There are two types of drought as conceptual drought and operational drought. The three parameters as the beginning, the end and the degree of severity of the drought can be identifying in operational drought by average precipitation in the whole region. One of the methods classified to measure drought is Reconnaissance Drought Index (RDI). Evapotranspiration is calculated using Penman-Monteith...

Drought is a complex and highly destructive natural phenomenon that affects portions of the United States almost every year, and severe water deficiencies can often become catastrophic for agricultural production. Evapotranspiration (ET) by crops is an important component in the agricultural water budget; thus, it is advantageous to include ET in agricultural drought monitoring. The main object...

The potential of modeling the FAO Penman-Monteith (FAO-56 PM) method for computing reference crop evapotranspiration (ETo) using feed-forward backpropagation artificial neural networks (FFBANN) with minimal measured climate data such as with the air temperature (maximum and minimum) was investigated using local climatic data from the Wa Meteorological weather station. Three FFBANN models were d...

Pakistan experiences a variety of climates ranging from a small humid patch in the north to extremely arid southern plains. Evapotranspiration is not a directly measurable element among agrometeorological parameters influencing crop growth and development. Many empirical and semi-empirical methods for estimation of crop evapotranspiration exist and are being used by individual scientists and re...

Water use of plants can be manifested in diurnal signal of soil moisture changes, and also of water table fluctuations in shallow water table environments. The signal can be especially strong in case of groundwater dependent forest vegetation with high water demand, where the water uptake is partly happening across the capillary zone. A new technique for water uptake estimation was elaborated o...

Evapotranspiration, a major component in terrestrial water balance and net primary productivity models, is difficult to measure and predict. This study compared five models of potential evapotranspiration (PET) applied to a ponderosa pine forest ecosystem at an AmeriFlux site in Northern California. The AmeriFlux sites are research forests across the United States, Canada, Brazil, and Costa Ric...

Restoration activities in the Central Valley of California and elsewhere require accurate evapotranspiration information, which can then be used for a wide variety of surface and subsurface hydrologic evaluations. However, directly measuring evapotranspiration can be difficult or impossible depending on the evaluation’s time frame. Transferability of measured evapotranspiration in time and spac...