Meenachil River Research Articles

Investigating the Impact of Recent and Future Urbanization on Flooding in an Indian River Catchment

Socioeconomic growth in India has caused massive infrastructure development which has resulted in extensive damage to the natural environment. A consequence of this urbanization has been extensive monsoon flooding in many locations within the country. The impact of recent land use and land cover (LULC) change because of urbanization and a series of future LULC scenarios is assessed for the Meenachil river basin in central Kerala, India. This catchment flows into the Kuttanad administrative area, which has the country’s lowest elevation, an increasing population, and currently suffers from regular flooding. Hydrological modeling using SHETRAN and hydraulic modeling using HEC-RAS predicts that an extreme event will produce a 105% rise in flood depth in 2100 compared to 2005. A scenario that incorporates Nature-based Solutions suggests the rise in flood depth could be reduced by 44%. A catchment response for future development is needed but is hindered by different administrative boundaries within the river basins that flow into the Kuttanad administrative area, and so this study concludes by providing regional-scale planning recommendations that integrate hydrologic components.

A comparative evaluation of streamflow prediction using the SWAT and NNAR models in the Meenachil River Basin of Central Kerala, India.

Reliable and accurate modelling of streamflow is still a challenging task due to their complex behaviour, need for extensive parameter for development as well as lack of complete or accurate data. In this study, the applicability of an emerging data-driven model, specifically a neural network autoregression (NNAR) model, was evaluated for the first time as a substitute to the physically based hydrological model Soil and Water Assessment Tool (SWAT) for predicting streamflow under data-scarce conditions and for immediate high-quality modelling results. The inputs to the NNAR model were the lagged values of the daily streamflow time series data, and the output was the predicted value for the next day. Using streamflow data that was windowed by 20 days, the NNAR model produced the best prediction. The results of the statistical metrics used to evaluate the performance of the NNAR model were satisfactory (R = 0.90, RMSE = 28.27, MAE = 11.92, R2 = 0.83), indicating a high degree of agreement between the predicted and observed streamflow. The NNAR model outputs demonstrated its ability to accurately predict streamflow in the river basin, even without an explicit understanding of the physical processes that govern the system.

Prioritization of CMIP5 based climate models in simulating precipitation using multicriteria decision making methods

Selecting climate models that are accurate in simulating observed weather is a difficult task for impact modellers. For more reliable future projections, model selection is desirable. The effectiveness of nine GCM-RCM combinations in simulating precipitation over the Meenachil river basin in Kerala is examined in this study using data from the CORDEX-SA datasets. Four performance indicators—correlation coefficient (R), percentage bias (PBIAS), skill score (SS), and root mean square error (RMSE)—were used to evaluate the models’ simulation abilities. The models were ranked based on their ability to simulate observed climate data measured over a baseline period (1980–2005) using the TOPSIS (Technique for Order Preference by Similarity to an Ideal Solution) method and the PROMETHEE-2 (Preference Ranking Organisation Method of Enrichment Evaluation) method of multi-criteria decision making approaches. Rankings of GCM-RCM combinations were carried out in both scenarios of equal and varying weight. The results of the study found that the top three precipitation prediction models for the Meenachil river basin are GFDL-RCA4, GFDL-RegCM4, and CNRM-RCA4.

Bacteriological Characteristics of Meenachil River, Kottayam, Kerala, South India: A Seasonal Study

The Meenachil River is a major river that runs through different taluks, viz. Meenachil, Vaikom and Kottayam of Kerala, India. The Meenachil River's bacteriological characteristics were investigated. Six Meenachil riverine stations were chosen for the investigation. Bacteriological parameters were studied in three different seasons during 2022: monsoon, postmonsoon, and premonsoon. Estimating bacterial production is a critical step in quantitatively understanding the function and contribution of bacteria in material cycling within given aquatic habitats.TCC and FCC values are high during the pre-monsoon season and low during the post-monsoon season.During pre-monsoon, total Coliform number ranged from 230 MPN/100ml to 1100 MPN/100ml, 93 MPN/100ml to 380 MPN/100ml during post-monsoon, and 149 MPN/100ml to 470 MPN/100 ml during monsoon. Escherichia, Citrobacter, Enterobacter, and Klebsilla are examples of coliform bacteria. The highest value of Coliform was 1100 MPN/100ml at station 1 Poonjar during the pre-monsoon period, and the lowest value was 93 MPN/100ml at station 6 Illikkal during the post-monsoon period. Faecal contamination is seen in all the six stations. The bacteria E.coli, Salmonella sp., Pseudomonas sp., Enterobacter aerogenes, Shigelle sp., Vibrio cholerae, Vibrio parahaemolyticus, Proteus sp., Klebsiella sp., have been isolated from various stations, primarily from stations 1, 2, 3, 4, 5, and 6. During pre-monsoon, station 1 in Pooonjar recorded the highest FCC value of 460 MPN/100 ml, while station 6 in Illikkal recorded the lowest value of 20 MPN/100 ml. Although the current situation is not dire or alarming, the river water needs to be closely monitored in order to improve its quality and allow for better and more sustainable management.

Freshwater Fish Diversity of Meenachil River, Kottayam, Kerala, South India

The present study was conducted to gain a better understanding of the variety of freshwater fishes found in the Meenachil River. The Meenachil river is one of Kerala's major rivers. The Meenachil River has an abundance of indigenous fishery resources as well as a high level of biodiversity. The current study was carried out to identify the fishes of the five Meenachil river stations. Poonjar (station 1), Erattupetta (station 2), Pala (station 3), Ettumanoor (station 4) and Kottayam (station 5) are the stations. The study was conducted at 15-day intervals for six months, from January 2021 to June 2021. Fish for the study were collected from various locations along the Meenachil River by local fishermen . Fish morphological and morphometric identification was accomplished using standard text. The current study identified 20 species from the Meenachil river, divided into 8 orders and 11 families. The order Cypriniformes dominated with seven, followed by Siluriformes with four species. Two species were identified in the Meenachil river that were endemic to the Western Ghats, and two were endangered. Station 4 Ettumanoor recorded the most fish diversity, while station 5 Kottayam recorded the least. According to this research, the Meenachil River has a diverse fish population.

Geographic Information System-Based Analysis of Fish Diversity Trends of River Meenachil, Southern Western Ghats, Kerala.

In this study, the fish fauna of different geographical zones of Meenachil River was investigated using the spatial interpolation techniques of the Geographical Information System. The variations in fish diversity trends during the pre-monsoon, monsoon, and post-monsoon seasons from 2016 to 2020 along the longitudinal gradient of the Meenachil River were determined using the Kriging interpolation method and semivariograms. Sixty-seven fish species belonging to 15 orders, 29 families, and 46 genera were recorded from the river during the study period. Twenty-five were endemic to the Western Ghats, three were exclusive to Kerala, five were nearly threatened, and three were vulnerable. The midstream of the river recorded maximum diversity indices ranging from (H’) 2.608 to 3.171, reflecting the outcome of local river conservation efforts, and the downstream station with the lowest range (H’) 2.305 -2.643. Cluster analysis showed the spatial similarities in fish diversities between sampling stations. Deterioration in water quality downstream was reflected in the fluctuating levels of TDS (ppm) (21.300±116.828 to 365.000±116.828), Conductivity(µSmcm-1) (42.500±252.372 to 815.000±252.372), Salinity(ppt) (0.100±0.083 to 0.400±0.083) and dissolved oxygen levels(mgL-1) (2.900±0.876 to 5.600±0.876). The study highlights the necessity to broaden local conservation efforts and implement legal measures to protect the habitats and the native fish fauna of the tourism-dominated lower stretches of the Meenachil River. By integrating data in spatial maps, the geographic component added by GIS gives a clearer insight into the various data and efficiently supports global conservation measures, enhancing biodiversity protection.

Phytoplankton Diversity in Midstream Region of Meenachil River, Kerala during Premonsoon and Monsoon Season

The scenic beauty and rich diversity of Meenachil River in Kerala make it a valuable freshwater resource for the region. This study aimed to explore the phytoplankton diversity in the midstream region of Meenachil River in Kerala during the pre-monsoon and monsoon seasons. Five different taxonomic groups were identified, which included Chlorophyceae, Bacillariophyceae, Cyanophyceae, Euglenophyceae, and Xanthophyceae, with a total of 39 species. Chlorophyceae was found to be the most prevalent group with 18 taxa, followed by Bacillariophyceae with 11 taxa, Cyanophyceae with 7 taxa, Euglenophyceae,with 2 taxa and Xanthophyceae with 1 taxon. The study revealed that the pre-monsoon season had a higher abundance of phytoplankton with 39 species, while the monsoon season had only 27 species.This research provides important insights into the phytoplankton diversity of Meenachil River in Kerala and highlights the significance of monitoring changes in phytoplankton abundance throughout the seasons for effective water resource management. The findings of this study will be beneficial for future research on water quality management and monitoring in rivers.

Assessment of Phytoplankton Diversity in Downstream Region of Meenachil River,kerala, During the Pre-monsoon and Monsoon Season

The present study aimed to assess the Phytoplankton diversity in the downstream of Meenachil River ,Kerala,during pre-monsoon and monsoon seasons. A total of 39 species belonging to five taxonomic divisions were identified, namely Chlorophyceae, Bacillariophyceae, Cyanophyceae, Euglenophyceae, and Xanthophyceae. The results revealed that Chlorophyceae was the dominant group, followed by Bacillariophyceae, Cyanophyceae, Euglenophyceae, and Xanthophyceae. The season-wise distribution of phytoplankton showed a higher abundance in the pre-monsoon season compared to the monsoon season. This study provides valuable insights into the phytoplankton diversity of Meenachil River, Kerala, and highlights the significance of monitoring seasonal changes in phytoplankton abundance for effective water resource management. The findings of this study can be useful for further research on water quality monitoring and management in rivers

Physico - Chemical and Biological Water Quality Analyses of Meenachil River, Kottayam, Kerala, South India

The Meenachil River is one of the major rivers that flows through the Kottayam District of Kerala, India. The water quality of the Meenachil River was studied. Five locations of the river were chosen. pH, Turbidity, Conductivity, Hardness, Calcium & Magnesium hardness, TDS, Calcium, Magnesium, Iron, Sulphate, Chloride, Fluoride, Nitrite, Nitrate, and DO were measured. From the study, it was observed that diverse human activities have an impact on the water quality of the Meenachil River. The present study showed that the pH of the water samples rose at several places, with sample 2 taken from Erattupetta having the lowest pH, indicating that the water sample 2 is acidic in nature. Due to the discharge of industrial and household wastewater, station 5 Kottayam has the highest conductivity, hardness, alkalinity, chloride, fluoride, nitrite, nitrate, TDS, and coliform count. Dissolved oxygen was extremely low in Kottayam region.

A Pilot Study on The Population Genetic Structure of the Selected Fish Species from Meenachil River, India

Meenachil River is the only river originating from Southern Western Ghats of India having human settlement right from the headwaters to the mouth. The river is subjected to human-induced stressors to varying extents, resulting in a drastic decline in riverine health and fish diversity. The population genetic structure of two species commonly distributed in different geographical zones of Meenachil River, Dawkinsia filamentosa and Pseudetroplus maculatus were studied using the 16S mitochondrial ribosomal RNA gene sequences. Haplotype clustering and the presence of unique haplotypes were identified by phylogenetic and network analysis. Six haplotypes were identified for D. filamentosa and ten for P. maculatus. The neutrality estimations of the upstream and midstream populations of the species revealed the presence of an excess of common alleles with neutral mutations indicating a population expansion after bottleneck and stabilizing selection. The downstream population revealed the presence of an excess of rare alleles with non-neutral mutations indicating a positive directional selection and population sub-division. Population expansion demonstrated star-like phylogenies with rare haplotypes separated by mutational steps from the ancestral haplotypes. The private haplotypes indicated the existence of selection pressure in the downstream zone of the river.

Qualitative Risk Assessment of Microbial Indicators in the Lower Reaches of Meenachil River, Kerala, India

Pristine natural freshwater resources being severely contaminated by microbiological pollutants is still a big issue in many parts of the world. In the present study, water samples taken from the upstream, midstream, and downstream reaches of the Meenachil River were analysed for the presence of microbial pollution indicators such as faecal coliforms (FC), faecal streptococci (FS), and Eschericia coli. The E. coli isolates were subjected to antimicrobial susceptibility tests and the multiple antibiotic resistance (MAR) indexes were calculated so as to delineate the potential risk posed by infections to humans and animals using the river for routine potable and recreational purposes. E. coli was consistently isolated from all the samples collected from the different zones of the river. Other faecal coliforms such as Klebsiella oxytoca, Citrobacter koseri, Enterobacter, Proteus vulgaricus, and Shigella boydii were also identified. Higher FC/FS ratios were noticed for the midstream and the downstream sites indicating the contamination from high-risk sources such as human and anthropogenic domestic wastes. The MAR index values of E. coli isolates ranged from 0.33 upstream, 0.416 for midstream and 0.583 for the downstream reaches. Given that E. coli is an ideal indicator of faecal pollution, their existence and extended survival of multiple antibiotic resistance natural freshwater pose a potential risk for the consumers. Rapid urbanization and resultant waste drainage in the downstream stretches of the river might have accelerated the deterioration of the water quality up to a certain extent. Furthermore, the riverine system as it flows downstream loses its self-purification capacity due to the loss of natural water drifts. This may be attributed to the periodic shutdown of the salinity barrier, Thanneermukkam Bund in the confluence zone of the river which results in a temporary stagnation of the running waters in the lower stretches.

Application of Hydrologic Engineering Centers Hydrologic Modeling System (HEC-HMS) Model for Modelling Flood in Sub Basin of Meenachil River, Kerala, India

Meenachil river basin, located in southern part of Kerala, is frequently liable to flood. It is an area predominant with agricultural land and falls under tropical humid zone. Hence, water resources planning and management and understanding of rainfall-runoff relationship along with its land characteristics, is necessary for irrigation scheduling, flood control and design of various engineering structures. HEC-HMS(Hydrologic Engineering Centers Hydrologic Modeling System) which is a widely used rainfall-runoff model was chosen for the simulation of watershed responses and generation of flood hydrographs. This research was done to establish the peak discharge rate of the river as well as calibrate and validate the HEC-HMS model for the Meenachil subbasin and obtain long-term flow data. The performance parameters NSE (Nash–Sutcliffe model efficiency) coefficient and R² (coefficient of determination) values were obtained above 0.7. The Error in Peak Flow and Volume were calculated below 20%. All these values indicated satisfactory performance of the model simulation both in the calibration (2013-2016) and validation (2017-2018) period. Curve number (61.46-79.93 mm), Initial abstraction(10.29-31.87 mm) and Lag time(208.27 min and 4456.2 min) were found to be the most sensitive parameters of the model. Simulated and observed stream flow values (viz. lowest peak flow of river was found during the year 2013 and it was predicted as 168.9 m³/s and observed as 158.5 m³/s) indicated that the model was able to predict and present credible results for the sub basin.

Migratory Fishes of Meenachil River, Southern Western Ghats, Kerala, India: Present Status, Threats and Conservation Strategies

Migratory Fishes of Meenachil River, Southern Western Ghats, Kerala, India: Present Status, Threats and Conservation Strategies

Impact evaluation and analysis at a river basin scale under projected climate and land-use change

Abstract This study evaluated the individual as well as integrated impacts of climate and land use change on streamflow over Meenachil River Basin, Kerala, India. The hydrological model SWAT was used to simulate future streamflow simulations under representative concentration pathway (RCP) 4.5 and 8.5 scenarios for the medium term (2025–2055) and long term (2056–2086). The land use land cover change was projected using land change modeler (LCM) of TerrSet software for the future period. Climate model simulations were taken to predict future streamflow at the regional scale, and an attempt was made to reduce the uncertainty associated with future predictions. According to the findings, streamflow was influenced by climate change (68.07%) and land use change (31.92%), with climate change having a higher contribution rate. The findings suggest that the combined impact of climate and land use change would increase streamflow in the future. The annual average streamflow is expected to decline (5.9%) in the medium term (2025–2055) under RCP 4.5 scenario and rise by 5.3% under RCP 8.5 scenario with reference to the observed streamflow for the period 1987–2017. However, in the long term, it is expected to rise by 10.56% under RCP 4.5 and 22.61% under RCP 8.5.

Fish Assemblage Pattern in Relation to Physico-Chemical Parameters of the Meenachil River, Southern Western Ghats, Kerala, India

Fish Assemblage Pattern in Relation to Physico-Chemical Parameters of the Meenachil River, Southern Western Ghats, Kerala, India

The impact of upstream land use land cover change on downstream flooding: A case of Kuttanad and Meenachil River Basin, Kerala, India

The outcome of a conventional planning process is often a spatial plan which integrates the physical and fiscal development proposals prepared based on an administrative boundary that is entirely arbitrary. Due to its obvious demerits, this study therefore attempts to establish the significance of the ecological boundary-based planning approach which could address most of the environmental problems of consideration. Accordingly, the Kuttanad Wetland System in Kerala, India, is taken a case study for detailed analysis and exploration of the concept. The study demonstrates the correlation between the elevation profile of the area and the flood water pattern and signified how elevation profile impacts the accumulation of floodwaters. It was followed by the land use land cover (LULC) change analyses under five scenarios during 2005, 2011, 2015, 2025 (projected), and a regulated condition (idealistic case). The hydrologic modeling using SWAT and HEC-RAS substantiated that the increasing built-up and wasteland with the reduction in vegetation would accelerate the surface runoff rate.11Surface runoff is precipitation runoff over the landscape (USGS, 2020). Runoff rate means the volume rate of movement or quantity of stormwater flowing past a given point for time, expressed in cubic feet per second or gallons per minute (Runoff Rate, 2021).The projected LULC map of 2025 signified that the intensity of floods increased when the percentage built-up and wasteland increased. Similarly, the sprawl when curbed along with upland afforestation and floodplain restoration, lowered the intensity of floods. The study concludes by putting planning recommendations and policies showcasing the significance of ‘eco-urban and regional planning’, as a new concept and a framework that must be pursued at the earliest.

Hydrologic flow regimes in humid tropics river basin.

The study is carried out to understand the impact of the land-use change in terms of alteration in flow regimes, which are understood to be a leading cause of ecological and environmental deterioration in riverine systems. Meenachil river in the humid tropical region of Kerala, India, is one of a kind river with human settlement along the banks for all its 78 kms of flow through the Kottayam District. The analysis of streamflow from four stream gauge stations was done using Range Variability Approach. The analysis was down as a two-time period analysis with the parametric approach with the period separation taken according to prior studies on land-use change. The analysis shows a high degree of alteration, which can be attributed to the land-use change and can be understood as the root cause for the deterioration of water quality and also the ecological distress, which is well documented in the downstream and watershed regions of the river.

Differential effect of neotectonic process on stream characteristics: a geomorphologic evaluation of the Meenachil River basin, Kerala, India

ABSTRACTMorphotectonic characteristics of the Meenachil River and its major tributaries in Kerala, India, were evaluated to understand the effects of tectonic processes on stream characteristics. Parameters such as longitudinal profile, stream length-gradient index (SL index), SL anomaly index, and transverse topographic symmetry factor (T) were considered. Longitudinal profiles of all the rivers show convexity and knickpoints in the segments between the headwaters and middle reaches, and further follow smooth profiles. Anomalies in longitudinal profiles were confirmed by the relatively high SL indexes. The SL anomaly index categorizes stream segments based on the severity of anomalies. The T index indicates the differential effect of tectonic processes in the river basin and in channel characteristics by showing spatial variation in its magnitude and orientation. Variations in the SL index, SL anomaly index, and T index in rivers flowing through similar lithology confirm the influence of differential effects of tectonic processes over the stream and networks and the nonequilibrium condition of the Meenachil River basin as a single unit.

Landform evaluation through hypsometric characterisation: an example from selected river basin in southern Western Ghats, India

Characteristics and spatial variation in geomorphic processes in the Meenachil river basin in southern Western Ghats, Kerala, India, is documented by analyzing the hypsometric parameters of 49 subwatersheds of 5th, 4th and 3rd order. Hypsometric curves and parameters such as hypsometric integral (Ea), maximum concavity (Eh), coordinates (a*, h*) of the curve-slope inflection point (I), normalized heights of the hypsometric curve at 20%, 50% and 80% of the area indicate spatial variation. Longitudinal profile of the river shows a highly disturbed region above, a flow length of 20km and relatively less disturbed area downstream. Hypsometric integral classifies most of the subwatershed into mature and mature to old age transition while varying shapes of the hypsometric curves imply the influence of tectonic uplift. Variation of hypsometric concavity in close spatial proximity also confirms the variation in the effect of tectonic processes in the region, where the combination of fluvial and diffusive process is active and are evident from the high hypsometric head and toe measurements. Repeated occurrences of earthquakes in the region confirm the presence of ongoing tectonic activity, which have direct bearing on the geomorphic characteristics of river basin.DOI: http://dx.doi.org/10.5755/j01.erem.73.4.19553

You are here: Home » Past Issues » Volume 13, 2018 - Number 2 » GEOSPATIAL TECHNIQUES FOR THE ANALYSIS OF HYPSOMETRIC PARAMETERS OF A HUMID TROPICAL RIVER BASIN, SOUTH WESTERN GHATS, INDIA, Carpathian Journal of Earth and Environmental Sciences, August 2018, Vol. 13, No. 2, p. 465 - 476; DOI:10.26471/cjees/2018/013/040 « Back Balakrishnan Nair AJAYKUMAR1*2 & Girish GOPINATH2 1Department

You are here: Home » Past Issues » Volume 13, 2018 - Number 2 » GEOSPATIAL TECHNIQUES FOR THE ANALYSIS OF HYPSOMETRIC PARAMETERS OF A HUMID TROPICAL RIVER BASIN, SOUTH WESTERN GHATS, INDIA, Carpathian Journal of Earth and Environmental Sciences, August 2018, Vol. 13, No. 2, p. 465 - 476; DOI:10.26471/cjees/2018/013/040 « Back Balakrishnan Nair AJAYKUMAR1*2 & Girish GOPINATH2 1Department