scholarly journals Evaluation of Extreme Dry and Wet Conditions Using Climate and Hydrological Indices in the Upper Part of the Gallikos River Basin

Proceedings ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 3
Author(s):  
Christos Mattas ◽  
Christina Αnagnostopoulou ◽  
Panagiota Venetsanou ◽  
Georgios Bilas ◽  
Georgia Lazoglou

Climate changes in the Mediterranean region, especially those related to changes in rainfall distribution and occurrence of extreme events, affect local economies. Agriculture is a sector strongly affected by climate conditions and concerns the majority of the Greek territory. The Gallikos river basin is an area of great interest regarding climate change impacts since it is an agricultural area depended on surface water resources and an area in which extreme events relatively often take place (e.g., floods). Long time series precipitation (27 years) and temperature data derived from measurement stations along with reanalysis data (ERA INTERIM) were used for the estimation of water availability and climate type over time in the area. The Standardized Precipitation Index and De Martonne aridity index was employed. The water flow measurements were correlated in order to investigate the interrelation between the different river branches and the extent of the meteorological changes effect in the basin. Descriptive statistics and cumulative curves were applied to check homogeneity of data. The results revealed that the climate type varies from semi arid to very wet, and water availability ranges from moderately dry to extremely wet years. Reanalysis data overestimate precipitation. The meteorological changes affect, at the same time, the entire basin since the flow rate peaks occur simultaneously in the hydrographic network at different areas.

2010 ◽  
Vol 14 (10) ◽  
pp. 1919-1930 ◽  
Author(s):  
T. Raziei ◽  
I. Bordi ◽  
L. S. Pereira ◽  
A. Sutera

Abstract. Space-time variability of hydrological drought and wetness over Iran is investigated using the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis and the Global Precipitation Climatology Centre (GPCC) dataset for the common period 1948–2007. The aim is to complement previous studies on the detection of long-term trends in drought/wetness time series and on the applicability of reanalysis data for drought monitoring in Iran. Climate conditions of the area are assessed through the Standardized Precipitation Index (SPI) on 24-month time scale, while Principal Component Analysis (PCA) and Varimax rotation are used for investigating drought/wetness variability, and drought regionalization, respectively. Singular Spectrum Analysis (SSA) is applied to the time series of interest to extract the leading nonlinear components and compare them with linear fittings. Differences in drought and wetness area coverage resulting from the two datasets are discussed also in relation to the change occurred in recent years. NCEP/NCAR and GPCC are in good agreement in identifying four sub-regions as principal spatial modes of drought variability. However, the climate variability in each area is not univocally represented by the two datasets: a good agreement is found for south-eastern and north-western regions, while noticeable discrepancies occur for central and Caspian sea regions. A comparison with NCEP Reanalysis II for the period 1979–2007, seems to exclude that the discrepancies are merely due to the introduction of satellite data into the reanalysis assimilation scheme.


Hydrology ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 49 ◽  
Author(s):  
Doan Quang Tri ◽  
Tran Tho Dat ◽  
Dinh Duc Truong

The objective of this study was to establish drought classification maps to simulate and calculate the lack of discharge in the Ba River basin in Vietnam. The maps were established using three meteorological drought indices (the Standardized Precipitation Index (SPI), the Drought Index (J), and the Ped Index (Ped)), the Soil and Water Assessment Tool (SWAT) model, and the hydrological drought index (KDrought). The results from the calculation of the SPI, Aridity Index (AI), and Ped at three stations (An Khe, Ayunpa, and MDrak) showed that the J index was suitable for the study area. Based on the J index, an extreme drought was predicted to occur at the Ayunpa, An Khe, and MDrak stations. During the calibration process, the SWAT Calibration Uncertainties Program (SWAT-CUP) model, with automatic algorithms, was used to select the parameters to optimize the SWAT model. For the calibration and validation, the observed discharge at two hydrology stations, An Khe and Cung Son, from the periods 1981–1991 and 1992–2002, respectively, were used. The simulated discharge was found to be acceptable, with the Nash–Sutcliffe efficiency (NSE), Percent bias (PBIAS), and R2 reaching good levels in both calibration and validation. The results from the calculation of the drought index (KDrought), and the established drought classification maps in 2016, showed that the most affected areas were the communes of the Gia Lai and Dak Lak provinces. The results from the simulation and calculations were found to be consistent with the situation that occurred in practice. The application of meteorological and hydrological drought indices, as well as the hydrological model, to support impact assessments of drought classification in space and time, as well as the establishment of forecasting and warning maps, will help managers to effectively plan policy responses to drought.


2017 ◽  
Vol 4 (3) ◽  
pp. 477-507 ◽  
Author(s):  
Somsubhra Chattopadhyay ◽  
Dwayne R. Edwards ◽  
Yao Yu ◽  
Ali Hamidisepehr

Water ◽  
2012 ◽  
Vol 4 (1) ◽  
pp. 63-84 ◽  
Author(s):  
Tingju Zhu ◽  
Claudia Ringler

Author(s):  
Tanja N. Williamson ◽  
Jeremiah G. Lant ◽  
Peter R. Claggett ◽  
Elizabeth A. Nystrom ◽  
Paul C.D. Milly ◽  
...  

2020 ◽  
Vol 186 ◽  
pp. 109544 ◽  
Author(s):  
Thundorn Okwala ◽  
Sangam Shrestha ◽  
Suwas Ghimire ◽  
S. Mohanasundaram ◽  
Avishek Datta

2014 ◽  
Vol 6 (2) ◽  
pp. 341-351 ◽  
Author(s):  
Chun Chang ◽  
Ping Feng ◽  
Fawen Li ◽  
Yunming Gao

Based on the Haihe river basin National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data from 1948 to 2010 and the precipitation data of 53 hydrological stations during 1957–2010, this study analyzed the variation of water vapor content and precipitation, and investigated the correlation between them using several statistical methods. The results showed that the annual water vapor content decreased drastically from 1948 to 2010. It was comparatively high from the late 1940s to the late 1960s and depreciated from the early 1970s. From the southeast to the northwest of the Haihe river basin, there was a decrease in water vapor content. For vertical distribution, water vapor content from the ground to 700 hPa pressure level accounted for 72.9% of the whole atmospheric layer, which indicated that the water vapor of the Haihe river basin was mainly in the air close to the ground. The precipitation in the Haihe river basin during 1957–2010 decreased very slightly. According to the correlation analysis, the precipitation and water vapor content changes showed statistically positive correlation, in addition, their break points were both in the 1970s. Furthermore, the high consistency between the precipitation efficiency and precipitation demonstrates that water vapor content is one of the important factors in the formation of precipitation.


Atmosphere ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 726
Author(s):  
Paul Carroll ◽  
Eeva Aarrevaara

Future climate conditions need to be considered in planning for urban areas. As well as considering how new structures would best endure in the future, it is important to take into account factors that contribute to the degradation of cultural heritage buildings in the urban setting. Climate change can cause an increase in structural degradation. In this paper, a review of both what these factors are and how they are addressed by urban planners is presented. A series of inquiries into the topic was carried out on town planning personnel and those involved in cultural heritage preservation in several towns and cities in Finland and in a small number of other European countries. The target group members were asked about observed climate change impacts on cultural heritage, about present steps being taken to protect urban cultural heritage, and also their views were obtained on how climate change impacts will be emphasised in the future in this regard. The results of the inquiry demonstrate that climate change is still considered only in a limited way in urban planning, and more interaction between different bodies, both planning and heritage authorities, as well as current research on climate change impacts, is needed in the field.


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