scholarly journals Rainfall Trends in Humid Temperate Climate in South America: Possible Effects in Ecosystems of Espinal Ecoregion

2021 ◽  
Author(s):  
Julian Alberto Sabattini ◽  
Rafael Alberto Sabattini
Keyword(s):  
Monthly Rainfall ◽  
Annual Rainfall ◽  
Temperate Climate ◽  
Rainfall Regime ◽  
Ratio Test ◽  
Von Neumann ◽  
Detection Analysis ◽  
Standard Normal ◽  
Precipitation Records ◽  
Entre Rios

In central Argentina, the annual rainfall regime shows increasing since the 2nd half of the 20th century. The aim of this work was to evaluate the long-term changes in the intensity of rainfall in the central-north region of Entre Ríos between 1945 and 2019, based only on daily precipitation records aggregated at yearly, monthly and seasonal levels. We used monthly rainfall data for the period 1945–2019 from 6 localities in Province of Entre Rios, Argentina. The change detection analysis has been conceded using Pettitt’s test, von Neumann ratio test, Buishand’s range test and standard normal homogeneity (SNH) test, while non-parametric tests including linear regression, Mann-Kendall and Spearman rho tests have been applied for trend analysis. Like the regional results, this study observed a sustained increase in monthly rainfall to the breaking point in the 1970s, but then the annual rate of increase was even higher. The average annual rainfall in the region prior to that date was 946 mm, while after the same 1150 mm, equivalent to 21.5% higher than the 1945–1977 average and 8.5% higher according to the historical average 1945–2019.

scholarly journals Annual, seasonal and monthly rainfall trend analysis in the Tafna watershed, Algeria

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Afaf Bouklikha ◽  
Mohammed Habi ◽  
Abdelkader Elouissi ◽  
Saaed Hamoudi
Keyword(s):  
Trend Analysis ◽  
Temporal Trends ◽  
Monthly Rainfall ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Monthly Precipitation ◽  
North West ◽  
The North ◽  
Mediterranean Regions ◽  
June July

AbstractScientists, since a long time, have paid attention on climate change and, in particular, rainfall decrease. These changes have resulted in modifications of the rainfall regime in many Mediterranean regions. This work is based on monthly rainfall data from 17 stations located in the Tafna catchment (North West of Algeria). The study aim is to identify long-term (1970–2016) spatial and temporal trends in annual, seasonal and monthly precipitation, using the innovative trend analysis (ITA) method. The approach is used to classify trends into “low”, “medium”, “high”, which should be taken in consideration in future studies on floods (“high”) and drought (“low”). The monthly rainfall shows a decreasing trend in all studied stations (100% of stations) during February, March, April, and May, the same phenomenon observed in the majority of stations for June, July (82% of stations), and December (58% of stations). Seasonal analysis indicates a downward trend in winter and spring. Using annual rainfall, the stations located in the north, west and central part of the Tafna show a decrease in rainfall (59% of stations).

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 CEH-GEAR: 1 km resolution daily and monthly areal rainfall estimates for the UK for hydrological use

2015 ◽  
Vol 8 (1) ◽  
pp. 83-112 ◽  
Author(s):  
V. D. J. Keller ◽  
M. Tanguy ◽  
I. Prosdocimi ◽  
J. A. Terry ◽  
O. Hitt ◽  
...  
Keyword(s):  
Monthly Rainfall ◽  
Annual Rainfall ◽  
National Database ◽  
Maximum Information ◽  
Weather Observations ◽  
The Republic ◽  
Areal Rainfall ◽  
The Uk ◽  
Rainfall Estimates

Abstract. The Centre for Ecology & Hydrology – Gridded Estimates of Areal Rainfall (CEH-GEAR) dataset was developed to provide reliable 1 km gridded estimates of daily and monthly rainfall for Great Britain (GB) and Northern Ireland (NI) (together with approximately 3500 km2 of catchment in the Republic of Ireland) from 1890 onwards. The dataset was primarily required to support hydrological modelling. The rainfall estimates are derived from the Met Office collated historical weather observations for the UK which include a national database of raingauge observations. The natural neighbour interpolation methodology, including a normalisation step based on average annual rainfall, was used to generate the daily and monthly rainfall grids. To derive the monthly estimates, rainfall totals from monthly and daily (when complete month available) read raingauges were used in order to obtain maximum information from the raingauge network. The daily grids were adjusted so that the monthly grids are fully consistent with the daily grids. The CEH-GEAR dataset was developed according to the guidance provided by the British Standards Institution. The CEH-GEAR dataset contains 1 km grids of daily and monthly rainfall estimates for GB and NI for the period 1890–2012. For each day and month, CEH-GEAR includes a secondary grid of distance to the nearest operational raingauge. This may be used as an indicator of the quality of the estimates. When this distance is greater than 100 km, the estimates are not calculated due to high uncertainty. CEH-GEAR is available free of charge for commercial and non-commercial use subject to licensing terms and conditions. doi:10.5285/5dc179dc-f692-49ba-9326-a6893a503f6e

scholarly journals An Analysis of Long-Term Rainfall Trends and Variability in the Uttarakhand Himalaya Using Google Earth Engine

2020 ◽  
Vol 12 (4) ◽  
pp. 709 ◽  
Author(s):  
Abhishek Banerjee ◽  
Ruishan Chen ◽  
Michael E. Meadows ◽  
R.B. Singh ◽  
Suraj Mal ◽  
...  
Keyword(s):  
River Basin ◽  
Temporal Trends ◽  
Google Earth ◽  
Monthly Rainfall ◽  
Annual Rainfall ◽  
Google Earth Engine ◽  
Spatio Temporal ◽  
Uttarakhand Himalaya ◽  
Rainy Days

This paper analyses the spatio-temporal trends and variability in annual, seasonal, and monthly rainfall with corresponding rainy days in Bhilangana river basin, Uttarakhand Himalaya, based on stations and two gridded products. Station-based monthly rainfall and rainy days data were obtained from the India Meteorological Department (IMD) for the period from 1983 to 2008 and applied, along with two daily rainfall gridded products to establish temporal changes and spatial associations in the study area. Due to the lack of more recent ground station rainfall measurements for the basin, gridded data were then used to establish monthly rainfall spatio-temporal trends for the period 2009 to 2018. The study shows all surface observatories in the catchment experienced an annual decreasing trend in rainfall over the 1983 to 2008 period, averaging 15.75 mm per decade. Analysis of at the monthly and seasonal trend showed reduced rainfall for August and during monsoon season as a whole (10.13 and 11.38 mm per decade, respectively); maximum changes were observed in both monsoon and winter months. Gridded rainfall data were obtained from the Climate Hazard Infrared Group Precipitation Station (CHIRPS) and Precipitation Estimation from Remotely Sensed Information Using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR). By combining the big data analytical potential of Google Earth Engine (GEE), we compare spatial patterns and temporal trends in observational and modelled precipitation and demonstrate that remote sensing products can reliably be used in inaccessible areas where observational data are scarce and/or temporally incomplete. CHIRPS reanalysis data indicate that there are in fact three significantly distinct annual rainfall periods in the basin, viz. phase 1: 1983 to 1997 (relatively high annual rainfall); phase 2: 1998 to 2008 (drought); phase 3: 2009 to 2018 (return to relatively high annual rainfall again). By comparison, PERSIANN-CDR data show reduced annual and winter precipitation, but no significant changes during the monsoon and pre-monsoon seasons from 1983 to 2008. The major conclusions of this study are that rainfall modelled using CHIRPS corresponds well with the observational record in confirming the decreased annual and seasonal rainfall, averaging 10.9 and 7.9 mm per decade respectively between 1983 and 2008, although there is a trend (albeit not statistically significant) to higher rainfall after the marked dry period between 1998 and 2008. Long-term variability in rainfall in the Bhilangana river basin has had critical impacts on the environment arising from water scarcity in this mountainous region.

scholarly journals Multifractal structure of the monthly rainfall regime in Catalonia (NE Spain): Evaluation of the non-linear structural complexity

2020 ◽  
Vol 30 (7) ◽  
pp. 073117 ◽  
Author(s):  
X. Lana ◽  
R. Rodríguez-Solà ◽  
M. D. Martínez ◽  
M. C. Casas-Castillo ◽  
C. Serra ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Monthly Rainfall ◽  
Rainfall Regime ◽  
Non Linear ◽  
Ne Spain

scholarly journals Climatic controls on diffuse groundwater recharge across Australia

2012 ◽  
Vol 9 (5) ◽  
pp. 6023-6062 ◽  
Author(s):  
O. V. Barron ◽  
R. S. Crosbie ◽  
D. Pollock ◽  
W. R. Dawes ◽  
S. P. Charles ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Vapour Pressure Deficit ◽  
Field Studies ◽  
Annual Rainfall ◽  
Temperate Climate ◽  
Relative Importance ◽  
Climate Type ◽  
Climate Parameters ◽  
Climate Controls ◽  
Temperature Climate

Abstract. Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modeling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types the total annual rainfall had a weaker correlation with recharge than the rainfall parameters reflecting rainfall intensity. In regions with winter-dominated rainfall, annual recharge under the same annual rainfall, soils and vegetation conditions is greater than in regions with summer-dominated rainfall. The relative importance of climate parameters other than rainfall is higher for recharge under annual vegetation, but overall is highest in the tropical climate type. Solar radiation and vapour pressure deficit show a greater relative importance than mean annual daily mean temperature. Climate parameters have lowest relative importance in the arid climate type (with cold winters) and the temperate climate type. For 75% of all considered cases of soil, vegetation and climate types recharge elasticity varies between 2 and 4, indicating a 20% to 40% change in recharge for a 10% change in annual rainfall Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.

scholarly journals Annual and monthly rainfall trend in plantation and spice farming Western Ghats districts

1970 ◽  
pp. 45
Author(s):  
K Kandiannan, K S Krishnamurthy, C K Thankamani, S J Ankegowda
Keyword(s):  
Coefficient Of Variation ◽  
Western Ghats ◽  
Monsoon Rainfall ◽  
Southwest Monsoon ◽  
Monthly Rainfall ◽  
Negative Trend ◽  
Annual Rainfall ◽  
Post Monsoon ◽  
The Nilgiris ◽  
Southwest Monsoon Rainfall

Rainfall analysis of important plantation and spices producing districts such as The Nilgiris (Tamil Nadu), Kodagu (Karnataka) Idukki (Kerala) and Wayanad (Kerala) with 100 years data (1901 to 2000) obtained from the India Meteorological Department (IMD), Pune indicated that mean annual rainfall were 1839.7mm, 2715.7mm, 2979.4mm and 3381.0mm with a coefficient of variation (CV) of 16.0%, 17.0%, 25.8% and 19.6%, respectively. The contribution of southwest monsoon(June-September) to the annual rainfall in these districts were 80.3% (Wayanad), 78.9% (Kodagu),  65.2% (Idukki) and 56.3%  (The Nilgiris) with corresponding CV of 24.1%, 20.6%, 32.5%, and 24.6%, respectively. The declining trend in mean annual rainfall was noticed for Idukki, Wayanad and The Nilgiris, whereas, for Kodagu, it was stable. The change was significant in Wayanad and The Nilgiris. Similar trend was also observed for the southwest monsoon rainfall. The maximum decline in annual and southwest monsoon rainfall was noticed in The Nilgiris followed by Wayanad. Pre and post monsoon rainfall receipts were comparatively less with high inter-annual variations. The pre-monsoon (March-May) receipt and its coefficient of variation (CV) was 252.4mm & 20.6% (Kodagu), 360.9mm & 36.5% (Idukki), 251.7mm & 36.6% (The Nilgiris) and 274.2mm & 54.2% (Wayanad). The post monsoon (October-December) rain was maximum in Idukki 548.1mm (CV 27.9%) followed by The Nilgiris 503.4mm(CV 31.3%), Wayanad, 333.1mm(CV 37.8%) and Kodagu 310.5mm (CV 32.7%). In all these districts there was a declining trend in the pre-monsoon rain with maximum decline in The Nilgiris. Similar declining trend was also observed in post-monsoon rain except for The Nilgiris, where the trend has been increasing. Overall, the study gives an indication that there was a spatial and temporal variation in rainfall amounts.  The maximum decline in annual rainfall and the southwest monsoon was observed in The Nilgiris and Wayanad. July was the rainiest month in all the districts studied. Significant negative trend was asscoaited with The Nilgiris for January, May, June, July and August months. Whereas, in Kodagu, no significant trend was observed for mean monthly rainfall, except for August. In Idukki, significant negative changes were noticed for January, March, October and December rainfall. Monthly rainfall of January, March, April and July monthly rainfall were showed significant negative trend in Wayanad,. These negative trends across important plantation and spices producing districts of the Western Ghats would affect not only the agricultural economy of this sector but also water resources.

scholarly journals Analysis of Decadal Rainfall and Temperature Trend in Warri, Nigeria

2021 ◽  
Vol 2 (2) ◽  
pp. 15-18
Author(s):  
Oyeleke Oluwaseun Oyerinde
Keyword(s):  
Temperature Trend ◽  
Monthly Rainfall ◽  
Rainfall Data ◽  
Annual Rainfall ◽  
Total Rainfall ◽  
Monthly Temperature ◽  
Increasing Trend ◽  
Temperature Ranges ◽  
The Mean ◽  
Using Data

This study investigates rainfall and temperature trend in Warri, Delta State, Nigeria using data derived from Nigerian Meteorological Agency between 2005 and 2015. Data was analyzed to reveal trend in temperature and rainfall values in the years under study and to determine whether there were significant variations. Analysis of rainfall data shows that 2007 had the lowest total rainfall over the 11 year period with a total annual rainfall of 2030.58 mm while 2015 was the year with the highest annual rainfall record of 3183.6 mm. The mean monthly Rainfall indicates that January has the lowest record of rainfall with a total of 36.9 mm while July is the month with highest value of 423.2 mm. Results further indicates that June has the lowest mean monthly temperature over the 11 year period of 20 ºC while March has the highest record of 29.6 ºC. Dominant temperature ranges between 26.1 oC and 26.8 ºC closely followed by 27.7–28.4 ºC which are quite close to the mean monthly values in the area. Analysis of rainfall data confirms an increasing trend.

scholarly journals Climatic controls on diffuse groundwater recharge across Australia

2012 ◽  
Vol 16 (12) ◽  
pp. 4557-4570 ◽  
Author(s):  
O. V. Barron ◽  
R. S. Crosbie ◽  
W. R. Dawes ◽  
S. P. Charles ◽  
T. Pickett ◽  
...  
Keyword(s):  
Groundwater Recharge ◽  
Vapour Pressure Deficit ◽  
Field Studies ◽  
Annual Rainfall ◽  
Temperate Climate ◽  
Climate Type ◽  
Climate Parameters ◽  
Climate Controls ◽  
Recharge Estimation ◽  
Temperature Climate

Abstract. Reviews of field studies of groundwater recharge have attempted to investigate how climate characteristics control recharge, but due to a lack of data have not been able to draw any strong conclusions beyond that rainfall is the major determinant. This study has used numerical modelling for a range of Köppen-Geiger climate types (tropical, arid and temperate) to investigate the effect of climate variables on recharge for different soil and vegetation types. For the majority of climate types, the correlation between the modelled recharge and total annual rainfall is weaker than the correlation between recharge and the annual rainfall parameters reflecting rainfall intensity. Under similar soil and vegetation conditions for the same annual rainfall, annual recharge in regions with winter-dominated rainfall is greater than in regions with summer-dominated rainfall. The importance of climate parameters other than rainfall in recharge estimation is highest in the tropical climate type. Mean annual values of solar radiation and vapour pressure deficit show a greater importance in recharge estimation than mean annual values of the daily mean temperature. Climate parameters have the lowest relative importance in recharge estimation in the arid climate type (with cold winters) and the temperate climate type. For 75% of all soil, vegetation and climate types investigated, recharge elasticity varies between 2 and 4 indicating a 20% to 40% change in recharge for a 10% change in annual rainfall. Understanding how climate controls recharge under the observed historical climate allows more informed choices of analogue sites if they are to be used for climate change impact assessments.

COMPARISON OF DEVELOPED AND PREVIOUSLY PUBLISHED UNIVARIATE MODELS FOR ESTIMATING EROSIVITY IN A COUNTRY WITH MEDITERRANEAN RAINFALL REGIME

2020 ◽  
Vol 51 (4) ◽  
pp. 1015-1024
Author(s):  
Keya & Karim
Keyword(s):  
Soil Conservation ◽  
Water Erosion ◽  
Annual Rainfall ◽  
Rainfall Regime ◽  
Rainfall Erosivity ◽  
Study Region ◽  
Precipitation Concentration Index ◽  
Explanatory Variables ◽  
Soil Conservation Measures ◽  
Rainfall Regimes

Information on the degree of water erosion is of imperative importance to professionals who are engaged in reducing soil losses via implementing soil conservation measures. Soil Conservation requires the knowledge of the factors controlling soil loss. Rainfall erosivity is one of the major controlling factors inducing water erosion. To achieve this objective, several univariate models were developed to estimate the rainfall erosivity in the upper part of Iraq. The database for models development was based on rainfall data of different time scales obtained from 25 stations distributed across the study region. The explanatory variables encompassed annual rainfall (P), Fournier index (FI), modified Fournier index (MFI) and precipitation concentration index (PCI). Additionally, the performance of a host of previously published univariate models were evaluated. Most of these models were derived for countries with Mediterranean rainfall regimes. It was observed that neither FI nor the PCI approaches were effective in capturing the variability of rainfall erosivity in the study area. Overall, the annual rainfall based models outperformed the Fournier and modified Fournier based models. The results also indicated that among eight developed models, the quadratic and linear forms of annual rainfall based models ranked first and second respectively. Additionally, the test of performance of a host of previously published models revealed they have restricted applications in Iraq.

Sign in / Sign up

Export Citation Format

Share Document