abstract in order to evaluation the effects of price policies (wheat guarantee price in each period and its price lag), environmental (planted area) and climatic (min and max average temperature, total annual precipitation, cold-day degree and hot-day degree) factors, we considered wheat yield in razavi-khorasan province (9 cities) for a 13-year statistical period (1371-72 to 1383-84). in this ...

Two methods based on the principle of maximum entropy (POME), the ordinary entropy method (ENT) and the parameter space expansion method (PSEM), are developed for estimating the parameters of a four-parameter exponential gamma distribution. Using six data sets for annual precipitation at the Weihe River basin in China, the PSEM was applied for estimating parameters for the four-parameter expone...

Functional Data Analysis (FDA) has recently made considerable progress because of easier access to the data that are essentially in the form of curves. Although functional modeling of Iranian precipitation based on temperature or humidity was done before, here we use functional analysis of variance and covariance to analyze the weather data collected randomly from Iranian weather stations in 20...

The accurate estimation of gridded daily precipitation is critical to hydrological modelling and water resource assessment. High resolution precipitation datasets based on gauge rainfall are the primary input to spatially distributed rainfall-runoff models and water balance calculations (e.g. Chiew et al., 2008). The spatial heterogeneity of rainfall variability is currently not captured adequa...

The phase of precipitation when it reaches the ground is a first-order driver of hydrologic processes in a watershed. The presence of snow, rain, or mixed-phase precipitation affects the initial and boundary conditions that drive hydrological models. Despite their foundational importance to terrestrial hydrology, typical phase partitioning methods (PPMs) specify the phase based on near-surface ...

Satellite precipitation products (SPPs) are critical data sources for hydrological prediction and extreme event monitoring, especially for ungauged basins. This study conducted a comprehensive hydrological evaluation of six mainstream SPPs (i.e., TMPA 3B42RT, CMORPH-RT, PERSIANN-RT, TMPA 3B42V7, CMORPH-CRT, and PERSIANN-CDR) over humid Xixian basin in central eastern China for a period of 14 ye...

In semiarid regions, periods of one to several consecutive months of scarcity of precipitation or low flow rates in rivers and streams frequently occur. In these regions, scarce precipitation considerably affects grazing activities on rangelands, irrigation agriculture, and flora and fauna of surface stream environments. This paper is concerned with estimating probabilities of occurrence for su...