نتایج جستجو برای: drought events

تعداد نتایج: 350639  

Drought is one of the environmental events and an inseparable part of climatic fluctuations. This phenomenon is one of the main characteristics of the various climates. Awareness of spatiotemporal behavior is effective in land planning. The spatial statistical methods provide the means by which they analyze the spatial patterns of random variables such as precipitation. In this study, using the...

2016
Taotao Chen Guimin Xia Tiegang Liu Wei Chen

Global warming has resulted in increasingly frequent and severe drought and/or precipitation events. Severe drought limits crop water availability and impacts agricultural productivity and socioeconomic development. To quantify drought-induced yield loss during the main crop stages in Liaoning province, China, aspects of drought episodes (magnitude, duration, and frequency) were investigated du...

Drought is one of the most complex natural hazards that affect natural systems and different parts of an ecosystem in various ways. Evaluation of drought behavior such as determining the time of its occurrence, understanding the relationships between types of drought, and recognizing its characteristics such as magnitude, severity, and duration of drought periods can be an important aid in wate...

2016
Agata Cieśla Filip Mituła Lucyna Misztal Olga Fedorowicz-Strońska Sabina Janicka Małgorzata Tajdel-Zielińska Małgorzata Marczak Maciej Janicki Agnieszka Ludwików Jan Sadowski

Increasing the drought tolerance of crops is one of the most challenging goals in plant breeding. To improve crop productivity during periods of water deficit, it is essential to understand the complex regulatory pathways that adapt plant metabolism to environmental conditions. Among various plant hormones and second messengers, calcium ions are known to be involved in drought stress perception...

2015
Donald A. Wilhite

Drought is a naturally occurring event that is associated with virtually all climatic regions. Given its slow onset and other characteristics, including its spatial dimensions and duration, impacts are difficult to assess and have been, historically, poorly documented. These impacts are strongly influenced by a society’s exposure to the hazard and the vulnerability of that society to the hazard...

Background: Sunflower (Helianthus annuus L.) is one of the important vegetable oil supplies in the world and in Iran, as well. It is classified as a drought semi-tolerant crop; however, its yield is adversely affected by drought stress. Understanding the initial events in sensing stress and the related physiologic and biochemical events thereafter, is crucial in designing droug...

2015
Donald A. Wilhite

Introduction Worldwide, economic damages attributed to natural disasters tripled from the 1960s The economic, social, and environmental costs and losses associated with drought are also increasing dramatically, although it is difficult to quantify this trend precisely because of the lack of reliable historical estimates of losses. White and Haas estimated in 1975 that the average annual crop lo...

The Standardized Precipitation Index (SPI) is the most common index for drought monitoring. Although the calculation of this index is usually done by using the gamma distribution fitting of precipitation data, studies have shown that for accurate monitoring of drought, the optimal distribution of precipitation in each month should be determined. On the other hand, in non-stationary time series,...

2013
L. Fernández-de-Uña P. Fonti I. Aranda I. Cañellas G. Gea-Izquierdo

Climatic scenarios for the Mediterranean Region forecast increasing frequency and intensity of drought events. We analyzed how Pinus sylvestris modifies its cambial phenology and intra-annual growth under enhanced drought conditions. For this purpose, a rainfall exclusion experiment was applied in 2012 to trees located in the lower elevation limit of a mountain forest in Central Spain. Prelimin...

2017
Gunnar Carnwath Cara Nelson

Significant increases in tree mortality due to drought-induced physiological stress have been documented worldwide. This trend is likely to continue with increased frequency and severity of extreme drought events in the future. Therefore, understanding the factors that influence variability in drought responses among trees will be critical to predicting ecosystem responses to climate change and...

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