Srishti Gaur - Ph.D. Student, Indian Institute of Technology, Kharagpur, India
Over the last few decades, India has experienced a significant land use land cover (LULC) changes including urbanisation, deforestation, agricultural expansion, and industrialization. Development of land resources may strengthen economic productivity, but simultaneously affect the sustainability of the natural resources. Here, the future LULC growth is projected under two scenarios, business-as-usual (BAU) and sustainable growth (SG) scenario, for the Subarnarekha basin of India.
The associated impacts of scenarios on hydrological processes are simulated using integrated modelling system that combines physically-based distributed hydrological model (MIKE SHE/MIKE HYDRO RIVER) and spatially explicit integrated LULC change model (Multilayer-perceptron Markov model). The dynamics of historical LULC over the Subarnarekha basin is performed for 1989-2011. The major LULC classes found in the basin are dense forest, water bodies, scrubland, built-up area, agricultural land, and barrendl and. Under BAU scenario future LULC is considered to follow the dynamics of historical LULC.
A sustainable growth scenario has been developed by considering the sustainable development goal-15, i.e., life on land. For achieving the SDG-15 goals, India has also committed to achieving Land Degradation Neutrality (LDN) set up by the United Nations Convention to Combat Desertification (UNCCD). Following the SDG-15 goals, India has planned to bring 1/3rd of the land under forest cover. Therefore, our scenario aims at increasing the forest cover by 7% by 2030 (1/3rd of the average per cent of dense forest over 1989-2011, i.e., 21.50%) mainly on the Scrublands, keeping the economic and population growth similar to BAU.
The predicted LULC under BAU scenario would lead to the expansion in built-up area and scrubland along with decrease in the magnitude of dense forest and agricultural land over 2030-2050. Consequently, increased overland flow (3.8%-8.2%) and runoff (3.7%-1.9%) and decreased Evapotranspiration (2.3%-3.1%) and infiltration (9.3%-17.7%) are obtained as compared to baseline period (2011). The findings obtained from SG scenario lead to reforestation over the basin over 2030-2050.
Consequently, the forested areas generated low overland flow (1.6%-6.6%) and runoff (1.9%-9.3%) with higher infiltration (4.2%-15.6%) and Evapotranspiration (0.9%-2.6%). The findings may provide valuable knowledge for future LULC planning in the basin. The study suggests incorporating citizen science approach in LULC planning to reflect local preferences in decision-making process.