scholarly journals Analysis of trend rainfall: Case of North-Eastern Algeria

2018 ◽  
Vol 36 (1) ◽  
pp. 105-115 ◽  
Author(s):  
Dounia Mrad ◽  
Yassine Djebbar ◽  
Yahia Hammar

AbstractThe climatic change is a reality largely recognized today in the scientific community. Nevertheless, its impact on precipitation, especially on annual, monthly and seasonally rainfall in arid and semi-arid regions is not yet certain. Indeed, very few studies have dealt with this matter in Algeria.In this context to examine spatial distribution of annual and seasonal rainfall an attempt has been made using the inverse distance weighting (IDW) method. Trends and magnitude estimate of change in rainfall series were detected by Mann–Kendall tests and Sen's test slope, has been applied to the data registered of 35 stations in the watershed Constantinois Seybouse Mellegue (CSM) North-Eastern Algeria over a period of 43 years (1969–2012).Results from spatial plot of annual rainfall showed that the rainfall increases with altitude, but is higher for the stations exposed to moist winds. It also increases from east to west and conversely decreases as one moves away from the coast to the south. From statistical method showed that there are increase trends at 95% confidence at annual scale in some rainfall stations with high altitude and coastal stations during winter season.

2020 ◽  
Vol 7 (3) ◽  
pp. 85-105
Author(s):  
HADJAB RAMZI ◽  
KHAMMAR HICHEM ◽  
REDJAIMIA LYLIA ◽  
MERZOUG DJEMOI ◽  
SAHEB MENOUAR

Groundwater of Oum-El-Bouaghi and its surroundings hosts a variety of microflora and fauna. This study investigated the relationship between the effect of human activity and the biodiversity and distribution of aquatic fauna in two semi-arid regions Sighus region (Oum-El-Bouaghi) and El Rahmouni (Constantine) in north-eastern Algeria. Fourteen wells and six springs were studied in two hydrographic basins, that of Constantine and Seybouse Melegue. Significant differences were revealed between the wells and springs in the two watersheds, making it possible to distinguish four groups of wells and two groups of springs. The overall faunal richness of the stations appeared to be weakly correlated with water quality, but on the other hand, the specific richness of the stygoby fauna, and even more so the abundance of stygoby species, decreased when water quality deteriorated.


1977 ◽  
Vol 13 (3) ◽  
pp. 217-223 ◽  
Author(s):  
A. Hadjichristodoulou

SUMMARYThere were significant differences in dry matter yield among five forage oat varieties tested at ten environments during 1970–75. The correlation coefficients between annual rainfall and DM yield varied with variety from 0·69 to 0·88, late varieties tending to give higher yields. Lateness, and high varietal response to annual rainfall and improved environmental conditions, can be used as selection criteria in semi-arid regions. Late varieties had higher DM and lower crude protein contents, and forage produced under lower rainfall conditions tended to have more DM and crude protein.


2020 ◽  
Vol 163 (3) ◽  
pp. 1247-1266 ◽  
Author(s):  
Hagen Koch ◽  
Ana Lígia Chaves Silva ◽  
Stefan Liersch ◽  
José Roberto Gonçalves de Azevedo ◽  
Fred Fokko Hattermann

AbstractSemi-arid regions are known for erratic precipitation patterns with significant effects on the hydrological cycle and water resources availability. High temporal and spatial variation in precipitation causes large variability in runoff over short durations. Due to low soil water storage capacity, base flow is often missing and rivers fall dry for long periods. Because of its climatic characteristics, the semi-arid north-eastern region of Brazil is prone to droughts. To counter these, reservoirs were built to ensure water supply during dry months. This paper describes problems and solutions when calibrating and validating the eco-hydrological model SWIM for semi-arid regions on the example of the Pajeú watershed in north-eastern Brazil. The model was calibrated to river discharge data before the year 1983, with no or little effects of water management, applying a simple and an enhanced approach. Uncertainties result mainly from the meteorological data and observed river discharges. After model calibration water management was included in the simulations. Observed and simulated reservoir volumes and river discharges are compared. The calibrated and validated models were used to simulate the impacts of climate change on hydrological processes and water resources management using data of two representative concentration pathways (RCP) and five earth system models (ESM). The differences in changes in natural and managed mean discharges are negligible (< 5%) under RCP8.5 but notable (> 5%) under RCP2.6 for the ESM ensemble mean. In semi-arid catchments, the enhanced approach should be preferred, because in addition to discharge, a second variable, here evapotranspiration, is considered for model validation.


2012 ◽  
Vol 518-523 ◽  
pp. 4489-4495
Author(s):  
Liang Ma ◽  
Chang Qing Zuo

Rainfall erosivity is an essential factor to reveal the response of water erosion to precipitation changes, and its spatial variation reveals erosion regional difference and water conservation regionalization. In this research, average annual rainfall erosivity in 1951 -2008 on China mainland is calculated through daily precipitation data from 711 meteorological stations. Precisions of 29 spatial interpolation models are quantitative compared including inverse distance weighting (IDW), radial basis function (RBF), kriging, cokriging (CK) and thin plate smoothing spline (TPS). Three variables cubic TPS is confirmed the optimum spatial interpolation model to rainfall erosivity on a large scale.


2020 ◽  
Vol 7 (3) ◽  
pp. 16-34 ◽  
Author(s):  
Redjaimia Lylia ◽  
Hadjab Ramzi ◽  
Khammar Hichem ◽  
Merzoug Djemoi ◽  
Saheb Menouar

The biodiversity and quality of subterranean waters were comparatively studied in the Tarf plain near Oum-El-Bouaghi and in the Ksar S’bahi in Oum-El-Bouaghi, in North-eastern Algeria. For this purpose, physicochemical and faunistic analyses were carried out on the water of ten stations located in the area of Tarf, and thirteen in the area of S’bahi. In the wells of Tarf, the average stygobiologic diversity was relatively high in the wells located upstream the dumping site from the city where the groundwater presented low contents of nitrates and orthophosphates. In contrast, the wells located in the spreading zone of Tarf wastewaters were characterized by the scarcity or the absence of stygobic species; in these latter wells, the water was highly polluted. It was rich in nitrates, nitrites, ammonium, and the conductivity was rather high. In the area of S’bahi, the faunistic inventory recorded ten species, some of which were living in hot springs. The subterranean water was highly mineralized. In the two studied areas, biodiversity decreased when well water was locally polluted.


1967 ◽  
Vol 5 (4) ◽  
pp. 139-143 ◽  
Author(s):  
E. R. Hoare

A land area can be considered semi-arid if it has an annual rainfall of less than 15 inches and if the evaporation from a water surface exceeds 45 inches. Such areas, under irrigation, can be highly productive agriculturally and can also provide congenial living conditions. The extension of irrigation to new territories could contribute greatly to feeding and clothing the world's population.


2014 ◽  
Vol 37 (5) ◽  
pp. 368-375 ◽  
Author(s):  
Nassira Riah ◽  
Gilles Béna ◽  
Abdelhamid Djekoun ◽  
Karine Heulin ◽  
Philippe de Lajudie ◽  
...  

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