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This paper describes the process of urbanization and land use change in the urban ecosystems of the National Capital Region (NCR) of Delhi, India. Two types of land use change are considered--from natural to urban and from agricultural to urban. Both types are explained in terms of economic variables known to be drivers of change. A panel data method was used, and economic variables were combined with GIS-based information on land use change during 1986-2004 for 11 administrative units of the NCR. The results suggest that investment in the construction sector plays a major role in converting the land from natural to urban areas, while differences in land productivity seems to be the major driver for change from agricultural to urban uses. [ABSTRACT FROM AUTHOR]

Urban transport has serious problems that are symptoms of the general process of rapid urbanization and environmental degradation. Policymakers in general and urban economists in particular have paid little attention to public transport system pricing leading to the absence of a financially viable, self-supporting urban transport system. In this paper, we report a partial equilibrium model developed by us, which captures transport tax reforms in the presence of certain transport externalities. Our theoretical model shows that the question of public transport subsidies to reduce congestion and provide quality transport services depends on three factors: (a) the extent to which such subsidies induce people to switch from private transport to public transport; (b) if the price elasticity of current users of public transport is higher, there may be a sharp rise in public transport ridership as a reaction to increased subsidies, which will have an undesirable effect; and (c) there is the danger that subsidies will cause a loss in productive efficiency. The numerical model of our paper for Delhi shows that the cross price elasticity of public transport demand with respect to the price of private transport is significant (0.63) in the off-peak period whereas the same in the peak period is somewhat low (0.16) and the combined effect of these elasticities will result in a considerable modal shift in favour of bus transport demand (19%) if the price of public transport were to be subsidized and private transport were to be priced optimally. Even without subsidy, the modal shift will be significant (18%), if the under-priced private transport modes are optimally priced keeping the current bus prices constant. This paper shows that there will be significant welfare gains in both these scenarios. [ABSTRACT FROM AUTHOR]

Urban land and its expansion have profoundly impacted the global environment, including the stress change in the earth's subsurface, even though urban land is a small fraction of the global land surface. Divulging such effects has never been more important, given the role of stress in determining the safety of the urban population against earthquakes. However, knowledge of this time-dependent non-linear effect of urbanization on the subsurface remains in the gray area. This study focuses on the area surrounding Delhi, the capital city of India, to understand the relative contribution of the building load created by rapid urbanization in exacerbating the subsurface state-of-stress. The results highlight that, since 2010, the modulation in the seismicity rate and the stability of basement thrust faults is linked not only to urbanization but also to decadal groundwater storage. Mounting evidence suggests that the rapid urbanization, and the resulting non-tectonic horizontal compression, stabilize faults in the Aravalli Delhi belt, which are destabilized due to the extensive groundwater extraction. This affects the decadal seismicity trend around the Aravalli Delhi fold belt. Nonetheless, the magnitude of this time-dependent deformation influence on the seismicity modulation remains uncertain. The findings from this study quantify the geomechanical impacts of urbanization in the Delhi area for the first time. [ABSTRACT FROM AUTHOR]

The National Capital Region of India (NCR Delhi) receives around 26 rainy days with majority of short duration high intensity rainfall events. Yet, the city faces severe waterlogging during south-west monsoon, and shortage of water in other seasons due to rapid urbanization and changing hydrological flow patterns. In an uncertain scenario, where spatiotemporal variability of rainfall at local scale is not very well understood, a location-specific robust model applicable for the megacity through interpretation of parameter estimates will improve understanding of extreme rainfall pattern with duration. Identification of the best-fit statistical model for prediction of short duration extreme events is done and parameters of the model are evaluated for different durations. The study finds that the 2-parameter gamma distribution and 3-parameter generalized extreme value (GEV) predict similar return levels of extreme intensity for short durations and short return periods. The shape parameter in GEV and shape and scale parameters in gamma explain the extreme quantile in the distribution responsible for prediction of high magnitude events. The more generic gamma model is robust and applicable at local scale, with pronounced shape parameter variations across durations (1–11.534, 2–8.264, 3–6.609 h). It is concluded that the knowledge of hourly variation in extreme rainfall events will help in informed decision making in this acutely water-stressed region of the world. Highlights: Short duration extreme rainfall events are frequent in semi-arid urban regions and characterization of these storms is important. The extreme rainfall pattern characteristics is defined through the parameter estimates of shape and scale of gamma distribution. Within 1 h duration rainfall events pattern, the higher shape factor identifies storms in a more wet regime (α-14.05) than the mean (α-11.534), while the lower shape factor identifies dry regime (α-9.018). The 4 h and 6 h events have the lowest shape factor and high scale factor, implying variation, and unpredictability. Short duration storms have the potential to cause flash floods, the hydrological insights provided by this study will be useful in similar geographical regions. [ABSTRACT FROM AUTHOR]