Impact of changing rainfall conditions on surface and groundwater resources in an experimental watershed in Greece

2013 ◽  
Vol 12 (2) ◽  
pp. 119-125
Keyword(s):  
Groundwater Resources ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Winter Rainfall ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
The Mean ◽  
Groundwater Reserves ◽  
The Impact

The present study concerns the impact of a change in the rainfall regime on surface and groundwater resources in an experimental watershed. The research is conducted in a gauged mountainous watershed (15.18 km2) that is located on the eastern side of Penteli Mountain, in the prefecture of Attica, Greece and the study period concerns the years from 2003 to 2008. The decrease in the annual rainfall depth during the last two hydrological years 2006-2007, 2007-2008 is 10% and 35%, respectively, in relation to the average of the previous years. In addition, the monthly distribution of rainfall is characterized by a distinct decrease in winter rainfall volume. The field measurements show that this change in rainfall conditions has a direct impact on the surface runoff of the watershed, as well as on the groundwater reserves. The mean annual runoff in the last two hydrological years has decreased by 56% and 75% in relation to the average of the previous years. Moreover, the groundwater level follows a declining trend and has dropped significantly in the last two years.

scholarly journals Rainfall erosivity in subtropical catchments and implications for erosion and particle-bound contaminant transfer: a case-study of the Fukushima region

2015 ◽  
Vol 12 (7) ◽  
pp. 7225-7266 ◽  
Author(s):  
J. P. Laceby ◽  
C. Chartin ◽  
O. Evrard ◽  
Y. Onda ◽  
L. Garcia-Sanchez ◽  
...  
Keyword(s):  
Nuclear Power ◽  
Soil Surface ◽  
Annual Rainfall ◽  
Spatial And Temporal Variation ◽  
Rainfall Regime ◽  
Rainfall Erosivity ◽  
Fine Soil ◽  
Run Off ◽  
The Mean ◽  
The Impact

Abstract. The Fukushima Dai-ichi nuclear power plant (FDNPP) accident in March 2011 resulted in a significant fallout of radiocesium over the Fukushima region. After reaching the soil surface, radiocesium is almost irreversibly bound to fine soil particles. Thereafter, rainfall and snow melt run-off events transfer particle-bound radiocesium downstream. Erosion models, such as the Universal Soil Loss Equation (USLE), depict a proportional relationship between rainfall and soil erosion. As radiocesium is tightly bound to fine soil and sediment particles, characterizing the rainfall regime of the fallout-impacted region is fundamental to modelling and predicting radiocesium migration. Accordingly, monthly and annual rainfall data from ~ 60 meteorological stations within a 100 km radius of the FDNPP were analysed. Monthly rainfall erosivity maps were developed for the Fukushima coastal catchments illustrating the spatial heterogeneity of rainfall erosivity in the region. The mean average rainfall in the Fukushima region was 1387 mm yr−1 (σ 230) with the mean rainfall erosivity being 2785 MJ mm ha−1 yr−1 (σ 1359). The results indicate that the majority of rainfall (60 %) and rainfall erosivity (86 %) occurs between June and October. During the year, rainfall erosivity evolves positively from northwest to southeast in the eastern part of the prefecture, whereas a positive gradient from north to south occurs in July and August, the most erosive months of the year. During the typhoon season, the coastal plain and eastern mountainous areas of the Fukushima prefecture, including a large part of the contamination plume, are most impacted by erosive events. Understanding these rainfall patterns, particularly their spatial and temporal variation, is fundamental to managing soil and particle-bound radiocesium transfers in the Fukushima region. Moreover, understanding the impact of typhoons is important for managing sediment transfers in subtropical regions impacted by cyclonic activity.

scholarly journals Deliberation of Hilly Areas for Water Harvesting Application in Western Crete, Greece.

2016 ◽  
Vol 18 (3) ◽  
pp. 621-629 ◽  
Keyword(s):  
Overland Flow ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Water Harvesting ◽  
Hydrological Conditions ◽  
Monthly Average ◽  
Dry Seasons ◽  
Harvesting Techniques ◽  
The Mean ◽  
Water Problems

<div> <p>The meteorological, physical and hydrological conditions prevailing in a hilly area, namely the region around Malaxa (Western Crete), are analyzed and investigated in relation to water harvesting applications. The literature relating to water harvesting techniques and applications is reviewed and the conclusions that have been drawn by other investigators concerning methods of water harvesting techniques and applications are outlined and discussed. Specific reasons for choosing this particular study area was given and the types and installation of equipment used are also described. The results indicate that despite the fact that the mean annual rainfall can be considered as high (940 mm), its distribution is very uneven and only 6% of it falls from May to September. This fact creates serious water problems in the area during the dry seasons. Also, mean annual and monthly average temperatures have values which contribute to the evapotranspiration of high amount of precipitation and may form frost and overland flow respectively, during some days. Furthermore, the annual runoff is estimated to be 248 mm and a part of this can be overland flow while the other part can be a throughflow. The occurrence of overland flow is also proved by the comparison of the infiltration and the intensities of rainfall with the return periods of 5 and 10 years. Additionally, the quantification of overland flow is made by collecting and analyzing it from experimental plots. By this method, we clarified that the quantity of overland flow is affected by the inclination of the ground, the density of vegetation and the compaction of the soil. These results, although all of them are not wholly conclusive, can present an advance for understanding the use of meteorological, physical and hydrological conditions for water harvesting applications in an area.</p> </div> <p>&nbsp;</p>

scholarly journals Precipitation concentration index (PCI) a tool to evaluate the distribution of Rainfall, Barishal, Bangladesh

2020 ◽  
Vol 8 (2) ◽  
pp. 193
Author(s):  
Sudip Saha
Keyword(s):  
Concentration Index ◽  
Research Work ◽  
Monthly Rainfall ◽  
Annual Rainfall ◽  
Winter Rainfall ◽  
Precipitation Concentration Index ◽  
Precipitation Concentration ◽  
The Mean ◽  
June July ◽  
The Right

The present research work reveals the mean annual rainfall of Barishal is 2087.34 mm for the investigated period. The maximum annual rainfall was 3390 mm in the year of 1960 and minimum annual rainfall was recorded as 1277 mm in the year of 1964. The annual rainfall is inversely correlated with time. The maximum monthly rainfall is recorded in the month of July. The amount of annual rainfall is strongly significantly positively correlated with the monthly rainfall of May, June, July, August and September. In Barishal, the value of skewness for all rainfall data are positive that indicate the data are skewed to the right. The positive value of kurtosis of the eleven months of the year (except July) means a peaked distribution and a negative value in the month of July reveals the flat distribution with the same mean and standard deviation. The annual PCI value is inversely proportional to the annual rainfall. The analyses of seasonal precipitation concentration index (SPCI) reveals that the rainfall is uniformly distributed in summer monsoon whereas the winter rainfall shows the dominance of strong irregularity in precipitation distribution.  

scholarly journals A non-stationary model for reconstruction of historical annual runoff on tropical catchments under increasing urbanization (Yaoundé, Cameroon)

2019 ◽  
Author(s):  
Camille Jourdan ◽  
Valérie Borrell-Estupina ◽  
David Sebag ◽  
Jean-Jacques Braun ◽  
Jean-Pierre Bedimo Bedimo ◽  
...  
Keyword(s):  
Land Use ◽  
Data Acquisition ◽  
Forest Cover ◽  
Land Use Changes ◽  
Annual Runoff ◽  
Distributed Model ◽  
Annual Rainfall ◽  
Runoff Coefficient ◽  
Experimental Modelling ◽  
The Impact

Abstract. Inter-tropical regions are nowadays faced to major land-use changes in data-sparse context leading to difficulties to assess hydrological signatures and their evolution. This work is part of the theme Panta Rhei of the IAHS, and aims to develop a combined approach of data acquisition and a new semi-distributed model taking into account land-use changes to reconstruct and predict annual runoff on an urban catchment. Applications were conducted on the Mefou catchment at Nsimalen (421 km2; Yaoundé, Cameroon) under rapid increase in urbanization since 1960. The data acquisition step combines an historical data processing and a short-term spatially-dense dedicated instrumentation (2017–2018), leading to 12 donor catchments, 6 from historical studies and 6 from the instrumentation presenting various topographic, soil and land-use characteristics. We developed an annual rainfall-runoff model based on mathematical relationships similar to the SCS model. The model needs the definition of a hydrological index I which is time variable and enables to take into account land-use changes and non-stationary relationships between rainfall and runoff. The index I is an empirical indicator defined as a combination of several components such as topography, soil, and land-use. The rules for the construction of I are obtained from data analysis on donor catchments. Then, the model was calibrated on donor catchments. Finally, two applications were conducted on eight target catchments composing the Mefou in order: (i) to study the spatial hydrological functioning and calculate the water balance during the short instrumentation period; (ii) to reconstruct the hydrograph at the Mefou and to simulate the impact of future scenarios of land-use and urbanization. Results show that that the Mfoundi catchment, integrating the three more urbanized sub-catchments, contributes near to 40 % of the Mefou despite covering only 23 % of the basin. The most urbanized sub-catchments present annual runoff coefficient about 0.86 against 0.24 for the most natural sub-catchments. The second result is the reconstruction of historical annual runoff from 1930–2017 with r2 = 0.68, RMSE = 99 mm and a mean absolute normalized error Ē = 14.5 % over the 29 observed years. The reconstruction of the annual runoff at Nsimalen confirms the moderate impact of urbanization on annual runoff before 1980. However, a decrease of about 50 % of the forest cover and an increase from 10 % to 35 % of the urban area between 1980 and 2017 are associated with an increase of 53 % of annual runoff coefficient for the Mefou at Nsimalen (0.44 against 0.29). Application for a fictive plausible scenario of urbanization in 2030 leads to an increase of more than 85 % of the annual runoff in comparison of the values observed in 1980. The coupled experimental-modelling approach proposed herein opens promising perspectives regarding the evaluation of the annual runoff in catchments under changes.

The Brigalow Catchment Study: II. Clearing brigalow (Acacia harpophylla) for cropping or pasture increases runoff

Soil Research ◽  
2007 ◽  
Vol 45 (7) ◽  
pp. 496 ◽  
Author(s):  
C. M. Thornton ◽  
B. A. Cowie ◽  
D. M. Freebairn ◽  
C. L. Playford
Keyword(s):  
Sampling Error ◽  
New South ◽  
Annual Runoff ◽  
Annual Rainfall ◽  
Total Runoff ◽  
South Wales ◽  
Average Annual Runoff ◽  
Paired Catchment ◽  
The Individual ◽  
The Impact

The Brigalow Catchment Study (BCS) was established to determine the impact on hydrology when brigalow land is cleared for cropping and grazing. The paired catchment study was commenced in 1965 using catchments of approximately 15 ha, with natural vegetation dominated by brigalow scrub (Acacia harpophylla). Three contiguous catchments were selected near Theodore in central Queensland to represent the extensive brigalow bioregion of central and southern Queensland and northern New South Wales (~40 Mha). The hydrology of the 3 catchments was characterised during a 17-year calibration period (1965–81). The catchments were considered hydrologically similar, with sufficient data available for an empirical comparison between catchments. In 1982, two of the catchments were cleared, with one developed for cropping and the other sown to improved pasture. The third catchment was used as an uncleared control. Hydrologic characteristics were then compared for the following 21 years. In their virgin state, the catchments behaved similarly, with average annual runoff being 5% of annual rainfall. Once cleared, total runoff from the cropping catchment increased to 11% of annual rainfall and total runoff from the pasture catchment increased to 9% of annual rainfall; however, timing of the individual runoff events varied between land uses. In order to confirm that changes in hydrology were a function of land use and not just seasonal variability or sampling error, several analytic techniques were used: a simple comparison of runoff totals, comparison of events, comparison of probability of exceedance for daily runoff, and comparison of predicted and observed runoff using a water balance modelling approach.

scholarly journals Livelihood diversification and climate change adaptation in Indo-Gangetic plains: implication of rainfall regimes

2015 ◽  
Vol 16 ◽  
pp. 77-94 ◽  
Author(s):  
Gopal D Bhatta ◽  
Pramod K Aggarwal ◽  
Amit Shrivastava
Keyword(s):  
Local Adaptation ◽  
Climatic Factors ◽  
Climatic Variability ◽  
Household Survey ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Livelihood Diversification ◽  
Gangetic Plains ◽  
High Rainfall ◽  
The Impact

We investigate whether spatial variations in climatic resource such as rainfall have prompted livelihood diversification, local adaptation and household food availability in Indo-Gangetic Plains using data from a household survey of 2660 farm-families carried out in India, Bangladesh and Nepal. We found that on-farm livelihood sources are higher in high rainfall regime (1300-1800 mm) compared to medium (<1300 mm) and very high rainfall regime (>1800 mm). The off-farm sources are higher in medium rainfall regime. Although a large number of changes are attributed to harvest better yield, yet farmers made numbers of changes in response to climatic variability as well. Although agricultural livelihood and local adaptation are restrained by several climatic and non-climatic factors; the amount of annual rainfall significantly affects livelihood diversification, and the impact of climatic stressors becomes more pronounced when there is interaction with other non-climatic factors. The results imply that livelihood and adaptation strategies should be tailor made along the climatic and non-climatic resources.

scholarly journals The Thames flood series: a lack of trend in flood magnitude and a decline in maximum levels

2012 ◽  
Vol 43 (3) ◽  
pp. 203-214 ◽  
Author(s):  
Terry Marsh ◽  
Catherine L. Harvey
Keyword(s):  
Flow Measurement ◽  
Management Practices ◽  
Annual Runoff ◽  
Winter Rainfall ◽  
Wide Range ◽  
Flood Magnitude ◽  
Major Floods ◽  
Warming World ◽  
The Impact ◽  
Substantial Rise

The flow series for the River Thames near its tidal limit is one of the most studied in the world. Its length and completeness, and the richness of the historical information which augments the formal flow record, ensures that the series is of immense value. However, the variability in flood magnitude and frequency that it captures needs to be interpreted with caution. The homogeneity of the time series is influenced by a wide range of factors, including changes in the hydrometric capability of the gauging station and the impact of differing water, river and land management practices on the flow regime. Nevertheless, both the daily flow series and the record of lock levels provide some reassuring signals regarding the resilience of the Thames to fluvial flood risk in a warming world. Since routine flow measurement began in 1883, the Thames basin has seen a substantial rise in air temperature and a tendency for both winter rainfall and annual runoff to increase. There is no trend in fluvial flood magnitude however, partly reflecting a decline in snowmelt contributions to major floods and annual maximum lock levels show a significant decline, reflecting a highly sustained programme of river management.

scholarly journals Development of groundwater levels as a consequense of climate change

2012 ◽  
Vol 20 (1) ◽  
pp. 29-34
Author(s):  
M. Pásztorová ◽  
J. Skalová ◽  
J. Vitková ◽  
M. Juráková
Keyword(s):  
Climate Change ◽  
Groundwater Level ◽  
Groundwater Resources ◽  
Winter Season ◽  
Water Levels ◽  
Rainfall Regime ◽  
Wetland Ecosystems ◽  
Groundwater Levels ◽  
Run Off ◽  
The Impact

Development of groundwater levels as a consequense of climate changeClimate change poses a significant threat to many wetland ecosystems. Wetlands exist in a transition zone between aquatic and terrestrial environments and can be affected by slight alterations in regional hydrology, which can influence climate change through air temperature changes, regional changes in a rainfall regime, surface run-off, snow, duration of the winter season, groundwater resources and evapotranspiration.Climate change in wetland areas is most significantly reflected in water levels and adjacent groundwater levels, and it can significantly change the hydroecological proportions of wetland ecosystems and endanger rare wetland fauna and flora communities. The focus of this paper is the impact of climate change on the groundwater level in the Záhorie Protected Landscape area in the Zelienka national nature reservation. The impact of the climate change was solved through the meteorological characteristic changes adapted by the GISS98 and CCCM2000 climatic scenarios. The groundwater level was determined by the HYDRUS-ET model for the time frames 2010, 2030 and 2075 in 20-year time intervals and consequently compared to the reference period of 1971-1990.

scholarly journals Assessing the middle – upper pleistocene aquifer vulnerability due to the seawater intrusion in Ca Mau peninsula

2019 ◽  
Vol 2 (4) ◽  
pp. 184-190
Author(s):  
Hai Hong Dao ◽  
Tu Dinh Nguyen
Keyword(s):  
Groundwater Resources ◽  
Aquifer Vulnerability ◽  
Salinity Intrusion ◽  
Policy Planning ◽  
Upper Pleistocene ◽  
Pleistocene Aquifer ◽  
Exploitation And Utilization ◽  
Groundwater Reserves ◽  
Over Exploitation ◽  
The Impact

The impact of climate change and over exploitation reduced the quality and groundwater reserves of the Ca Mau peninsula. This study used the GALDIT index to assess the vulnerability of groundwater resources due to salinity intrusion under exploitation and sea level rise. The GALDIT index results showed that the damage caused by the salinity intrusion of the Middle - Upper Pleistocene aquifer (qp2-3)was from moderate to high. The most vulnerable areas were Ca Mau and Soc Trang, accounting for 54.52% of the studied area, the average vulnerabbe areas were Kien Giang and Bac Lieu. This result could be used as a basis for policy planning, exploitation and utilization of sustainable groundwater resources, and to develop appropriate recommendations for people in the studied area.

Temporal Variations in Rainfall Volume in the Southwest of Western Australia

2021 ◽  
Vol 60 (1) ◽  
pp. 23-32
Author(s):  
P. Philip ◽  
B. Yu
Keyword(s):  
Western Australia ◽  
Daily Rainfall ◽  
Southern Annular Mode ◽  
Temporal Variations ◽  
Annual Rainfall ◽  
Minor Role ◽  
Rainfall Depth ◽  
Rainfall Volume ◽  
A Minor ◽  
The Relationship

AbstractRainfall in the southwest of Western Australia (SWWA) has decreased significantly over recent decades. Previous studies documented this decrease in terms of the change in rainfall depth or decrease in the frequency of rainfall events for selected sites. Although rainfall volume is of vital importance to determine water resources availability for a given region, no study has yet been undertaken to examine the change in rainfall volume in SWWA. The aim of this study is to examine the spatiotemporal changes in rainfall volume and to attribute this change to the changes in wet area and rainfall depth. Gridded daily rainfall data at 0.05° resolution for the period from 1911 to 2018 were used for an area of 265 952 km2 in SWWA. For the whole region and most zones, rainfall volume decreased, which was mostly due to a decrease in the wet area, despite an increase in the mean rain depth. In the regions near the coast with mean annual rainfall ≥ 600 mm, 84% of the decrease in rainfall volume could be attributed to a decrease in the wet area, whereas the decrease in rainfall depth only played a minor role. The regions near the coast with a higher number of rain days showed a decreasing trend in wet area, and the regions farther inland with a lower number of rain days showed an increasing trend in wet area. On the coast, the rate of decrease in rainfall has been reduced, and heavy rainfall, in fact, has increased over the past 30 years, although there was no concurrent change in the southern annular mode (SAM). This suggests that the relationship between SAM and rainfall could have changed and that other climate drivers could also be responsible for the recent rainfall trend and variations in the coastal regions of SWWA.

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