Analyze the temporal pattern of rainfall over the basin
Pro Research Analysisby 
Searched over 200M research papers
Consensus Meter
Temporal Pattern of Rainfall Over Various River Basins
Introduction to Rainfall Patterns and Their Importance
Understanding the temporal patterns of rainfall is crucial for effective water resource management, flood control, and agricultural planning. This article synthesizes findings from multiple studies to provide a comprehensive overview of rainfall trends across different river basins globally.
Rainfall Trends in the Pearl River Basin
Annual and Seasonal Rainfall Trends
Research on the Pearl River Basin in China indicates a slight decrease in both annual and seasonal rainfall across most areas from 1959 to 2012. Monthly rainfall distribution was irregular, with no significant trends detected, but rainfall seasonality increased in most areas.
Influence of ENSO Events
The study also highlighted the impact of El Niño-Southern Oscillation (ENSO) and El Niño Modoki (ENSO_M) events on seasonal drought patterns. ENSO events predominantly influenced autumn droughts in the Pearl River Delta, while ENSO_M events affected autumn droughts in the middle-upper reaches and northern parts of the middle-lower reaches.
Rainfall Variability in the Amazon Basin
Intensification of Rainfall
In the Amazon Basin, rainfall patterns have shown significant changes from 1982 to 2018. Wet areas in the western basin have become wetter, with an annual increase of 182 mm of rainfall, while eastern and southern regions, affected by deforestation, have experienced significant drying trends.
Local Alterations and Dry Days
The Tocantins region, for example, has seen an increase in the number of dry days during both wet and dry seasons, highlighting the complex interplay between local landscape changes and broader climatic factors.
Rainfall Trends in Indian River Basins
Extreme Rainfall Events
Analysis of rainfall data from 1901 to 2015 across 85 Indian river basins revealed an upward trend in extreme rainfall events, particularly in the post-urbanization era (1971-2015). This trend is attributed to urbanization and climatic factors, with a notable increase in the magnitude of extreme rainfall events.
Seasonal Variability
In the Nagavali and Vamsadhara basins, a decreasing trend in rainfall extremes was observed in the post-1950 period, except during the monsoon season, which showed an increasing trend. This indicates a higher vulnerability to floods in these regions.
Rainfall Patterns in the Indus, Ganga, and Brahmaputra Basins
Regional Differences
The Indus basin has shown a positive rainfall trend, while the Ganga and Brahmaputra basins have experienced a significant decrease in monsoonal and annual rainfall. The precipitation concentration index (PCI) indicated an irregular distribution with no significant trend.
Impact on Water Storage
The study also found a significant increase in mean annual temperature and a decrease in terrestrial water storage (TWS) over the region, suggesting that changes in rainfall and temperature patterns are contributing to reduced water availability.
Rainfall Trends in the Wainganga Basin
Long-Term Trends
In the Wainganga basin, a significant decreasing trend in annual rainfall was observed from 1901 to 2012, with a notable change year around 1948. Seasonal analysis showed a non-significant increasing trend in post-monsoon rainfall, while monsoon rainfall exhibited a significant decreasing trend.
Rainfall Extremes in the Pearl River Basin
Regional Frequency Analysis
A detailed study on the Pearl River Basin categorized the region into six clusters based on topography and mean precipitation patterns. The analysis revealed that excessive precipitation events were more frequent in certain regions, contributing to flood risks.
Rainfall Variability in the Nile Basin
Spatial and Temporal Variability
In the Nile Basin, significant temporal variability in annual and seasonal rainfall was observed. The study identified three distinct groups of stations with different rainfall patterns, influenced by various climatic drivers such as the Indian Ocean and Atlantic Ocean.
Rainfall Concentration in the Mantaro River Basin
Daily Rainfall Analysis
In the Mantaro River Basin, high-intensity rainfall events accounted for a significant portion of the total annual rainfall, leading to frequent floods and landslides. The study highlighted the importance of analyzing daily rainfall data to understand the spatial distribution of extreme weather events.
Conclusion
The temporal patterns of rainfall across different river basins show significant variability influenced by climatic factors, local landscape changes, and broader environmental trends. Understanding these patterns is essential for managing water resources, mitigating flood risks, and planning for agricultural sustainability. The studies reviewed provide valuable insights into the complex dynamics of rainfall variability and its implications for different regions.
Sources and full results
Most relevant research papers on this topic