Assessment of drought hazard, exposure, vulnerability, and risk for rice cultivation in the Mun River Basin in Thailand

Abstract

When assessing drought risk, most studies focus on hazard and vulnerability, paying less attention to exposure. Here, we propose a comprehensive drought risk assessment scheme combining hazard, exposure, and vulnerability. At the Mun River Basin, 90% of rice cultivation is rain-fed and regularly encounters droughts resulting in the lowest yields in the country. The water deficit calculated with respect to rice water requirement is used to assess drought hazard and is estimated at monthly time steps. We use drought severity and frequency for hazard estimation and population and rice field characteristics for exposure. Vulnerability is represented by physical and socioeconomic factors and coping and adaptive capacity. Between 1984 and 2016, monthly precipitation during the rice-growing season was insufficient to meet rice water needs at all growth stages (July-November). The hazard is more severe in October and November, which can lead to significantly reduced yields. People and rice fields in the center part of the basin are more exposed to drought than in other parts. Extensive areas are under high and moderate vulnerability due to low coping capacity. The higher drought risks appear in the last 2 months of the growing season and decrease from north to south, while the risk map of total precipitation demonstrates that most of the areas have low and very low risk. This emphasizes the importance of monthly time series analysis to calculate agricultural drought hazard and risk. Consequently, we recommend using the hazard and risk maps for October and November instead of the total precipitation to develop solutions to improve rice yield.

Spatiotemporal Distribution and Risk Assessment of Heat Waves Based on Apparent Temperature in the One Belt and One Road Region

“…For each determinant, we used different data to calculate the contribution of this determinant to heat wave risk (Table 2). We first standardize each data to 0-1, then use the same weight to calculate each determinant, and then standardize each determinant to calculate the heat wave risk with the same weight, the relationships of which are convenient to schematize in a mathematical form [53,[80][81][82], defined as Equation (11). It should be noted that hazard is calculated using the 30-year average of HWF, HWTD and HWMAT, which is based on ARTT = 80, ATT = 29 and DT = 3.…”

Changes in the reference evapotranspiration and contributions of climate factors over the Indo–China Peninsula during 1961–2017

“…Despite ICP being in the tropical region, it often suffers from droughts, which have exerted disastrous consequences on people's life and social‐economic developments. In 2013, about 3,850 km 2 of agricultural areas and 9 million people in Thailand were influenced by droughts, and the total damage hit $90 million (Prabnakorn et al ., 2019). (d) Researches regarding the ICP ET 0 changes and the relevant causes are still very limited.…”

“…The specific objectives of the current study are to (a) comprehensively analyse the annual and monthly changes in ET 0 in ICP, (b) separate the individual contributions of each climatic factor to the annual and monthly ET 0 changes, and (c) identify the dominant factors of such changes by comparing the individual contributions of climatic factors. The present study can, thus, throw light on the spatiotemporal changes of ET 0 in response to climate change and help address the related implications for the variations of weather and climate systems, ecosystems/biodiversity, and droughts in ICP (Thilakarathne and Sridhar, 2017; Prabnakorn et al ., 2019; Chhin et al ., 2020).…”

Risk analysis and influencing factors of drought and flood disasters in China

“…Based on the social attributes of drought disasters, the impacts of climate change, population growth and socioeconomic vulnerability on drought disasters are comprehensively considered (Ahmadalipour et al, 2019). More studies choose indicators from the perspectives of hazard, exposure, sensitivity and resistance capacity to measure the risk of drought (Pei et al, 2018;Prabnakorn et al, 2019). Similar to drought, a flood risk assessment can establish an index system from the perspective of floodrelated factors.…”