Water Quality, Soil Characteristics and Vegetation Diversity Along Effluent-dominated Rivers in Western Rajasthan, India

Abstract

This study aimed at analysing water quality of effluent-dominated seasonal rivers and its impacts on soil and vegetation. Effluent-inflicted, river-edge and non-polluted areas were selected at 5 places along Luni, Bandi and Jojari rivers in western Rajasthan. Water of rivers exhibited high pH (7.6-8.6), electrical conductivity (EC 2.45-38.3 dSm-1), total dissolved and suspended solids, alkalinity and Na (1.50-30.00 gL-1), K, Ca and Mn (25.2-2439.3 µgL-1) concentrations and low NH4-N (1.08-20.69 mgL-1), NO3-N (0.44-9.10 mgL-1) and PO4-P (3.10-13.40 mgL-1). Most variables were highest for Luni and lowest for Bandi River. Cu, Co, Se, Cd and Pb concentrations were <180 µgL-1. Soil pH, EC and PO4-P were highest along Bandi, whereas NH4-N, NO3-N and K were highest along Jojari River in both 0-30 and 30-60 cm soil layers. Effluent-inflicted soils exhibited high pH, EC and PO4-P, whereas non-polluted soils showed high NH4-N, NO3-N and K availability. These soil variables decreased downstream. Plant species number ranged between 34 along Luni and 20 along Jojari (total 10 trees, 10 shrubs and 29 herbaceous). Species richness (R) and diversity (H’) of trees were highest along Bandi. Shrubs and herbaceous R, H’ and evenness (e’) were high along Luni. Least diverse vegetation was along Jojari. Non-polluted area exhibited high tree R and H’, whereas river-edge showed high herbaceous R and H’. Effluent-inflicted area showed high salts and low diversity, but dominated by Aeluropus lagopoides, Paspalum virgatum, Phragmites karka, Tamarix ericoides, etc., which can be used in restoring such degraded urban areas.