نتایج جستجو برای: drought indices

تعداد نتایج: 112757  

2004
Ian J. Cottingham Steve Goddard Shifeng Zhang X. Wu K. Lu A. Rutledge William J. Waltman

The National Agricultural Decision Support System (NADSS) is a web based geospatial decision support system used to aid producers and decision makers in analyzing and effectively mitigating the effects of drought. The NADSS application is unique in its implementation, containing web-based implementations of commonly utilized drought indices including the Newhall Simulation Model (NSM), Palmer D...

Journal: :desert 2014
behnaz asefjah faezeh fanian zahra feizi azam abolhasanizarjo hadi paktinat

drought detecting is a necessary aspect of drought risk management. it is generally performed usingdifferent drought indices that are effectively continuous functions of rainfall and other hydro- meteorologicalvariables. a number of drought indices have been introduced and used in various countries to date. in thecurrent research, four meteorological drought indices including the standardized p...

2011
Xanthos Papakonstantinou Lazaros S. Iliadis Elias Pimenidis Fotis P. Maris

This is an intelligent modeling of the evolution of drought and forest fires, due to climate change in Cyprus. Original annual wild fire data records (1979-2009) and data regarding meteorological parameters were used. A flexible modeling approach was proposed towards the determination of drought risk indices in all of the country. Cyprus was divided in eight polygons corresponding to eight mete...

2015
Donald A. Wilhite

The goal of the WMO Expert Meeting on Agricultural Drought Indices was to move forward in the selection of a single drought index that would be used worldwide in the assessment of agricultural drought and its severity. This chapter discusses the challenges in identifying a single index to accomplish this task. Given the complexities of drought and its diverse sectoral impacts, this is a formida...

2016
Petr Máca Pavel Pech

The presented paper compares forecast of drought indices based on two different models of artificial neural networks. The first model is based on feedforward multilayer perceptron, sANN, and the second one is the integrated neural network model, hANN. The analyzed drought indices are the standardized precipitation index (SPI) and the standardized precipitation evaporation index (SPEI) and were ...

Journal: :علوم گیاهان زراعی ایران 0
خدیجه مختاری فر دانشجوی سابق کارشناسی ارشد، بخش زراعت و اصلاح نباتات دانشگاه شهید باهنر کرمان روح اله عبدالشاهی استادیار بخش زراعت و اصلاح نباتات دانشگاه شهید باهنر کرمان

in order to increase drought tolerance in bread wheat, an appropriate breeding program based on inheritance of drought tolerance is recommended. in the present study, nine bread wheat cultivars and their f2 progenies were evaluated in a randomized complete block design under normal and drought stress conditions. nine sensitivity/tolerance indices were calculated for studied genotypes and stress...

2013
Ning Zhang Yang Hong Qiming Qin Lin Zhu

In this article, the performance of the Visible and Shortwave infrared Drought Index (VSDI), a drought index recently developed and validated in Oklahoma, United States, is further explored and validated in China. The in-situ measured soil moisture from 585 weather stations across China are used as ground-truth data, and five commonly used drought indices are compared with VSDI for surface drou...

2017
W. J. Waltman

Drought is the dominant process of crop loss nationally and within Nebraska. Nearly twothirds of the 18.6 million harvested acres are covered by crop insurance (USDA/RMA, 2003; USDA/NASS, 2003). For the most part, Nebraska’s crop losses range from $50 to 75 million in non-drought years, but the losses approach nearly $200 million in drought years, such as 2000. The past growing season (2002) cr...

2009
M. M. Heikal

Environmental stress, especially drought stress, can play an important role in the reduction of the plant growth stage, specifically duringgermination in arid and semi arid regions in Iran.. In order to study the effects of drought stress on germination indices in wheat cultivars, an experiment was conducted in factorial form, using a completely randomized design of four replications. In this e...

Journal: :Remote Sensing 2016
Wenzhe Jiao Lifu Zhang Qing Chang Dongjie Fu Yi Cen Qingxi Tong

Drought is a complex hazard, and it has an impact on agricultural, ecological, and socio-economic systems. The vegetation condition index (VCI), which is derived from remote-sensing data, has been widely used for drought monitoring. However, VCI based on the normalized difference vegetation index (NDVI) does not perform well in certain circumstances. In this study, we examined the utility of th...

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