Climate change impact on flood and extreme precipitation increases with water availability

Abstract

The hydrological cycle is expected to intensify with global warming, which likely increases the intensity of extreme precipitation events and the risk of flooding. The changes, however, often differ from the theorized expectation of increases in water‐holding capacity of the atmosphere in the warmer conditions, especially when water availability is limited. Here, the relationships of changes in extreme precipitation and flood intensities for the end of the twenty-first century with spatial and seasonal water availability are quantified. Results show an intensification of extreme precipitation and flood events over all climate regions which increases as water availability increases from dry to wet regions. Similarly, there is an increase in the intensification of extreme precipitation and flood with the seasonal cycle of water availability. The connection between extreme precipitation and flood intensity changes and spatial and seasonal water availability becomes stronger as events become less extreme.

Informal risk-sharing between smallholders may be threatened by formal insurance: Lessons from a stylized agent-based model

“…However, when the whole risk-sharing network is affected by a large-scale extreme event such that many households suffer substantial losses simultaneously, private transfers can no longer provide buffering [10,11]. Droughts or floods, which both are expected to increase under climate change [12][13][14][15], are an example of such shocks. Insurance products specifically designed for the needs of low-income households in developing countries, known as microinsurance or inclusive insurance, are seen as an effective tool to address these challenges and are therefore highly promoted and supported by governments in recent years.…”

Modelling potential climate change impacts on sediment yield in the Tsitsa River catchment, South Africa

“…It is widely accepted that climate change will bring about large changes in the hydrological cycle, most likely causing increased frequency and intensity of extreme rainfall events (Nearing et al, 2004;Seneviratne et al, 2012;Tabari, 2020). Numerous studies have shown that extreme rainfall events lead to increased runoff and sedimentation of reservoirs (Msadala et al, 2010;Mullan, 2013;Pretorius 2017).…”

“…Concerns over water security and climate change tend to focus on water availability and the hydrological cycle and fewer studies are concerned with the effects of climate change on water quality, particularly from a sedimentation perspective. Potential impacts of climate change on water security include decreased quality and quantity of available water and increased inter-annual variability (Kusangaya et al, 2014;Seneviratne et al, 2012;Tabari, 2020); increase in drought intensity and return period (Davis-Reddy and Vincent, 2017;Tabari, 2020); and increased evapotranspiration (Wu et al, 2009). Yet, climate change is also projected to affect runoff and erosion rates (Nearing et al, 2004, Mullan et al, 2012, Mullan 2013Simonneaux et al, 2015).…”

Scenarios of sustainable irrigation expansion in the 21st century

“…Both the SIDI and future estimates of sustainable irrigation potential were thus derived using present-day crop water requirements and surface water availability quantities. However, future calorie production and the sustainable irrigation expansion potential will be impacted by climate change through its alteration of precipitation amount and timing, the occurrence of extreme events 35 , as well as changing soil moisture and crop water requirements 23 . Changes in water availability and demand and higher exposure to heat extremes are, for example, projected to negatively impact local agricultural production and reduce potential benefits of CO2 fertilization in the Mediterranean, Central America, the Caribbean, South Africa and Australia 36,37 .…”