C O N T E N T S - Physical Land Resources - Vrije Universiteit Brussel

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characteristics of the geological formations which host groundwater. Aquifer testing ateach borehole consists of two phases: (a) a step drawdown test, followed by (b) aconstant discharge test. The step drawdown test is conducted to evaluate the efficiencyof the constructed well, and how it performs under different pumping regimes.Compaction of aquifer material by the drilling process, plugging of the walls of theborehole by drilling mud, incorrectly sized and placement of filter material, incorrectscreen type or width all contribute in lowering the water level in the well. Each of thesefactors has a negative impact, increasing the rate of lowering of the water level, whencompared to the expected drawdown in the water level based on theoretical grounds.The constant discharge test, which usually normally lasts 24 hours is conducted tomeasure how the well will perform under likely operational conditions and to make adetermination of aquifer characteristics. This allows some indication as to the longtermimpact on the aquifer and its performance on the operation of the well. Analysisof data is thus normally done using the Jacob straight-line method, assuming therequired assumptions are met. In this research, Characterization of the Well-Field atWangwa farms, Chisamba area, Zambia is done by interpretation and analysis of datafrom thirty three (33) single-well pumping tests, and by using geostatistics tocharacterize the spatial distribution of transmissivity. VarioWin and GSLIB for Windows,geostatistical software is used to interpolate the calculated transmissivity at Wangwafarms. Hydraulic step tests indicates that, most of the wells tested are affected by thewell losses (12 Wells with less than 30% efficiency), while at 7 wells the aquifer is thedominant factor with well efficiency of more than 50%, 8 wells are affected by both thewell losses and aquifer losses factors. The limited data at the remaining 5 wellsprecludes a determination, and the cause is mainly due to non stabilization of the stepsduring pumping. The results of the tests indicates that the aquifer is confined andfractured (double-porosity), and the spatial structure from geostatistical interpolationreveals that high transmissive area are associated with structural lineaments andcontacts of geological formations.- 36 -
PhD. Theses 2007LE QUOC HungIntegrated Analysis of Sub-Tropical Mountain Karst Geohydrology in NWVietnam by Field and Multisource Remotely Sensed DataPromotor: F. De SmedtRemotely sensed data has become an important source for geoscientists to understandthe earth. With the rapidly growing availability of remotely sensed data and fieldsurveys, there is an urgent demand to interpret and analyze these data. Remote sensingis a promising technology to support geohydrological studies, mainly because of thepotential to observe areas and entire river basins rather than single points. With thesuccesful development of computer science, geographic information systems (GIS) andimage processing systems, it has become feasible to digitally interpret multiple types ofremotely sensed and thematic map data. In spite of this promise, the application ofremote sensing in geohydrological studies has been slow, especially in developingcountries. This work aims to develop and apply integrated methods combining theinformation obtained by geohydrological field mapping and those obtained byanalyzing multi-source remotely sensed data in a GIS environment for betterunderstanding the geohydrological characteristics of the sub-tropical vegetated karstregion in Vietnam. The study focuses on two important mountainous areas: Suoimuoicatchment and Tamduong valley. Remote sensing analyses are applied, which includelineament analysis and its application for fractured zone studies, fusion method andgeological mapping.An effective approach for the delineation of fracture zones is based on lineamentindices extracted from satellite imagery. The complete procedure of lineament analysisconsists of four steps: (1) extraction, (2) correction, (3) indices and lineament indicesdensities, (4) fractured zone definition. The accuracy of extracted lineaments dependsstrongly on the spatial resolution of the imagery. The most suitable band for lineamentextraction in the Suoimuoi catchment is the NIR band. It is tested and shown here thatextracted lineaments from the NIR ASTER imagery are considerably less noisy and showa higher accuracy than lineaments extracted from other imagery. Three lineamentindices are defined as: (1) lineament frequency, (2) length, and (3) intersection. Therelationship between fractured rock and groundwater is investigated. However, a highlevel of fractured rock does not guarantee the presence of groundwater in the Suoimuoi- 37 -
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Page 8 and 9: * ManagementIUPWARE's management co
Page 10 and 11: an assessment on the basis of these
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Page 18 and 19: NGOC MAI KimEstuarine Energy Evalua
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Page 26 and 27: TESFAGIORGIS Kibrewossen BirhanuGro
Page 28 and 29: * Theses promoted by KULDHIRAY K. C
Page 30 and 31: PHYLARES MSc. ThesesAcademic Year 2
Page 32 and 33: LE HOANG NguyenThe Initial UNESCO
Page 34 and 35: SHAHEEN SamiNitrate Pollution and G
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Page 40 and 41: concentrations were on average abou
Page 42 and 43: Transient simulations, which encomp
Page 44 and 45: is calibrated and validated on part
Page 46 and 47: Climate Change Induced Tidal Flat M
Page 48 and 49: eak the inter particle bonds. Final
Page 50 and 51: development. Achieving a healthy, s
Page 52 and 53: Measuring and Modelling the Impact
Page 54 and 55: the WetSpa model. The modifications
Page 56 and 57: Suspended Solids and Sediments in t
Page 58 and 59: occurring along large parts of the
Page 60 and 61: Geology and Mineral Resources (RIGM
Page 62 and 63: Technical support for the modelling
Page 64 and 65: progress of the PhD research of Tes
Page 66 and 67: geosciences and water resources man
Page 68 and 69: Dr. Jim Butler 2007 Darcy lecturer
Page 70 and 71: 7. PUBLICATIONS and PRESENTATIONSFo
Page 72 and 73: Batelaan, O. and F. De Smedt, 2007.
Page 74 and 75: Nel, J.M., Xu, Y. and O. Batelaan,
Page 76 and 77: C. Anibas presented ‘Determinatio
Page 78 and 79: LIST OF PUBLICATIONS IN THE SERIES"
Page 80 and 81: 8. MEMBERS OF THE LABORATORY ON 31.
Page 82 and 83: etween governments, private sector,
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C O N T E N T S - Physical Land Resources - Vrije Universiteit Brussel

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