[1] In this paper, we evaluate the performance of 19 coupled general circulation models (CGCMs) in twentieth-century simulations of the Sahel during the 1970s to 1990s. Correlation, regression, and cluster analyses are applied to observations and model outputs including Sahel monthly precipitation, evaporation, soil moisture, and sea surface temperature (SST). We find that only eight CGCMs (hit...

this research studies the potential impact of climate change on future trend and changes of two well known drought indicators namely rdi and spi in yazd meteorological station, in central part of iran. for this purpose, data of hadcm3 model that were resulted from gcm-runs based on the ipcc-sres scenarios of a2 and b2 were acquired and analyzed for projection of daily tmin, tmax and precipitati...

introduction: climate change is one of the most significant challenges in sustainable development that has negative effects on land and marine ecosystems. this phenomenon leads to imbalances that cause effects including hydrological changes, increased soil erosion, increased runoffs and reduced groundwater aquifer feeding, etc. effects of climate changes over the past decade have significantly ...

We used twelve Landsat scenes from the 1980s–2009 and regional 2000–2009 MODIS data to examine the long-term trend in the normalized difference vegetation index (NDVI) within unburned areas of the Alaskan boreal forest. Our analysis shows that there has been a declining trend in NDVI in this region, with the strongest ―browning trend‖ occurring in eastern Alaska where the climate during the gro...

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...

The loess hilly-gully region is a focus region of the "Grain for Green" program in China. Drought is the main problem in the study region. Precipitation and temperature are two indicators that directly characterize climatic drought. A thorough analysis of the precipitation, temperature and drought characteristics of the loess hilly-gully region can clarify the current water and heat conditions ...

We analyzed potential land degradation processes in semiarid regions worldwide using long time series of remote sensing images and the Normalized Difference Vegetation Index (NDVI) for the period 1981 to 2011. The objectives of the study were to identify semiarid regions showing a marked decrease in potential vegetation activity, indicative of the occurrence of land degradation processes, and t...

[1] A robust ring-width chronology developed from two sites of Picea schrenkiana in the central Tien Shan area of northwest China was employed to study regional drought variability. Our analyses demonstrate both temperature and precipitation have significant effects on tree growth, thus both should be considered for climate reconstruction. Regional drought history (1675–2002 A.D.) was therefore...

The aim of this study is to analyze the characteristics of drought such as intensity, cumulative curves and trends, based on SPEI (Standardized Precipitation Evapotranspiration Index) at 8 stations in Korea from 1981 to 2010. The traditional SPEI is based on Thornthwaite equation for estimating evapotranspiration; SPEI_th. However, a standard of agricultural water management in Korea suggests F...