نتایج جستجو برای: monthly data including ph
تعداد نتایج: 3257198 فیلتر نتایج به سال:
C. L. Wu and K. W. Chau* 2 Dept. of Civil and Structural Engineering, Hong Kong Polytechnic University, 3 Hung Hom, Kowloon, Hong Kong, People’s Republic of China 4 5 *Email: [email protected] 6 ABSTRACT 7 Data-driven techniques such as Auto-Regressive Moving Average (ARMA), K-Nearest-Neighbors (KNN), and 8 Artificial Neural Networks (ANN), are widely applied to hydrologic time series predi...
Historical changes in instrumentation and recording practices have severely compromised the temporal homogeneity of radiosonde data, a crucial issue for the determination of long-term trends. Methods developed to deal with these homogeneity problems have been applied to a near–globally distributed network of 87 stations using monthly temperature data at mandatory pressure levels, covering the p...
Background: Today, air pollution is one of the major problems in large cities including Isfahan. Methods: The objective of this study was to investigate the variations of ozone (O3), carbon monoxide (CO), nitric oxide (NO), nitrogen dioxide (NO2), nitrogen oxides (NOx), sulphur dioxide (SO2), and particulate matter (PM10) concentrations in different months at three stations and also to explore ...
Kappa distribution is a positively skewed distribution which is used in analyzing precipitation, wind speed and streamflow data. In this paper, first a three-parameter Kappa distribution that introduced by Park et al. (2009) is studied and then four different methods of estimation including Moments, L-Moments, Maximum Likelihood and Maximum Product Spacing Method are presented in order to estim...
suspended sediment estimation is an important factor from different aspects including, farming, soil conservation, dams, aquatic life, as well as various aspects of the research. there are different methods for suspended sediment estimation. this study aims to estimate suspended sediment using feed forward neural network with error back propagation with levenberg-marquardt back propagation algo...
This paper uses the Hilbert–Huang transform (HHT) method to make time–frequency diagnostic analyses of four monthly time series of the global precipitation: MERG (1900– 2008), REOF (1900–2008), GPCP (1979–2009), and CMAP (1979–2009). All these data are the global land and ocean average of precipitation anomalies with respect to the mean of the entire data period. The MERG and REOF are spectral ...
There are numerous methods to estimate missing values of which some are used depending on the data type and regional climatic characteristics. In this research, part of the monthly precipitation data in Sarab synoptic station, east Azerbaijan province, Iran was randomly considered missing values. In order to study the effectiveness of various methods to estimate missing data, by seven classic s...
Background and purpose: Sand flies are widespread in Iran and are vectors of leishmaniasis and pappatci fever in most parts of the country including Southern Khorasan Province. Faunistic and ecological studies of these flies are necessary in order to implement proper vector control programs. This research was conducted to determine the sand flies fauna in Southern Khorasan province. Materials ...
The purpose of this study is analyzing the trend of drought characteristics in Hamedan Province In this regard, the corrected standardized precipitation index (SPImod) was calculated based on the monthly precipitation data from 11 synoptic and rain gauge stations during the period of 1985-2013. Drought characteristics, including severity, duration and interarrival time were defined and extracte...
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