Common weaknesses of current drought indexes were analyzed. First, most of the current indexes are not precise enough in detecting the onset, end, and accumulated stress of drought. Second, they do not effectively take into account the aggravating effects of runoff and evapotranspiration, which build up with time. Third, they have a limited usefulness in monitoring ongoing drought because they ...

Drought is a natural hazard that has significant impact on economic, agricultural, environmental, and social aspects. In the present study details analysis of rainfall data has been carried out for the years 1981-2011. Standard precipitation index (SPI) has been used to evaluate the precipitation deficit in the Karun watershed of Iran. The results indicated that 1981-82,82-83,83-84,84-85,88-89,...

The focus of this paper is on the grassland productivity response to drought under background climate change. There an established lag impact ecosystems events, which may have additional effects subsequent events. Meanwhile, due change interference, influence over past 50 years not simply equal algebraic sum all historical In Inner Mongolia grassland, precipitation deficit plays a leading role ...

Quantitative estimates of increased heat transfer by atmospheric H2O vapor during the Albian greenhouse warming suggest that the intensified hydrologic cycle played a greater role in warming high latitudes than at present and thus represents a viable alternative to oceanic heat transport. Sphaerosiderite d18O values in paleosols of the North American Cretaceous Western Interior Basin are a prox...

decreasing changes of climatic elements such as: daily precipitation, weekly precipitation, seasonal precipitation and annual precipitation can be toward to drought phenomena. the recognition it and planning for passing it, could be decreasing of disasters, because create of drought is slow but it effects is very damages. the aim of this paper is descriptive analyze and it type of research is a...

[1] The oxygen isotope content of nocturnal ecosystem respiration (dOR) was examined in forests along a precipitation gradient in Oregon, USA, to determine whether site-to-site variation in dOR was more strongly related to variation in d O of precipitation or to evaporative processes that isotopically modify water pools within ecosystems. Measurements were made over 4 years at sites ranging in ...

[1] The forecast atmospheric hydrologic cycle of the Polar version 3.1.1 of the Weather Research and Forecasting model (WRF) is examined for December 2006 – November 2007. The domain is similar to the Arctic System Reanalysis (ASR), an assimilation of model fields and Arctic observations being conducted partly by the Byrd Polar Research Center. Simulations are performed in 48 h increments initi...

The North American Monsoon delivers warm season precipitation to much of the southwestern United States, yet the importance of this water source for forested ecosystems in the region is not well understood. While it is widely accepted that trees in southwestern forests use winter precipitation for earlywood production, the extent to which summer (monsoon season) precipitation supports latewood ...