Flooding Time Research Articles

A Logistic Regression Model for the Prediction of Vegetation Recruitment in the Kinu River, Japan

ABSTRACTVegetation overgrowth in rivers worldwide is a considerable problem because it can potentially reduce the flood‐flowing capacity and cause biodiversity loss. In this study, we developed a model to predict vegetation recruitment during the initial stages of secondary succession, which leads to vegetation overgrowth. This study chose a logistic regression model to predict vegetation recruitment because of its simplicity and lower computational load than machine learning. The model was designed for the Kinu River in Japan which is associated with extensive vegetation overgrowth. Data for the model development were obtained from unmanned aerial vehicle (UAV) aerial surveys and public databases. To ensure the model's applicability beyond the training rivers, we trained the logistic regression model across different river flows and geomorphic characteristics, including normal and flood times and gravel and sand beds. The results indicated that the logistic regression model with three explanatory variables, namely distance from the river stream, relative height, and vegetation existence history, was optimal for all rivers, with F‐measures in the range of 0.79‐0.85. In addition, using UAV imagery allows for high‐spatial resolution in predicting vegetation recruitment. The best model prediction map of vegetation recruitment demonstrated that it could accurately predict the vegetation distribution along the main river channel for gravel and sand beds. The simplicity of the present model would be advantageous when applied to other rivers with similar topographic and biological characteristics within the same river segment without hydrodynamic calculations.

Soil Residual Activity of Tetflupyrolimet and the Influence of Soil Moisture and Flood Timeliness on Barnyardgrass Efficacy

ABSTRACT Tetflupyrolimet is the first herbicide with a novel site of action to be commercialized for use in agronomic crops in three decades. Direct-seed rice field experiments were conducted at research facilities near Stuttgart (silt loam), AR, and Keiser (clay), AR, to evaluate tetflupyrolimet as a preemergence herbicide versus commercial standards. Greenhouse experiments determined the influence of soil moisture on pre- and postemergence (POST) barnyardgrass control with tetflupyrolimet and clomazone, and the impact of a delayed flood on efficacy when POST-applied. For the field experiments, clomazone, tetflupyrolimet, and quinclorac were applied individually PRE at 336 and 560, 134 and 224, and 336 and 560 g ai ha-1, respectively, on a silt loam and clay soil, along with clomazone plus tetflupyrolimet and clomazone plus quinclorac at the same rates. The soil moisture experiment included a single PRE and POST application of clomazone at 336 g ai ha-1, tetflupyrolimet at 134 g ai ha-1, and a mixture at the respective rates, on a silt loam soil at 50, 75, and 100% of field capacity. For the flood timing experiment, tetflupyrolimet was applied to 2- to 3-leaf barnyardgrass at 134 g ai ha-1, and a flood was established at 4 hr after treatment (HAT) and 5 and 10 d after treatment (DAT). Barnyardgrass control with a tetflupyrolimet and clomazone mixture was comparable to clomazone plus quinclorac when averaged over all evaluations on silt loam and clay texture soils (≥91%). Soil moisture interacted with herbicide treatments for PRE and POST barnyardgrass efficacy when averaged over DAT, with tetflupyrolimet plus clomazone generally providing the greatest and most consistent control across regimes. Flooding barnyardgrass at 4 HAT provided superior control to later flood timings. Tetflupyrolimet is an effective residual barnyardgrass herbicide, and the addition of clomazone will aid in providing consistent control across varying soil moisture conditions.

Determination of the inflow time of maximum floods in a dam

A methodology is proposed for the determination of the maximum floods entering a dam based on the analysis of different regression relationships between parameters characterized and identified from the maximum floods of a cascade dam system. It is possible to know the behavior of the inflow time of the maximum floods to a dam, taking as an application case the El Caracol dam in the Balsas river basin in Mexico. The characterization of the hydrographs made it possible to define models that provide advanced knowledge of the maximum flows and the time at which they will enter the dam, thus offering a model for forecasting maximum floods in a dam system.

Modelling the dynamic performance of stormwater drainage systems integrated with infiltration trenches

ABSTRACT Urban flooding caused by urbanization and climate change is a critical challenge for city infrastructures. Infiltration trenches are a green infrastructure system that collects and temporarily stores rainwater. In this study, the efficiency of 12 infiltration trenches in Kayseri province of Turkey was analyzed using InfoWorks ICM. These analyses are characterized by 5 different return periods and 4 different distributions of rainfall over time. The model was validated with a historical rainfall event and showed good results according to statistical validation methods. The study also provides alternative solutions by including the effect of different infiltration ratios and simulations of different infiltration trench designs. Infiltration trenches, which were appropriately located, reduced flood depth and initial flooding time even during high return periods. By analyzing multiple infiltration trenches together, testing different scenarios and combining field application and modeling, the study provides outputs that will help urban flood management applications.

Fruiting traits and seedling regeneration of the relict mangrove plant Nypa fruticans Wurmb in China

Abstract Nypa fruticans Wurmb is both a relic plant and a true mangrove. In China, wild populations are distributed only on Hainan Island and face significant challenges in regeneration from seedlings. This study explored the underlying causes of recruitment limitation by examining seed morphological traits from three distinct populations (Haikou, Wenchang and Wanning) and analysing seed germination and seedling growth characteristics under varying conditions. The key findings are as follows: fruiting and seed-setting rates for N. fruticans were notably low, standing at only 21 and 40%, respectively. The Wanning population exhibited significantly higher rates compared to the other two populations. Under natural conditions, the germination and seedling emergence rates were also modest, at 36.58 and 22.99%, respectively. The germination and emergence rates of the Wanning population were significantly greater than those of the Haikou and Wenchang populations. Meanwhile, seeds from a single population did not differ in germination rates among three in situ N. fruticans habitats, but seedling emergence rates differed significantly. Optimal conditions for seed germination involved a light intensity of 60%, a salinity of 5‰ and a flooding time of 8 h/day. In natural settings, these three environmental factors fall short of the ideal conditions. The study underscores that light, salinity and flooding are primary factors contributing to the limitations in N. fruticans seedling recruitment. In addition to advocating increased investment in scientific research and technology to address seed source issues, we recommend heightened efforts in habitat restoration, in situ conservation and the optimization of relocation and field return strategies to bolster N. fruticans populations.

Characterizing Changes in Paddy Rice Flooding Time over the Sanjiang Plain Using Moderate-Resolution Imaging Spectroradiometer Time Series

Rice is a primary food crop, and rice production ensures food security and maintains social stability with great significance. Flooding paddy rice fields as an important step in rice production affects the entire growth process of rice. The selection of flooding time is highly correlated with paddy rice yield and water resource utilization. In the background of global warming, early flooding in high-latitude paddy rice planting areas can ensure that rice has sufficient growing time to increase yield. However, overly early flooding may cause waste of water resources due to insufficient heat. Currently, research on flooding timing is relatively lacking, and monitoring of temperature during flooding is particularly deficient. To respond to climate change, it is necessary to explore whether the current flooding schedule meets the actual needs. Based on MODIS surface reflectivity data, we identified the First Flooding Day (FFD) and Peak Flooding Day (PFD) in the Sanjiang Plain. Using MODIS Land Surface Temperature (LST) data and meteorological station-provided air temperature data, we analyzed the corresponding LST and air temperature for PFD from 2008 to 2024. The main conclusions are as follows: (1) both FFD and PFD in the Sanjiang Plain have a trend of advancing year by year, with PFD showing stronger advancement than FFD; (2) the LST and air temperature during flooding in the Sanjiang Plain show a downward trend year by year; and (3) by 2024, the flooding temperature of paddy rice fields in the Sanjiang Plain has generally met the needs for the next step of production. This study first attempts to use high-temporal-resolution remote sensing images to identify the flooding time of paddy fields and achieve timely monitoring of flooding and changes in flooding temperature.

Mapping a Novel Metric for Flash Flood Recovery Using Interpretable Machine Learning

Abstract Flash floods are one of the most devastating natural disasters, yet many aspects of their severity and impact are poorly understood. The recession limb is related to postflood recovery and its impact on communities, yet it remains less documented than the rising limb of the hydrograph to predict the peak discharge and timing of floods. This work introduces a new metric called flash flood recovery or recoveriness, which is the potential for recovery of a watershed to preflood conditions. Using a comprehensive database of 78 years and supervised machine learning algorithms, flash flood recovery is mapped in the conterminous United States. A suite of geomorphological and climatological variables is used as predictors to provide probabilistic estimates of recoveriness. Slope index, river basin area, and river length are found to be the most significant predictors to predict recoveriness. Several new localized hotspots were identified, such as the western slopes of the Appalachians consisting of Kentucky, Tennessee, and West Virginia and the interlinked areas of western Montana and northern Idaho. This new metric can be useful for prioritizing relief and rehabilitation efforts as well as precautionary measures for disaster risk reduction.

Climate Change-Driven Hydrological Shifts in the Kon-Ha Thanh River Basin

Climate change is projected to bring substantial changes to hydroclimatic extremes, which will affect natural river regimes and have wide-ranging impacts on human health and ecosystems, particularly in Central Highland Vietnam. This study focuses on understanding and quantifying the projected impacts of climate change on streamflow in the Kon-Ha Thanh River basin, using the Soil and Water Assessment Tool (SWAT) between 2016 and 2099. The study examined projected changes in streamflow across three time periods (2016–2035, 2046–2065, and 2080–2029) under two scenarios, Representative Conversion Pathways (RCPs) 4.5 and 8.5. The model was developed and validated on a daily scale with the model performance, yielding good performance scores, including Coefficient of Determination (R2), Nash-Sutcliffe Efficiency (NSE), and Root Mean Squared Error (RMSE) values of 0.79, 0.77, and 50.96 m3/s, respectively. Our findings are (1) streamflow during the wet season is projected to increase by up to 150%, particularly in December, under RCP 8.5; (2) dry season flows are expected to decrease by over 10%, beginning in May, heightening the risk of water shortages during critical agricultural periods; and (3) shifts in the timing of flood and dry seasons are found toward 2099 that will require adaptive measures for water resource management. These findings provide a scientific foundation for incorporating climate change impacts into regional water management strategies and enhancing the resilience of local communities to future hydroclimatic challenges.

Numerical study of impact pressure and force of cascading dam-break floods on the downstream dam

Cascading dam-break floods are among the most catastrophic natural disasters, causing significant casualties worldwide. Currently, research on cascading dam-break scenarios primarily focuses on the gradual dam-breaching and flood evolution processes. However, the research on the impact of cascading dam-break flood on downstream dam surface is rarely reported. Therefore, this study addresses this gap by establishing a shallow water hydrodynamic model based on the finite volume method. We conduct a numerical investigation into the effects of various parameters, including dam spacing, channel bed slope, initial water depths in upstream, middle and downstream reservoirs, and different cascading dam-break processes (two-stage and three-stage), on the impact on the downstream dam surface. The following conclusion can be drawn: factors such as dam spacing, bed slope and water depth have a significant impact on the impact pressure and force of downstream dam surface. All other conditions remain unchanged, the larger the dam spacing, the higher the peak and average values of downstream impact pressure, and the later the arrival time of dam-break floods on the downstream dam. The greater the bed slope, the higher the impact pressure, and the earlier the arrival time of the dam-break floods. The deeper the upstream or middle water depth, the greater the peak value and occurrence time of the impact pressure. The smaller the downstream water depth, the lower the impact pressure. The impact time of the three-stage dam-break floods is slightly later than that of the two-stage dam-break floods, but its peak and average impact pressure are higher. This study offers valuable scientific guidance and technical support for disaster prevention and mitigation strategies concerning cascading dam-break floods.

Heterogeneous effects of climate change on displacement-inducing disasters

With an estimated 357.7 million internal displacements caused since 2008, weather-related disasters are a major driver of human mobility worldwide. As climate change is projected to increase the frequency and intensity of extreme weather events in many parts of the world, it is important to better understand how trends in weather patterns related to global warming have affected the intensity of disasters that have caused displacements. Here we combined observational and counterfactual climate data with global internal displacement records to estimate how climate change has affected precipitation and wind speeds at the time and location of floods and storms that led to internal displacements. We estimate that, on average, climate change increased precipitation and decreased wind speeds during such events by +3.7% and − 1.4%, respectively. However, the variability across events is considerable (±28.6 and ± 6.6%, respectively), highlighting the large signal of natural variability of the weather system as compared to the global warming signal. Our results caution against overstating the role of climate change in displacement-inducing disasters in the past, especially compared to socio-economic and development factors of vulnerability and adaptive capacity that determine whether weather-related hazards turn into disasters.’

The Effect of Dam Break Speed on Flood Evolution in a Downstream Reservoir of a Cascade Reservoir System

The dam break flood is one of the potential causes of catastrophic events in cascade hydropower hub groups. Investigating the movement patterns of dam break flooding among reservoir groups under different dam break speeds is crucial for flood prevention and emergency response. In this study, the evolution characteristics of dam break floods were investigated in a cascading reservoir system, focusing on different break speeds of the upstream dam. The results indicate that the dam break speed determines the concavity or convexity of the water level curve changes in the upstream reservoir. Accordingly, dam breaks are classified into three modes: instant dam break, fast dam break, and slow dam break. An approximate critical speed has been identified to differentiate between the fast dam break and slow dam break. Further investigation into the evolution patterns of dam break floods in downstream reservoirs under different break modes was conducted. Correspondingly, the flood peak discharge and peak arrival time of the dam break floods vary differently with break speed under different break modes. Finally, a theoretical analysis for the flood peak discharge at the dam site during gradual dam break at a certain speed was established, which is able to predict the over-dam flood peak discharge in fast and slow dam break modes. This study is based on a combination of laboratory flume experiments and three-dimensional numerical simulations. This study has theoretical significance for the reinforcement of public infrastructure safety and the prevention of natural disasters.

Numerical simulation of the movement of the water surface with macroscopic particles during a partial dam break for various complex reliefs

In this paper, it was considered a numerical simulation of the water surface movement during the partial collapse of the destruction of a dam with complex terrain. The numerical simulations took into account debris after a partial collapse of the dam, which imitates debris and moves downstream with the water flow. Carrying out these calculations brings the results closer to the real scenario. The mathematical model was based on the Navier–Stokes equations and uses the turbulent large eddy method (LES) model describing the flow of an incompressible viscous fluid. To describe the movement of a two-phase fluid, the volume of fluid (VOF) methods for the phase were used, and the Discrete Phase Model (DPM) and Macroscopic Particle Model (MPM) were used to describe the movement of particles. For the numerical solution of this system of equations, the Pressure Implicit Split Operator (PISO) numerical algorithm was chosen. The results show that the model is accurate and capable of handling very complex interactions such as particle transport or hydrodynamic actions on structures if the appropriate scales are reproduced. Also in this work, a three-dimensional (3D) model of the flow of a dam break on uneven terrain was considered and combined problems were performed that are closer to real conditions. For combined problems, flood zones and flood times were determined, knowledge of which will help evacuate people from dangerous areas. The accuracy of the 3D model and the selected numerical algorithm were verified using two natural measurements.

Experimental Study on Factors Influencing the Efficiency of Hot Water Injection in Offshore Heavy Oil Reservoirs

Abstract In response to the problem of low final recovery rate in conventional water flooding development of offshore heavy oil, the Bohai LD5 heavy oil field was taken as the target area. Through one-dimensional oil displacement efficiency experiments, the influence of crucial injection and production parameters on oil displacement efficiency, such as temperature, injection rate, injection production ratio, timing of hot water flooding, and injection medium, was studied. The key injection and production parameters were optimized, and the main controlling factors affecting the efficiency of hot water flooding after water flooding were identified through data analysis. Propose an optimization approach for thermal injection media and quantitatively evaluate the oil recovery efficiency under different injection and production parameters. Research has shown that for the Bohai LD5 heavy oil field, the optimal combination of injection and production parameters is: an injection rate of 2mL/min, injection temperature of 110°C, and timing of conversion to flooding at a recovery rate of 20% to 30% (water content of 55% to 70%). The hot water composite flue gas has the best oil recovery effect, considering both oil recovery efficiency and on-site construction conditions. The degree of influence of various factors on the efficiency of hot water flooding is as follows: temperature>timing of hot water flooding (recovery degree)>injection rate. Under low temperature (within 110 °C) conditions, temperature is the main factor affecting the efficiency of hot water flooding. The overall recovery rate of different injection media shows a trend of hot water composite>hot water>cold recovery.

The timing of Missoula floods: Implications for the age of Grand Coulee (eastern Washington, USA)

Abstract The Channeled Scabland of eastern Washington (USA) was formed by outburst floods from glacial Lake Missoula. Despite chronological advances, the timing of erosion in the main flood channels is unresolved. In particular, it is still uncertain whether upper Grand Coulee, the largest canyon in the Channeled Scabland, was incised during or prior to the last glaciation. We report 10Be exposure ages from erratics in upper Grand Coulee, glacial Lake Columbia, and surrounding flood routes. Flood-transported boulders on the high-elevation east rim of Grand Coulee date to ca. 17–15 ka. Ages from boulders on the floor of Grand Coulee indicate later flooding at ca. 14 ka, which post-dated canyon incision and occurred after inundation of the Telford-Crab Creek scabland at ca. 15–14.5 ka. Prior hydraulic modeling and dating suggest the entrance to Grand Coulee was blocked by rock and that canyon incision was incomplete at ca. 17 ka; hence, we interpret the 17–15 ka exposure ages on the east rim to coincide with flow over a retreating cataract during canyon incision. Our results indicate incision of Grand Coulee was completed between 17 ka and 14 ka. The short duration of canyon incision suggests that glacial Lake Missoula generated some of the most erosive outburst floods in Earth's history.

Factors influencing shorebird use of post‐harvest flooded rice fields in California's Sacramento Valley

AbstractBecause of the importance of the Central Valley of California, USA, to shorebirds along the Pacific Flyway, conservation investments have been made in the area's agricultural fields and managed wetlands. Increasingly, landowner incentive programs are being used to deliver shorebird habitat, presenting opportunities to answer remaining questions about which implementation strategies and field management practices are most effective at attracting birds. To provide management guidance for these investments, we collected and analyzed 5 years of data (2014–2018) on shorebird abundance in flooded rice fields enrolled in a dynamic habitat incentive program. The program incentivized flooding in fallow and post‐harvest rice fields in seasons when habitat is relatively sparse, specifically the early fall and late spring. Across nearly 9,000 field observations over 5 years, we explored the relationship between abundance and density (birds/ha) of shorebirds and vegetation cover, soil clay, landscape‐level flooding, and local flood timing, duration, and depth. We observed more shorebirds in fields that were approximately 50% flooded, had water depths of 5–10 cm, and had minimal rice straw or stubble cover, with strong or very strong evidence for each of these relationships. We found that the timing of habitat provisioning was important, with moderate evidence that earlier fall flooding and strong evidence that the duration of fall flooding was associated with higher shorebird density. We observed lower shorebird densities in locations with ample flooded rice habitat in surrounding areas, potentially because shorebirds spread out across the landscape. We found very strong evidence that flooding consistency, either at a site that was continually flooded over many months or a site that had been flooded in previous years, was associated with higher shorebird density. Soil clay content was associated with decreased observed shorebird density, potentially through its influence on the ability of shorebirds to forage for invertebrate prey. These results suggest best practices for shorebird habitat creation in agricultural landscapes, providing important information for conservation and population recovery.

Change and coincidence risk analysis of floods in the Mahanadi River Basin, India

ABSTRACT Coincidence flood risk due to the simultaneous flood occurrences on both mainstream and its tributary results in downstream inundation of a confluence. Therefore, this study was taken up for coincidence flood risk analysis of Mahanadi River basin considering the annual maximum (AM) and the peak over threshold (POT) series. In this study, the Mann–Kendall trend test was performed to analyze the trend in flood magnitudes, while circular statistics was used to analyze the persistence in flood timing. The joint distributions between the streams were established using bivariate copula functions considering flood magnitudes and occurrence dates as variables. The results of MK test revealed a mixture of significant and insignificant trends for AM series for the selected stations, while the trends were insignificant for POT series. Additionally, the flood occurrence dates showed a high level of persistence. It is evident from the results that the coincidence risk is high for Seorinarayan–Bamnidhi confluence point with a risk value of 7.63 × 10−3. The coincidence risk increases mostly from late July to mid-September, and the coincidence risk is high for more frequently occurring flood events. The obtained results will help in prioritizing flood hazard zones for effective flood mitigation strategies in Mahanadi River basin.

A step closer towards active and flexible consumers: enhancing involvement through energy consumption feedback

The level of consumer awareness and comprehension, during a period of abundant energy services, has a crucial role in their initial adoption and later engagement with the services. Digital energy platforms bring the ≫intangible electricity≪ closer to people’s daily lives and encourage new ways of thinking about and consuming energy. Energy feedback connects consumer’s consumption to their daily activities and provides insights. It enables them to learn about the consumption, learn how to reduce or optimise it and later, learn how to be flexible when needed. Besides investigating how familiar are the Slovenian households with their own consumption and energy related behaviour, the goal of this paper is also to investigate their preferences in visualizing their electricity consumption. The consumption estimation was validated on real case study using data from 642 Slovenian households. Results show that consumers that use electricity for space and water heating, underestimated their consumption up to 22.5%. A categorization of households based on their water and space heating systems is also presented.

Germplasm Resource Status and Seed Adaptability of Nypa fruticans Wurmb, an Endangered Species in China

Nypa fruticans, commonly known as the Nipa palm, belongs to the true mangrove plants of the Arecaceae family. In China, it is naturally distributed only on Hainan Island and designated as a second-class National Key Protected Wild Plants List. Field research and indoor simulation experiments were systematically employed to study the resource status of N. fruticans and the adaptation of seed germination to environmental factors. The results showed that: (1) Four natural populations of N. fruticans, approximately 9319 trees within a total area of 3.96 hm2, were distributed in Haikou, Wenchang, Qionghai, and Wanning on Hainan Island. Only the Wanning population was developed in small patches, while other populations were scattered sporadically. (2) A total of 23 mangrove species belonged to 19 genera in 13 families, which were recorded in all study sites, of which 18 were true mangroves and 5 were semi-mangrove species. The vertical structures of 4 N. fruticans communities exhibited the consistent pattern, characterized by distinct layers including the tree, shrub, and herb layers. However, notable differences in species composition and dominant species were observed among the layers of each community. (3) The population dynamics of N. fruticans in Haikou, Qionghai, and Wanning were declining, while the population in Wenchang was growing. (4) Seed germination of N. fruticans was not resistant to strong light and required some shade treatment with an optimal light intensity of 60%. The suitable salinity range for seed germination was 0‰ to 10‰. With the increase of salinity, the germination rate and seedling rate showed an increasing and then decreasing trend with maximum values of 63.3% and 50.0% at 5‰, which showed the sensitivity of seed germination to salinity, with low salinity promoting germination whereas high salinity inhibiting germination. Around 8 h/d of flooding time was most suitable for the seed germination, and 10 h/d was a critical flooding time. This study provides a theoretical basis for population recovery, resource utilization, and other further research of N. fruticans.

Anti-seasonal flooding drives substantial alterations in riparian plant diversity and niche characteristics in a unique hydro-fluctuation zone.

Human-induced disturbances such as dam construction and regulation have led to widespread alterations in hydrological processes and thus substantially influence plant characteristics in the hydro-fluctuation zones (HFZs). To reveal utilization of limited resources and mechanisms of inter-specific competition and species co-existence of plant communities based on niche breadth and overlap under the different HFZs of the Three Gorges Reservoir (TGR) in China, we conducted a field investigation with 368 quadrats on the effects of hydrological alterations on plant diversity and niche characteristics. The results showed anti-seasonal flooding precipitated the gradual disappearance of the original diverse niches, resulting in the reduction of plant species richness and functional diversity and more obvious competition among plant species with similar resource requirements. Annuals, perennials and shrubs accounted for 71.23%, 27.39% and 1.37%, respectively, suggesting that annuals and flood-tolerant riparian herbs were favored under such novel flooding conditions. A consistent increase in species number, Shannon-Wiener diversity index and Simpson dominance index with altitude was inconsistent with hump-shaped diversity-disturbance relationship of the intermediate disturbance hypothesis, while the opposite trend was observed for the Pielou evenness index. This species distribution pattern might be caused by several synergetic attributes (e.g., the submergence depth, plant tolerant capacity to flooding, life form, dispersal mode and inter-specific competition). Vegetation types shifted from xerophytes to mesophytes and eventually to hygrophytes with the increasing flooding time in the HFZs. Hydrological alterations proved to be the paramount driver of vegetation distribution in the different HFZs. The niche analysis provided the first insights on the mechanisms of resource utilization and inter-specific competition, of which annuals could germinate quickly after soil drainage to achieve the greatest competitive advantages and occupy a larger niche space than other plants. Vegetation was still in the early stage of primary succession in the novel riparian forests. Therefore, vegetation restoration strategies should be biased towards herbaceous plants, due to annuals with better environmental adaptability, supplemented by shrubs and small trees. To establish a complete reference system for vegetation restoration, natural vegetation monitory plots in the different succession stages should be established in the different HFZs of the TGR, and their environmental conditions, community structures and inter-specific relationships further analyzed.

Times series record of water quality analysis during flood time in Cauvery River basin, Tamil Nadu, India

We determine the spatial and temporal changes in the physicochemical and nutritional parameters of water quality in the Cauvery River basin. We also analyze the effects of anthropogenic and natural factors on the physicochemical and nutritional parameters. The river water samples were collected over a time series record of 6-h intervals for 6 days during and after flooding time. The combination of physicochemical and nutritional parameters generated a large dataset, which was processed using statistical analysis. In addition, statistical analysis was used to calculate the correlation coefficients and plot the regression equations relating various parameters to electrical conductivity (EC). The resulting average values of pH, EC, and total dissolved solids (TDS) showed significant differences in the time series record of the study period (i.e., pH = 8.24, EC = 220 S/m, and TDS = 157.1 mg/L). The values of the following nutritional parameters in floodwater were also determined: orthophosphate = 0.13 mg/L, phosphate = 0.1 mg/L, nitrite = 2.11 mg/L, nitrate = 0.79 mg/L, and ammonia = 4.47 mg/L. Our findings indicates that flooding can deteriorate the groundwater quality, resulting in a decrease in water quality and an increase in contamination levels, which can have detrimental effects on both the environment and human health. This information is crucial to decision making in flood risk management, water resource planning, and conservation efforts to protect both human and ecological systems.