In this paper, an attempt has been made to document consequences of river sand mining on water qu... more In this paper, an attempt has been made to document consequences of river sand mining on water quality and instream biota in an alluvial channel as Kangsabati River, India. Water Quality Index (WQI) is used to identify the adverse effects of water quality on species diversity, richness, and evenness of the aquatic community. Physicochemical parameters (PP) such as pH, dissolved oxygen, total dissolved solids, electric conductivity, salinity, biological oxygen demand, magnesium cation, and turbidity are analyzed from 27 representative sampling stations as sandchar, mining, and pit sites along the upper, middle, and lower course. Pearson correlation indicates that pH and magnesium cation is the most significant parameters with WQI. Principal component analysis denotes good water quality (< 50) concentrated in sandchar sites, while poor (50–70) and very poor (> 70) water qualities are presence in mining and pit sites. Applying Simpson’s index, Simpson’s index of diversity, Simpson’s reciprocal index, and Shannon–Wiener diversity index on instream biota, those vary from sandchar (0.19, 0.81, 5.57, and − 1.34) to mining (0.11, 0.89, 9.23, and − 1.39) and pit sites (0.12, 0.90, 10.68, and − 1.50). Maximum Margalef’s index of species indicated the richness of species types in mining sites (4.62), with minimum mean values in sandchar sites (3.64). Contrastingly, Pielou’s evenness index is high in sandchar sites (− 1.05) and low in mining sites (− 1.49). Therefore, significant physicochemical parameters such as PH, dissolved oxygen, magnesium cation, and electric conductivity changes the diversity index, species richness and evenness in mining and pit along the middle and lower courses caused by sand mining.
Sand mining adversely behaves with changing river system, especially in the bedload transport pro... more Sand mining adversely behaves with changing river system, especially in the bedload transport process. This study aims to find out the relationships between river water flows, sediment transport regime in bedload transport and also tries to determine how instream mining affect the sediment inflow and channel planform change. The field study has been conducted in three selected sites on Kangsabati River situated in the lower, middle and upper course. Several established equations were applied to derive the results from water flow and sediment regime. GSTAT was used to prepare coarse medium (CM) diagrams and tractive current deposits to analyze the trend of sediment throughout the river course. Sediment and bedload transport were measured using Ackers and White (J Hydraul Eng Div ASCE 99(hy11):2041–2060, 1973) and Meyer-Peter–Muller methods (IAHSR 2nd meeting, Stockholm, appendix 2. IAHR, 1948). Shear stress and critical shear stress were computed using Shields (Application of similarity principles and turbulence research to bedload movement, 1936) and DuBoys equations whereas Friend and Sinha’s method (Braiding and meandering parameters, vol 75, No 1, Geological Society, London, 1993) was used to detect irregular planform response caused by sand mining. Regression analysis denotes that mining intensity can be change the shear stress (R2 = 0.972); velocity (R2 = 0.683); grain diameter (R2 = 0.555) and sediment concentration (R2 = 0.997) on bedload transport. Mining activities can be changes of hydraulic responses as well as interruption of sediment and bedload transport throughout the channel. In context of sand mining, planform response denotes that thalweg shifting leads to massive sandchar deposition in upper course, huge channel incision causes river bank erosion in middle course and pool–riffle alteration expanded in channel and pit area in lower course.
In this paper, an attempt has been made to document consequences of river sand mining on water qu... more In this paper, an attempt has been made to document consequences of river sand mining on water quality and instream biota in an alluvial channel as Kangsabati River, India. Water Quality Index (WQI) is used to identify the adverse effects of water quality on species diversity, richness, and evenness of the aquatic community. Physicochemical parameters (PP) such as pH, dissolved oxygen, total dissolved solids, electric conductivity, salinity, biological oxygen demand, magnesium cation, and turbidity are analyzed from 27 representative sampling stations as sandchar, mining, and pit sites along the upper, middle, and lower course. Pearson correlation indicates that pH and magnesium cation is the most significant parameters with WQI. Principal component analysis denotes good water quality (< 50) concentrated in sandchar sites, while poor (50–70) and very poor (> 70) water qualities are presence in mining and pit sites. Applying Simpson’s index, Simpson’s index of diversity, Simpson’s reciprocal index, and Shannon–Wiener diversity index on instream biota, those vary from sandchar (0.19, 0.81, 5.57, and − 1.34) to mining (0.11, 0.89, 9.23, and − 1.39) and pit sites (0.12, 0.90, 10.68, and − 1.50). Maximum Margalef’s index of species indicated the richness of species types in mining sites (4.62), with minimum mean values in sandchar sites (3.64). Contrastingly, Pielou’s evenness index is high in sandchar sites (− 1.05) and low in mining sites (− 1.49). Therefore, significant physicochemical parameters such as PH, dissolved oxygen, magnesium cation, and electric conductivity changes the diversity index, species richness and evenness in mining and pit along the middle and lower courses caused by sand mining.
Sand mining adversely behaves with changing river system, especially in the bedload transport pro... more Sand mining adversely behaves with changing river system, especially in the bedload transport process. This study aims to find out the relationships between river water flows, sediment transport regime in bedload transport and also tries to determine how instream mining affect the sediment inflow and channel planform change. The field study has been conducted in three selected sites on Kangsabati River situated in the lower, middle and upper course. Several established equations were applied to derive the results from water flow and sediment regime. GSTAT was used to prepare coarse medium (CM) diagrams and tractive current deposits to analyze the trend of sediment throughout the river course. Sediment and bedload transport were measured using Ackers and White (J Hydraul Eng Div ASCE 99(hy11):2041–2060, 1973) and Meyer-Peter–Muller methods (IAHSR 2nd meeting, Stockholm, appendix 2. IAHR, 1948). Shear stress and critical shear stress were computed using Shields (Application of similarity principles and turbulence research to bedload movement, 1936) and DuBoys equations whereas Friend and Sinha’s method (Braiding and meandering parameters, vol 75, No 1, Geological Society, London, 1993) was used to detect irregular planform response caused by sand mining. Regression analysis denotes that mining intensity can be change the shear stress (R2 = 0.972); velocity (R2 = 0.683); grain diameter (R2 = 0.555) and sediment concentration (R2 = 0.997) on bedload transport. Mining activities can be changes of hydraulic responses as well as interruption of sediment and bedload transport throughout the channel. In context of sand mining, planform response denotes that thalweg shifting leads to massive sandchar deposition in upper course, huge channel incision causes river bank erosion in middle course and pool–riffle alteration expanded in channel and pit area in lower course.
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Papers by Rajkumar Bhattacharya