Abstract: North Sea Caspian Pattern Index (NCP) refers to an atmospheric teleconnection between the North Sea and North Caspian at the 500 hPa geopotential height level. The aim of this study is to search for effects of NCP on annual and seasonal mean temperature and also annual and seasonal precipitation totals in the Aegean region of Turkey. The study contains the data that consist of 46 years obtained from nine meteorological stations. To determine the relationship between NCP and the climatic parameters, firstly the Pearson correlation coefficient method was utilized. According to the results of the analysis, most of the stations in the region have a high negative correlation NCPI in all seasons, especially in the winter season in terms of annual and seasonal mean temperature (statistically at significant at the 90% level). Besides, high negative correlation values between NCPI and precipitation totals are observed during the winter season at the most of stations. Furthermore, the NCPI values were divided into two group as NCPI(-) and NCPI(+), and then mean temperature and precipitation total values, which are grouped according to the NCP(-) and NCP(+) phases, were determined as annual and seasonal. During the NCPI(-), higher mean temperature values are observed in all of seasons, particularly in the winter season compared to the mean temperature values under effect of NCP(+). Similarly, during the NCPI(-) in winter season precipitation total values have higher than the precipitation total values under the effect of NCP(+); however, in other seasons there no substantial changes were observed between the precipitation total values. As a result of this study, significant proof is obtained with regards to the influences of NCP on the temperature and precipitation regime in the Aegean region of Turkey.
Abstract: This study extends the use of the Drainage Area Regionalization (DAR) method in generating synthetic data and calibrating PyTOPKAPI stream yield for an ungauged basin at a daily time scale. The generation of runoff in determining a river yield has been subjected to various topographic and spatial meteorological variables, which integers form the Catchment Characteristics Model (CCM). Many of the conventional CCM models adapted in Africa have been challenged with a paucity of adequate, relevance and accurate data to parameterize and validate the potential. The purpose of generating synthetic flow is to test a hydrological model, which will not suffer from the impact of very low flows or very high flows, thus allowing to check whether the model is structurally sound enough or not. The employed physically-based, watershed-scale hydrologic model (PyTOPKAPI) was parameterized with GIS-pre-processing parameters and remote sensing hydro-meteorological variables. The validation with mean annual runoff ratio proposes a decent graphical understanding between observed and the simulated discharge. The Nash-Sutcliffe efficiency and coefficient of determination (R²) values of 0.704 and 0.739 proves strong model efficiency. Given the current climate variability impact, water planner can now assert a tool for flow quantification and sustainable planning purposes.
Abstract: Given the increasing energy demand in the world as well as limited fossil energy fuel resources, it is necessary to use renewable energy resources more than ever. Developing a hybrid energy system is suggested to overcome the intermittence of renewable energy resources such as sun and wind, in which the excess electrical energy can be converted and stored. While these resources store the energy, they can provide a more reliable system that is really suitable for off-grid applications. In hybrid systems, a methodology for optimal sizing of power generation systems components is of great importance in terms of economic aspects and efficiency. In this study, a hybrid energy system is designed to supply an off-grid sample load pattern with the aim of supplying necessary energy and minimizing the total production cost throughout the system life as well as increasing the reliability. For this purpose, the optimal size and the cost function of these resources is determined and minimized using evolutionary algorithms and system efficiency is studied with real-time load and meteorological information of Kazerun, a city in southern Iran under different conditions.
Abstract: Drought is an inevitable part of the earth’s climate. It occurs regularly with no clear warning and without recognizing borders. In addition, its impact is cumulative and not immediately discernible. Iran is located in a semi-arid region where droughts occur periodically as natural hazard. Standardized Precipitation Index (SPI), Surface Water Supply Index (SWSI), and Palmer Drought Severity Index (PDSI) are three well-known indices which describe drought severity; each has its own advantages and disadvantages and can be used for specific types of drought. These indices take into account some factors such as precipitation, reservoir storage and discharge, temperature, and potential evapotranspiration in determining drought severity. In this paper, first all three indices are calculated in Aharchay river watershed located in northwestern part of Iran in East Azarbaijan province. Next, based on two other important parameters which are groundwater level and solar radiation, two new indices are defined. Finally, considering all five aforementioned indices, a combined drought index (CDI) is presented and calculated for the region. This combined index is based on all the meteorological, hydrological, and agricultural features of the region. The results show that the most severe drought condition in Aharchay watershed happened in Jun, 2004. The result of this study can be used for monitoring drought and prepare for the drought mitigation planning.
Abstract: Every year, fog formation over the Indo-Gangetic Plains (IGPs) of Indian region during the winter months of December and January is believed to create numerous hazards, inconvenience, and economic loss to the inhabitants of this densely populated region of Indian subcontinent. The aim of the paper is to analyze the spatial and temporal variability of winter fog over IGPs. Long term ground observations of visibility and other meteorological parameters (1971-2010) have been analyzed to understand the formation of fog phenomena and its relevance during the peak winter months of January and December over IGP of India. In order to examine the temporal variability, time series and trend analysis were carried out by using the Mann-Kendall Statistical test. Trend analysis performed by using the Mann-Kendall test, accepts the alternate hypothesis with 95% confidence level indicating that there exists a trend. Kendall tau’s statistics showed that there exists a positive correlation between time series and fog frequency. Further, the Theil and Sen’s median slope estimate showed that the magnitude of trend is positive. Magnitude is higher during January compared to December for the entire IGP except in December when it is high over the western IGP. Decade wise time series analysis revealed that there has been continuous increase in fog days. The net overall increase of 99 % was observed over IGP in last four decades. Diurnal variability and average daily persistence were computed by using descriptive statistical techniques. Geo-statistical analysis of fog was carried out to understand the spatial variability of fog. Geo-statistical analysis of fog revealed that IGP is a high fog prone zone with fog occurrence frequency of more than 66% days during the study period. Diurnal variability indicates the peak occurrence of fog is between 06:00 and 10:00 local time and average daily fog persistence extends to 5 to 7 hours during the peak winter season. The results would offer a new perspective to take proactive measures in reducing the irreparable damage that could be caused due to changing trends of fog.
Abstract: The correct estimation of reference evapotranspiration (ETₒ) is required for effective irrigation water resources planning and management. However, there are some variables that must be considered while estimating and modeling ETₒ. This study therefore determines the multivariate analysis of correlated variables involved in the estimation and modeling of ETₒ at Vaalharts irrigation scheme (VIS) in South Africa using Principal Component Analysis (PCA) technique. Weather and meteorological data between 1994 and 2014 were obtained both from South African Weather Service (SAWS) and Agricultural Research Council (ARC) in South Africa for this study. Average monthly data of minimum and maximum temperature (°C), rainfall (mm), relative humidity (%), and wind speed (m/s) were the inputs to the PCA-based model, while ETₒ is the output. PCA technique was adopted to extract the most important information from the dataset and also to analyze the relationship between the five variables and ETₒ. This is to determine the most significant variables affecting ETₒ estimation at VIS. From the model performances, two principal components with a variance of 82.7% were retained after the eigenvector extraction. The results of the two principal components were compared and the model output shows that minimum temperature, maximum temperature and windspeed are the most important variables in ETₒ estimation and modeling at VIS. In order words, ETₒ increases with temperature and windspeed. Other variables such as rainfall and relative humidity are less important and cannot be used to provide enough information about ETₒ estimation at VIS. The outcome of this study has helped to reduce input variable dimensionality from five to the three most significant variables in ETₒ modelling at VIS, South Africa.
Abstract: The major objective of this study was to analyze the trend and variability of rainfall in the middle Mahandi river basin located in eastern India. The trend of variation of extreme rainfall events has predominant effect on agricultural water management and extreme hydrological events such as floods and droughts. Mahanadi river basin is one of the major river basins of India having an area of 1,41,589 km2 and divided into three regions: Upper, middle and delta region. The middle region of Mahanadi river basin has an area of 48,700 km2 and it is mostly dominated by agricultural land, where agriculture is mostly rainfed. The study region has five Agro-climatic zones namely: East and South Eastern Coastal Plain, North Eastern Ghat, Western Undulating Zone, Western Central Table Land and Mid Central Table Land, which were numbered as zones 1 to 5 respectively for convenience in reporting. In the present study, analysis of variability and trends of annual, seasonal, and monthly rainfall was carried out, using the daily rainfall data collected from the Indian Meteorological Department (IMD) for 35 years (1979-2013) for the 5 agro-climatic zones. The long term variability of rainfall was investigated by evaluating the mean, standard deviation and coefficient of variation. The long term trend of rainfall was analyzed using the Mann-Kendall test on monthly, seasonal and annual time scales. It was found that there is a decreasing trend in the rainfall during the winter and pre monsoon seasons for zones 2, 3 and 4; whereas in the monsoon (rainy) season there is an increasing trend for zones 1, 4 and 5 with a level of significance ranging between 90-95%. On the other hand, the mean annual rainfall has an increasing trend at 99% significance level. The estimated seasonality index showed that the rainfall distribution is asymmetric and distributed over 3-4 months period. The study will help to understand the spatio-temporal variation of rainfall and to determine the correlation between the current rainfall trend and climate change scenario of the study region for multifarious use.
Abstract: Vector-borne diseases are transmitted to humans by mosquitos, sandflies, bugs, ticks, and other vectors. Some are re-transmitted between vectors, if the infected human has a new contact when his levels of infection are high. The vector is infected for lifetime and can transmit infectious diseases not only between humans but also from animals to humans. Some vector borne diseases are very disabling and globally account for more than one million deaths worldwide. The mosquitoes from the complex Culex pipiens sl. are the most abundant in Portugal, and we dispose in this moment of a data set from the surveillance program that has been carried on since 2006 across the country. All mosquitos’ species are included, but the large coverage of Culex pipiens sl. and its importance for public health make this vector an interesting candidate to assess risk of disease amplification. This work focus on ports and airports identified as key areas of high density of vectors. Mosquitoes being ectothermic organisms, the main factor for vector survival and pathogen development is temperature. Minima and maxima local air temperatures for each area of interest are averaged by month from data gathered on a daily basis at the national network of meteorological stations, and interpolated in a geographic information system (GIS). The range of temperatures ideal for several pathogens are known and this work shows how to use it with the meteorological data in each port and airport facility, to focus an efficient implementation of countermeasures and reduce simultaneously risk transmission and mitigation costs. The results show an increased alert with decreasing latitude, which corresponds to higher minimum and maximum temperatures and a lower amplitude range of the daily temperature.
Abstract: The study assessed the potential and economic viability of stand-alone wind systems for embedded generation, taking into account its benefits to small off-grid rural communities at 40 meteorological sites in Nigeria. A specific electric load profile was developed to accommodate communities consisting of 200 homes, a school and a community health centre. This load profile was incorporated within the distributed generation analysis producing energy in the MW range, while optimally meeting daily load demand for the rural communities. Twenty-four years (1987 to 2010) of wind speed data at a height of 10m utilized for the study were sourced from the Nigeria Meteorological Department, Oshodi. The HOMER® software optimizing tool was engaged for the feasibility study and design. Each site was suited to 3MW wind turbines in sets of five, thus 15MW was designed for each site. This design configuration was adopted in order to easily compare the distributed generation system amongst the sites to determine their relative economic viability in terms of life cycle cost, as well as levelised cost of producing energy. A net present value was estimated in terms of life cycle cost for 25 of the 40 meteorological sites. On the other hand, the remaining sites yielded a net present cost; meaning the installations at these locations were not economically viable when utilizing the present tariff regime for embedded generation in Nigeria.
Abstract: The purpose of this study is to analyze the temporal
and spatial variability of thermal conditions in the Republic of
Armenia. The paper describes annual fluctuations in air temperature.
Research has been focused on case study region of Armenia and
surrounding areas, where long–term measurements and observations
of weather conditions have been performed within the National
Meteorological Service of Armenia and its surrounding areas. The
study contains yearly air temperature data recorded between 1961-
2012. Mann-Kendal test and the autocorrelation function were
applied to detect the change trend of annual mean temperature, as
well as other parametric and non-parametric tests searching to find
the presence of some breaks in the long term evolution of
temperature. The analysis of all records reveals a tendency mostly
towards warmer years, with increased temperatures especially in
valleys and inner basins. The maximum temperature increase is up to
1,5°C. Negative results have not been observed in Armenia. The
patterns of temperature change have been observed since the 1990’s
over much of the Armenian territory. The climate in Armenia was
influenced by global change in the last 2 decades, as results from the
methods employed within the study.
Abstract: Nowadays, illegal logging has been causing many
effects including flash flood, avalanche, global warming, and etc. The
purpose of this study was to maintain the earth ecosystem by keeping
and regulate Malaysia’s treasurable rainforest by utilizing a new
technology that will assist in real-time alert and give faster response
to the authority to act on these illegal activities. The methodology of
this research consisted of design stages that have been conducted as
well as the system model and system architecture of the prototype in
addition to the proposed hardware and software that have been
mainly used such as microcontroller, sensor with the implementation
of GSM, and GPS integrated system. This prototype was deployed at
Royal Belum forest in December 2014 for phase 1 and April 2015 for
phase 2 at 21 pinpoint locations. The findings of this research were
the capture of data in real-time such as temperature, humidity,
gaseous, fire, and rain detection which indicate the current natural
state and habitat in the forest. Besides, this device location can be
detected via GPS of its current location and then transmitted by SMS
via GSM system. All of its readings were sent in real-time for further
analysis. The data that were compared to meteorological department
showed that the precision of this device was about 95% and these
findings proved that the system is acceptable and suitable to be used
in the field.
Abstract: The Greater Athens Area (GAA) faces photochemical
and particulate pollution episodes as a result of the combined effects
of local pollutant emissions, regional pollution transport, synoptic
circulation and topographic characteristics. The area has undergone
significant changes since the Athens 2004 Olympic Games because
of large scale infrastructure works that lead to the shift of population
to areas previously characterized as rural, the increase of the traffic
fleet and the operation of highways. However, few recent modelling
studies have been performed due to the lack of an accurate, updated
emission inventory. The photochemical modelling system
MM5/CAMx was applied in order to study the photochemical and
particulate pollution characteristics above the GAA for two distinct
ten-day periods in the summer of 2006 and 2010, where air pollution
episodes occurred. A new updated emission inventory was used
based on official data. Comparison of modeled results with
measurements revealed the importance and accuracy of the new
Athens emission inventory as compared to previous modeling
studies. The model managed to reproduce the local meteorological
conditions, the daily ozone and particulates fluctuations at different
locations across the GAA. Higher ozone levels were found at
suburban and rural areas as well as over the sea at the south of the
basin. Concerning PM10, high concentrations were computed at the
city centre and the southeastern suburbs in agreement with measured
data. Source apportionment analysis showed that different sources
contribute to the ozone levels, the local sources (traffic, port
activities) affecting its formation.
Abstract: This paper discusses micrometeorological aspects of the urban climate in three cities in Western São Paulo State: Presidente Prudente, Assis and Iepê. Particular attention is paid to the method used to estimate the components of the energy balance at the surface. Estimates of convective fluxes showed that the Bowen ratio was an indicator of the local climate and that its magnitude varied between 0.3 and 0.7. Maximum values for the Bowen ratio occurred earlier in Iepê (11:00 am) than in Presidente Prudente (4:00 pm). The results indicate that the Bowen ratio is modulated by the radiation balance at the surface and by different clusters of vegetation.
Abstract: This paper presents a grid synchronization technique based on adaptive notch filter for SPV (Solar Photovoltaic) system along with MPPT (Maximum Power Point Tracking) techniques. An efficient grid synchronization technique offers proficient detection of various components of grid signal like phase and frequency. It also acts as a barrier for harmonics and other disturbances in grid signal. A reference phase signal synchronized with the grid voltage is provided by the grid synchronization technique to standardize the system with grid codes and power quality standards. Hence, grid synchronization unit plays important role for grid connected SPV systems. As the output of the PV array is fluctuating in nature with the meteorological parameters like irradiance, temperature, wind etc. In order to maintain a constant DC voltage at VSC (Voltage Source Converter) input, MPPT control is required to track the maximum power point from PV array. In this work, a variable step size P & O (Perturb and Observe) MPPT technique with DC/DC boost converter has been used at first stage of the system. This algorithm divides the dPpv/dVpv curve of PV panel into three separate zones i.e. zone 0, zone 1 and zone 2. A fine value of tracking step size is used in zone 0 while zone 1 and zone 2 requires a large value of step size in order to obtain a high tracking speed. Further, adaptive notch filter based control technique is proposed for VSC in PV generation system. Adaptive notch filter (ANF) approach is used to synchronize the interfaced PV system with grid to maintain the amplitude, phase and frequency parameters as well as power quality improvement. This technique offers the compensation of harmonics current and reactive power with both linear and nonlinear loads. To maintain constant DC link voltage a PI controller is also implemented and presented in this paper. The complete system has been designed, developed and simulated using SimPower System and Simulink toolbox of MATLAB. The performance analysis of three phase grid connected solar photovoltaic system has been carried out on the basis of various parameters like PV output power, PV voltage, PV current, DC link voltage, PCC (Point of Common Coupling) voltage, grid voltage, grid current, voltage source converter current, power supplied by the voltage source converter etc. The results obtained from the proposed system are found satisfactory.
Abstract: At the present time, awareness, education, computer
simulation and information systems protection are very serious and
relevant topics. The article deals with perspectives and possibilities of
implementation of emergence or natural hazard threats into the
system which is developed for communication among members of
crisis management staffs. The Czech Hydro-Meteorological Institute
with its System of Integrated Warning Service resents the largest
usable base of information. National information systems are connected to foreign systems,
especially to flooding emergency systems of neighboring countries,
systems of European Union and international organizations where the
Czech Republic is a member. Use of outputs of particular information
systems and computer simulations on a single communication
interface of information system for communication among members
of crisis management staff and setting the site interoperability in the
net will lead to time savings in decision-making processes in solving
extraordinary events and crisis situations. Faster managing of an
extraordinary event or a crisis situation will bring positive effects and
minimize the impact of negative effects on the environment.
Abstract: In this paper air quality conditions in Makkah and
Leeds are compared. These two cities have totally different climatic
conditions. Makkah climate is characterised as hot and dry (arid)
whereas that of Leeds is characterised as cold and wet (temperate).
This study uses air quality data from 2012 collected in Makkah,
Saudi Arabia and Leeds, UK. The concentrations of all pollutants,
except NO are higher in Makkah. Most notable, the concentrations of
PM10 are much higher in Makkah than in Leeds. This is probably due
to the arid nature of climatic conditions in Makkah and not solely due
to anthropogenic emission sources, otherwise like PM10 some of the
other pollutants, such as CO, NO, and SO2 would have shown much
greater difference between Leeds and Makkah. Correlation analysis is
performed between different pollutants at the same site and the same
pollutants at different sites. In Leeds the correlation between PM10
and other pollutants is significantly stronger than in Makkah. Weaker
correlation in Makkah is probably due to the fact that in Makkah
most of the gaseous pollutants are emitted by combustion processes,
whereas most of the PM10 is generated by other sources, such as
windblown dust, re-suspension, and construction activities. This is in
contrast to Leeds where all pollutants including PM10 are
predominantly emitted by combustions, such as road traffic.
Furthermore, in Leeds frequent rains wash out most of the
atmospheric particulate matter and suppress re-suspension of dust.
Temporal trends of various pollutants are compared and discussed.
This study emphasises the role of climatic conditions in managing air
quality, and hence the need for region-specific controlling strategies
according to the local climatic and meteorological conditions.
Abstract: Parabolic solar trough systems have seen limited
deployments in cold northern climates as they are more suitable for
electricity production in southern latitudes. A numerical dynamic
model is developed to simulate troughs installed in cold climates and
validated using a parabolic solar trough facility in Winnipeg. The
model is developed in Simulink and will be utilized to simulate a trigeneration
system for heating, cooling and electricity generation in
remote northern communities. The main objective of this simulation
is to obtain operational data of solar troughs in cold climates and use
the model to determine ways to improve the economics and address
cold weather issues.
In this paper the validated Simulink model is applied to simulate a
solar assisted absorption cooling system along with electricity
generation using Organic Rankine Cycle (ORC) and thermal storage.
A control strategy is employed to distribute the heated oil from solar
collectors among the above three systems considering the
temperature requirements. This modelling provides dynamic
performance results using measured meteorological data recorded
every minute at the solar facility location. The purpose of this
modeling approach is to accurately predict system performance at
each time step considering the solar radiation fluctuations due to
passing clouds. Optimization of the controller in cold temperatures is
another goal of the simulation to for example minimize heat losses in
winter when energy demand is high and solar resources are low.
The solar absorption cooling is modeled to use the generated heat
from the solar trough system and provide cooling in summer for a
greenhouse which is located next to the solar field.
The results of the simulation are presented for a summer day in
Winnipeg which includes comparison of performance parameters of
the absorption cooling and ORC systems at different heat transfer
fluid (HTF) temperatures.
Abstract: This article deals with geographical conditions in
terrain and their effect on the movement of vehicles, their effect on
speed and safety of movement of people and vehicles. Finding of the
optimal routes outside the communication is studied in the Army
environment, but it occur in civilian as well, primarily in crisis
situation, or by the provision of assistance when natural disasters
such as floods, fires, storms etc., have happened. These movements
require the optimization of routes when effects of geographical
factors should be included. The most important factor is the surface
of a terrain. It is based on several geographical factors as are slopes,
soil conditions, micro-relief, a type of surface and meteorological
conditions. Their mutual impact has been given by coefficient of
deceleration. This coefficient can be used for the commander`s
decision. New approaches and methods of terrain testing,
mathematical computing, mathematical statistics or cartometric
investigation are necessary parts of this evaluation.
Abstract: The Blue Nile Basin is the most important tributary of
the Nile River. Egypt and Sudan are almost dependent on water
originated from the Blue Nile. This multi-dependency creates
conflicts among the three countries Egypt, Sudan, and Ethiopia
making the management of these conflicts as an international issue.
Good assessment of the water resources of the Blue Nile is an
important to help in managing such conflicts. Hydrological models
are good tool for such assessment. This paper presents a critical
review of the nature and variability of the climate and hydrology of
the Blue Nile Basin as a first step of using hydrological modeling to
assess the water resources of the Blue Nile. Many several attempts
are done to develop basin-scale hydrological modeling on the Blue
Nile. Lumped and semi distributed models used averages of
meteorological inputs and watershed characteristics in hydrological
simulation, to analyze runoff for flood control and water resource
management. Distributed models include the temporal and spatial
variability of catchment conditions and meteorological inputs to
allow better representation of the hydrological process. The main
challenge of all used models was to assess the water resources of the
basin is the shortage of the data needed for models calibration and
validation. It is recommended to use distributed model for their
higher accuracy to cope with the great variability and complexity of
the Blue Nile basin and to collect sufficient data to have more
sophisticated and accurate hydrological modeling.
Abstract: Fugitive particulate matter (PM) is a major source of
airborne pollution in the Middle East countries. The meteorological
conditions and topography of the area makes it highly susceptible to
wind-blown particles which raise many air quality concerns. Air
quality tools such as field monitoring, emission factors and dispersion
modeling have been used in previous research studies to analyze the
release and impacts of fugitive PM in the region. However, these
tools have been originally developed based on experiments made for
European and North American regions. In this work, an experimental
campaign was conducted on April-May 2014 in a construction site in
Doha city, Qatar. The ultimate goal is to evaluate the applicability of
the existing emission factors for construction sites in dry and arid
areas like the Middle East.