Ecosystem services in NCT Delhi

Abstract

National Capital Region (NCR) is the fastest sprawling urban agglomeration in India. The growing demand for land due to increasing pressure of population is affecting the land use pattern in National Capital Territory (NCT) Delhi. It is comprehended that urban sprawl and resulting changes in land use land cover are significantly impacting ecosystem services and functions in NCT Delhi which are difficult to quantify and measure. The study area covers an area of 1504.42 km2. The NCR Planning Board measures 9.02 % increase in built-up area and 7.52 % decrease in agriculture area in NCT Delhi from 1999 to 2012. The central objective is to quantify changes in land use/land cover and ecosystem services due to urban sprawl in NCT Delhi. The eight land use land cover categories were identified using data provided by European Space Agency for 1991, 2003, and 2010. In nineteen years time period, the major changes in land use/land cover has been observed in Built-up, Agricultural land and Forests. The Built-up, agricultural land and forest have changed, respectively, 14.9 %, -13.7 %, and 30.5 % from 1991 to 2010. Further, the coefficients published by Costanza et al. (Nature, 387:253-260, 1997) were used to quantify changes in ecosystem services delivered by each land use land cover category. The value of ecosystem services is estimated by multiplying the land area of each biome by the value coefficient of the equivalent biome which has been used as the proxy for that land use land cover category. The valuation of ecosystem services shows only a 0.62 % net decline in the total ecosystem services in the study area. If we assume a linear decrease in the ecosystem services, it shows a net cumulative loss of US$ 5.54 million over the 19 years time period of the study. The decline is relatively small that could be attributed to the sharp decrease in the agricultural land utilization. When we assume the ±50 % shift in the value coefficient of river bed, the estimated annual ecosystem service values changed ±34.89 % (US$ 3.85 ha-1 per year) between 1991 and 2010. Further, the contribution of the various ecosystem functions was measured to the overall total value of the ecosystem services across all the time periods. The additional sensitivity analysis suggests that the estimated ecosystem value is inelastic with respect to that coefficient. It is concluded that the continued decrease in ecosystem services will lead to the lesser access of services at higher cost, especially to the poor, so further policy formation and land reclamation should be based on the study of environmental losses.