Propagation and Characteristics of Hydrometeorological Drought Under Changing Climate in Irish Catchments

Abstract

Hydrometeorological droughts are complex hazards expressed through the relative deviation in water availability relative to long-term average conditions. They are typically slow onset, propagating through the water cycle to affect different social, economic, and environmental sectors at different temporal and spatial scales (Ayantobo et al., 2017;Gaitán et al., 2020;Quevauviller & Gemmer, 2015). Furthermore, flash droughts with rapid onset propagate through different spatial-temporal scales, from atmospheric to surface conditions (Shah et al., 2022). Although drought is predominantly caused by a lack of precipitation, soil moisture and streamflow, other factors, like prolonged abstraction and rising atmospheric evaporative demand (AED), can affect drought incidence and propagation. Moreover, the development and propagation of drought is governed by hydrological processes at different spatial scales including precipitation, evapotranspiration, overland flow, soil moisture, groundwater storage and discharge (Ganguli et al., 2022;Sutanto & Van Lanen, 2022). Detailed investigation is thus required to evaluate associated linkages among various types of hydrometeorological drought to understand the likely impacts of climate change on drought characteristics (magnitude, frequency, duration and propagation) at the

Climate change impacts on spatial and seasonal meteorological drought characteristics for the island of Ireland

“…They highlight widespread (including western Europe) increases in drought frequency and intensity in spring and summer, with more modest changes in autumn and decreased drought frequency in winter in northern Europe. Our findings are also consistent with recent studies that highlight a tendency towards shorter, more intense meteorological and hydrological droughts during summer for Ireland from long‐term observations and reconstructions (Meresa et al, 2023; O'Connor et al, 2022; Vicente‐Serrano et al, 2020). Such short and intense summer droughts are typically perceived as flash droughts, with significant impact on atmospheric aridity and the depletion of soil moisture, with associated challenges for management (Qing et al, 2022).…”

“…Poorly productive aquifers with limited permeability are unlikely to accept additional recharge, while those with high recharge coefficients are likely to be more sensitive to changes in winter rainfall (Cantoni et al, 2017; Williams & Lee, 2008), with the impact of increased meteorological drought in spring and summer possibly offset by increased storage. However, additional research is required to better understand how changes in meteorological drought may propagate to other components of the hydrological system (e.g., Meresa et al, 2023). The 2018 drought also resulted in degraded water quality, affecting sensitive riverine species and habitats (Mellander & Jordan, 2021).…”

“…Despite evident vulnerability to droughts, few studies have assessed projected changes in drought characteristics with climate change for Ireland. One study by Meresa et al (2023) evaluated future changes in drought for six catchments using 12 CMIP6 climate models finding large increases in the frequency and magnitude of summer meteorological and hydrological drought. In other seasons and on annual timescales little change in drought severity was found, indicating the importance of seasonal evaluation.…”

Drought Spatial Extent and Dependence Increase During Drought Propagation From the Atmosphere to the Hydrosphere

“…Locally, projected increases in evapotranspiration (Dezsi et al., 2018) may lead to an increase in the likelihood of precipitation deficits propagating to streamflow and groundwater because of intensified soil drying. Projections for Irish catchments show that this is indeed the case when looking at the end of the century (Meresa et al., 2023). Similarly, the probability of meteorological droughts propagating to hydrological events, shows modest increases under the climate change projections considered.…”

The Main Impact Factors for the Propagation from Meteorological Drought to Socio-Economic Drought from the Perspective of a Small Area, Based on a Practical Survey

“…Over the past few decades, a number of researchers have proposed a series of drought indices to identify, evaluate and predict drought events, such as the standardized precipitation index (SPI) and the Palmer drought severity index (PDSI) [3][4][5]. Generally, drought is divided into four categories, i.e., meteorological drought, hydrological drought, agricultural drought and socio-economic drought, between which a natural propagation chain is formulated [6,7]. When precipitation falls below a specific threshold, meteorological drought occurs first, and the deficiency of precipitation further leads to a decrease in runoff and soil moisture, triggering hydrological drought and agricultural drought, which may have an impact on the safety of the water supply and food production, ultimately resulting in socio-economic drought.…”