Evaluating long-term variability in precipitation and temperature in eastern plateau region, India, and its impact on urban environment

Abstract

In the present study, the long-term variability in precipitation and temperatures was analyzed in relation to the urban environment of Ranchi Metropolitan Region, eastern plateau region, India. The daily meteorological observations of 5 decades (1961–2010) indicated an increasing mean temperature (0.4 °C) and decreasing cumulative precipitation in the Ranchi, capital region of the state Jharkhand. The results exhibited a declining precipitation patterns in the recent decade as compared to the earlier 4 decades. The high daily monsoon rainfall intensity with low cumulative precipitation can be observed during post-2000 periods, which indicate a highly erratic nature of precipitation in the region. Temporal census data demonstrated that the Ranchi urban region faced enormous proliferation in the human population (21 times) during the period 1927–2010 and thereby induced the extensive alteration in land use/land cover and rapid built-up expansion (> 5 times) as evidenced by the temporal satellite-based observations. The increasing annual per capita land consumption (361.50%) together with annual per capita loss of heat sink zones (96.3% during 1927–2010) and high influx of vehicles (563% during 1997–2010) influenced the local and regional climatic variable in the region. The results indicate that the rapid and haphazard urban sprawl in the last few decades and increase in built-up and impervious surface largely contributed in increasing the land surface temperature (34–42 °C) as compared to the rural environment (30–38 °C), which perhaps could be the region for the changes in climate and weather pattern of the area.