scholarly journals Calculation of meteorological water balance in Iraq

2020 ◽  
Vol 2 (1) ◽  
pp. 84-89
Author(s):  
Hussein Ilaibi Zamil Al-Sudani ◽  

The hydrology section is divided into two main components, surface and groundwater. One of the most important outcomes in the water balance equation for any natural area or water body is Evapotranspiration and it is also a crucial component of the hydrologic cycle. Prediction of monthly evapotranspiration can be obtained depending on observed monthly average temperatures at a meteorological station in each year. Calculating of water balance in Iraq depending on meteorological data and Thornthwaite method was the aim of this research. Results of corrected potential evapotranspiration (PEc) obtained from applying Thornthwaite formula were compared with annual and monthly rainfall in thirty two meteorological station in order to estimate actual evapotranspiration (AE). The results showed that the annual summation of rainfall increased from south west towards north east according to the increasing ratio of rainfall due to the impact of Mediterranean climate condition on Iraq. Actual evapotranspiration depends directly on water excess during calculating water balance. Water surplus contour map indicates increased values towards north-east direction of Iraq, where water surplus depends directly on both rainfall and actual evapotranspiration.

2021 ◽  
Vol 43 ◽  
pp. e56026
Author(s):  
Gabriela Leite Neves ◽  
Jorim Sousa das Virgens Filho ◽  
Maysa de Lima Leite ◽  
Frederico Fabio Mauad

Water is an essential natural resource that is being impacted by climate change. Thus, knowledge of future water availability conditions around the globe becomes necessary. Based on that, this study aimed to simulate future climate scenarios and evaluate the impact on water balance in southern Brazil. Daily data of rainfall and air temperature (maximum and minimum) were used. The meteorological data were collected in 28 locations over 30 years (1980-2009). For the data simulation, we used the climate data stochastic generator PGECLIMA_R. It was considered two scenarios of the fifth report of the Intergovernmental Panel on Climate Change (IPCC) and a scenario with the historical data trend. The water balance estimates were performed for the current data and the simulated data, through the methodology of Thornthwaite and Mather (1955). The moisture indexes were spatialized by the kriging method. These indexes were chosen as the parameters to represent the water conditions in different situations. The region assessed presented a high variability in water availability among locations; however, it did not present high water deficiency values, even with climate change. Overall, it was observed a reduction of moisture index in most sites and in all scenarios assessed, especially in the northern region when compared to the other regions. The second scenario of the IPCC (the worst situation) promoting higher reductions and dry conditions for the 2099 year. The impacts of climate change on water availability, identified in this study, can affect the general society, therefore, they must be considered in the planning and management of water resources, especially in the regional context


2021 ◽  
Author(s):  
AHMET IRVEM ◽  
Mustafa OZBULDU

Abstract Evapotranspiration is an important parameter for hydrological, meteorological and agricultural studies. However, the calculation of actual evapotranspiration is very challenging and costly. Therefore, Potential Evapotranspiration (PET) is typically calculated using meteorological data to calculate actual evapotranspiration. However, it is very difficult to get complete and accurate data from meteorology stations in, rural and mountainous regions. This study examined the availability of the Climate Forecast System Reanalysis (CFSR) reanalysis data set as an alternative to meteorological observation stations in the computation of potential annual and seasonal evapotranspiration. The PET calculations using the CFSR reanalysis dataset for the period 1987-2017 were compared to data observed at 259 weather stations observed in Turkey. As a result of the assessments, it was determined that the seasons in which the CFSR reanalysis data set had the best prediction performance were the winter (C'= 0.76 and PBias = -3.77) and the autumn (C' = 0.75 and PBias = -12.10). The worst performance was observed for the summer season. The performance of the annual prediction was determined as C'= 0.60 and PBias = -15.27. These findings indicate that the results of the PET calculation using the CFSR reanalysis data set are relatively successful for the study area. However, the data should be evaluated with observation data before being used especially in the summer models.


2019 ◽  
Vol 48 (3) ◽  
pp. 3-9
Author(s):  
Peter Gerginov ◽  
Dimitar Antonov

Loess and loess-like sediments cover approximately 13% of the Bulgarian territory, mainly within the Danubian plain. From the Danube River to the Fore-Balkan, the loess soils form a loess complex where its depth varies from 50–60 meters in the north to few meters in the south, respectively. Widespread loess sediments possess a specific feature: they typically form deep unsaturated zones. Quantification of the near surface water balance is extremely important for evaluating land-atmosphere interactions, and the impact of land-use change on the subsurface flow and the evapotranspiration rate is an essential term in this quantification. In the frames of a scientific project, an automatic weather station was installed in a typical plain terrain of the loess complex in Northeast Bulgaria, recording meteorological data from September 2015 to February 2017. This study provides a mathematical description of processes (i.e., Penman-Monteith and Hargreaves Methods) used to estimate daily evapotranspiration rates implemented into the numerical model HYDRUS-1D, as well as a respective rate investigation of months with and without intensive rainfalls. Overall results indicate that using the Hargreaves formula for evaluation of the potential evapotranspiration leads to overestimation between 10% and 20%, respectively for a “wet” and “dry” month.


2021 ◽  
Vol 325 ◽  
pp. 08010
Author(s):  
Gita Ivana Suci Lestari Faski ◽  
Ignasius Loyola Setyawan Purnama

Global climate change that occurred in this century can affect the pattern of rain and increase in temperature on earth. This study aims to determine and analyze the increase in rainfall, air temperature, potential evapotranspiration and actual evapotranspiration in the Bengkulu watershed. For this reason, the regional rainfall is calculated using the Thiessen Polygon, the mean air temperature of the watershed based on the median elevation, potential evapotranspiration using the Thornthwaite Method and actual evapotranspiration using the basis of the difference in rainfall to potential evapotranspiration. The results showed that every year there was an increase in rainfall, air temperature, potential evapotranspiration and actual evapotranspiration in the Bengkulu Watershed. In the 2009-2013 period, the average annual rainfall of 3,581 mm increased to 3,641 mm in the 2014-2018 period. For air temperature, the average monthly air temperature in the Bengkulu Watershed for the 2009-2013 period was 25.8°C, while the air temperature in the 2014-2018 period was 26.1°C. This means that in a period of 5 years there is an increase in temperature of 0.3°C. Furthermore, due to the increase in air temperature, there was an increase in the average monthly potential evapotranspiration from the 2009-2013 period to the 2014-2018 period, namely from 1,493 mm to 1,537 mm, while for actual evapotranspiration there was an increase from 1,486 mm to 1,518 mm.


2012 ◽  
Vol 9 (11) ◽  
pp. 13231-13249 ◽  
Author(s):  
E. Joetzjer ◽  
H. Douville ◽  
C. Delire ◽  
P. Ciais ◽  
B. Decharme ◽  
...  

Abstract. The present study compares three meteorological drought indices (scPDSI, SPI and SPEI respectively) and their ability to account for the variations of annual mean river discharge on both interannual and climate change timescales. The Standardized Runoff Index (SRI) is used as a proxy of river discharge. The Mississippi and Amazon river basins provide two contrasted testbeds for this analysis. All meteorological drought indices are derived from monthly 2-meter temperature and/or precipitation, using either gridded observations or outputs of a global climate model. The SPI based solely on precipitation is not outperformed by the SPEI (accounting for potential evapotranspiration) and the scPDSI (based on a simplified water balance) at detecting interannual SRI variations. Under increasing concentrations of greenhouse gases, the simulated response of the areal fraction in drought is highly index-dependent, suggesting that more physical water balance models are needed to account for the impact of global warming on hydrological droughts.


MAUSAM ◽  
2021 ◽  
Vol 60 (4) ◽  
pp. 455-460
Author(s):  
P. K. SINGH ◽  
L. S. RATHORE ◽  
B. ATHIYAMAN ◽  
K. K. SINGH ◽  
A. K. BAXLA ◽  
...  

Studies of water balance have been carried out for Ranchi taking 35 years (1970-2004) of climate data. Ranchi has annual water need of 1754 mm, rainfall of 1460 mm, actual evapotranspiration (AE) of 860 mm, water surplus (WS) of 600 mm and water deficit (WD) of 894 mm. The aridity index values were analyzed to assess the frequency of drought experienced of this region. The study reveals that during the above period, Ranchi has experienced 11 percent of large drought and severe drought, but only 3 per cent disastrous droughts in 35 years. Moderate drought category is observed to be most common with 23 per cent probability. Analyses of periods will contagious drought indicate that during the five year period 1980-84 and 1995-99, moderate, large and severe droughts were experienced.


2020 ◽  
Vol 54 (1A) ◽  
pp. 99-109
Author(s):  
Rebwar Dara

The aim of this study was to analyze the climatic data parameters in an interesting catchment, northern Iraq, the Koysinjaq catchment. The climatic conditions were further utilized in the water balance technique. The investigated periods (2000-2019) of meteorological data were used to assess the climatic and drought conditions in Koysinjaq Basin. In terms of water availability, the mean annual rainfall was 595mm and relative humidity was 50.3%, whereas regarding the water losses elements, the total monthly evaporation is 2058.3 mm, temperature, wind speed and sunshine were 22.3 oC, 2 m/sec, and 7.8 hr/day respectively. Kharrufa method was employed to define potential evapotranspiration, and identify periods of water surplus and deficit. The results indicated that total potential evapotranspiration, water surplus and deficit are 2209.04 mm, 258.2 mm, and 1872.4 mm respectively. Different methods were used for climate classification like Mather, Unep, and Al-Kubaisi, the results of these classifications show that climate is dry-sub humid according to the first classification, semi-arid according to the second classification, and humid to moist according to the third classification.


2019 ◽  
Vol 13 (26) ◽  
pp. 51-57
Author(s):  
Qusai Y. AL-Kubaisi

Mandali Basin is located between latitudes (33◦ 39' 00" and 33◦54' 55") to the north and longitudes (45ο 11' 00" and 45ο 40' 00") to theeast; to the east of Diyala province at the Iraqi-Iranian border; thebasin area is approximately 491 km2.From the study of climate reality of the basin between 1990-2013and assessment of the basic climate transactions, it was foundthat the annual rate of rainfall is 253.02 mm, the relative humidity(44.4%), the temperature (21.3 ◦C), wind speed (2.08 m /sec.),sunshine (8.27 h/day) and evaporation of the basin class (a) (271.98mm) and corrected potential evapotranspiration (80.03 mm). Theresults of the data analysis show that, there are three basic periods ofclimate variability wet period, semi wet and dry period.This study shows that, there is water surplus of 60.87% of therainfall amount which is equivalent to 154.03 mm, the amount ofrunoff is 7.47 mm, and the amount of water recharge is 146.56mm.


1972 ◽  
Vol 3 (4) ◽  
pp. 183-198 ◽  
Author(s):  
MARKÚS Á. EINARSSON

The paper describes the results of estimations of potential evapotranspiration (Ep) in Iceland using Penman's equation. The calculations are based on distribution maps for global radiation for the period 1958-1967 previously developed by the author, and meteorological data from 28 weather stations for the same period. The distribution of Ep for the year and for the summer (April-September) are mapped. Further, the difference between precipitation and potential evapotranspiration (P-Ep) is calculated and mapped for the year as a whole and for the two periods April-September and May-August according to the values of Ep and precipitation normals (P) for the years 1931-1960.


2021 ◽  
Vol 912 (1) ◽  
pp. 012095
Author(s):  
N Anggraini ◽  
B Slamet

Abstract Evapotranspiration plays a big role in the hydrology process. Potential Evapotranspiration (PET) always keeps soil moisture available, although an amount of water evaporates through evaporation and transpiration. The Thornthwaite equation uses air temperature and latitude from meteorological observations for estimating PET. Medan City is one of the biggest cities in Indonesia that have a problem with land-use change that affected water balance. This study is to estimate the PET and to learn the water balance in Medan City. The monthly temperature data for the period 2011-2020 is collected from three meteorological stations for estimating PET using the Thornthwaite equation. The highest monthly temperature is in Belawan Maritime Meteorological Station yet the lowest rainfall. The trends of PET depend on the month. The highest PET in Jan.-Apr. and Sep.-Dec. are in Belawan Maritime Meteorological Station, while the highest PET in May-Aug. is in Indonesia Agency for Meteorology Climatology and Geophysics Region I Medan. The P-PET has shown negative and positive values. The lowest P-PET is found in Belawan Maritime Meteorological Station in March and the highest P-PET is found in Indonesia Agency for Meteorology Climatology and Geophysics Region I Medan in October.


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