an important and fundamental issue in iran is to utilize water and to avoid wasting it. therefore, climate change can be considered as an effective factor on water resources. the most tangible climate change phenomenon is drought which is much important to be identified. in this study, the effect of climate changes on flow rate in bashar river, shahmokhtar station of yasouj city was evaluated u...

Quantifying the spatial integrity and patterns of dry/wet events over land is essential to understand how local hydrological regime responds environmental changes. Spatial aggregation changes in dry wet areas have not been studied extensively. Based on a patch-mosaic landscape model, we analyzed at two levels corresponding design during 1949 2018. At level, global degree increased initially the...

Available energy (often expressed in terms of potential evaporation) and precipitation largely determine annual evapotranspiration and runoff rates in a region. The ratio of annual potential evaporation to precipitation, referred to as the aridity index by Budyko, has been shown to describe the evaporation ratio (the ratio of annual evapotranspiration to precipitation) of catchments from a rang...

abstract drought is a natural creeping event that starts due to lower moisture compared to normal condition. this phenomenon impacts all aspects of human activities. however there is neither any detailed definition nor a general and proper index for drought monitoring. in this study, fuzzy logic has been applied to deal with inherent uncertainties of the real world data. we presented a fuzzy mo...

Drought is one of the most important weather-induced phenomena which may have severe impacts on different areas such as agriculture, economy, energy production, and society. A number of drought indices have been introduced and used in various countries to date. In the current study, four meteorological drought indices including Percent of Normal Precipitation Index (PNPI), Standard Index of Ann...

drought is one of the most important weather-induced phenomena which may have severe impacts on different areas such as agriculture, economy, energy production, and society. a number of drought indices have been introduced and used in various countries to date. in the current study, four meteorological drought indices including percent of normal precipitation index (pnpi), standard index of ann...