نتایج جستجو برای: drought index
تعداد نتایج: 424034 فیلتر نتایج به سال:
the objective of this study is to develop a novel methodology integrating remote sensing, geographic information system technology and local spatial autocorrelation geo-computation for quick drought assessment. one group of drought indices, based on the condition of the vegetation, includes the normalized difference vegetation index (ndvi), anomaly of normalized difference vegetation index (ndv...
Drought is a climatic anomaly that associates with a significant decrease (lack) of precipitation and water resources availability, which spreads on vast temporal and spatial scales, and significantly affects various aspects of life and environment. One of the most common methods of drought assessing and monitoring is calculating drought indices (DIs). Drought areal and temporal extent and its ...
This paper examines past drought and assesses future drought scenarios for the Arkansas Red River Basin using two common drought indexes, the Standardized Precipitation Index (SPI) and Palmer Drought Severity Index (PDSI). Historical climate data within the 1900–2009 time frame were used to derive the past drought index estimates. The projected climate data under two greenhouse gas emission sce...
Remote sensing indices are used to analyze the Spatio-temporal distribution of drought conditions and to identify the severity of drought. This study, using various drought indices generated from Madis and TRMM satellite data extracted from Google Earth Engine (GEE) platform. Drought conditions in Marivan city from February to November for the years 2001 to 2017 were analyzed based on spatial a...
the aim of this research is to analyze the performance of 8 drought’s index in isfahan, kerman and yazd province and choose the best index. for this purpose, used monthly and yearly rainfall data in the period of 30 years (1985-2014) and also used 8 drought indexes in 20 meteorological stations of central iran which the accuracy of each index in determining drought is examined. also zoning in a...
Post-anthesis drought stress is the most important problem affecting wheat production in dryland fields, specially in Mediterranean regions. The main objective of this research was to evaluate drought tolerance indices in dryland wheat genotypes under post-anthesis drought stress. The research was including two different experiments. In each experiment, twenty dryland bread wheat genotypes were...
This study assesses the applicability of remote sensing data for retrieval of key drought indicators including the degree of moisture deficiency, drought duration and areal extent of drought within different land cover types across the landscape. A Normalized Vegetation Supply Water Index (NVSWI) is devised, combining remotely sensed climate data to retrieve key drought indicators over differen...
the standardized precipitation index (spi) has become a popular measure of drought across the globe. in this study, standardized precipitation index (spi) was used in annual period of time to survey on drought. also, in order to zonation frequency of drought, geographic information system (gis) software and kriging method used for extracting dry areas. the zoning maps show most severe drought i...
Drought is a major environmental disaster in many parts of the world. Knowledge about the timing, severity and extentof drought can aid planning and decision-making. Drought indices derived from in-situ meteorological data have coarsespatial and temporal resolutions, thus, obtaining a real-time drought condition over a large area is difficult. This studyused advanced very high resolution radiom...
Observed alternation of global and local meteorological patterns governs increasing drought impact, which puts at risk ecological balance and biodiversity of the alpine forest. Despite considerable attention, drought impact on forest ecosystems is still not entirely understood, and comprehensive forest drought monitoring has not been implemented. In this study, we proposed to bridge this gap ex...
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