Low Flooding Research Articles

Determination of Optimal Meshness of Sewer Network Based on a Cost—Benefit Analysis

Urban pluvial flooding occurs when the capacity of sewer networks is surcharged due to large amounts runoff produced during intense rain events. Rapid urbanization processes and changes in climate increase these events frequency. Effective and sustainable approaches for the reduction in urban floods are necessary. Although several gray, green and hybrid measures have been studied, the influence of network structure on flood occurrence has not yet been systematically evaluated. This study focuses on evaluating how different structures of a single urban drainage network affect flood volumes and their associated damages. Furthermore, a cost–benefit analysis is used to determine the best network structure. As a case study, a sewer subnetwork in Dresden, Germany was selected. Scenarios corresponding to different layouts are developed and evaluated using event-wise hydrodynamic simulation. The results indicate that more meshed structures are associated with lower flood volumes and damage. Moreover, all analyzed scenarios were identified as cost-effective, i.e., the benefits in terms of flood damage reduction outweighed the costs related to pipe installation, operation and maintenance. However, a predominantly branched structure was identified as the best scenario. The present approach may provide a new cost-effective solution that can be integrated into the development of different mitigation strategies for flood management.

Pedosedimentary environments in the Caspian Lowland during MIS5 (Srednaya Akhtuba reference section, Russia)

Srednaya Akhtuba outcrop provides a detailed record of the Late Pleistocene continental and marine deposits and paleosols from MIS5 to MIS1. The MIS5 chronozone is presented by a continuous pedosedimentary sequence with three well-developed paleosols. The paper is based on the study of depositional environment and pedostratigraphy, with OSL chronological framework and precise altitude references. Field data are supported by chemical analyses, micromorphology, and clay mineralogy. A detailed study of MIS5 paleosols was first conducted for the Lower Volga area. Pedosedimentary sequence at that time developed on the river terrace in a backswamp and/or wetland influenced by extremely slow-moving stream after long seasonal floods. Thin loess layers were deposited during the brief episodes of low flood activity, while fluvial heavy loams – at the time of more intensive flooding. Mollic Gleysols and Fluvic Chernozems have been formed in the arid or semi-arid climate with seasonal freezing under productive wet meadows. Changes in the depositional environment resulted in the formation of welded paleosols, marked by textural difference, cryogenic levels, and accretionary humus horizons. Despite the complicated depositional pattern and the influence of seasonal floods, the MIS5 pedosedimentary sequence may serve as a good stratigraphic marker for the onset of Late Pleistocene allowing correlation with loess-paleosol sequences of the whole Ponto-Caspian region and linking it with the global stratigraphic schemes.

A pore-scale study of foam-microemulsion interaction during low tension gas flooding using microfluidics - Tertiary recovery

The emerging EOR technology of Low-Tension-Gas (LTG) flooding has been proven to be successful for tertiary oil recovery in laboratory scale coreflooding experiments. However, there has not been a detailed study of the pore-scale phenomena which occur during LTG flooding. In the current study, alternate injection of a suitable surfactant formulation and air has been used to simulate the mechanism of LTG flooding in a borosilicate water-wet micromodel. The main phenomenon that was investigated was the interaction between different microemulsion types (Winsor I and III) and foam. Results show that presence of foam facilitates faster and better oil displacement. Microemulsion equilibration time was improved in the presence of foam, due to increased mixing of the liquid phases. Presence of trapped gas helped to divert the flowing surfactant/microemulsion to regions with trapped remaining oil and thus improved oil recovery. For equilibrated Type III microemulsion, completely miscible flooding (or ultralow tension displacement) was observed. For Type I systems, oil-in-water macroemulsions were observed. For equilibrated Type III microemulsion, the presence of foam mainly improved the oil recovery rate. In case of Type III surfactant solution injection, the presence of foam improved both the oil recovery rate and the overall oil recovery. For Type I systems, the presence of foam enabled the transition of oil-in water macroemulsions to water-entrained macroemulsions, thus improving both the oil recovery rate and the overall oil recovery.

Flood hazard assessment in large plain basins with a scarce slope in the Pampean Plain, Argentina.

Floods are one of the most common natural phenomena and represent a serious hazard when they affect human activities. Structural measures are commonly used to mitigate them; however, these do not always give good results, mainly in plain areas with scarce slope. In this sense, the generation of a flood hazard map contributes to adequate hazard management and disaster prevention. The aim of this work is to evaluate the flood hazard areas in hydrological plain basins with scarce slope, taking as a case study the Samborombón river basin located in the Pampean Plain, Argentina. For this, a flood hazard map was made based on the analytical hierarchy process and using a GIS, taking into account physical aspects of the terrain, observations, and field measurements. Likewise, the map was validated using satellite images and the inhabitants in danger in the basin were quantified. The results show that the flood hazard areas correspond mainly to the floodplain of rivers and tributaries, while the main and secondary divide zones have low flood hazard sectors. On the other hand, numerous urban settlements were identified within flood hazard areas, these being urban settlements in the vicinity of old urban centers and new gated communities with high value homes, quantifying 1961 inhabitants at flood hazard and showing poor territorial planning. The methodology proposed gives to the management agencies the possibility of generating land use maps, as well as designing mitigation and contingency plans after a large rainfall event.

Enhancing Oil Recovery by Low Concentration of Alkylaryl Sulfonate Surfactant without Ultralow Interfacial Tension

AbstractSurfactant flooding plays a critical role in chemically enhanced oil recovery over the last half century, with the widely accepted mechanism of ultralow interfacial tension (IFT) by forming middle‐phase microemulsions with high concentration of a lead surfactant and a cosurfactant. However, it is found practically from field trials that high oil recovery efficiency can be obtained from low concentration surfactant flooding without forming microemulsions, and the principle behind has not been clearly unraveled yet. Here the solubilization of paraffin oil by the micelles formed with a commercial enhanced oil recovery surfactant, raw naphthenic arylsulfonates (NAS), was investigated using ultraviolet‐visible (UV–Vis) spectroscopy, dynamic light scattering (DLS), and transmission electron microscopy (TEM). It is found that paraffin oil can be well solubilized inside the NAS micelles, and mainly localized in the hydrophobic core of the micelles. The solubilization capacity of NAS micelles increases with increasing its concentration, and the size of micelles increases, but morphology of the micelles remains spherical with increasing the amount of paraffin oil, along with an appearance transition from transparent to opaque until the maximum solubilization capacity is reached. Core flooding results with crude oil indicate that in the presence of 0.24 wt.% polymer, addition of 0.1, 0.2, 0.5, and 1.0 wt.% NAS can get oil recovery factor of 24.1%, 27.0%, 30.5%, and 38.3%, which increases linearly with increasing NAS concentration though with the interfacial tension values only in the magnitude of 10−2 mN m−1 level. These findings prove preliminarily micellar solubilization can help increasing oil recovery efficiency even without ultralow IFT.

Default options and insurance demand

Default options may provide a low-cost way of influencing behaviour without modifying incentives and constraining choices between alternatives. However, an improved understanding is needed on whether they are effective when individuals have experience with making the choice in practice and have preferences for specific alternatives. We study whether defaults can be used to increase insurance coverage against low-probability/high-impact risks, like floods, and whether past flood insurance purchases and flooding experience moderate the effect of defaults. Our study uses a naturally occurring difference in experience, comparing the surveyed flood insurance choices of 1,187 homeowners, half of whom are in the Netherlands, where flood insurance penetration rates are low and recent flooding caused minor losses, and the other half of whom are in the United Kingdom (UK), where the opposite is true. We find defaults are effective amongst homeowners with little to no flood-related experience: in the Netherlands defaults increase the likelihood of insuring by between 17 and 18 percentage points. Although there is no overall effect of defaults in the UK, defaults increase flood insurance coverage for risk averse individuals, and those who have no reported previous flood experience and have not purchased flood insurance. Anticipated regret about not having insurance coverage in the event of a flood, and perceptions about the insurance cost explain between 34 and 37 percent of the relationship between the default and flood insurance demand. We discuss policy implications of our findings.

The FLOod Probability Interpolation Tool (FLOPIT): A Simple Tool to Improve Spatial Flood Probability Quantification and Communication

Understanding flood probabilities is essential to making sound decisions about flood-risk management. Many people rely on flood probability maps to inform decisions about purchasing flood insurance, buying or selling real-estate, flood-proofing a house, or managing floodplain development. Current flood probability maps typically use flood zones (for example the 1 in 100 or 1 in 500-year flood zones) to communicate flooding probabilities. However, this choice of communication format can miss important details and lead to biased risk assessments. Here we develop, test, and demonstrate the FLOod Probability Interpolation Tool (FLOPIT). FLOPIT interpolates flood probabilities between water surface elevation to produce continuous flood-probability maps. FLOPIT uses water surface elevation inundation maps for at least two return periods and creates Annual Exceedance Probability (AEP) as well as inundation maps for new return levels. Potential advantages of FLOPIT include being open-source, relatively easy to implement, capable of creating inundation maps from agencies other than FEMA, and applicable to locations where FEMA published flood inundation maps but not flood probability. Using publicly available data from the Federal Emergency Management Agency (FEMA) flood risk databases as well as state and national datasets, we produce continuous flood-probability maps at three example locations in the United States: Houston (TX), Muncy (PA), and Selinsgrove (PA). We find that the discrete flood zones generally communicate substantially lower flood probabilities than the continuous estimates.

Flood vulnerability assessment using a fuzzy rule-based index in Melbourne, Australia

The City of Moreland is a densely populated urban area in Melbourne and has suffered from riverine and overland flooding during the past few years. Therefore, it is necessary to conduct a flood vulnerability analysis in the region to determine the necessary measures for better flood risk management. A fuzzy rule based flood vulnerability index was developed in this study considering hydrological, social, and economic aspects of flood damages to assess and map the flood vulnerability of MC. It was found that 51.6% of the area (corresponds to 26.21 km2) falls under very low and low flood vulnerability zones, whereas 7.6% of the total area are classified as high and very high flood vulnerable zones. The outcomes of the present study will help the concerned authorities in the study area to identify flood prone areas and develop flood mitigation strategies to minimise the damages caused by floods.

Effect of water level and water quality on small‐sized and juvenile fish assemblages in the littoral zones of the Zambezi/Chobe floodplain

AbstractThe effect of flooding phase and water quality on the littoral fish species of the Zambezi/Chobe floodplain was assessed between March 2017 and February 2018. Using the similarity percentage analyses (SIMPER), a 61.9% dissimilarity was detected in fish assemblages among the four flooding phases of the Zambezi/Chobe floodplain (rising, peak, recession and low flooding phase). Cichlids (63.1%) were the most dominant taxa during the peak flooding phase while cyprinids were dominant during the rising (40.7%), recession (45.3%) and low flooding phases (40.9%), respectively. Juveniles of the two commercially important species, Oreochromis andersonii and Coptodon rendalli, were among the four abundant species across the four flooding phases of the Zambezi/Chobe floodplain. Higher densities of these two species were in synchrony with the peak flooding phase, characterised by high levels of dissolved oxygen (5.7 ± 1.0 mg/L), neutral pH (7.9) and moderate water temperature (27.6 ± 1.1°C). During the flood recession phase, a severe decline in juvenile of the commercially important species (O. andersonii and C. rendalli) coincided with fish migration off the littoral zone into the main river at a mean size between 70 and 80 mm SL. Generally, the observed variations in the fish species composition during the different stages of flooding might reflect the influence of water quality and water volume to sustain large fish assemblages on the littoral zone of the Zambezi/Chobe floodplain. Any change in the natural flow and reduction in water volume of the Zambezi/Chobe floodplain might negatively affect the recruitment of juvenile fish into adult populations.

A pore-scale study of foam-microemulsion interaction during low tension gas flooding using microfluidics- secondary recovery

The most commonly used methods for secondary oil recovery have been waterflood and immiscible gas flood. However, these methods leave behind substantial amount of residual oil. Past laboratory scale Low-Tension-Gas (LTG) coreflooding experiments have shown secondary oil recovery up to 80% OOIP (Original Oil in Place) for low permeability (sub 10mD) reservoirs. LTG flooding combines the well-known concepts of Surfactant EOR, where a surfactant solution is injected to lower oil-water IFT to ultra-low values (10−3 dyne/cm), and Foam EOR, where foam is generated in-situ by the co-injection of gas to provide mobility control to the oil displacement. While past LTG coreflooding experiments for secondary recovery have demonstrated promising oil recovery, the exact pore-scale mechanisms involved during secondary LTG flooding are yet to be studied. The most important questions to be addressed are the oil-displacement mechanisms in equilibrated and non-equilibrated microemulsion systems (Winsor Type I and Type III), the impact of foam on the microemulsion equilibration, and the overall oil recovery value and rate as functions of these factors. The study was conducted in a borosilicate water-wet micromodel with a porous network reflective of actual rock pore network. Alternate slugs of microemulsion/surfactant solution and gas were injected into the micromodel to re-create secondary LTG flooding on the pore-scale. Unique oil displacement flow mechanisms were identified for Type I and Type III microemulsion systems. Oil displacement flow mechanisms also varied depending on whether the injected liquid was equilibrated microemulsion or non-equilibrated surfactant solution. Oil-in-water macroemulsions were characteristic of non-equilibrated Type I systems, and water-entrained macroemulsions were characteristic of non-equilibrated Type III systems. Foam generated in-situ was observed to improve microemulsion equilibrium rate and oil recovery rates for secondary LTG flooding.

Fluctuations in the rotifer population of a tropical estuary in Kerala concurrent to the century’s largest deluge

Rotifers, because of their small size, slow motility, and high calorific value forms an important live feed in aquaculture. The present study was conducted to elucidate the impact of the massive flood that occurred in Kerala during August 2018 on the estuarine hydrography and rotifer community of Cochin estuary, the largest tropical monsoonal estuary along the southwest coast of India. Sampling conducted in seven stations from the inlets to the upstream during the pre-flood, flood, and post-flood periods revealed conspicuous changes in the zooplankton community of the estuary, especially the rotifers. The decline in the rotifer abundance from pre-flood (17.6 ± 26.3 ind 100 m−3) to flood (1.3 ± 2.6 ind 100 m−3) followed by a sharp increase in the post-flood period (86 ± 129.8 ind 100 m−3) indicated the impact of the flood on the rotifer population. A conspicuous change was also noticed in their community structure with the genus, Keratella dominating during the low saline, pre-flood, and flood periods and the genus, Brachionus and specifically the species, Brachionus plicatilis dominating during the relatively high saline post-flood period. The species, Filinia longiseta var. acaudata (Filinia saltator, Gosse, 1886), hitherto not recorded from the study area, was observed exclusively after the flood. Cochin estuary (CE), being a monsoonal estuary where the high freshwater discharges associated with monsoon results in the washing out of a majority of the rotifer population, this scenario was much more aggravated by the massive flood that occurred during August 2018. However, with the reduction in the floodwater discharges, the concomitant increase noticed in the rotifer abundance indicates their rapid adaptation and proliferation strategies towards favourable hydrographic conditions in the estuary.

Micellar solubilization of petroleum fractions by heavy alkylbenzene sulfonate surfactant

The primary mechanism of surfactant enhanced oil recovery (EOR) has always been ascribed to ultralow interfacial tension (IFT) between oil and dispalcing fluid by forming middle-phase microemulsion. However, it is found in field trials that oil can be largely produced by low concentration surfactant flooding without producing microemulsion. Herein, a widely used EOR surfactant, heavy alkylbenzene sulfonate (HABS) was selected to investigate its micellar solubilization behavior for petroleum fractions, alkanes and aromatics, by using UV–Vis spectroscopy, dynamic light scattering, transmission electron microscopy, small-angle neutron scattering (SANS) and fluorescent microscope. Increasing the surfactant concentration resulted in increase of solubilization capacity, and the micellar size increases with the addition of additives, accompanied by an appearance transition from transparent to opaque before and after the maximum solubilization capacity. Alkanes is situated in the micellar core, while aromatics resides in the palisade layer. The evolution from micelle to emulsion has been proved to be a disperse phase mutations once the maximum solubilization capacity is reached. These findings provide support for the contribution of micellar solubilization to surfactant EOR process.

Does inequality-adjusted human development reduce the impact of natural disasters? A gendered perspective

Abstract This paper examines how inequality-adjusted human development (IHD) helps minimize male and female flood fatalities across 19 Indian states between 1983 and 2013. We investigate if a higher achievement in the IHD index has affected male and female flood deaths differently while controlling for direct spending on disaster adaptation measures and socio-political factors. The empirical results suggest that Indian states with better IHDI score experience lower flood fatalities in aggregate. A 10% increase in IHDI at the sample mean results in the probability of 38 fewer total deaths from floods. Furthermore, we find a gender-differentiated impact of disasters as males suffer fewer flood fatalities than females with a rise in IHDI. The findings suggest that an additional 10% increase in IHDI at the sample mean results in the probability of 26 fewer male deaths from floods, and the same 10% rise in IHDI shows the probability of 12 fewer female deaths due to floods. Women’s involvement in social, political, and economic decision-making measured through women’s participation in voting in elections, grant them access to flood mitigation and aversion measures, which can reduce the impact of a disaster. However, the current participation rate is not adequate to reduce female flood mortality substantially. Women’s socially constructed responsibilities impose constraints on their participation in activities outside the household, including their mobility to the non-agricultural sector, and therefore, reduce access to warning information, which can increase vulnerability to disasters.

Numerical simulation of sediment transport, phytoplankton biomass and salinity recovery processes in Lake Pontchartrain due to Bonnet Carré Spillway flood release

The Bonnet Carré Spillway (BCS) was constructed from 1929 to 1936 to protect the city of New Orleans from the Mississippi River floods. When the water stage of the Mississippi River is over 5.18 m of flood stage, BCS will be opened to divert the excessive flood water into the Gulf of Mexico through Lake Pontchartrain. During these flood release events, large amounts of freshwater, sediment and nutrients were discharged into the lake and significantly affected its water quality and aquatic environment. A numerical model (CCHE2D) developed at the National Center for Computational Hydroscience and Engineering (NCCHE), the University of Mississippi, was applied to simulate the dynamic process of hydrodynamics and associated temporal and spatial distributions of sediment, salinity and phytoplankton in Lake Pontchartrain due to the BCS flood release events. Three events occurred in 1997, 2008 and 2011, representing the median, low, and high flood discharge cases, were selected for this study. The simulated results were compared with field measured data and satellite imageries obtained from USGS, US Army Crop of Engineers and NOAA, and good agreements were obtained. The effects of nutrients and suspended sediment on the growth of phytoplankton as well as the occurrence of algal bloom in the lake were analyzed. The processes of salinity recovery in the lake were also discussed. The results obtained from this research provide useful information for analyzing the impacts of flood release event on the aquatic ecosystems in Lake Pontchartrain.

Hydroperiod and Salinity Interactions Control Mangrove Root Dynamics in a Karstic Oceanic Island in the Caribbean Sea (San Andres, Colombia)

Mangroves sustain high soil accretion and carbon sequestration rates, yet it is still unknown if they can keep pace with increasing sea level rise (SLR) across a wider range of coastal geomorphic settings. Because accretion rates are controlled by mineral sediment inputs and organic matter accumulation, it is paramount to assess the relative contribution of root productivity to soil formation. Here, we evaluated root biomass, production, and turnover in three mangrove ecotypes to evaluate the role of soil nutrient limitation, stressors, and hydroperiod in controlling root dynamics in San Andres Island (SAI), a karstic oceanic island in the Caribbean Sea. Root production was modulated by soil stress conditions and not by nutrient availability as it has been reported for other karstic environments. The lowest root biomass allocation, and both production and turnover of fine roots were measured under low flooding duration, and low salinity (<20 PSU) and sulfide concentrations (0.84 ± 0.4 mM). Yet, when soil stress conditions increased during high flooding duration (6207 h y–1) and low oxygen conditions (Eh), root tissues reached the highest biomass and production values, including a relative fast turnover of fine roots (<2 mm; 0.75 y–1). Our results follow the predictions of the plant root longevity cost-benefit hypothesis where plants maintain roots only until the efficiency of resource acquisition is maximized by water and nutrient acquisition. Because of the importance of groundwater in controlling porewater salinity and mangrove root productivity in karstic oceanic islands such as SAI, water use and coastal development should be regulated in the short term to avoid the loss of mangrove area and concomitant ecosystem services.

Flood Risk Assessment of Communities to Flood Hazards in Central Niger Delta, Nigeria

The study examined the risk assessment of communities in the Central Niger Delta, Nigeria with a view to employing analytical hierarchical ranking process technique. The study considered the landuse, elevation, soil texture and proximity to active river channels as factors determining flood vulnerability (FV) while factors such as accessibility, social infrastructure, water supply, agriculture, commercial activities and disaster preparedness of communities were used for flood exposure (FE) using purposive sampling technique. Both FV and FE were combined together using UNION Module of ArcGIS 10.5 to produce flood risk map of the Central Niger Delta. Descriptive statistics using frequency and percentages were used for the data analysis. Findings revealed that 20.25%, 51.66% and 28.09% of the entire study area were lowly vulnerable, moderately vulnerable and highly vulnerable to flood. Similarly, 0.3%, 45.7% and 54.8% were lowly exposed, moderately exposed and highly exposed to flood. However, 14.3%, 28.3% and 57.4% of the study area had low flood risk, moderate flood risk and high flood risk respectively. The study concluded that majority of the area in the Central Niger Delta is risky to flood. It is recommended among others that channelization and dredging of River Niger Creeks in the study area are important in order for the river to accommodate more volume of water whenever there is excessive rainfall.

Flood susceptibility mapping using a geomorphometric approach in South Australian basins

Watershed characteristics and their hydrological responses can have severe effects on the occurrence and extent of floods. Therefore, this study focuses on the integration of geospatial techniques and remote sensing data to identify watershed terrain characteristics and evaluate the influence of these characteristics on flood susceptibility in South Australia. Data from the Shuttle Radar Topography Mission (SRTM) and geologic and topographic maps and a geographic information system (GIS) were used to delineate drainage basins, measure morphometric parameters and link different parameters to evaluate the degree of flood vulnerability. Depending on their relations to the flood hazards, the morphometric parameters were categorized into two groups; then, a rank score was assigned to each group. Finally, the flood susceptibility of the basins was visualized, and the basins were classified into low, intermediate and high flood hazard areas. The results show that approximately 45.7, 44.7 and 9.7% of the study area is at risk of high, medium and low degrees of flooding, respectively. The results were validated through secondary data relating to historic floods. The causes of flooding were analysed using rainfall and road density data, while the consequences of flooding were verified by the population distribution across the study area. The findings of this study can be used to support decision-makers in planning and investing in mitigation measures, especially in highly susceptible areas of South Australian basins.

Capillary desaturation curve: does low salinity surfactant flooding significantly reduce the residual oil saturation?

Different oil displacement experiments conducted on sandstone and carbonate samples show that low salinity water (LSW) injection can reduce the residual oil saturation (ROS). Recently, surfactant flooding (SF) in combination with low salinity water (known as low salinity surfactant (LSS) flooding) is proposed as a potentially promising hybrid enhanced oil recovery (EOR) process. A lower ROS is reported for a LSS process compared to that seen in SF or with LSW at the same capillary number. The capillary desaturation curve (CDC) is a well-known tool to study the effect of viscous and capillary forces on ROS for different EOR techniques. In this study, ROS data of various LSW, SF, and LSS flooding experiments at different capillary numbers are collected to develop a CDC to analyze the performance of the hybrid LSS method. This can help to analyze the effect of the hybrid method on an extra improvement in sweep efficiency and reduction in residual oil. A lower ROS is observed for LSS compared to LSW and SF in the same capillary number range. Our study shows different behaviors of the hybrid method at different ranges of capillary numbers. Three regions are identified based on the capillary number values. The difference in ROS is not significant in the first region (capillary number in the range of 10−7–10−5), which is not applicable in the presence of surfactant due to the low interfacial tension value. A significant reduction in ROS is observed in the second region (capillary number in the range of 10−5–10−2) for LSS compared to SF. This region is the most practical range for SF and LSS flooding. Hence, the application of LSS provides a noticeable benefit compared to normal EOR techniques. In the third region (capillary numbers greater than 10−2), where the surfactant flooding is a better performer, the difference in ROS is negligible.

A novel security scheme using deep learning based low overhead localised flooding algorithm for wireless sensor networks

A wireless specially appointed system is a self-sorting out, self-arranging confederation of remote frameworks. Wireless ad-hoc network gadgets (WANET) will interface and leave the system non-concu...

Effect of salicylic acid on growth and yield under abiotic stress: An overview

Biotic and abiotic stresses are the major constraint to limit the production of crops in agriculture. Biotic stress includes attack of insect, pest, bacteria, virus and fungus while extreme and low temperature, drought, flood, salinity and heavy metal stress are the major cause of abiotic stress. The reduction in the performance of plant growth was started from the negative effect of chlorophyll synthesis or degradation under wide range of environmental stress. The generation of harmful free radicles or reactive oxygen species (ROS) like O2, H2O2 and OH. Salicylic acid (SA) improves plant growth and development by improving rate of photosynthesis by protecting the damage of chloroplast, protein and DNA against the wide range of environmental stress including both biotic and abiotic stress. Application of SA also accelerate the production of osmolyte like proline and antioxidant enzymes like CAT, POD, SOD that help to scavenge free radicles safely from the cell.