scholarly journals Elevation-Dependent Trends in Precipitation Observed over and around the Tibetan Plateau from 1971 to 2017

Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2848
Author(s):  
Wenfeng Hu ◽  
Junqiang Yao ◽  
Qing He ◽  
Jing Chen
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Extreme Precipitation ◽  
Strong Dependence ◽  
The Tibetan Plateau ◽  
Total Precipitation ◽  
Annual Total Precipitation ◽  
Annual Total ◽  
Extreme Precipitation Indices ◽  
Precipitation Indices

The Tibetan Plateau (TP) are regions that are most sensitive to climate change, especially extreme precipitation changes with elevation, may increase the risk of natural disasters and have attracted attention for the study of extreme events in order to identify adaptive actions. Based on daily observed data from 113 meteorological stations in the Tibetan Plateau and the surrounding regions in China during 1971–2017, we calculated the annual total precipitation and extreme precipitation indices using the R ClimDex software package and explored elevation-dependent precipitation trends. The results demonstrate that the annual total precipitation increased at a rate of 6.7 mm/decade, and the contribution of extreme precipitation to total precipitation increased over time, and the climate extremes were enhanced. The annual total, seasonal precipitation, and precipitation extreme trends were observed in terms of elevation dependence in the Tibetan Plateau (TP) and the surrounding area of the Tibetan Plateau (TPS) during 1971–2017. There is growing evidence that the elevation-dependent wetting (EDWE) is complex over the TP. The trends in total precipitation have a strong dependence on elevation, and the EDWE is highlighted by the extreme precipitation indices, for example, the number of heavy precipitation days (R10) and consecutive wet days (CWD). The dependence of extreme precipitation on elevation is heterogeneous, as other extreme indices do not indicate EDWE. These findings highlight the precipitation complexity in the TP. The findings of this study will be helpful for improving our understanding of variabilities in precipitation and extreme precipitation in response to climate change and will provide support for water resource management and disaster prevention in plateaus and mountain ranges.

scholarly journals Spatial and Temporal Patterns of the Extreme Precipitation across the Tibetan Plateau (1986–2015)

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1453 ◽  
Author(s):  
Junnan Xiong ◽  
Zhiwei Yong ◽  
Zegen Wang ◽  
Weiming Cheng ◽  
Yi Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Extreme Precipitation ◽  
Temporal Pattern ◽  
Alpine Meadow ◽  
The Tibetan Plateau ◽  
Desert Steppe ◽  
Trend Slope ◽  
Extreme Precipitation Indices ◽  
Precipitation Indices ◽  
Increasing Trends

The Tibetan Plateau is one of the most vulnerable areas to extreme precipitation. In recent decades, water cycles have accelerated, and the temporal and spatial characteristics of extreme precipitation have undergone dramatic changes across the Tibetan Plateau, especially in its various ecosystems. However, there are few studies that considered the variation of extreme precipitation in various ecosystems, and the impact of El Niño-Southern Oscillation (ENSO), and few researchers have made a quantitative analysis between them. In this study, we analyzed the spatial and temporal pattern of 10 extreme precipitation indices across the Tibetan Plateau (including its four main ecosystems: Forest, alpine meadow, alpine steppe, and desert steppe) based on daily precipitation from 76 meteorological stations over the past 30 years. We used the linear least squares method and Pearson correlation coefficient to examine variation magnitudes of 10 extreme precipitation indices and correlation. Temporal pattern indicated that consecutive wet days (CWD) had a slightly decreasing trend (slope = −0.006), consecutive dry days (CDD), simple daily intensity (SDII), and extreme wet day precipitation (R99) displayed significant increasing trends, while the trends of other indices were not significant. For spatial patterns, the increasing trends of nine extreme precipitation indices (excluding CDD) occurred in the southwestern, middle and northern regions of the Tibetan Plateau; decreasing trends were distributed in the southeastern region, while the spatial pattern of CDD showed the opposite distribution. As to the four different ecosystems, the number of moderate precipitation days (R10mm), number of heavy precipitation days (R20mm), wet day precipitation (PRCPTOT), and very wet day precipitation (R95) in forest ecosystems showed decreasing trends, but CDD exhibited a significant increasing trend (slope = 0.625, P < 0.05). In the other three ecosystems, all extreme precipitation indices generally exhibited increasing trends, except for CWD in alpine meadow (slope = −0.001) and desert steppe (slope = −0.005). Furthermore, the crossover wavelet transform indicated that the ENSO had a 4-year resonance cycle with R95, SDII, R20mm, and CWD. These results provided additional evidence that ENSO play an important remote driver for extreme precipitation variation in the Tibetan Plateau.

scholarly journals Cenários de Mudanças Climáticas no Estado da Bahia através de Estudos Numéricos e Estatísticos (Climate Change Scenarios in Bahia through Numerical and Statistical Studies)

2013 ◽  
Vol 5 (5) ◽  
pp. 1019 ◽  
Author(s):  
Gildarte Barbosa Silva ◽  
Werônica Meira Souza ◽  
Pedro Vieira Azevedo
Keyword(s):  
Climate Change ◽  
Climatic Variability ◽  
Climatic Changes ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Climate Change Scenarios ◽  
Total Precipitation ◽  
Annual Total Precipitation ◽  
Annual Total ◽  
Statistical Studies

Este trabalho teve como objetivo investigar a ocorrência ou ausência de mudanças climáticas no período de 1970 a 2006, em algumas microrregiões do estado da Bahia: Irecê, Oeste, Sudoeste e Baixo Médio São Francisco, através de índices de tendências de mudanças climáticas obtidos da precipitação pluviométrica e das temperaturas máxima e mínima diárias das estações climatológicas das respectivas regiões e de cenários de mudanças climáticas. Utilizou-se os índices de detecção de mudanças climáticas sugeridos pela OMM calculados a partir dos dados de precipitação e das temperaturas máxima e mínima diárias através do software RClimdex 1.9.0. No estudo numérico foi utilizado o modelo BRAMS. Observou-se que na região de Irecê houve tendência de diminuição da precipitação total anual e aumento da intensidade das chuvas diárias. Na região Oeste houve aumento no número de dias com temperaturas elevadas, aumento nas temperaturas mínimas diárias e aumento na intensidade das chuvas. Na região Sudoeste houve uma  tendência de um pequeno aumento dos totais anuais de chuvas. Na região do Baixo Médio São Francisco houve aumento no número de dias com temperatura máxima diária, diminuição das chuvas diárias e da precipitação total anual. Essa variação na precipitação na região pode ser atribuída à circulação de grande escala, enquanto a intensidade das chuvas pode ter influência na variabilidade climática. Cabe aos gestores desse país encarar essa realidade com muita responsabilidade e, sugira ações e medidas eficazes para combatê-la, capacitando a sociedade como um todo para conviver com essa nova realidade. Palavras-chave: Mudanças climáticas; estudos numéricos; índices de tendências climáticas.   Climate Change Scenarios in Bahia through Numerical and Statistical Studies   ABSTRACT This work had as objective to investigate the occurrence or absence of climatic changes in the period of 1970 the 2006, in some microregions of the state of the Bahia: Irecê, Oeste, Sudoeste and Baixo Médio São Francisco, through indexes of trends of climatic changes with data of daily total precipitation and the daily temperatures maximum and minimum of the climatological stations of the respective regions and climate change scenarios. One used the indexes of detection of climatic changes suggested by WMO calculated from the data of daily precipitation and the daily temperature through software RClimdex 1.9.0. The study used numerical model BRAMS. It was observed that in the region of Irecê it had trend of reduction of the annual total precipitation and increase in the intensity of daily rains. In the region Oeste it had increase in the number of days with raised temperatures, increase in the daily minimum temperatures and increase in the intensity of rains. In the Sudeste region it had a trend of a small increase of the annual rain totals. In the region of the Baixo Médio São Francisco it had increase the number of days with daily maximum temperature, reduction of daily rains and the annual total precipitation. This variation in the precipitation in the region can be attributed to the circulation of great scale, while the intensity of rains can have influence in the climatic variability. It is the managers of this country face that reality as something that must be faced with great responsibility, and suggest actions and effective measures to combat it enabling the society as a whole to deal with this new reality.Keywords: Climatic changes; numerical studies; climate trends. 

scholarly journals Impact of Climate Change on Precipitation Extremes over Ho Chi Minh City, Vietnam

Water ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 120
Author(s):  
Dao Nguyen Khoi ◽  
Nguyen Trong Quan ◽  
Pham Thi Thao Nhi ◽  
Van Thinh Nguyen
Keyword(s):  
Climate Change ◽  
Extreme Precipitation ◽  
Precipitation Amount ◽  
Heavy Precipitation ◽  
Weather Generator ◽  
Ho Chi Minh City ◽  
Future Period ◽  
Extreme Precipitation Indices ◽  
Precipitation Indices ◽  
Extreme Indices

In the context of climate change, the impact of hydro-meteorological extremes, such as floods and droughts, has become one of the most severe issues for the governors of mega-cities. The main purpose of this study is to assess the spatiotemporal changes in extreme precipitation indices over Ho Chi Minh City, Vietnam, between the near (2021–2050) and intermediate (2051–2080) future periods with respect to the baseline period (1980–2009). The historical extreme indices were calculated through observed daily rainfall data at 11 selected meteorological stations across the study area. The future extreme indices were projected based on a stochastic weather generator, the Long Ashton Research Station Weather Generator (LARS-WG), which incorporates climate projections from the Coupled Model Intercomparison Project 5 (CMIP5) ensemble. Eight extreme precipitation indices, such as the consecutive dry days (CDDs), consecutive wet days (CWDs), number of very heavy precipitation days (R20mm), number of extremely heavy precipitation days (R25mm), maximum 1 d precipitation amount (RX1day), maximum 5 d precipitation amount (RX5day), very wet days (R95p), and simple daily intensity index (SDII) were selected to evaluate the multi-model ensemble mean changes of extreme indices in terms of intensity, duration, and frequency. The statistical significance, stability, and averaged magnitude of trends in these changes, thereby, were computed by the Mann-Kendall statistical techniques and Sen’s estimator, and applied to each extreme index. The results indicated a general increasing trend in most extreme indices for the future periods. In comparison with the near future period (2021–2050), the extreme intensity and frequency indices in the intermediate future period (2051–2080) present more statistically significant trends and higher growing rates. Furthermore, an increase in most extreme indices mainly occurs in some parts of the central and southern regions, while a decrease in those indices is often projected in the north of the study area.

scholarly journals The Decrasing Trend of Precipitation Observed at Watesheds in Padang for The Period 1975-2013

2017 ◽  
Vol 1 (2) ◽  
pp. 222
Author(s):  
Ratna Wilis ◽  
Sugeng Nugroho
Keyword(s):  
Extreme Precipitation ◽  
Rain Gauge ◽  
Homogeneity Test ◽  
Total Precipitation ◽  
Dipole Mode ◽  
Precipitation Condition ◽  
Precipitation Frequency ◽  
Increasing Trend ◽  
Extreme Precipitation Indices ◽  
Precipitation Indices

One of the consequences of the ongoing climate change is the increasing likelihood of extreme precipitation frequency in the future, which causes the declining trend of total precipitation that affects water debits in the watersheds and brings difficulties to a city like Padang that is situated near the watersheds. In order to elaborate on this, a number of extreme precipitation indices recommended by ETCCDMI was utilized to assess the extreme precipitation condition for the period 1975-2013. These indices were calculated based on the rain-gauge stations along the watersheds in and around Padang. Before processing the data, a series of homogeneity test were undertaken to make sure the data were comparable. The results showed that there was a significant declining trend on the total annual precipitation (PRCPTOT), an increasing trend of the number of days without rain (R0) and a decreasing frequency of the number of days with precipitation of more than 50 mm in the Batang Kuranji Watershed. The results suggested that atmospheric circulations, such as El Nino and positive Dipole Mode, have played their role on the trend as a result of their intensified frequency due to global warming.

scholarly journals Spatiotemporal Variations of Extreme Precipitation Events in the Jinsha River Basin, Southwestern China

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Dan Zhang ◽  
Wensheng Wang ◽  
Shuqi Liang ◽  
Shunjiu Wang
Keyword(s):  
Climate Change ◽  
Extreme Precipitation ◽  
Abrupt Change ◽  
Precipitation Amount ◽  
Spatiotemporal Variations ◽  
Jinsha River ◽  
Extreme Precipitation Events ◽  
Extreme Precipitation Indices ◽  
Precipitation Indices ◽  
Precipitation Events

Climate extremes have attracted widespread attention for their threats to the natural environment and human society. Based on gauged daily precipitation from 1963 to 2016 in four subregions of the Jinsha River Basin (JRB), four extreme precipitation indices developed by the Expert Team on Climate Change Detection and Indices (ETCCDI) were employed to assess the spatiotemporal variations of extreme precipitation events. Results show the following: (1) Max one-day precipitation amount (RX1day), max consecutive five-day precipitation amount (RX5day), precipitation on very wet days (R95p), and number of heavy precipitation days (R10mm) showed increasing trends in four subregions except for the decline of R10mm in the southeastern and RX5day in the midsouthern. Extreme precipitation has become more intense and frequent in most parts of the JRB. (2) In space, the four extreme precipitation indices increased from the northwest to the southeast. Temporal trends of extreme precipitation showed great spatial variability. It is notable that extreme precipitation increased apparently in higher elevation areas. (3) The abrupt change of extreme precipitation in the northwestern, midsouthern, and southeastern mainly appeared in the late 1990s and the 2000s. For the midnorthern, abrupt change mainly occurred in the late 1980s. This study is meaningful for regional climate change acquaintance and disaster prevention in the JRB.

scholarly journals Contrasting Evolution Patterns of Endorheic and Exorheic Lakes on the Central Tibetan Plateau and Climate Cause Analysis during 1988–2017

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1962
Author(s):  
Zhilong Zhao ◽  
Yue Zhang ◽  
Zengzeng Hu ◽  
Xuanhua Nie
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
Climatic Factors ◽  
Global Climate ◽  
Rapid Expansion ◽  
Annual Precipitation ◽  
The Tibetan Plateau ◽  
Lake Area ◽  
Climate Change Research ◽  
Mean Temperature

The alpine lakes on the Tibetan Plateau (TP) are indicators of climate change. The assessment of lake dynamics on the TP is an important component of global climate change research. With a focus on lakes in the 33° N zone of the central TP, this study investigates the temporal evolution patterns of the lake areas of different types of lakes, i.e., non-glacier-fed endorheic lakes and non-glacier-fed exorheic lakes, during 1988–2017, and examines their relationship with changes in climatic factors. From 1988 to 2017, two endorheic lakes (Lake Yagenco and Lake Zhamcomaqiong) in the study area expanded significantly, i.e., by more than 50%. Over the same period, two exorheic lakes within the study area also exhibited spatio-temporal variability: Lake Gaeencuonama increased by 5.48%, and the change in Lake Zhamuco was not significant. The 2000s was a period of rapid expansion of both the closed lakes (endorheic lakes) and open lakes (exorheic lakes) in the study area. However, the endorheic lakes maintained the increase in lake area after the period of rapid expansion, while the exorheic lakes decreased after significant expansion. During 1988–2017, the annual mean temperature significantly increased at a rate of 0.04 °C/a, while the annual precipitation slightly increased at a rate of 2.23 mm/a. Furthermore, the annual precipitation significantly increased at a rate of 14.28 mm/a during 1995–2008. The results of this study demonstrate that the change in precipitation was responsible for the observed changes in the lake areas of the two exorheic lakes within the study area, while the changes in the lake areas of the two endorheic lakes were more sensitive to the annual mean temperature between 1988 and 2017. Given the importance of lakes to the TP, these are not trivial issues, and we now need accelerated research based on long-term and continuous remote sensing data.

Spring phenology outweighed climate change in determining autumn phenology on the Tibetan Plateau

2021 ◽  
Vol 41 (6) ◽  
pp. 3725-3742
Author(s):  
Jie Peng ◽  
Chaoyang Wu ◽  
Xiaoyue Wang ◽  
Linlin Lu
Keyword(s):  
Climate Change ◽  
Tibetan Plateau ◽  
The Tibetan Plateau ◽  
Spring Phenology
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