Geostatistical tools for better characterization of the groundwater quality [Elektronische Ressource] : case studies for the coastal quarternary aquifers in the Nam Dinh area/Vietnam / vorgelegt von Hoang Duc Nghia

Do Minh Si

Informations

• Publié par: ernst-moritz-arndt-universitat_greifswald
• Publié le: 01 janvier 2008
• Nombre de lectures: 24
• Langue: Deutsch
• Poids de l'ouvrage: 7 Mo

Extrait

GEOSTATISTICAL TOOLS FOR BETTER
CHARACTERIZATION OF THE GROUNDWATER
QUALITY – CASE STUDIES FOR THE COASTAL
QUATERNARY AQUIFERS
IN THE NAM DINH AREA/VIETNAM




I n a u g u r a l d i s s e r t a t i o n

zur

Erlangung des akademischen Grades

doctor rerum naturalium (Dr. rer. nat.)

an der Mathematisch-Naturwissenschaftlichen Fakultät

der

Ernst-Moritz-Arndt-Universität Greifswald


vorgelt von

Hoang Duc Nghia

geboren am 01, January, 1977

in Hue, Vitnam

Greifswald, 2008


































Dekan: ....................................................................................................................


1. Gutachter : ....................................................................................................................

2. Gutachter: ....................................................................................................................


Tag der Promotion: ................................................................................................................
Erklärung






Hiermit erkläre ich, daß diese Arbeit bisher von mir weder an der Mathematisch-
Naturwissenschaftlichen Fakultät der Ernst-Moritz-Arndt-Universität Greifswald noch einer anderen
wissenschaftlichen Einrichtung zum Zwecke der Promotion eingereicht wurde.
Ferner erkläre ich, daß ich diese Arbeit selbständig verfaßt und keine anderen als die darin
angegebenen Hilfsmittel benutzt habe.




Hoang Duc Nghia

Table of content  
Contents 
CHAPTER 1 INTRODUCTION ...................................................................................................................... 1
1.1 Motivation................................................................................................................................................. 1
1.2 Why Geostatistics ?.... 2
1.3 Background and hydrogeological settings of test site: Nam Dinh Area............................................... 4
1.3.1 Study Area........ 4
1.3.2 Hydrological system and climate..................................................................................................... 5
1.3.3 Geological history............................................................................................................................ 6
1.3.4 Hydrogeological setting................................................................................................................... 7
1.4 Objective and approach............................................................................................................................. 9
1.5 Outline of the thesis.10
CHAPTER 2 CLASSIFYING WATER- TYPE GROUPS AND GRAPHICAL HYDROCHEMICAL DATA
ANALYSES .................................................................................................................................................. 12
2.1 Introduction............................................................................................................................................. 12
2.2 Methodology............ 13
2.3 Materials.................. 16
2.4 Results and discussion 18
2.4.1 Major ion comparison.................................................................................................................... 18
2.4.2 Graphical methods......................................................................................................................... 22
2.5 Conclusions.............. 31
CHAPTER 3 EXPLORATIVE STATISTICAL DATA ANALYSIS OF THE WATER .............................. 32
3.1 Introduction............................................................................................................................................. 32
3.2 Methodology............ 33
3.3 Materials.................. 34
3.4 Results and discussions........................................................................................................................... 36
3.4.1 Description data............................................................................................................................. 36
3.4.2 Exploratory data analysis and display ........................................................................................... 40
3.4.3 The quantitative variability of the groundwater chemistry due to the seasonal changes............... 43
3.5 Conclusions and discussion..................................................................................................................... 46
CHAPTER 4 TEMPORAL AND SPATIAL VARIABILITY OF THE GROUNDWATER QUALITY IN
THE COASTAL QUATERNARY AQUIFERS, THE NAM DINH AREA/VIETNAM
A CASE STUDY BASED ON KRIGING TECHNIQUES .................................................................................. 48
4.1 Introduction.............. 48
4.2 Methodology............ 49
4.2.1 Variogram....... 49
4.2.2 Kriging........................................................................................................................................... 51
4.3 Materials.................. 53
4.4 Results...................... 53
4.4.1 Variography.... 53
4.4.2 Spatial interpolation....................................................................................................................... 57
4.5 Discussion and Conclusions.................................................................................................................... 69
CHAPTER 5 CHARACTERIZATION OF THE GROUNDWATER CHEMISTRY IN THE COASTAL
QUATERNARY AQUIFERS, THE NAM DINH AREA - AN ASSESSMENT BASED ON CLUSTERING
AND PCA APPROACHES................................................................................................................................... 71
5.1 Introduction.............. 71
5.2 Methodology............ 72
5.2.1 Cluster analysis.............................................................................................................................. 72
5.2.2 Principle component analysis ........................................................................................................ 72
5.2.3 Regionalization analysis ................................................................................................................ 73
5.3 Materials.................. 73
5.4 Results...................... 74
5.4.1 Cluster analysis.............................................................................................................................. 74
5.4.2 Principle component analysis. ....................................................................................................... 79
5.4.3 Regionalization 82
5.5 Discussion and Conclusions.................................................................................................................... 86
CHAPTER 6 ASSESSING THE RISK OF ARSENIC CONTAMINATION IN THE COASTAL
QUATERNARY AQUIFERS IN THE NAM DINH AREA/VIETNAM: A CASE STUDY BASED ON
INDICATOR KRIGING ....................................................................................................................................... 88
6.1 Introduction.............. 88
6.2 Hydrogeological setting .......................................................................................................................... 89
6.3 Objectives................ 89
6.4 Results...................... 90
6.4.1 Exploratory data ............................................................................................................................ 90
6.4.1 Indicator variogram analysis.......................................................................................................... 91
6.4.2 Estimation of local dpf .................................................................................................................. 92
6.4.3 Mapping the probability of exceeding the threshold. .................................................................... 92
6.5 Discussion and conclusions..................................................................................................................... 94
CHAPTER 7 SYNTHESIS............................................................................................................................. 95
7.1 Introduction............................................................................................................................................. 95
7.2 Optimizing the data analyses on groundwater chemistry........................................................................ 95
7.3 Conclusions and discussion 97
7.4 Future perspectives on groundwater investigation and exploration of the area ...................................... 98
REFERENCES ………………………………………………………………………………………………….100
 
List of figures 

Fig. 1.1 The outline map of the Nam Dinh area ....................................................................