Assessment of spatial variation in water quality of Doodhganga stream in Kashmir Himalaya

Abstract

The present study was carried out during April 2018 to assess the spatial variability in water quality of Doodhganga-a stream in Kashmir Himalaya and the assessment of land use land cover (LULC) of the four selected sites [Yousmarg (Site-A), Nowhar (Site-B), Chadoora (Site-C) and Barzulla (Site-D)] based on differential anthropogenic pressures. At each site samples were collected from three locations (which served as three replications) and data was represented as mean value of all locations. At Site-A (comparatively clean site), the mean value of parameters viz. temperature, pH, electrical conductivity, BOD, total hardness, sulphate, orthophosphate and ammonical nitrogen increased significantly downstream with minimum mean value recorded as 10 ±0.1◦C, 7.7 ±0.02, 72.2 ±0.06 µScm-1, 1.5 ±0.5mgL-1, 67.2 ±0.5mgL-1, 9.2 ±0.2mgL-1, 0.09 ±0.01mgL-1 and 0.53 ±0.01mgL-1 respectively. On the other hand maximum mean value for all these parameters viz. 20.6 ±0.03◦C, 8.1 ±0.01, 179.8 ±0.23 µScm-1, 3.5 ±0.06mgL-1, 259.2 ±0.5mgL-1, 29.6 ±0.3mgL-1, 0.35 ±0.01mgL-1 and 0.82 ±0.01mgL-1 where recorded at Site-D. Similarly, dissolved oxygen recorded maximum mean value at Site-A (8.6 ±0.08mgL-1) and decreased significantly downstream and its minimum mean value was recorded at Site-D (6.0 ±0.5mgL-1). Land use/land cover (LULC) of Doodhganga watershed revealed considerable change in some LULC classes during the selected time period (2000-2018). Total share of area under agricultural field, mixed plantation, water body and wetlands reduced by 3.23%, 1.61%, 0.14% and 0.04% respectively. On the other hand, built up, and horticulture/orchards increased by 3% and 1.46% respectively. Change in physico-chemical characteristics of water of Doodhganga stream elucidates increased pollution load downstream.