Wetlands are an integral part of the fragile ecosystem in the North Western Himalaya. The state of Jammu and Kashmir has several wetlands but those located close to urban areas are showing signs of deterioration due to land use change, a new study has revealed.
One such is Narkara, a semi-urban wetland located on the outskirts of Srinagar, which has shrunk a great deal in the past half a century. The area under agriculture has decreased by 78% - from 22.63 square kilometers in 1965 to 5 square kilometers in 2016. The decrease in agriculture area is mainly due to a rise in built up area which has gone up by 28 times in the past five decades.
The analysis of land cover data from 2016 shows that the catchment of Narkara wetland is now predominantly an urban setting with built-up areas covering 37.12% of the total catchment area. The pace of urbanization has been more pronounced after 1980, according to the study done by researchers from the University of Kashmir.
The researchers used very high resolution satellite data (3 meter) to assess the changes occurring in the wetland over different time periods. The observations were then validated through ‘ground truth’ surveys. They also analyzed impact of land use change on health of the wetland by estimating soil loss in its catchment using a method called Revised Universal Soil Loss Equation in GIS. The analysis showed decline in soil erosion in the catchment area from 106 tonnes in 1965 to 62 tonnes in 2016. This reduction is attributed to barren lands and agriculture being taken over by built-up area.
"The reckless urbanization both within Narkara and its catchment not only affects the hydrology and ecology of this important semi-urban wetland but also increases vulnerability of people to flooding in this part of Himalaya because wetlands act as natural sponges and flood protection system"
“The reckless urbanization both within Narkara and its catchment not only affects the hydrology and ecology of this important semi-urban wetland but also increases vulnerability of people to flooding in this part of Himalaya because wetlands act as natural sponges and flood protection system,” pointed out Dr Irfan Rashid, Assistant Professor in the Department of Earth Sciences at the University of Kashmir, while speaking to India Science Wire.
The gradual squeezing of wetlands is affecting their buffering capacity to withhold flood waters and storm water runoff. This was seen during the 2014 floods when residential areas in the outskirts of Srinagar, which used to be traditional floodplains, were inundated for more than three weeks.
“Wetland areas across Kashmir have been reported to be shrinking primarily due to unplanned land system changes affecting the buffering capacity of these ecologically and socioeconomically important systems to withhold flood waters. It is amply clear from land use analysis that expansion of built-up areas has resulted into shrinkage of agriculture fields. The lack of a comprehensive wetland conservation policy has turned wetland areas into concrete jungle mainly due to encroachments,” Rashid said.
The catchment of Narkara is predominantly a semi-urban setting with settlements, agricultural fields and table lands locally called karewas which are barren denuded landscapes. The wetland is a breeding ground for water fowl species that migrate from Russia and Central Asia during winters.
The study was done by Sheikh Aneaus and Irfan Rashid (Geoinformatics Program, Department of Earth Sciences, University of Kashmir). The study results have been published in Arabian Journal of Geosciences.
India Science Wire