Srinagar: A study has revealed that the Dal lake has lost has lost 24.49% of its area during the last 157 years due to unregulated change in Land use and land cover (LULC).
“An assessment of the multi-date and multi-source spatial data revealed that the lake has significantly reduced in size with the area having shrunk by 7.8sq.km from 31.85 sq.km in 1859 to 24. km in 1979; however, the lake area has remained more or less constant at 24 sq.km during the past 34 years,” states the study ‘Linking Human-Biophysical Interactions with the Trophic Status of Dal Lake, Kashmir Himalaya’.
The study has been conducted by Department of Earth Sciences, University of Kashmir as a research grant provided by the Space Application Centre (SAC), Indian Space Research Organization (ISRO), Ahmadabad for the project titled “Bio-optical characterization of Optically Complex Dal Waters”.
The study analyses the long-term biophysical and demographic changes in Dal lake using a repository of historical, remote sensing, socio-economic and water quality data.
“From the analysis of the multi-source and multi-date data, it is observed that the lake has lost 24.49% of its area during the last 155 years. The unregulated changes in the LULC within and in the vicinity of the lake showed significant changes in the built up area. This is corroborated by the census data which shows higher than national population growth rate. These changes in the land system and demography have adversely impacted the water quality of the lake as evident from the very high concentration of nitrate nitrogen and orthophosphate phosphorous,” states the study conducted by Prof Shakil Ahmad Romshoo Professor and Head, Department of Earth Sciences, Kashmir University besides Irfan Rashida ,Muzamil Amina , Shabir A Khanday, and Prakash Chauhan.
It states that the growth and expansion of the aquatic vegetation has reduced the open water spread of the lake to 10.5 sq.kms , a reduction of 50% compared to the water spread in 1859. “The proliferation of floating aquatic vegetation has severely impeded the transmission of sunlight into the lake subsurface, impairing photosynthesis and allied biogeochemical processes in the water column and thus accelerating the lake eutrophication. The analysis indicated that 32% of the lake falls under sever degradation, 48% under medium degradation while as 20% of the lake waters are relatively clean,” it states.
The study recommends installation at least six additional STPs to prevent the synergistic impact of land use and anthropogenic activities on water quality of the lake, as the three existing operational STPs are inadequate.
“Keeping in view the failure of the previous efforts by the lake managers to relocate the lake dwellers, whose livelihood is linked to services and products provided by the lake, the long-term efforts need to focus on densifying one or two human settlements within the lake by moving there people from less dense hutments, installing the wastewater treatment plants there, restricting the agriculture and olericulture activities within and in the vicinity of the lake and removing the post 1970s floating garden landmasses from the lake interiors by dredging it on scientific basis,” it states.
“These steps, if taken in the right earnest, have potential to substantially improve the health of this socio-culturally, economically and ecologically important lake ecosystem, inter alia, increasing the open water spread of the lake,” it states.
Prof Shakil Ahmad Romshoo said the study uses the multi-source data to look at the changes within the lake since 1859 and in the vicinity since 1960s and briefly explains the reasons for the changes observed during the last 155 years.
“The study suggests densifying a few hutments within the lake and removal of the floating garden land masses. We have identified about 10, 000 kanals of the lake area under built-up and floating gardens and some of it could be apportioned for various uses like built-up, tourist infrastructure, museums, parks and expansion of the open waters, This is a big idea for eco-tourism,economic driven self-sustaining model for lake conservation that needs discussion and scientific assessment at various levels,” Prof Romshoo said.
Pertinently, the Government in 2015 had taken the settlement record of 1895 by then settlement Commissioner Sir Walter Lawrence as yardstick for area of the lake. In his settlement record, Lawrence had recorded total area of the lake as 9.9846 Sq miles (25.86 sq. Kms) comprising water surface is 7,0346 sq miles 18.21 sq.Kms and 2.96 Sq miles (7.65 sq. Kms) as Land Mass, fixed cultivation, habitation dembs etc.