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Noureddine Merniz, Ali Tahar and Amine M. Benmehaia

Abstract

In the present study, time series for annual, monthly rainfall and number of rainy days per year were analysed to quantify spatial variability and temporal trends for 22 rainfall stations distributed in northeastern Algeria for the period 1978–2010. The Mann–Kendall test and the Sen’s slope estimator were applied to assess the significance and magnitude of the trend. The results showed that precipitation decreases spatially from North to South and from East to West. The application of the Mann–Kendall test (for 0.05% threshold) to the time series data showed that for annual precipitation, no station showed statistically significant trends, unlike the number of rainy days, where there was a significant negative trend in four stations (Jijel, Constantine, Oum El Bouaghi and Tébessa). For the monthly time series, significant positive trends were observed during the months of September in the coastal stations and July for the plateaus and southern Saharan Atlas stations, while significant negative trends were recorded during the months of February and March for the stations of the extreme East in the study area. These results revealed that for the period analysed, there was no significant climate change in northeastern Algeria but there is a seasonal delay having important agroecological implications.

Open access

Rustinsyah Rustinsyah and Ratna A. Prasetyo

Abstract

The fostering and empowerment of water user associations (WUAs) has been regulated by the Minister of Agriculture since 2012. However, the implementation of this guideline varies. Some water user associations have achieved improvement, while some others have not. This study discusses how a WUA in the villages that use Bengawan Solo River water has successfully managed the irrigation. One of the factors leading to the success of this WUA is the stakeholder engagement in the agricultural irrigation management and farm business. This study was conducted from June 2016 to June 2017 by employing a qualitative approach. It aimed to identify and understand the stakeholder engagement in agricultural irrigation management by: 1) conducting an analysis on stakeholder power and interest indices, 2) mapping the positions, responsibilities, and obligations of stakeholders, and 3) identifying the stakeholder engagement in agricultural irrigation management. The research results are as follows: a) the analysis using Likert scale showed that the power index reached a value of 0.76, while the interest index reached a value of 0.78; b) the mapping of internal stakeholders, especially the responsibilities and obligations, has been regulated under the Articles of Incorporation of WUAs and obligations of external stakeholders, especially the government in making government regulations, irrigation infrastructure support, and flood prevention; c) cooperation of the stakeholders has an important role in the agricultural irrigation management and in solving the problems faced by WUAs.

Open access

Chokri Bedoui

Abstract

This study was conducted with a view to quantifying soil erosion in arid lands of Tunisia. To do this, we have opted to use the RUSLE model based on geographic information systems. By collecting data on rainfall, soils, vegetation, slopes and conservation practices separately as a layer and determining the pixel values for each of these factors, a quantified assessment of erosion in the basin is obtained. The data superposition and computing, following the model equations and protocol, allowed us to know the spatialized water erosion values at the pixel level. For the whole catchment, the study showed values oscillating between 0 and 163 Mgꞏha−1ꞏyear−1 with an average annual rate of 3 Mgꞏha−1ꞏyear−1. With such a low R (rainfall erosivity) factor (between 21.43 and 21.88 MJꞏmmꞏha–1ꞏh–1ꞏyear–1) itself related to low monthly and annual rainfall amounts, the region experiences locally very high annual erosion rates. Soil protection through conservation practices has saved the basin from even higher erosion. While plains cultivated and equipped with contour benches often suffer from low rates of erosion (less than 2 Mg·ha–1·year–1), unused slopes are neglected without protection, resulting in significantly high rates of erosion.

Open access

Małgorzata Gałczyńska, Natalia Mańkowska, Justyna Milke and Marta Buśko

Abstract

The paper presents the assessment of possibilities and limitations of the use of Lemna minor, Hydrocharis morsus-ranae and Ceratophyllum demersum in removing metals from contaminated waters. Synthetically discussed the role of these species in phytotechnology and their importance in the assessment of surface water status. The variability of concentration of selected metals in waters and the content of metals in the organs of the analysed plants are presented. Their advantages and disadvantages in removing metals from waters due to biological features have been characterized. Minimum and maximum efficiency of metal removal depending on the scale of water pollution was determined. It was found that analysed plants can be used for phytoremediation of metals from water, but the limitation of effectiveness of treatments is the toxicity of these metals to plants and the time of exposure. The highest removal efficiency can be obtained thanks to the use of sequences of single-species filtration systems.

Open access

Marian Poniewiera, Iwona Jelonek and Wioleta Błaszczak-Bąk

Abstract

The purpose of the work described in the article was to find the optimal location of the pumping station for the mining area Krzyżowice III Hard Coal Mine “Pniówek”. Mining exploitation causes lowering of the area and changes in water relations. Hence, it is necessary to perform a gravitational, and if it is impossible, forced outflow of water. Localization of the pumping station should assure removal of excess water and prevent flooding. Not only was the present relief taken into account, but also the entire period of the mine’s existence. On the basis of the results of airborne laser scanning a digital terrain model (DTM) was generated. Then a catchment division was made for the entire analyzed area. The article presents the workflow of performing the simulation as the area will be changed due to forecasted mining operations. A practical way to solve the problem of simplifying large amounts of data was also shown. The obtained source materials were developed with the use of the Geolisp software. The system operates in a CAD graphic environment and allows for automation of the most frequently performed works in the field of mining map preparation. The Geolisp cooperates with EDN-OPN program. Thanks to this fact it is possible to combine the obtained results of calculations of predicted deformations of the mining area and the rock mass with the digital map.

Open access

Bogumił M. Nowak and Mariusz Ptak

Abstract

The article presents the analysis of water level fluctuations in Lake Powidzkie in the years 1961–2015. The study shows a considerable decrease in mean water levels in the aforementioned multiannual period, averaging 9 cmꞏdecade−1. Such a situation is caused by natural as well as anthropogenic factors, co-determining water relations in the study area. The natural factors include the amount and distribution of precipitation, increase in air temperature and evaporation size, unfavourable relations between the lake and catchment or hydrogeological conditions. Anthropogenic factors particularly include long-term transformations of the natural environment in the region, currently associated with meliorations accompanying the nearby opencast brown coal mines and exploitation of groundwaters for municipal purposes. Water shortages occurring during dry periods were shown not to be compensated in the study area in humid years. This is particularly related to the regional lowering of the aquifer remaining in close relations with Lake Powidzkie. Counteracting the unfavourable hydrological situation is done through hydrotechnical infrastructure which partially limits water outflow from the lake through damming.

Open access

Krzysztof Micun and Sławomir Roj-Rojewski

Abstract

The aim of the study was to determine the morphological characteristics of selected spring-heads in the Knyszyńska Primeval Forest and to identify lithological conditions in areas where groundwater flows to the surface. During the study, detailed bed level measurements of the spring-head areas were conducted. Lidar laser data obtained from the Central Department of Geodetic and Cartographic Documentation in Warsaw were also used for the analysis of morphometry. Based on the data, the detailed contour maps were created in the Surfer 12 programme and the basic parameters of the morphometry of the studied springs were determined. To detect lithological conditions, granulometric analyses were conducted and the filtration coefficient of aquifers in the individual spring-heads was calculated using Hazen and USBSC empirical models. Due to the morphological situation, the examined objects were classified as sub-slope and riverbank spring-heads. In terms of shape, spring-head alcoves are classified as basin-shaped, bowl-shaped and spindle-shaped alcoves. Different morphological processes prevail in each of these types. Basin-shaped alcoves are formed mainly by lateral erosion, bowlshaped alcoves by seepage erosion, landsliding and accumulation in the bottom, spindle-shaped alcoves by seepage erosion, headward erosion, breaking and collapsing. In the investigated outflows of groundwater aquifers are sands and glacifluvial sands with gravel of varying grain size. The lithological variation of aquifers in the spring-heads, directly affects the rate of groundwater filtration in different parts of the alcoves, which in turn leads to different morphogenetic processes and results in changes in the morphology of the spring-head alcoves.

Open access

Fares Laouacheria, Said Kechida and Moncef Chabi

Abstract

Flood modelling is an effective way to manage the stormwater network in cities. It aims to understand and predict the behaviour of stormwater network so that it can test and evaluate effective solutions to structural and operational problems. So simulation modelling stays a preoccupation for building a successful hydraulic modelling in urban areas. This study investigates the impact of the design rainfall on the hydraulic modelling results for the Azzaba stormwater network located in the North-East of Algeria by using the Storm Water Management Model (SWMM). Four scenarios of design rainfall events were compared for 10, 25 and 50-year return periods, where we used double triangle and composite curves for the design rainfall event definition. The results show the impact of the choice of design rainfall on the behaviour of the stormwater network, from which the results of simulation by the double triangle method for the short durations represents a great risk on the probability that the stromwater network can overflow and flood the city, with a difference in peak discharge estimated at 62.97% and 58.94% for 2 h and 3 h events compared to the peak discharge simulated by the composite rainfall method.

Open access

Cherif Rezzoug

Abstract

To resist against a hostile environment, the oases of Saoura developed ingenious techniques of catchment and sharing of water to exploit the rare and precious waters of the groundwater. But the intervention of modern irrigation techniques has disrupted the entire oasis system inside the oasis such as the spring, the palm grove and the ksar. These techniques have overexploited the groundwater supplying the palm grove in terms of quantity and quality.

For centuries, the oases of Mougheul used only the source (with a flow of 25 dm3∙s−1 in 2001) which is inside the oasis to irrigate the parcels and herds. After the year 2005, the state decided to supply the city of Bechar with drinking water through the catchment field of Mougheul through five modern boreholes, which had a profound impact on the oasis, its surroundings, and the whole artesian source.

In this work, we study the impact of the use of modern catchment systems on the water source and the life of the Mougheul population. By interviewing farmers and landowners about the impact of groundwater scarcity on the oasis. This allowed knowing the current state of the oasis and the reasons for its deterioration.

Open access

Fatima Zahra Merzougui, Ahmed Makhloufi and Touhami Merzougui

Abstract

The article analyses the water quality of the Lower Cretaceous aquifer in the Beni-Ounif syncline. To this end, 42 samples were taken for physico-chemical analysis and 28 for microbiological analysis in March, May and October 2017 from 14 sampling points. The results of physico-chemical analysis were processed by multi-variety statistical analysis methods: principal component analysis (PCA) and hierarchical cluster analysis (HCA) coupled to hydro chemical methods: Piper diagram.

The PCA allowed us to explore the connections between physico-chemical parameters and similarities between samples and to identify the most appropriate physico-chemical elements to describe water quality.

The HCA allowed us to classify the sampling points according to the similarity between them and thus reduce them for the next follow-up analysis.

Waters of the syncline are characterized by medium to low mineralization (320 < EC < 7600 μS∙cm–1 and 200 < RS < 4020 mg∙dm−3) and hardness of between 22 and 123°f. Only 19% of the samples show NO3 concentrations exceeding the Algerian standards.

Microbiologically, the study reports the presence of bacteria: coliforms (<8 CFU∙0.1 dm−3), Streptococcus D (<1100 CFUꞏ0.1 dm–3), Clostridium sulphito-reducer of vegetative form (<90 CFUꞏ0.02 dm–3) and sporulate (<4 CFUꞏ0.02 dm–3), total aerobic mesophilic flora at 22°C (<462 CFUꞏ0.001 dm–3) and at 37°C (<403 CFUꞏ0.001 dm–3). It must be noted that no presence of thermo-tolerant coliforms is observed.