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Featured researches published by Sven Knutsson.


Central European Journal of Engineering | 2014

Modeling the risk of groundwater contamination using modified DRASTIC and GIS in Amman-Zerqa Basin, Jordan

Abdulla M. Al-Rawabdeh; Nadhir Al-Ansari; Ahmed A. Al-Taani; Fadi L. Alkhateeb; Sven Knutsson

Amman-Zerqa Basin (AZB) is the second largest groundwater basin in Jordan with the highest abstraction rate, where more than 28% of total abstractions in Jordan come from this basin. In view of the extensive reliance on this basin, contamination of AZB groundwater became an alarming issue. This paper develops a Modified DRASTIC model by combining the generic DRASTIC model with land use activities and lineament density for the study area with a new model map that evaluates pollution potential of groundwater resources in AZB to various types of pollution. It involves the comparison of modified DRASTIC model that integrates nitrate loading along with other DRASTIC parameters. In addition, parameters to account for differences in land use and lineaments density were added to the DRASTIC model to reflect their influences on groundwater pollution potential. The DRASTIC model showed only 0.08% (3 km2) of the AZB is situated in the high vulnerability area and about 30% of the basin is located in the moderately vulnerable zone (mainly in central basin). After modifying the DRASTIC to account for lineament density, about 87% of the area was classified as having low pollution potential and no vulnerability class accounts for about 5.01% of the AZB area. The moderately susceptible zone covers 7.83% of the basin’s total area and the high vulnerability area constitutes 0.13%. The vulnerability map based on land use revealed that about 71% of the study area has low pollution potential and no vulnerability area accounts for about 0.55%, whereas moderate pollution potential zone covers an area of 28.35% and the high vulnerability class constitutes 0.11% of AZB. The final DRASTIC model which combined all DRASTIC models shows that slightly more than 89% of the study area falls under low pollution risk and about 6% is considered areas with no vulnerability. The moderate pollution risk potential covers an area of about 4% of AZB and the high vulnerability class constitutes 0.21% of the basin. The results also showed that an area of about 1761 km2 of bare soils is of low vulnerability, whereas about 28 km2 is moderately vulnerable. For agriculture and the urban sector, approximately 1472 km2 are located within the low vulnerability zone and about 144 km2 are moderately vulnerable, which together account for about 8% of the total agriculture and urban area. These areas are contaminated with human activities, particularly from the agriculture. Management of land use must be considered when changing human or agricultural activity patterns in the study area, to reduce groundwater vulnerability in the basin. The results also showed that the wells with the highest nitrate levels (81–107 mg/l) were located in high vulnerable areas and are attributed to leakage from old sewage water.


Journal of Hydrologic Engineering | 2013

Water Harvesting and Reservoir Optimization in Selected Areas of South Sinjar Mountain, Iraq

Nadhir Al-Ansari; Mohammad Ezz-Aldeen; Sven Knutsson; Saleh Zakaria

AbstractIraq is experiencing water-resource shortages which are expected to become more severe in the future. It is believed that rainwater harvesting will be one of the solutions to overcome this problem. In this paper, rainwater harvest modeling techniques were applied to the Sinjar area of northwest Iraq for agricultural purposes. A watershed modeling system (WMS) and linear programming (LP) optimization techniques were applied to maximize the irrigated area, which could be supplied by each selected reservoir for the period 1990–2009. This technique proved to be efficient for solving large-scale water supply problems with multiple parameters and constraints, including the required input data for the model. Two scenarios of operation were considered for each main basin. In the first, each reservoir was operated as a separate unit while, in the second, all reservoirs within the basin were operated as one system. Both scenarios gave encouraging results but Scenario 2 provided better results.


Gff | 1990

Origin of silty fracture fillings in crystalline bedrock

Roland Pusch; Lennart Börgesson; Sven Knutsson

Abstract Silty fillings in subhorizontal fractures of large area are occasionally found at shallow depth in Swedish bedrock. The soil was deposited after widening of the fractures due to the rock stress conditions at the edge of retreating ice sheets, a probable further implication being artesian conditions leading to hydraulic lifting. It is concluded that if the rate of ice retreat was sufficiently high, the basal part of the ice would be adfrozen to still frozen rock, and highly pressurized meltwater discharged through interconnected, steep and flat-lying fractures, which became filled with soil material transported with the water.


Waste Management & Research | 2016

Landfill site selection using geographic information system and analytical hierarchy process: A case study Al-Hillah Qadhaa, Babylon, Iraq

Ali Chabuk; Nadhir Al-Ansari; Hussain Musa Hussain; Sven Knutsson; Roland Pusch

Al-Hillah Qadhaa is located in the central part of Iraq. It covers an area of 908 km2 with a total population of 856,804 inhabitants. This Qadhaa is the capital of Babylon Governorate. Presently, no landfill site exists in that area based on scientific site selection criteria. For this reason, an attempt has been carried out to find the best locations for landfills. A total of 15 variables were considered in this process (groundwater depth, rivers, soil types, agricultural land use, land use, elevation, slope, gas pipelines, oil pipelines, power lines, roads, railways, urban centres, villages and archaeological sites) using a geographic information system. In addition, an analytical hierarchy process was used to identify the weight for each variable. Two suitable candidate landfill sites were determined that fulfil the requirements with an area of 9.153 km2 and 8.204 km2. These sites can accommodate solid waste till 2030.


Hydrological Sciences Journal-journal Des Sciences Hydrologiques | 2013

Sedimentation and new operational curves for Mosul Dam, Iraq

Issa E. Issa; Nadhir Al-Ansari; Sven Knutsson

Abstract Mosul Dam is one of the biggest hydraulic structures in Iraq. Its storage capacity is 11.11 × 109 m3 at a maximum operation level of 330 m a.s.l. The dam became operational in 1986 and no survey has been conducted to determine its storage capacity and establish new operational curves since this date. A topographic map of scale 1:50 000 dated 1983 was converted into triangulated irregular network (TIN) format using the ArcGIS program to evaluate the operational curves. Then the reservoir was surveyed in 2011 to establish the reduction in its storage capacity and to develop new operational curves. The results indicated that the reduction in the storage capacity of the reservoir was 14.73%. This implies that the rate of sedimentation within the reservoir was 45.72 × 106 m3 year−1. These results indicate that most of the sediment was deposited within the upper zone of the reservoir where the River Tigris enters the reservoir. Editor D. Koutsoyiannis Citation Issa, E.I., Al-Ansari, N., and Knutsson, S., 2013. Sedimentation and new operational curves for Mosul Dam, Iraq. Hydrological Sciences Journal, 58 (7), 1456–1466.


Central European Journal of Engineering | 2014

Long term effect of climate change on rainfall in northwest Iraq

Nadhir Al-Ansari; Mawada Abdellatif; Salahalddin S. Ali; Sven Knutsson

Middle East, like North Africa, is considered as arid to semi-arid region. Water shortages in this region, represents an extremely important factor in stability of the region and an integral element in its economic development and prosperity. Iraq was an exception due to presence of Tigris and Euphrates Rivers. After the 1970s the situation began to deteriorate due to continuous decrease in discharges of these rivers, are expected to dry by 2040 with the current climate change. In the present paper, long rainfall trends up to the year 2099 were studied in Sinjar area, northwest of Iraq, to give an idea about its future prospects. Two emission scenarios, used by the Intergovernmental Panel on Climate Change (A2 and B2), were employed to study the long term rainfall trends in northwestern Iraq. All seasons consistently project a drop in daily rainfall for all future periods with the summer season is expected to have more reduction compared to other seasons. Generally the average rainfall trend shows a continuous decrease. The overall average annual rainfall is slightly above 210 mm. In view of these results, prudent water management strategies have to be adopted to overcome or mitigate consequences of future severe water crisis.


Journal of civil engineering and architecture | 2014

Climate Change and Future Long-Term Trends of Rainfall at North-East of Iraq

Nadhir Al-Ansari; Mawada Abdellatif; Mohammad Ezeelden; Salahalddin S. Ali; Sven Knutsson

Iraq is facing water shortage problem despite the presence of the Tigris and Euphrates Rivers. In this research, long rainfall trends up to the year 2099 were studied in Sulaimani city northeast Iraq to give an idea about future prospects. The medium high (A2) and medium low B2 scenarios have been used for purpose of this study as they are more likely than others scenarios, that beside the fact that no climate modeling canter has performed GCM (global climate model) simulations for more than a few emissions scenarios (HadCM3 has only these two scenarios) otherwise pattern scaling can be used for generating different scenarios which entail a huge uncertainty. The results indicate that the average annual rainfall shows a significant downward trend for both A2 and B2 scenarios. In addition, winter projects increase/decrease in the daily rainfall statistics of wet days, the spring season show very slight drop and no change for both scenarios. However, both summer and autumn shows a significant reduction in maximum rainfall value especially in 2080s while the other statistics remain nearly the same. The extremes events are to decrease slightly in 2080s with highest decrease associated with A2 scenario. This is due to the fact that rainfall under scenario A2 is more significant than under scenario B2. The return period of a certain rainfall will increase in the future when a present storm of 20 year could occur once every 43 year in the 2080s. An increase in the frequency of extreme rainfall depends on several factors such as the return period, season of the year, the period considered as well as the emission scenario used.


Journal of Water Resource and Protection | 2014

Future Prospects for Macro Rainwater Harvesting (RWH) Technique in North East Iraq

Nadhir Al-Ansari; Mawada Abdellatif; Saleh Zakaria; Yaseen T. Mustafa; Sven Knutsson

Countries in Middle East and North Africa (MENA region) are considered as arid and semi-arid areas that are suffering from water scarcity. They are expected to have more water shortages problem due to climatic change. Iraq is located in the Middle East covering an area of 433,970 square kilometers populated by 31 million inhabitants. One of the solutions suggested to overcome water scarcity is Rainwater Harvesting (RWH). In this study Macro rainwater harvesting technique had been tested for future rainfall data that were predicted by two emission scenarios of climatic change (A2 and B2) for the period 2020-2099 at Sulaimaniyah Governorate north east of Iraq. Future volumes of total runoff that might be harvested for different conditions of maximum, average, and minimum future rainfall seasons under both scenarios (A2 and B2) were calculated. The results indicate that the volumes of average harvested runoff will be reduced when average rainfall seasons are considered due to the effect of climatic change on future rainfall. The reduction reached 10.82 % and 43.0% when scenarios A2 and B2 are considered respectively.


Journal of civil engineering and architecture | 2013

Medium-Deep or Very Deep Disposal of Highly Radioactive Waste?

Roland Pusch; Gunnar Ramqvist; Sven Knutsson; Mohammed Hatem Mohammed

Commonly proposed concepts, like KBS-3V, for disposal of highly radioactive waste imply construction at medium depth (400-600 m) in granitic rock, which is excellent for constructing a stable repository. VDH (very deep boreholes) represent an alternative concept with the advantage that the rock is much less permeable and that the very salt, heavy groundwater is stagnant. Both require engineered barriers in the form of canisters and waste-embedding clay but for somewhat different purposes. Canisters are the most important waste-isolating barriers for KBS-3V but are less important for VDH. The waste-embedding clay is needed for preserving the KBS-3V canisters by being tight and ductile, but plays a minor role for the VDH. The backfilled deposition tunnels in a KBS-3V repository provide very limited hindrance of radionuclides to move to the biosphere while the clay seals of VDH effectively prevent possibly released radionuclides to reach up to the biosphere. Comparison of the KBS-3V and VDH concepts indicates that the last mentioned one has several advantages but that certain issues remain to be worked on for becoming a number one candidate.


Geotechnical Testing Journal | 1994

An image analysis method for studying movements in granular and solid bodies

L. Gustafsson; Sven Knutsson

A method based on image analysis of video recordings is presented for studying and measuring movements in granular materials. The method is easy to use, does not require any tracers, and makes extensive experiments feasible. Calibration tests show good repeatability. Measurements are presented of movements in a sand mass into which a piston is driven. The method is also useful for studying the deformation of solid bodies. The deformation of undrained clay specimens subjected to uniaxial forces is demonstrated using the proposed method.

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Nadhir Al-Ansari

Luleå University of Technology

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Roland Pusch

Luleå University of Technology

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Varoujan Sissakian

Luleå University of Technology

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Jan Laue

Luleå University of Technology

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Issa E. Issa

Luleå University of Technology

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Roland Pusch

Luleå University of Technology

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Peter Viklander

Luleå University of Technology

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Hans Mattsson

Luleå University of Technology

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Mohammed Hatem Mohammed

Luleå University of Technology

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