Bharathapuzha River Research Articles

Shifts in bioclimatic zones mirror climate change signals in a tropical agriculture‐dominated Bharathapuzha River basin of southern Western Ghats (India)

AbstractAssessing anthropogenic climate change in a regional context is challenging due to the spatial heterogeneity of climatic variables and is more complicated than at the global scale. Especially in the Tropics, such spatial variations are expected to increase, warranting the identification of homogeneous climatic zones for assessing regional climate change. The present study explores the ability of bioclimatic variables in defining regional climatic zones, and the detection of climate change therein. We hypothesize that the identification of homogeneous climatic zones based on bioclimatic variables could be an effective approach rather than the conventional extreme climate‐based indices to identify climate change signals. To demonstrate the hypothesis, bioclimatic variables representing the generalized climatic characteristics of a tropical river basin were derived from observed gridded datasets of rainfall and temperature. Clusters of homogeneous climatic zones were identified, and their temporal variations were analysed to examine the existence of climate change. The results indicate that despite the spatial heterogeneity in extreme climate‐based indices, the bioclimatic variables‐based approach renders a meaningful representation of the regional climatic pattern. Investigation of bioclimatic zones of the study area helped to identify a shift in its climatic zones with a slant towards drier conditions. Further, future changes in climatic zones were identified from 13 different GCMs that participated in the CMIP6, projecting drier conditions over the basin, with varying spatial extend based on future emission scenarios. The study significantly contributes towards the identification of climatologically fragile regions in changing climate, which is an essential component in developing any regional climate change adaptation and mitigation strategy.

Avifaunal assemblage patterns in Bharathapuzha River Basin, Kerala, India

Bharathapuzha, the second largest west-flowing river in the Western Ghats, originates from the northern and southern parts of the Palghat gap and debouches into the Arabian Sea at Ponnani. This river is exposed to high levels of anthropogenic pressures. This study looks into avifaunal assemblage patterns and the factors influencing the structure of bird communities in different ecological zones of the Bharathapuzha River Basin. The syntropic birds and flocking birds contribute variations in the bird community assemblage in the river basin. For the water-dependent and water-associated birds, mudflats, water flow, riverside vegetation, and distance from the forest were found to be the influencing factors in the migratory season. The study also emphasized the importance of protecting these river-associated habitats for the conservation of birds.

A study on the assessment of pollution and strategies for rejuvenation of Bharathapuzha river in Kerala, India

A study on the assessment of pollution and strategies for rejuvenation of Bharathapuzha river in Kerala, India

A study on the assessment of pollution and strategies for rejuvenation of Bharathapuzha river in Kerala, India

A study on the assessment of pollution and strategies for rejuvenation of Bharathapuzha river in Kerala, India

Diversity and Distribution of Birds in the Bharathapuzha river basin, Kerala, India

Bharathapuzha River is the second largest, west-flowing river in Kerala, Western Ghats. This river is exposed to high levels of anthropogenic and natural pressures. This study attempts to understand the diversity and distribution of birds in this river basin. The observations were made from October 2017 to July 2019 in 70*1 km2 grids distributed in three strata (i.e., upper, middle, and lower reaches). A total of 262 bird species were recorded from the river basin. The diversity and richness of birds were found high in the upper reaches of the river and the species abundance was found more in the lower reaches. Due to the high turnover of migratory species, the rank abundance model for upper and lower reaches showed a high degree of dominance while middle reaches showed a relatively even distribution of abundances. Deforestation, sand mining, and water pollution were found to be the major threats in the river basin. Hence the results show the importance of the protection and rejuvenation of the ecosystems associated with the river for the conservation of avian diversity in the region.

Soil Erosion Estimation of Kunthippuzha Watershed Using GIS and RUSLE Model

Soil erosion is an environmental crisis in the world today that threatens the natural environment and also agriculture. Erosion removes the top fertile soil, degrades soil fertility, water quality and soil productivity. The soil erosion risk assessment is helpful for land evaluation in the regions where soil erosion is a major threat for sustainable agriculture. Modelling can provide a quantitative and consistent approach to estimate soil erosion and sediment yield under a wide range of conditions. The soil erosion and erosion prone areas in the Kunthippuzha sub-watershed of Bharathapuzha river basin, Kerala, India was estimated using RUSLE. The study area is having a drainage area of 950 km2 up to the gauging station. The estimation was done for 1990 to 2021. The estimated rainfall erosivity, soil erodibility, Slope length and slope steepness factor and crop management factors range from 929.36 and 980.38 MJ mm ha-1 h-1 yr-1, 0.01387 to 0.0385 t ha h ha−1 MJ−1 mm−1, 0 to 9.77 and 0.057796 to 1.0999. The results indicate that the estimated total annual potential soil loss of about 842175 t/y is comparable with the measured sediment of 845500 t/yr during the years 1990-2021. The soil erosion rate categorized into six classes based on the erosion severity, the major portion (60%) of the study area comes under very slight erosion zone and only a small portion (14%) comes under severe and very severe erosion zone. Result suggests the area of the north-eastern part suffers from a high soil erosion risk due to steep slope. The results can certainly aid in implementation of soil management and conservation practices to reduce the soil erosion in the Kunthippuzha sub-watershed.

Occurrence of South American sucker armoured catfish (Pterygoplichthys pardalis) in the Gayathripuzha River, Palakkad, Kerala

An intensive survey was undertaken and reported the existence of an invasive armoured sailfin catfish Pterygoplichthys pardalis from the Bharathapuzha River, Palakkad, Kerala, India, and its invasion as one of the foremost threats to the endemic aquatic biodiversity of Kerala. It belongs to the Genus Pterygoplichthys (Siluriformes: Loricariidae) which is known as popular aquarium fish that constitutes one of the most successful aquatic freshwaters invasive taxa, having achieved global distribution. The invasion occurred through aquarium fish culture and trading and is intensified by the distribution through rainstorm flooding and irrigation canal. The fish were identified based on morphological tests, identified fishes ranged in length (9.50-31.75cm) and weight (8.16-129.80 g). Distribution leads to understanding the changes and disturbances in fish species composition and the negative impact on the riverine ecosystem.

The seasonal oscillation of physico-chemical parameters and phytoplankton distribution from South West Coast of India (Bharathapuzha river basin)

This work aimed to determine the limnological status of the Bharathapuzha river basin using the physicochemical and biological parameters (phytoplankton) throughout the period from November 2018 to October 2019. A total of 168 species were identified, belonging to five different classes, Bacillariophyceae, Chlorophyceae, Euglenophyceae, Dinophyceae, and Cyanophyceae. The most dominant classes obtained from the study area are Bacillariophyceae, Chlorophyceae and Euglenophyceae. The present study revealed that species distribution depends upon the physico-chemical parameters and attained their maximum density during pre-monsoon, whereas minimum populations were observed during monsoon. The diversity profile was higher during pre-monsoon and lower in monsoon season. Canonical Correspondence Analysis revealed that temperature, nitrate, silicate, and DO have a more significant influence on phytoplankton abundance.

Assessment of Salt Water Intrusion from Ponnani to Tavanur along the Banks of River Bharathapuzha in Kerala

Groundwater is one of the major sources for irrigation and domestic purposes. The groundwater demand for various purposes is increasing in coastal areas. The population density in the coastal region is high and the health of people depends on the quality of water used. Ponnani, in the Malappuram district, is a thickly populated coastal town of Kerala where the availability of good quality drinking water is lacking. The study was undertaken to analyze the fluctuation of the water table and its effects on salinity intrusion and to understand the suitability of groundwater for drinking and irrigation purposes in the coastal belt of the Tavanur-Ponnani region. Six regions, Tavanur, Nariparambu, Chamaravattom, Purathur, Eswaramangalam and Ponnani are included in the study area. The water level was measured from observation wells in the field at monthly intervals, and samples were collected for water quality analysis during the period 2015 to 2021. The results obtained indicate that there is saline water intrusion in the coastal stretch of Purathur, Padinjarekkara and Ponnani regions of the Bharathapuzha river basin, and both salinity and EC is having an increasing trend in almost all wells during this period. The problem was found to be severe during dry periods (March-May) of the year in the Purathoor and Ponnani regions with salinity and EC rising to about 1800 mg L-1 and 1400 µs cm-1, respectively in the pre-monsoon period, which can be used for drinking only in the absence of an alternate source. In these areas, the groundwater available during the summer months becomes unsuitable even for irrigation purposes. During the monsoon season (June-November), the problem is less severe. Hence, it is recommended to restrict the use of groundwater at least to a lateral distance of 5 km from the seashore along the banks of the river.

Assessment of deep aquifer groundwater quality in a geographically unique climatic region of Southern Western Ghats, India using water quality indices

AbstractWater quality index (WQI) models are generally used in hydrochemical studies to simplify complex data into single values to reflect the overall quality. In this study, deep groundwater quality in the Chittur and Palakkad Taluks of the Bharathapuzha river basin of Kerala, India, was assessed by employing the WQI method developed by the Canadian Council of Ministers of the Environment (CCME). The assessment of overall water quality is indispensable due to the specific characteristics of the study area, such as geography, climate, over‐drafting, and prevalent agricultural practices. Forty representative samples were collected from the study area for monsoon (MON) and pre‐monsoon (PRM) seasons. The results showed a general increase of contents from MON to PRM. The major cations were spread in the order Ca2+>Na+>Mg2+>K+ and the anions HCO3−>Cl−>CO32− based on their relative abundance. Among various parameters analysed, alkalinity and bicarbonate levels during MON were comparatively high, which is indicative of carbonate weathering, and 90% of the samples failed to meet the World Health Organization (WHO, 2017)/Bureau of Indian Standards (BIS, 2012) drinking water guidelines. The CCME WQI analysis revealed that nearly 50% of the samples during each season represented good and excellent categories. The samples in the poor category comprised 10% in MON and 15% in PRM. The overall WQI exhibited 15% of poor category samples as well. The spatial depiction of CCME WQI classes helped to expose zones of degraded quality in the centre to eastward parts. The spatial and temporal variations of CCME WQI classes and different physicochemical attributes indicated the influence of common factors attributing to the deep groundwater quality. The study also revealed inland salinity at Kolluparamba and Peruvamba stations, where agricultural activities were rampant with poor surface water irrigation.

Runoff Prediction of Bharathapuzha River Basin using Artificial Neural Network and SWAT Model

An attempt was made to model the non-linear system of rainfall-runoff process from Bharathapuzha River basin using an information processing paradigm, Artificial Neural Network (ANN). The results were compared with the outputs of the semi-distributed, physically-based SWAT (Soil and Water Assessment Tool) model. The ANN modelling was done using back propagation learning algorithm, tan sigmoid transfer function, and model input strategy having rainfall and other climatic variables as input by assigning number of layers as 5, 10, 15, 20, 25, 30, and 40. Different models were evaluated with respect to coefficient of correlation (r), coefficient of determination (R2 ), and root mean square error (RMSE). Among the ANN models, ANN-BP-A-5 (six input variables, 5 hidden layers) performed best, followed by ANN-BP-A40 (six input variables, 40 hidden layers). Comparison of ANN predicted runoff of the best models (ANN-BP-A-5 and ANNBP-A40) with the SWAT predicted runoff revealed that the simulated runoff using SWAT was more correlated to observed runoff than ANN predicted runoff. The ANN models underestimated the flow during the rainy season, and gave an overestimation during the summer season. However, the R2 values of 0.666 and 0.649 obtained for ANN-BP-A-5 and ANN-BP-A40, respectively, indicated that the performances of ANN models were satisfactory and ANN model can also be used for runoff prediction in data scarce areas.

Hydrological Impact Assessment of Future Climate Change on a Complex River Basin of Western Ghats, India

Climate change (CC) affects millions of people directly or indirectly. Especially, the effect of CC on the hydrological regime is extensive. Hence, understanding its impact is highly essential. In this study, the Bharathapuzha river basin (BRB) lying in the Western Ghats region of southern India is considered for CC impact assessment, as it is a highly complex and challenging watershed, due to its varying topographical features, such as soil texture, land use/land cover types, slope, and climatology, including rainfall and temperature patterns. To understand the CC impact on the hydrological variables at BRB in the future, five downscaled global circulation models (GCMs) were used, namely BNU-ESM, Can-ESM, CNRM, MPI-ESM MR, and MPI-ESM LR. These GCMs were obtained for two representative concentration pathway (RCP) scenarios: 4.5 representing normal condition and 8.5 representing the worst condition of projected carbon and greenhouse gases concentration on the lower atmosphere. To obtain the continuous simulation of hydrological variables, the SWAT hydrological model was adopted in this study. Results showed that rainfall pattern, evapotranspiration, and soil moisture will increase at moderate to significant levels in the future. This is especially seen during the far future period (i.e., 2071 to 2100). Similar results were obtained for surface runoff. For instance, surface runoff will increase up to 19.2% (RCP 4.5) and 36% (RCP 8.5) during 2100, as compared to the average historical condition (1981–2010). The results from this study will be useful for various water resources management and adaptation measures in the future, and the methodology can be adopted for similar regions.

Spatio-temporal variations in hydrochemistry and quality of surface water in Bharathapuzha River Basin, Kerala, India

ABSTRACT The Bharathapuzha river (Length = 209 km; Area = 6186 km2; order (N) = 8th) is the second-largest river in Kerala State, India. The midland part of the river (Area = 1854 km2) has been studied to bring out the variation in hydrochemistry and quality due to anthropogenic and geological influences. The study area is the ‘rice-bowl’ of the State and is characterized by its unique geography, sub-humid to semi-arid climate, industrial activities, and intense agricultural practices. The major ion chemistry of the Bharathapuzha river, based on surface water from 27 locations for three seasons, is mainly controlled by carbonate weathering, with Ca2+ and HCO3 − ions dominating the composition. Gibbs plots revealed rock–water interaction as the major mechanism controlling the surface water chemistry, and scatter diagrams revealed carbonate weathering significantly and silicate weathering marginally contributing the ions to the surface water. Majority of the water quality parameters exhibited values within the desirable limits of WHO guidelines and Bureau of Indian Standards for drinking purposes, and showed distinct seasonal variations. Quality degradation was observed at some locations, where the tributaries were close to industrial units and domestic dwellings. Strong correlation results of K+ with Cl− and PO4 3-, and the presence of organochlorine pesticides aldrin and heptachlor indicate the use of nutrients and pesticides in the study area. The quality assessment revealed that 44% of samples in monsoon, 67% in post-monsoon, and 33% in pre-monsoon were suitable for drinking and domestic purposes, and almost all samples except one were found to be suitable for irrigational purpose.

Identification of Influential Geomorphologic Parameters on Runoff Characteristics of the Thuthapuzha River Basin in Kerala, India

Aims: Geomorphological parameters are signature for the conversion of rainfall into runoff. The morphometric analysis using GIS gives platform for deriving the geomorphological parameter of the river basin. Due to intercourse between stream network and landscape, geomorphological parameters are driving force for the conversion of rainfall into runoff. For finding parameter which is more significant contribution to runoff, statistical analysis gives better solution. The morphological parameters of the watershed are derived and then use landform equation for getting geomorphological parameters. Derived parameters are subjected for the factor analysis using Minitab 18 software.
 Place and Duration of Study: Study is conducted on Thuthapuzha River basin which is tributary of Bharathapuzha River located in Kerala, India has been selected and it is conducted on Department of Soil and water Conservation Engineering, Kelappaji College of Agricultural Engineering (KCAET), Tavanur, between June 2017 and July 2018.
 Methodology: From seventeen Micro-watershed the geomorphological parameters are derived and subjected to factor analysis. Interpretation of factor loadings, communalities, variance, % variance, factor score gibes more influencing parameters on runoff.
 Results: The total percentage variance explained by all the factors is about 83.9%, which gives the analysis is a good approach. Runoff factor exhibits the highest percentage variance of about 37% among the percentage variance explained by each factor. The highest correlation coefficient is obtained between runoff factor and the length of overland flow, and the constant of channel maintenance which are more significant parameters of river basin. Total variance explained by all three factors is 11.247 where runoff factor exhibits the highest variance of 5.192. Highest factor score is obtained from length of overland flow having factor score 0.190 followed by elongation ratio, form factor having factor score of 0.165 and 0.152 respectively which can be used as independent variable in case of regression models.

Mapping, Inventory and Change Detection of Wetlands of Thavanur Grama Panchayath using Multispectral Satellite Imagery

Wetlands are the submerged or waters saturated lands, both natural and man-made, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water, the depth of which at low tide does not exceed 6 meters. Effective wetlands management and protection are critical. Accurate and comprehensive wetland classification maps as well as spatiotemporal change information are essential for ecological protection and local government decisions. Wetland mapping and classification help to preserve and improve wetland quality.
 A study was conducted on wetland mapping, inventory and change detection wetlands of Thavanur Grama Panchayath in Malappuram district of Kerala using multispectral satellite imageries of high resolution (2.4x2.4m) during the year 2020-2021. The image processing was carried out by Visual Interpretation Technique. The accuracy of mapping was assessed by kappa coefficient.
 The various wetland classes found in Thavanur Grama Panchayath were Aquaculture, Marshy land, River and other ponds and small waterbodies. The major wetlands identified in the Panchayath were Ayankalam kayal, Maravanchery kaayal, Varo kaayal, Thavanur kaayal (marshy type wetlands), Bharathapuzha River, Ayankalam aquaculture, Mathur aquaculture and several other ponds. The change detection analysis showed that the percentage change in wetland during the decade was found maximum for pond and well (-33.18%). The major land use changes during the period 2008 and 2018 were that coconut plantation increased by 70.79 ha, paddy land decreased by 61.62 ha and marshy land decreased by 7.04 ha. The kappa coefficient of mapping was obtained as 0.93 which indicted good accuracy.

RIPARIAN VEGETATION AND ECONOMIC UTILITY: A SURVEY FROM BHARATHAPUZHA RIVER, KUMBIDI, PALAKKAD, KERALA

The present study was conducted in Bharathapuzha River near Kumbidi has documented the vegetation, habit, habitat, and species diversity along with the river. The floristic exploration started from September 2021–to February 2022. The Bharathapuzha River is the second-longest west-flowing river that drains into the Arabian Sea in Kerala this originated from the Annamalai hills. Kumbidi is a village in Pattambi taluk of Palakkad district in the Indian state of Kerala. This documentation has collected 25 species under 12 families for herbarium and their characters were also recorded. Key word: Bharathapuzha River, Riparian vegetation, Kumbidi, Palakkad

Trends in Streamflow in Relation to Water Retention Structures: A Case Study in Bharathpuzha River Basin, India

Lack of availability of land, water and other natural resources along with climate change has caused a major threat for increasing the agricultural production on par with the increasing population. Bharathapuzha river is considered as the cradle of civilization in Kerala state, India. The river flow is highly affected by increased water use and reduced recharge caused due to increasing population, urbanization and unscientific management practices. Even though, watershed development activities in river basins help in conserving water in the upstream areas for agricultural, domestic and other uses, very few research have been done to understand its effect on the flow regime in the lower reaches. A number of dams, check dams and other conservation structures have been constructed in Bharathapuzha catchment area during the past and hence its effect on the downstream flow need to be studied. The calibrated and validated SWAT model was applied to Bharathapuzha river basin for studying the impact of watershed interventions on the water balance of the area. The simulated monthly streamflow was analyzed during 2007 to 2011 after addition of Water Retention Structures (WRS) @ 0.05%, 0.1% and 0.2% of the land area. The results indicated that even though the total annual flow decreased, the flow during the summer months (baseflow) increased due to the addition of the conservation structures. The increase in river flow was highest during the period January to April when the river had lean flow. It was found that SWAT model can be used as an effective tool to study the impact of water retention structures in a watershed. The conservation structures help to store water in the upper reaches for irrigation and domestic purpose, and at the same time it helps in increasing the summer flow. This helps to maintain a better environmental flow regime. Hence while planning the conservation measures in a watershed so as to meet the demand of the upstream users, care should be taken to avoid the negative impact that can happen in the downstream.

Establishing a statistical relation between meteorological and hydrological drought indices

Abstract Investigation of the hydrological drought behaviour of the Bharathapuzha river basin of Kerala, India, on account of the meteorological drought condition of the watershed was carried out in this study with the aid of four popular drought indices. Statistical relations were established between the indices using polynomial regression models to help in predictions. A study on the decadal spatial variation of hydrological drought behaviour over the basin was also conducted. The cross-correlation study was also performed to understand the propagation of hydrological drought in the event of meteorological drought. The results reveal a slight decrease in the spatial extent of hydrological drought over time. The correlation between meteorological and hydrological drought indices was found to be more assertive at grid locations G1 and G4. According to the findings, the strongest correlation of 0.8 in the propagation of meteorological to hydrological drought was observed at a lag of 3 months over a 12 -month timescale. Run theory reveals that the river basin is subjected to hydrological drought over 54–65% of the months in the historic period. Regression analysis suggests that the cubic model outperforms the other models.

Application of Swat Model to Assess the Impact of Climate Change on the Hydrology of Bharathapuzha River Basin

Application of Swat Model to Assess the Impact of Climate Change on the Hydrology of Bharathapuzha River Basin

Comparison of Open Source DEM’s for Morphometric Analysis of Micro Watersheds: A Case Study from the Midlands of Kerala

Morphometric analysis with the help of remote sensing and GIS is now widely used to prioritise micro watersheds for planning interventions for soil and water conservation. DEM is the main digital data used to perform the morphometric analysis. There are different types of DEMs available to perform morphometric analysis using GIS techniques. But, no authentic information is available on the degree of accuracy levels of these DEMs to quantitatively determine various morphometric parameters for the watersheds in Kerala, with typical undulating and sloping terrain features. Hence, this research has been initiated to evaluate the quality of three popular DEMs viz. SRTM(Shuttle Radar Topography Mission), CARTOSAT(Cartography and satellite) and ASTER(Advanced spaceborne thermal emission and reflection Radiometer), each with 30 m spatial resolution. Two small sub watershed of Bharathapuzha river basin have been chosen for the study which are lying near to Valanchery town in Malappuram district. More than 21 morphometric parameters including drainage network, basin geometry, basin texture and basin relief characteristics were computed using these three types of DEMs and the outputs compared with google earth map. The results shows that the SRTM 30m DEM is characterized by higher accuracy compared to CARTOSAT and ASTER and has got better matching with google earth map data sources.