Trans-boundary variations of urban drought vulnerability and its impact on water resource management in Singapore and Johor, Malaysia

Abstract

Low-latitude areas generally experience relatively large precipitation totals, but droughts/dry spells do occur periodically and are potentially hazardous in these regions -especially within rapidly developing urban settlements. These areas typically have high water demand and therefore may potentially be subjected to water scarcity. Effective local water resource management lowering risks and vulnerabilities to drought is thus paramount, and these policies may be affected in regions with national borders sharing a common transboundary water resource. In this study, we (a) quantify and identify drought episodes using the Palmer Drought Severity Index in the neighbouring equatorial regions of Singapore and Johor, Malaysia, and (b) qualitatively examine each region's drought impacts and consequent responses through archival research over the past fifty years. The data indicate that both frequencies and intensities of drought episodes in both Singapore and Johor have increased over time, suggesting greater exposure to this hazard. However, there are distinct variations in drought impacts in Singapore and Johor, and how each region addresses water resource management to drought with varying degrees of success. Despite the close geographical proximity, significant variations in regional adaptive capacities suggest that different drought vulnerabilities exist. We discuss the efficacy of drought responses over different time scales, and suggest that a combination of demand-and supply-side policies, especially in the long-term, should be considered to reduce vulnerability to this hazard.

Assessment of temperature extremes and climate change impacts in Singapore, 1982–2018

“…Singapore is located between the longitude of 103 o 36 0 -104 o 25 0 E and latitude of 1 o 09 0 -1 o 29 0 N (Li et al, 2016a;Chuah et al, 2018). It has a total land area of about 720 km 2 .…”

Integrated Urban Water Management and Water Security: A Comparison of Singapore and Hong Kong

“…Looking to the medium-term, there are increasing concerns about the availability and quality of imported water for Singapore. Although Johor has plentiful water resources, with total demand for all sectors making up less than one quarter of available surface water resources, a combination of climatic variability and water resource mismanagement has led to frequent water supply disruptions in Johor during periods of drought [58]. Water quality in the Johor catchments has also declined due to pollution [59] and rising salinity [58].…”

“…Although Johor has plentiful water resources, with total demand for all sectors making up less than one quarter of available surface water resources, a combination of climatic variability and water resource mismanagement has led to frequent water supply disruptions in Johor during periods of drought [58]. Water quality in the Johor catchments has also declined due to pollution [59] and rising salinity [58]. Shortages in Malaysia could also exacerbate social and political tensions, increasing supply risk associated with imported water.…”

Ensemble Drought Exposure Projection for Multifactorial Interactive Effects of Climate Change and Population Dynamics: Application to the Pearl River Basin

“…Drought is a frequent climate condition and can occur anywhere worldwide, even in tropical rainforests and desert areas (Svoboda & Fuchs, 2017). It has a widespread and significant impact on the human production activities and natural environment, mainly affecting water resources, fisheries, forestry, agriculture, and human life (Chuah et al., 2018; Thomas et al., 2013). As a common natural hazard, drought can cause substantial economic losses every year (Liu et al., 2018; Zhou, Huang, Wang, & Cheng, 2018).…”