Changes of precipitation extremes indices in São Francisco River Basin, Brazil from 1947 to 2012

Bezerra, Bergson Guedes; Silva, Lindenberg L.; Silva, Cláudio Moisés Santos e; Carvalho, Gilvani Gomes de

doi:10.1007/s00704-018-2396-6

Cited by 86 publications

(71 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Thus, extreme precipitation events have garnered attention from governments and researchers around the world. Previous researchers have extensively studied changes in extreme precipitation on various scales (e.g., global [5,6], continental or regional [7][8][9][10], national [11][12][13], and district or river basin [14][15][16]). The results have shown that the frequency and intensity of extreme precipitation event occurrences over land regions have increased to some extent in recent decades, particularly in mid/high-latitude regions in the Northern Hemisphere.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Precipitation Extremes in the Source Region of the Yangtze River during 1960–2016

Zhou

Liang

Zhao

et al. 2018

Water

View full text Add to dashboard Cite

The source region of the Yangtze River (SRYR) on the central Tibetan Plateau has seen one of the most significant increases in temperature in the world. Climate warming has altered the temporal and spatial characteristics of precipitation in the SRYR. In this study, we analyzed the temporal trends and spatial distributions of extreme precipitation in the SRYR during 1960–2016 using 11 extreme precipitation indices (EPIs) derived from daily precipitation data collected at five meteorological stations in the region. The trends in the EPIs were estimated using the linear least squares method, and their statistical significance was assessed using the Mann–Kendall test. The results show the following. Temporally, the majority of SRYR EPIs (including the simple daily intensity index, annual maximum 1-day precipitation (RX1day), annual maximum 5-day precipitation (RX5day), very wet day precipitation, extremely wet day precipitation, number of heavy precipitation days, number of very heavy precipitation days, and number of consecutive wet days) exhibited statistically nonsignificant increasing trends during the study period, while annual total wet-day precipitation (PRCPTOT) and the number of wet days exhibited statistically significant increasing trends. In addition, the number of consecutive dry days (CDD) exhibited a statistically significant decreasing trend. For the seasonal EPIs, the PRCPTOT, RX1day, and RX5day all exhibited nonsignificant increasing trends during the wet season, and significant increasing trends during the dry season. Spatially, changes in the annual and wet season EPIs in the study area both exhibited significant differences in their spatial distribution. By contrast, changes in dry season PRCPTOT, RX1day, and RX5day exhibited notable spatial consistency. These three indices exhibited increasing trends at each station. Moreover, there was a statistically significant positive correlation between the annual PRCPTOT and each of the other EPIs (except CDD). However, the contribution of extreme precipitation to annual PRCPTOT exhibited a nonsignificant decreasing trend.

show abstract

Section: Introductionmentioning

confidence: 99%

Analysis of Precipitation Extremes in the Source Region of the Yangtze River during 1960–2016

Zhou

Liang

Zhao

et al. 2018

Water

View full text Add to dashboard Cite

show abstract

“…* Available on http://www.theplantlist.org/. Accessed in Oct 12, 2018. events indices associated with nighttime temperature in the Brazilian semiarid 31,32 . Furthermore, there is evidence of an intensification of aridity and the expansion of semiarid lands in the Northeast Brazil 33,34 , which may directly influence on the dynamics of the Caatinga tropical forest.…”

mentioning

confidence: 99%

Seasonal variation in net ecosystem CO2 exchange of a Brazilian seasonally dry tropical forest

Mendes

Campos

Silva

et al. 2020

Sci Rep

Self Cite

View full text Add to dashboard Cite

forest ecosystems sequester large amounts of atmospheric co 2 , and the contribution from seasonally dry tropical forests is not negligible. thus, the objective of this study was to quantify and evaluate the seasonal and annual patterns of co 2 exchanges in the Caatinga biome, as well as to evaluate the ecosystem condition as carbon sink or source during years. in addition, we analyzed the climatic factors that control the seasonal variability of gross primary production (Gpp), ecosystem respiration (R eco) and net ecosystem co 2 exchange (nee). Results showed that the dynamics of the components of the co 2 fluxes varied depending on the magnitude and distribution of rainfall and, as a consequence, on the variability of the vegetation state. Annual cumulative NEE was significantly higher (p < 0.01) in 2014 (−169.0 g C m −2) when compared to 2015 (−145.0 g C m −2) and annual NEP/GPP ratio was 0.41 in 2014 and 0.43 in 2015. Global radiation, air and soil temperature were the main factors associated with the diurnal variability of carbon fluxes. Even during the dry season, the NEE was at equilibrium and the Caatinga acted as an atmospheric carbon sink during the years 2014 and 2015. CO 2 concentration has a high interannual variability due to its absorption by terrestrial ecosystems (carbon sinks) 1-5. However, despite this variability, data show a systematic increase in CO 2 throughout the years 6,7. In South America, the Amazon forest is an example of a terrestrial carbon sink (considering its 20-year mean behavior), although it has occasionally behaved as CO 2-neutral or even a carbon source in the last years 8. Interannual variability and trends in CO 2 sinks are controlled by different biogeographic regions. The annual mean behavior of sinks is controlled mainly by highly productive lands, such as wet tropical forests (i.e. the Amazon forest) 5. On the other hand, semiarid environments control the global scale trends observed in the last few decades 9,10. Despite its prominent role, there is still much to be studied and investigated regarding CO 2 exchanges in these regions, which are still much less understood than wet forests or croplands 5,10. According to the literature 10 , gaps in understanding CO 2 exchanges in these environments have limited our ability to understand and predict interannual and decadal variations on global scale carbon cycle. There are a few inherent difficulties when quantifying CO 2 exchanges in semiarid environments, such as the rapid expansion of some of its areas due to climate change and anthropic activities 11,12. Studies show that some regions in South America are becoming more arid, such as the Amazon 13,14 ; the Brazilian semiarid region, dominated by the Caatinga biome, which is a seasonally dry tropical forest (SDTF) 15-17 and the Cerrado, which is a Brazilian savanna-type vegetation 18 .

show abstract

“…The river basin has 639,219 km 2 of drainage area, which covers 8% of the total area of the country. Approximately 60% of its area is inserted in the semiarid region where most tributaries are intermittent, rainfall is irregular and evaporation rates are high (Bezerra et al, 2018; Comitê da Bacia Hidrográfica do Rio São Francisco, 2016).…”

Section: Case Studymentioning

confidence: 99%

Multi-level governance application to a shared river basin

Assis

Ribeiro

Silva

2020

RBRH

View full text Add to dashboard Cite

Water governance systems must be effective in establishing policies capable of guiding decision making. Their framework needs to weigh the intrinsic complexity of inter-scale and multi-level interactions. Aspects such as decentralization and stakeholder engagement are pillars to be considered. In shared river basins (international or national), there are challenges to overcome since there is a need for managing water at different scales and multiple levels. This study aims to analyse the degree of implementation of the National Water Resources Policy in a shared federal basin in Brazil (the São Francisco River Basin) considering the basin as a whole (macro level) and its micro level (the 34 sub-basins that compose it). Multi-level interrelationships in the implementation of water policy are analysed. To this end, OECD Water Governance Principle 2 (“Manage water at the appropriate scales”) is considered as the basis for this analysis. An adaptation of the OECD Water Governance Indicator Framework methodology is used to classify the 34 sub-basins at different stages of water policy implementation. The outcomes indicate deficiencies in the process of water policy implementation in sub-basins. There is a need for better interactions at the federal, state and river basin levels to strengthen the governance system.

show abstract

Changes of precipitation extremes indices in São Francisco River Basin, Brazil from 1947 to 2012

Cited by 86 publications

References 47 publications

Analysis of Precipitation Extremes in the Source Region of the Yangtze River during 1960–2016

Analysis of Precipitation Extremes in the Source Region of the Yangtze River during 1960–2016

Seasonal variation in net ecosystem CO2 exchange of a Brazilian seasonally dry tropical forest

Multi-level governance application to a shared river basin

Contact Info

Product

Resources

About