<p>Droughts and floods are ubiquitous. Numerous studies have reported amplification in the severity and frequency of these events across different regions globally. However, the long-term impact of climate change on the frequency of droughts and floods occurring simultaneously remains uncertain. Hence, this paper aims to analyze the evolving characteristics of flood-drought co-occurrence in India, seeking to decipher the role of climate change in their interaction. A copula-based joint probability approach is used to analyse the changing nature of joint probabilities for compound drought-flood events in a particular year. Additionally, the Standardised Weighted Average of Precipitation (SWAP) index is employed to identify drought and flood events. The study area is further partitioned into homogeneous clusters based on drought and flood characteristics using Self-Organizing Maps (SOM). Gridded rainfall data from the India Meteorological Department at a 0.25-degree grid is utilized. This findings revealed that the maximum number of grid points shows an increase in monthly SWAP values in summer; however, most grid points show a decrease in monthly SWAP values in all other seasons. However, a reduction in monthly SWAP values is observed during winter at majority of the grid points. The drought and flood analysis revealed that more grid points show decreasing values for both flood and drought return periods corresponding to 5-year, 10-year, and 25-year when each period is compared with its preceding period, suggesting an increased frequency of floods and droughts in succeeding periods. We have noticed that more grid points showed considerable changes in the drought return period. But fewer grid points showed a substantial shift in flood return periods. In addition, an increase in the frequency of less-intensity flood events in many parts of India compared to high-intensity flood events is observed. However, we did not find any increase in the co-occurrence of floods and droughts.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Deciphering the intra annual dynamics of evolving compound flood-drought interaction in Indian hydrology: insights from a copula-based approach

  • Salvadi Chetan Kumar,
  • Velpuri Manikanta,
  • Manoj Kumar Jain,
  • Vivek Gupta

摘要

Droughts and floods are ubiquitous. Numerous studies have reported amplification in the severity and frequency of these events across different regions globally. However, the long-term impact of climate change on the frequency of droughts and floods occurring simultaneously remains uncertain. Hence, this paper aims to analyze the evolving characteristics of flood-drought co-occurrence in India, seeking to decipher the role of climate change in their interaction. A copula-based joint probability approach is used to analyse the changing nature of joint probabilities for compound drought-flood events in a particular year. Additionally, the Standardised Weighted Average of Precipitation (SWAP) index is employed to identify drought and flood events. The study area is further partitioned into homogeneous clusters based on drought and flood characteristics using Self-Organizing Maps (SOM). Gridded rainfall data from the India Meteorological Department at a 0.25-degree grid is utilized. This findings revealed that the maximum number of grid points shows an increase in monthly SWAP values in summer; however, most grid points show a decrease in monthly SWAP values in all other seasons. However, a reduction in monthly SWAP values is observed during winter at majority of the grid points. The drought and flood analysis revealed that more grid points show decreasing values for both flood and drought return periods corresponding to 5-year, 10-year, and 25-year when each period is compared with its preceding period, suggesting an increased frequency of floods and droughts in succeeding periods. We have noticed that more grid points showed considerable changes in the drought return period. But fewer grid points showed a substantial shift in flood return periods. In addition, an increase in the frequency of less-intensity flood events in many parts of India compared to high-intensity flood events is observed. However, we did not find any increase in the co-occurrence of floods and droughts.