Societal response to monsoon variability in Medieval South India: Lessons from the past for adapting to climate change

Abstract

Future climate change will challenge society’s ability to adequately manage water resources, particularly in the developing world. The response of past societies to climatic variability, particularly in terms of water management, can provide useful insights into the timing and scale of response to future events. We present a regional case study from South India to illustrate the influence of climate on shaping the rise and economic prosperity of the Chola Kingdom from 850 to 1280 ce – a period approximately coinciding with the Medieval Climatic Anomaly. An investigation of instrumental and proxy climatic data sets between 500 and 2010 ce indicates that the period between ~850 and ~1300 ce, a time of frequent El Niño-like conditions, was associated with a substantial increase in North-East Indian monsoon rainfall (NEIMR), whereas South-West Indian monsoon rainfall (SWIMR) suffered substantial deficits. The spatial pattern and chronology of water harvesting infrastructure development under Chola rule indicate that these features were concentrated in the NEIMR-receiving regions of southeastern India and that their construction peaked during El Niño-dominated intervals. Overall, enhanced NEIMR conditions and adaptation strategies practiced in the Chola’s territory, combined with less favorable climatic conditions over the neighboring kingdoms, appears to have underpinned the well-documented political and economic strengths of the Chola superpower. We infer that the water management infrastructure promoted by the Chola rulers helped to buffer the consequences of climatic extremes in later history, whether droughts (e.g. the El Niño-related mega-drought of 1876–1878) or floods (because the reservoirs can contain surplus runoff). More recently, however, a preference for groundwater irrigation and other landscape changes driven by population pressure has made the region more vulnerable to the incidence of heavy NEIMR episodes, as illustrated by the severe floods of 2015. Future climate adaptation planning in South India should appreciate the merits of restoring and expanding the currently decaying legacy of Chola-style ‘no regrets’ water management infrastructures.

Regional Soil Patterns as Indicators of Late Cenozoic Change in the Critical Zone: A Baseline Synthesis for the Landscapes of Peninsular India

“…Widespread manuring in a densely populated rural society primarily organised around mixed farming systems has helped to partly compensate for deficiencies in organic matter of the exposed B horizons. Given also the shallow weathering fronts and relatively thin saprolite (C horizon), saturated overland flow on the low-angle pediment slopes is high and has promoted widespread runoff harvesting opportunities, with thousands of water storage ponds used for surface irrigation by villagers-many of them many more than 1,000 years old (Bourgeon, 1987;Gunnell and Anupama, 2003;Shanmugasundaram et al, 2017). This has allowed wet rice cultivation on most valley Inceptisols-whether calcareous (Figure 5) or not (Figure 6)-despite the semi-arid climate.…”

Holocene Monsoonal Variations Over Southern India: Looking Into Its Antecedents

“…Temple tanks were built to collect rainwater and supply it for home and agricultural use during the non-rainy season (Pandey et al, 2003;Ramachandran, 2006;Rajan, 2013;Meter et al, 2014). In addition to temple tanks, the Chola rulers favored the construction of multifunctional manmade lakes, also known as tanks, which were primarily used to collect runoff water for irrigation for example Veeranam Lake and Chembarambakkam Lake are two major man-made water bodies during the Chola period (Shanmugasundaram et al, 2017). Overall, the Chola's territory strengthened and adapted to the declining NEMR conditions.…”

Municipal finance and resilience lessons for urban infrastructure management: a case study from the Cape Town drought

“…More 275 recently, Muller (2018, p. 111) has narrowed in on water service financing and argues, 'water could become a lead sector in the process of developing appropriate models for financing the implementation of adaptation'. Unprecedented shifts in climate varia-280 bility and unpredictability are increasingly recognised to pose significant financial risks to sunk investments, such pipes and dams, and their ability to successfully perform under altered climate regimes (Allan et al 2013;Rockström et al 2014;Welle and Birkmann 285 2016;Shanmugasundaram et al 2017;Varrani and Nones 2017;Muller 2018). The understanding of risk among water managers associated with climate variability will determine water managers, and other stakeholders', appetites to pursue more expensive 290 options which might deliver climate-independent water sources (Crookes 2018).…”