variables for assessing flooding susceptibility.

A preliminary study on the distribution of breeding sites of BIOMPHALARIA GLABRATA in the municipality of peri mirim, a low endemicity area for schistosomiasis in northeast Brazil

Information on areas colonized by snails that transmit Schistosoma mansoni is essential for planning schistosomiasis control measures. Therefore, the purpose of this study was to map the natural breeding sites of Biomphalaria spp. in the municipality of Peri Mirim, Maranhão, Brazil. The snails were manually collected and the breeding sites were geo-referenced (seven in the urban area and five in flooded fields), from November 2017 to March 2018. In the laboratory, the snails were examined for the presence of larval stages of S. mansoni identified by morphology and internal anatomy analysis. While no snails were found in the urban area, sixteen B. glabrata were collected in the flooded fields. No S. mansoni or other trematode infections were detected. Wild rodents, most likely Holochilus sciureus that could act as S. mansoni reservoirs, were also found in the flooded fields. These data indicate possible risk areas for further outbreaks of schistosomiasis transmission in the municipality of Peri Mirim.KEY WORDS: Baixada Maranhense; malacological survey; planorbidae; spatial analysis.

Analysis on dynamic characteristics of polymer flooding and influencing factors of flooding effect in Daqing Oilfield

Polymer flooding technology after years of painstaking research, from the initial pilot field experiment, to the later industrial field experiment, now has entered the stage of industrialization. During this period, a series of technical applications in the field of polymer flooding were established, forming a supporting system for polymer flooding, laying a solid foundation for the large-scale application of polymer flooding, which is widely used in the oilfield. And polymer flooding technology has achieved remarkable results in Daqing Oilfield. This paper analyzes the dynamic characteristics of polymer flooding technology in Daqing Oilfield and the influencing factors of displacement effect.

A regression-based approach to compute the pixels sensitivity map of linear accelerator portal imaging devices.

To determine the pixel sensitivity map (PSM) for amorphous silicon electronic portal imaging devices (EPIDs) using a single flood field signal. A raw EPID signal results from the incident particle energy fluence, the inherent pixels response, and the background signal. In large open fields, particle energy fluence is a slow-varying signal that is locally considered spatially constant. Pixels response is a fast and abrupt varying behavior. The background signal is due to the EPID panel electronics, which is determined during radiation absence. To determine the PSM, after correcting for the background signal, we apply a model that captures the underlying smooth particle energy fluence-induced signal. This fluence signal-fitted model is then used to determine the PSM. Here, we use a polynomial-based regression surface model in both x and y dimensions. To validate the generated PSM, we measure beams and compute PSMs for multiple beam energies with and without flattening filters and for multiple source-to-imager distances. Since the PSM is a detector characteristic, it should be independent of those variables. We also intercompare measurements of fixed slit fields with the EPID being shifted between measurements. The fluence signal of the flattening filter-free (FFF) beams was optimally modeled as a 12th degree polynomial surfaces, which had 0.1% residuals near the central axis. The 6 and 10MV FFF PSMs were within ˜0.1%, and independent of the EPID SID, suggesting that the PSM is energy independent. The 6, 10, and 15MV flattened-beam PSMs were well modeled as 12th degree polynomial surfaces, which were equivalent within ˜0.24% but differed from the FFF PSM by up to 0.5% near the beam central axis. Applying the FFF PSMs to the flattened-beam measurements reduced the central-axis deviation between the raw and corrected signal to 0.1%, confirming the PSM energy independence hypothesis. When the FFF PSM is utilized, output verification with shifted slit deliveries agreed within ˜0.5% for all beam energies, which is within the radiation delivery uncertainty of ˜0.57%. PSM for MV EPIDs can be determined by separating out the slowly varying, well-behaved fluence signal from the pixel-to-pixel sensitivity variations. The quality of the PSM is found to be dependent on the quality of the surface fit, which is best for the 6MV FFF beam measured at SID equal to 180cm. Within fitting errors, the PSM is independent of beam energy for 6, 10, and 15MV beams with and without flattening filters. The PSM generation does not require shifting the EPID panel nor multiple EPID panel irradiations and should be usable for linacs with fixed geometry EPIDs.

Relationship between ionomics and transcriptomics of rice plant in response to arsenite stress

Paddy rice cultivated in flooded fields tends to accumulate more arsenic than other terrestrial crops. Ionomic profiling and transcriptomic variations of rice plants were investigated to understand the molecular mechanism used to counteract arsenite [As(III)] stress. The total concentrations of 29 elements in the rice shoots and roots under control and As(III) stress conditions were determined by inductively coupled plasma mass spectrometry (ICP-MS). Ionomic differences between rice tissues under different conditions were identified through principal component analysis. Compared to their external conditions, the genomic composition plays a more important role in rice ionomics. In the transcriptome analyses, a total of 3812 differentially expressed genes (DEGs) were identified in the As(III)-treated shoots compared to the control shoots. The significant DEGs generated by gene ontology enrichment analysis were mainly associated with transmembrane transporters and ion binding, which were directly correlated with ionomics. Upregulation of transporter genes correlated with nutrient elements was observed, indicating that the rice plants tended to translocate more nutrients, such as potassium, phosphate and ammonium, to cope with As(III) toxicity. Transcriptomics also showed overexpression of aquaporins and ABC transporters for detoxification of As(III) in rice plants. Further investigation is necessary for a deeper insight into the molecular mechanism involved in the ionomics of rice plants.

Development of a modular high-sensitivity high-uniformity gamma camera for radiation monitoring applications

One direct way to improve the gamma camera’s sensitivity is using large-area gamma detectors. During construction of a large-area gamma camera, achieving high uniformity (including both spatial uniformity and events count map uniformity) across the entire active area is a major challenge. Another fabrication concern is that large-scale gamma sensors (mainly with reference to scintillators) and photoelectric converters such as position-sensitive photomultiplier tubes (PSPMTs) and silicon photomultipliers (SiPMs) are required. In this work, to design a large-area gamma camera with high uniformity, a 22×22 CsI(Na) array with a pitch size of 4.6×4.6 mm 2 is divided into four optically isolated 11×11 modules, where each module is coupled independently to an 8×8 SiPM array (6.13×6.13 mm 2 per channel) and is then read out using separate preamplifier electronics. The preamplified signals for each module are sampled independently via their respective analog-to-digital converters (ADCs) and the digitized signals are then processed in a single field-programmable gate array (FPGA). Extra dead zones and optical losses are avoided between the modules as a result of the optimal design used in the junction area for the four modules. This modular concept leads to a high counting rate capability. 2D flood field images of the 22×22 CsI(Na) array are obtained under uniform irradiation using 241Am. The counting rate measurements are performed using 137Cs under various attenuation conditions. The sensitivity is tested and compared with existing devices. The results show that high uniformity (1.43) and high counting rate capability (∼72% improvement) are achieved. Thanks to the large-area gamma sensor, the gamma camera developed in this paper achieves highest sensitivity among the listed devices (Locating 137Cs producing 0.6±0.02μSv/h in < 10 s). The principles developed in this paper can be applied to the construction of large-area radiation detectors.

First record of Scolia rufiventris Fabricius, 1804 (Hymenoptera: Scoliidae) from Pantanal, Brazil

The first record of the wasp Scolia rufiventris Fabricius, 1804 is reported for the state of Mato Grosso do Sul and the Brazilian Pantanal in the Abobral region, in an area with predominance of flooded fields and Cambarazal dominance. The registration of the species contributes to the knowledge of the diversity of insects in the Pantanal, mainly in view of the last events of devastation by large-scale fires.

The Impact of Agricultural Activities on Habitat Use by the Wood Sandpiper and Common Greenshank in Rice Fields

Rice fields provide important inland stopover sites for migratory shorebirds. However, stopover duration and habitat use depend on the environmental conditions in the rice fields, which constantly change due to agricultural activities. This study determined the characteristics of habitat use in two shorebird species, the Wood Sandpiper Tringa glareola and Common Greenshank T. nebularia, in rice fields with different habitat conditions resulting from physical changes (field type: fields flooded after plowing, with high water levels after harrowing, or with low water levels after harrowing) and chemical changes (pesticide use: environmentally friendly or conventional farming) from agricultural activities around the time the migratory shorebirds arrive. The study was conducted during the spring stopover periods of these shorebird species in 2015 (May 2–20, 19 days) and 2016 (May 2–21, 20 days), during which we observed the characteristics of their habitat use and estimated the densities of potential prey. Both Wood Sandpiper and Common Greenshank were observed to use flooded fields with low water levels after harrowing. As for pesticide use, potential prey animals were most densely populated in environmentally friendly fields, for which only the large-bodied Common Greenshanks showed selection. This species-specific habitat use seems to be closely associated with body size-dependent prey availability and prey species selection. The small-bodied Wood Sandpiper was more affected by physical than chemical factors. These findings suggest that rice fields—major inland stopover sites for shorebirds—provide different habitats depending on agricultural activities. The study results also have practical implications for future improvement of inland shorebird habitat through efficient rice field management sensitive to the needs of migratory shorebirds.

Influence of Soil Moisture Zones on Rice Water Weevil (Coleoptera: Curculionidae) Populations in Furrow Irrigated Rice

Water conservation is an important factor for production of rice in the United States because of declining aquifer levels, but little research has been done to evaluate insect management in rice systems integrating water conservation practices. Rice water weevil, Lissorhoptrus oryzophilus Kuschel, is an important insect pest of rice in the U.S. Rice water weevil is a semiaquatic species that relies on flooded conditions to complete larval development, so water conservation practices are likely to impact their pest status. The study was conducted across the Mississippi River alluvial floodplain to compare rice water weevil population densities in different zones of a furrow irrigated rice field to a conventionally flooded rice field. All locations were sampled at 3, 4, and 5 wk after the initial irrigation. Larval densities were greatest in the lower end of furrow irrigated fields and in the adjacent flooded rice field compared with the upper and middle sections that did not hold standing water when averaged across three sample dates. Also, rice water weevil densities were greater during week five than week three. In terms of rice yields, the top third of furrow irrigated rice fields, the section that remained mostly dry, produced lower rough rice yields than all other sections and the flooded field. These results suggest that rice water weevil populations can be lower in a furrow irrigated rice system. As a result, more research is needed to determine whether a spatial management plan can be developed based on soil moisture zones in furrow irrigated rice.

Effect of Soil Water Content and Soil Texture on Phytophthora cinnamomic Infection on Cork and Holm Oak

Phytophthora cinnamomi is an important soil borne plant pathogen, associated to decline of cork and holm oak stands in Iberian Peninsula. This decline results from a complex of biotic and abiotic interactions culminating in root infection. Field observations in cork and holm oak sites suggested an enhancement of soil moisture and texture in decline processes. Greenhouse assays were developed to evaluate the impact of soil moisture and texture on the severity of root infection on both species. Seedlings were potted in P. cinnamomi infested soils with different textures (loamy-sand, clay and silty- loam) combined with different watering regimes (flooding, normal irrigation, and irrigation till wilting and field capacity). The impact of P. cinnamomi infection was assessed through plant biomass, water consumption and root severity. The infection caused either losses of plant biomass (root and shoot) as plants water consumption, in both species, depending on soil moisture and texture. Holm oak plants were more susceptible to P. cinnamomi infection than cork oak, with higher mortality and root degradation. To minimize the risk of infection, watering managing appeared to be an essential condition to optimize plant growth and survival taking also into account the texture and moisture of the soil.

Improving nitrogen‐use efficiency by using ridge tillage in rice paddy soils

AbstractNitrogen (N) fertilizers are increasingly being used to meet crop demand for the expanding human population. However, historical N‐use efficiency (NUE) is low for rice paddy fields compared to upland ecosystems. This study aimed to investigate the fate of N fertilizer and compared NUE under different tillage regimes in a rice‐based agroecosystem. A long‐term field study of tillage regimes (i.e. flooded paddy field, conventional tillage and ridge tillage) and 15N isotope tracer methods (in situ and incubation) was used to determine N fertilizer fate and uptake. Nitrogen uptake by rice (which represents NUE) significantly differed between tillage regimes (p &lt; .05). Nitrogen‐use efficiency was 31% of applied N fertilizer for ridge tillage, which was the highest among the three tillage regimes, while the lowest NUE occurred for conventional tillage (17%). The soil residual N for ridge tillage was significantly higher (21%), than for the flooded paddy field or conventional tillage. The total gaseous N loss was highest for ridge tillage (28%) and lowest for conventional tillage (17%). Ammonia (NH3) volatilization accounted for the largest proportion of gaseous loss from N fertilizer for all three tillage regimes. However, the largest loss of applied N was with water (runoff and leaching), where N loss accounted for 20% of applied N for ridge tillage but up to 54% for conventional tillage. Ridge tillage changed the soil micro‐topography and water regimes leading to better N conservation. Based on these results, adoption of ridge tillage should significantly improve NUE for rice paddy fields.

TOTAL SUSPENDED SOLID DISTRIBUTION IN HAU RIVER USING SENTINEL 2A SATELLITE IMAGERY

Abstract. This research was applied high-resolution Sentinel-2A imagery which aims to monitor a suitability of MultiSpectral Imager (MSI) at higher resolution (10 m) for mapping of Total Suspended Solids (TSS) ) in the upper reaches of the Mekong Delta – An Giang province. The field survey is carried out to collect TSS at random distribution sites outside full-dyke protection. A remote sensing algorithm with a regression function method is developed to estimate TSS concentration automatically to select between the most sensitive TSS and water reflectance relationship. The regression analytical algorithm is predicted the output values based on normalized suspended material index (NSMI) (r2 = 0.92), showing the MSI sensor’s great potential to estimate TSS. The results confirm that suspended materials in the surface water reached the minimum of 10.36 mg/l and the maximum of 328.56 mg/l in An Giang province, the suspended materials distributional tendency with high content was mainly in flooded fields near the upstream of the basin of Hau river, especially in areas without the dike enclosure and the content was low in the areas within the dike enclosure. These findings promote further research in water quality studies relying on both operational Sentinel-2A and Sentinel-2B imageries with great implications to improve the understanding of turbid coastal and inland water environments.

Characterization of DMI Response and Prediction of Halcyon Machine Performance Check Using Machine Learning Algorithms

Digital megavoltage imaging (DMI) detector is a standard imaging device installed on Halcyon treatment machines to measure the x-ray intensity transmitted through a patient during the treatment session and for daily quality assurance (QA) using the MPC system. In this study, we characterized the digital megavoltage imaging (DMI) response for the machine performance check (MPC) on Halcyon treatment machine and predicted the performance of DMI using the machine learning algorithms to improve the accuracy of DMI dosimetry. The measured flood-field image on the DMI segmented to 9 regular grids of 9 × 9 cm2 size with the central grid positioned at the isocenter to evaluate the uniform response over time across the different cross-section of the DMI surface area. The time-resolved MPC beam output changes evaluated through comparison with the ion chamber measurements over 30 days. Also, the image ghosting effect evaluated for the repeated and time-delay MPC beam output change, and the raw flood field data was analyzed. Four different machine learning (ML) algorithms (linear regression, support vector regression (SVR), k-nearest neighbor (KNN), and random forest) were trained and tested with 757 days measurement, aiming to predict our MPC output change and flood field. The accuracy of the predictive data calculated by assessing its deviation from the test data in terms of root mean square error (RMSE). The stability of DMI across the different cross-sections was a maximum of 0.8 % deviation over 30 days compared to the center grid. The time-resolved measurement of MPC output compare to the ion chamber showed a gradual increase in the output deviation up to 0.4% over 30 days. The test result of the ghosting effect for the repeat MPC measurements shows the maximum output difference - 0.95% compared to fresh MPC with 5 minutes time-delay. The recovering rate of MPC output was 0.02 for 5 - 40 minutes and with a gradual rise afterward. After an approximate of 10-hour delay, the MPC measurement will fully recover its full response. The predicted MPC output changes agree with test data to within RMSE of 0.281, 0.266, 0.270, and 0.302 % for linear, SVR, KNN, and random forest models, respectively. On the average, predictive raw flood field agrees with test data within RMSE of 2.030, 1.794, 2.943, and 3.979% for linear, SVR, KNN, and random forest models, respectively. Generally, the SVR ML algorithm has the highest degree of accuracy. From this study, the DMI panel will lose its response function by 1.799% (∼2%) in 365 days usage. The characteristic of the DMI for MPC measurement was presented, and ML algorithms will be useful for preventive maintenance. Further study warranted to develop DMI response correction based on the current study and also appropriate QA strategy of DMI needs to be in place.

Applying floodplain geomorphology to flood management (The Lower Vistula River upstream from Plock, Poland)

Abstract Using remote sensing extended on geological and topographical maps and verified by the field work, we present the flood management and study the geomorphic features of the floodplain of a large, sand bed, untrained but embanked river in order to determine the flood hazard and to predict future flood scenarios. In geomorphological mapping, we focus on the landforms: crevasse channels and splays, flood basin, chute channels, side arms, floodplain channels, dunes and fields of aeolian sand. We base the flood risk assessment on consultations with environmental engineers who design new technical structures that control inundation (cut-off walls and lattice levees). We describe a levee breach as a result of piping (inner erosion) in a high hydraulic gradient condition and its effect (scour hole) as an erosional landform consistent with the repetitive pattern of erosion and deposition formed by an overbank flow on a floodplain. We reveal an existence of homogenous morphodynamic reaches in the river valley.

Atrazine residues in flooded and nonflooded soil and effects on soybean

AbstractAtrazine applied at planting is commonly used for weed control in corn. With global climate change causing an increase in river flooding in the United States over the past decade, producers need information to determine the best course of action in flooded fields treated with atrazine into which they wish to immediately plant soybean. Studies were designed to understand the effect of flooding on atrazine residual activity including atrazine concentration, soybean injury, and soybean yield. In 2012, soybean yield in flooded treatments was reduced by prior atrazine application. In 2014, soybean injury was &lt;10% in all plots, and nonflooded, atrazine-treated soils had yields equal to the nontreated. Findings from this research indicated that it is possible for producers to consider replanting soybean after atrazine application, with appropriate changes to product labeling.

Radioactive 3D printing for the production of molecular imaging phantoms

Quality control tests of molecular imaging systems are hampered by the complexity of phantom preparation. It is proposed that radioisotopes can be directly incorporated into photo-polymer resins. Use of the radio-polymer in a 3D printer allows phantoms with more complex and reliable activity distributions to be produced whilst simplifying source preparation.Initial tests have been performed to determine the practicality of integrating Tc-99m into a photo-polymer and example phantoms produced to test suitability for quality control. Samples of build and support resins were extracted from the print cartridges of an Objet30Pro Polyjet 3D printer. The response of the resin to external factors including ionising radiation, light and dilution with Tc-99m pertechnetate were explored. After success of the initial tests the radio-polymer was used in the production of different phantoms. Radionuclide dose calibrator and gamma camera acquisitions of the phantoms were used to test accuracy of activity concentration, print consistency, uniformity and heterogeneous reproducibility. Tomographic phantoms were also produced including a uniform hot sphere, a complex configuration of spheres and interlacing torus’s and a hot rod phantom.The coefficient of variation between repeat prints of a 12 g disk phantom was 0.08%. Measured activity within the disks agreed to within 98 ± 2% of the expected activity based on initial resin concentration. Gamma camera integral uniformity measured across a 3D printed flood field phantom was 5.2% compared to 6.0% measured with a commercial Co-57 flood source. Heterogeneous distributions of activity were successfully reproduced for both 2D and 3D imaging phantoms. Count concentration across regions of heterogeneity agreed with the planned activity assigned to those regions on the phantom design.3D printing of radioactive phantoms has been successfully demonstrated and is a promising application for quality control of Positron Emission Tomography and Single Photon Emission Computed Tomography systems.

Diet Impacts on Climate and Health: New Zealand's Experience.

Diet Impacts on Climate and Health: New Zealand's Experience.