scholarly journals Appraising standardized moisture anomaly index (SZI) in drought projection across China under CMIP6 forcing scenarios

2021 ◽  
Vol 37 ◽  
pp. 100898
Author(s):  
Gengxi Zhang ◽  
Xiaoling Su ◽  
Vijay P. Singh ◽  
Olusola O. Ayantobo
Keyword(s):  
Anomaly Index

scholarly journals A global dataset of standardized moisture anomaly index incorporating snow dynamics from 1948 to 2010

2021 ◽  
Author(s):  
Lei Tian ◽  
Baoqing Zhang ◽  
Pute Wu
Keyword(s):  
Large Scale ◽  
Spatial Scales ◽  
Arctic Region ◽  
Drought Indices ◽  
Source Data ◽  
Different Types ◽  
Drying Trend ◽  
Energy Processes ◽  
Data Assimilation System ◽  
Anomaly Index

Abstract. Drought indices are hard to balance in terms of versatility (effectiveness for multiple types of drought), flexibility of timescales, and inclusivity (to what extent they include all physical processes). A lack of consistent source data increases the difficulty of quantifying drought. Here, we present a global monthly drought dataset from 1948 to 2010 based on a multitype and multiscalar drought index, the standardized moisture anomaly index incorporating snow dynamics (SZIsnow), driven by systematic fields from an advanced data assimilation system. The proposed SZIsnow dataset includes different physical water‒energy processes, especially snow processes. Our evaluation of the dataset demonstrates its ability to distinguish different types of drought across different timescales. Our assessment also indicates that the dataset adequately captures droughts across different spatial scales. The consideration of snow processes improved the capability of SZIsnow, and the improvement is particularly evident over snow-covered high-latitude (e.g., Arctic region) and high-altitude areas (e.g., Tibetan Plateau). We found that 59.66 % of Earth's land area exhibited a drying trend between 1948 and 2010, and the remaining 40.34 % exhibited a wetting trend. Our results also show that the SZIsnow dataset successfully captured the large-scale drought events that occurred across the world; there were 525 drought events with an area larger than 500,000 square kilometers globally during the study period, of which nearly 70 % had a duration longer than 6 months. Therefore, this new drought dataset is well suited to monitoring, assessing, and characterizing drought, and can serve as a valuable resource for future drought studies.

Analysis of agronomic drought over North Africa using remote sensing satellite data

2021 ◽  
Author(s):  
Mehrez Zribi ◽  
Simon Nativel ◽  
Michel Le Page
Keyword(s):  
Remote Sensing ◽  
Water Content ◽  
Soil Water ◽  
Soil Water Content ◽  
North Africa ◽  
Vegetation Cover ◽  
Remote Sensing Data ◽  
Study Region ◽  
Semi Arid Region ◽  
Anomaly Index

<p>This paper aims to analyze the agronomic drought in a highly anthropogenic  semi-arid region, North Africa. In the context of the Mediterranean climate, characterized by frequent droughts, North Africa is particularly affected. Indeed, in addition to this climatic aspect, it is one of the areas most affected by water scarcity in the world. Thus, understanding and describing agronomic drought is essential. The proposed study is based on remote sensing data from TERRA-MODIS and ASCAT satellite, describing the dynamics of vegetation cover and soil water content through NDVI and SWI indices. Two indices are analyzed, the Vegetation Anomaly Index (VAI) and the Moisture Anomaly Index (MAI). The dynamics of the VAI is analyzed for different types of regions (agircultural, forest areas). The contribution of vegetation cover is combined with the effect of soil water content through a new drought index combining the VAI and MAI. A discussion of this combination is proposed on different study areas in the study region. It illustrates the complementarity of these two informations in analysis of agronomic drought.</p>

scholarly journals Evaluation of the drainage system of Zagros Basin (Greater Zab River, northern Iraq) and insights into tectonic geomorphology

2020 ◽  
Vol 13 (22) ◽  
Author(s):  
Ziyad Elias ◽  
Varoujan K. Sissakian ◽  
Nadhir Al-Ansari
Keyword(s):  
Drainage System ◽  
Tectonic Activity ◽  
Mature Stage ◽  
Tectonic Geomorphology ◽  
Drainage Basins ◽  
Main Trunk ◽  
Northern Iraq ◽  
Clastic Rocks ◽  
North Iraq ◽  
Anomaly Index

AbstractGeomorphological evaluation was carried out for three drainage basins named Hareer, Dwaine, and Hijran, which are tributaries of the Greater Zab River in the northern part of Erbil Governorate, the Iraqi Kurdistan Region, north Iraq. The exposed rocks in the three basins are mainly clastic rocks (sandstone, claystone, and conglomerate, with subordinate gypsum and limestone beds). However, in the uppermost parts of the basins, thick and massive carbonate rocks are exposed. Tectonically, the three basins are located in the Low Folded and High Folded Zones, which belong to the Zagros Fold–Thrust Belt. The main aim of the current study is to deduce the tectonic activity of the area occupied by the studied three basins. We have used and interpreted Radar Topography Mission (SRTM) data to perform the geomorphological evaluation. Different geomorphological indices and forms were used to deduce the tectonic activity of the area occupied by the three basins. Accordingly, seven orders of streams were identified in the three basins. The number of the streams with low order (i.e., 1) joining with higher order (i.e., 6 and 7) is considerably higher in the three basins. The Hat values of the three basins are 12,971, 10,479, and 7014 in Hareer, Dwaine, and Hijran basins, respectively. The values of hierarchical anomaly index (Δa) of the three basins are 1.87, 1.35, and 2.37 in Hareer, Hijran, and Dwaine basins, respectively. It was observed that the shape of Hareer and Shakrook anticlines has a significant impact on the main trunk of the channel. Therefore, when an anticline and syncline are close to each other (due to thrust faulting), then the hierarchical anomaly increases because the river trunk receives a lot of first-order streams, e.g., in Dwaine and Hijran basins. The lateral growth in the eastern part of Safin anticline had caused increasing of the Δa. The increased hierarchical anomaly index is attributed to the existence of faults and lineaments, which represent weakness zones. The hypsometric curves of the three basins have a typical shape of old stage with rejuvenation in their central and terminal portions which is changed into mature stage, most probably due to the local uplift which is caused by normal, thrust, and strike–slip (oblique) faults which exist in the study area and the near surroundings. The Bs and Hat values in Hareer, Dwaine, and Hijran basins indicate that the basins exhibit low, medium, and high tectonic activity, respectively.

Short-Impending Earthquake Anomaly Index Extraction of GNSS Continuous Observation Data in Yunnan, Southwestern China

2018 ◽  
Vol 29 (1) ◽  
pp. 230-236 ◽  
Author(s):  
Min Hong ◽  
Desheng Shao ◽  
Tengfei Wu ◽  
Shuangxi Zhang ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Southwestern China ◽  
Observation Data ◽  
Continuous Observation ◽  
Anomaly Index

scholarly journals A variabilidade da precipitação nas sub-bacias do Alto e do Médio Jaguaribe e seu efeito sob os açudes Castanhão e Orós, localizados no estado do Ceará

2021 ◽  
Vol 14 (1) ◽  
pp. 025
Author(s):  
Sâmia de Sousa Rocha ◽  
João Roberto Façanha De Almeida
Keyword(s):  
Water Supply ◽  
The State ◽  
Semiarid Region ◽  
Weather Events ◽  
Historical Series ◽  
Anomaly Index ◽  
Heavy Rains

Os grandes períodos de seca e as fortes chuvas são características da variabilidade pluviométrica do semiárido do estado do Ceará e para melhor caracterizar tais acontecimentos existem diversos métodos. Dentre eles, o Índice de Anomalia de Chuvas (IAC) que foi aplicado neste trabalho e teve como base a série histórica publicada no portal HidroWeb da Agência Nacional das Águas (ANA) durante o período de 1969 a 2019. O enfoque do estudo se deu nas sub-bacias do Alto e Médio Jaguaribe, onde se localizam, respectivamente, os açudes Orós e Castanhão. Com isto, calculou-se o IAC para sete postos pluviométricos identificando os anos secos e chuvosos e os classificando de acordo com a intensidade. Posteriormente, realizou-se através do coeficiente de correlação de Pearson a correlação entre a variação da precipitação e dos níveis volumétricos dos açudes. Conclui-se que houve uma proporção entre a quantidade de anos secos e chuvosos na região, pois, em ambas bacias foram identificados 27 anos secos e 24 anos úmidos. O menor IAC encontrado foi de -4,55 em 1993 na região do Médio Jaguaribe e o maior foi de 6,77 em 1985 no Alto Jaguaribe. Observou-se também que a correlação se mostrou forte obtendo valores de 0,74 para o açude Castanhão e de 0,72 no Orós, ou seja, o fator precipitação influencia diretamente no aporte hídrico de açudes e por isto, é tão crucial o entendimento de séries históricas e de acontecimentos climáticos nas regiões do Nordeste brasileiro.  Study of pluviometric variability in cearense semiarid and the efect on Orós and Castanhão daws A B S T R A C TThe large dry and heavy rains periods are characteristics of the rainfall variance on the semiarid region in the State of Ceará and there are several methods to characterize better such events. Among them, the Rains Anomaly Index (RAI) was applied in this work based on the historical series extracted from ANA between the periods of 1969 to 2019. The focus of the study was the region of the Upper Jaguaribe and Middle Jaguaribe basins, where the Orós and Castanhão dams are located, respectively. Thus, the RAI was calculated for 7 pluviometric stations identifying the dry and humid years and classifying them according to the intensity, afterward, through the Pearson method, the correlation between the RAI and the variation of the volumetric levels of the dams was performed. Therefore, it’s possible to conclude that was a proportion between the number of dried and humid years in the region, for as much in both basins were identified 27 dry and 24 humid years. It was also observed that the correlation proved to be strong, obtaining values of 0.74 for the Castanhão reservoir and 0.72 in Orós, that is, the precipitation factor directly influences the water supply of dams and, therefore, the understanding of series and climatic events is so crucial in the Northeast regions of Brazil.Keywords: Weather Events. Northeast brazilian. RAI.

scholarly journals Índice de anomalia de chuvas da Microrregião do Cariri Ocidental Paraibano

2020 ◽  
Vol 13 (6) ◽  
pp. 2628
Author(s):  
Renata Richelle Santos Diniz ◽  
Maria Leide Silva Alencar ◽  
Shayenny Alves de Medeiros ◽  
Hugo Orlando Carvallo Guerra ◽  
Julio Cesar Rodrigues de Sales
Keyword(s):  
El Niño ◽  
Weather Forecasting ◽  
El Nino ◽  
Climatic Variability ◽  
Series Data ◽  
Dry Period ◽  
Rainy Period ◽  
Semi Arid Region ◽  
Atmospheric Phenomena ◽  
Anomaly Index

A região semiárida do Brasil tem como particularidade a grande irregularidade na precipitação, comportamento esse decorrente de um conjunto de fatores, desde características geográficas, como também fenômenos atmosféricos. Por essa razão, o presente trabalho teve como objetivo analisar a variabilidade climática da microrregião do Cariri Ocidental Paraibano composto por 17 munícipios, através da utilização do Índice de Anomalia de Chuva (IAC) e correlacionar a classificação desse índice com a ocorrência, intensidade e influência do Fenômeno El Niño. Foram utilizados dados pluviométricos de um período de 21 anos (1999-2019) disponibilizados pela AESA (Agência Executiva de Gestão das Águas do Estado da Paraíba) aplicados no cálculo do IAC que nos permitiu identificar a intensidade e duração dos períodos secos e úmidos da série, foram empregados também dados do El Niño, concedidos pelo Centro de Previsão de Tempo e Estudos Climáticos (CPTEC) e Instituto de Pesquisas Espaciais (INPE). As incidências de anomalias (negativas e positivas) de precipitação foram analisadas mensalmente e anualmente. A climatologia temporal da precipitação da microrregião do Cariri Ocidental paraibano mostrou que seu período chuvoso inicia-se no mês de janeiro a maio, em contrapartida o período seco ocorre entre os meses de junho a dezembro, sendo setembro tido como o mês mais seco. O mês de agosto contabilizou o maior número de vezes no qual foi classificado como mês úmido (17 vezes), e julho o mês que foi classificado como mais repetidamente seco (9 vezes). Ainda utilizando o cálculo do IAC, foi possível determinar a quantidade de anos secos (10 anos) e úmidos (11 anos), ressaltando que o ano de 2012 foi o único classificado como ano de seca extremamente alta, onde o mesmo foi classificado como um ano de El Nino de intensidade forte. Assim conclui-se a importância da metodologia empegada para o acompanhamento interanual da precipitação pluviométrica da região do Cariri Ocidental paraibano vindo a tornar esses dados obtidos extremamente úteis para uma melhor compreensão da interação do fenômeno atmosférico El Niño e o regime de chuvas da região semiárida.Palavras- chave: IAC, Período Seco, Período Chuvoso, semiárido, climatologia. Rain anomaly index of the Cariri Western Paraibano Microregion A B S T R A C TThe semi-arid region of Brazil is characterized by the great irregularity in precipitation, a behavior that results from a set of factors, from geographical characteristics, as well as atmospheric phenomena. For this reason, the present work aimed to analyze the climatic variability of the micro region of Cariri Oeste Paraibano composed of 17 municipalities, using the Rain Anomaly Index (IAC) and correlate the classification of this index with the occurrence, intensity and influence of the El Niño Phenomenon. Rainfall data from a period of 21 years (1999-2019) made available by AESA (Executive Water Management Agency of the State of Paraíba) was used in the calculation of the IAC, which allowed us to identify the intensity and duration of the dry and wet periods of the series , data from El Niño, granted by the Center for Weather Forecasting and Climate Studies (CPTEC) and the Institute for Space Research (INPE), were also used. The incidence of precipitation anomalies (negative and positive) were analyzed monthly and annually. The temporal climatology of precipitation in the Cariri Western Paraiba micro-region showed that its rainy period starts in the month of January to May, in contrast the dry period occurs between the months of June to December, with September being the driest month. The month of August had the highest number of times in which it was classified as a wet month (17 times), and July the month that was classified as the most repeatedly dry (9 times). Still using the IAC calculation, it was possible to determine the number of dry (10 years) and wet (11 years) years, emphasizing that 2012 was the only year classified as an extremely high drought year, where it was classified as a El Nino year of strong intensity. Thus, we conclude the importance of the methodology used for interannual monitoring of rainfall in the region of Western Cariri in Paraíba, making these data extremely useful for a better understanding of the interaction of the atmospheric phenomenon El Niño and the rain regime of the semiarid region.Keywords: IAC, Dry Period, Rainy Period, semiarid, climatology.

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