Large scale application of an environmental tracer approach [Elektronische Ressource] : spatio-temporal patterns of hydrochemistry in a semi-arid grassland / Frauke Katrin Barthold

Barthold, Frauke

Informations

• Publié par: justus-liebig-universitat_giessen
• Publié le: 01 janvier 2010
• Nombre de lectures: 14
• Langue: English
• Poids de l'ouvrage: 3 Mo

Extrait

LARGE SCALE APPLICATION OF AN ENVIRONMENTAL TRACER
APPROACH: SPATIO-TEMPORAL PATTERNS OF
HYDROCHEMISTRY IN A SEMI-ARID GRASSLAND









FRAUKE KATRIN BARTHOLD


















A dissertation submitted to the Department of Natural Sciences and prepared at the
Department of Agricultural Sciences, Nutritional Sciences and Environmental
Management of the
Justus-Liebig-Universität Gießen, Germany
for the degree of Doctor of natural Sciences (Doctor rerum naturalium).

thSubmitted May 18 , 2010
thDefended July 9 , 2010


Referees

Prof. Hans-Georg Frede Justus-Liebig-Universität Gießen
Prof. Kellie B. Vaché Oregon State University
Prof. Lorenz King Justus-Liebig-Universität Gießen
Prof. Peter Felix-Henningsen Justus-Liebig-Universität Gießen




































The photograph on the front cover is used with kind permission of M. Wiesmeier.





TABLE OF CONTENTS
LIST OF FIGURES ................................................................................................................... IV
LIST OF TABLES .................. VIII
1 SYNOPSIS ..................................................................................................................1
1.1 INTRODUCTION ........................................................................ 1
1.2 GENERAL OBJECTIVE ................................. 4
1.3 STUDY AREA ............................................................................ 4
1.4 THESIS OUTLINE ....................................... 9
1.5 SUMMARY OF RESULTS ............................................................................................ 10
1.6 LIMITATIONS OF THIS STUDY ..................... 15
1.7 FUTURE RESEARCH ................................................................................................. 16
2 GAUGING THE UNGAUGED BASIN: A TOP-DOWN APPROACH IN A LARGE SEMIARID WATERSHED
IN CHINA ................................................................................................................. 21
2.1 INTRODUCTION ...................................................................... 22
2.2 MATERIAL AND METHODS ....................................................................................... 23
2.2.1 STUDY AREA .............................. 23
2.2.2 FIELD DATA COLLECTION .............................................................................. 24
2.2.3 MODEL DESCRIPTION .................. 25
2.3 TOP-DOWN APPROACH ........................................................................................... 27
2.3.1 STEP 1: FIELD RECONNAISSANCE AND DATA COLLECTION .................................... 27
2.3.2 STEP 2: PERCEPTUAL MODEL DEVELOPMENT .................................................... 28
2.3.3 STEP 3: RESERVOIR MODEL CONCEPTUALIZATION ............. 29
2.3.4 STEP 4: EVALUATION USING HYDROCHEMICAL DATA AND REJECTION OF INITIAL
MODEL ..................................................................................................... 30
2.3.5 STEP 5: REAL FIELD CAMPAIGN ..... 33
2.4 CONCLUSIONS ....................................................................................................... 34


I


3 IDENTIFICATION OF GEOGRAPHIC RUNOFF SOURCES IN A DATA SPARSE REGION: HYDROLOGICAL
PROCESSES AND THE LIMITATIONS OF TRACER BASED APPROACHES .......................................... 35
3.1 INTRODUCTION ...................................................................... 36
3.2 STUDY AREA .......................................... 38
3.2.1 PHYSICAL CHARACTERIZATION ...................................... 38
3.2.2 HYDROLOGY .............................................................. 42
3.3 MATERIAL AND METHODS ....................................................... 44
3.3.1 DATA COLLECTION ..................................................... 44
3.3.2 LABORATORY ANALYSES ............................................... 45
3.3.3 DATA ANALYSIS .......................... 46
3.4 RESULTS ............................................................................................................... 48
3.4.1 TEMPORAL VARIATION OF RAINFALL AND RUNOFF ............. 48
3.4.2 ISOTOPIC COMPOSITION OF GROUNDWATER .................................................... 50
3.4.3 IDENTIFICATION OF END MEMBERS ................................. 51
3.4.4 CONTRIBUTION OF END MEMBERS TO RUNOFF ................. 55
3.5 DISCUSSION .......................................................................................................... 59
3.6 CONCLUSIONS ....... 63
4 EMMA: ESTIMATING THE VALUE OF LARGE TRACER SETS VERSUS SMALL TRACER SETS .................. 65
4.1 INTRODUCTION ...................................................................................................... 66
4.2 MATERIAL AND METHODS ....................................................................................... 68
4.2.1 STUDY AREA .............................. 68
4.2.2 DATA SET.................................................................................................. 70
4.2.3 END MEMBER MIXING ANALYSIS (EMMA) PROCEDURE ..... 71
4.2.4 AUTOMATION ........................................................................................... 73
4.3 RESULTS ............................................... 76
4.3.1 PRINCIPAL COMPONENT ANALYSIS AND EIGENVECTOR ANALYSIS ........................... 76
4.3.2 EMMA - TRACER SET SIZES AND COMPOSITION ............................................... 77


II


4.3.3 EMMA – DIMENSIONALITY AND END MEMBER COMBINATIONS .......................... 77
4.3.4 EMMA – END MEMBER CONTRIBUTIONS ....................................................... 78
4.4 DISCUSSION .......................................................................... 83
4.4.1 TRACER SET THRESHOLD .............................................. 83
4.4.2 VALIDITY OF MODEL CONCEPT ....................................... 84
4.4.3 SELECTION OF TRACER SET SIZE AND COMPOSITION............ 89
4.5 CONCLUSIONS ....................................................................................................... 90
5 REFERENCES ............................................. 91
ACKNOWLEDGMENTS........................................................................... 100
ERKLÄRUNG ...................................................... 103



III


LIST OF FIGURES
Figure 1-1. The lines represent observed and simulated discharge with SWAT
2(Nash-Sutcliffe-Efficiency (NSE) = 0.22 and R = 0.16) [after Schäfer,
2009]. .................................................................................................................. 3
Figure 1-2. The maps show (a) the location of the Xilin River Basin in Inner
Mongolia, China and (b) the extent of the Xilin River Basin and
location of the subcatchment that was chosen as principal study area. ........... 5
Figure 1-3. Mean monthly precipitation and temperature (1975-2003), Xilinhot,
China. .................................................................................................................. 6
Figure 1-4. The maps show (a) hillshade of the Xilin River subcatchment with
superimposed land use, (b) the soil map based on World Reference
Base (WRB) Reference Soil Groups (RSGs) from [Barthold et al., under
review] and (c) geology of the study area. Landuse was classified
based on a Landsat TM7 image from August 17th, 2005. The
1:200,000 geological map of the Inner Mongolian Bureau of Geology
1973 was modified and information was lumped into 9 new
geological map units based on formation processes and age. .......................... 8
Figure 1-5. Impressions of the Xilin river catchment. (Please see detailed figure
caption on p.13.) ............................................................................................... 14
Figure 1-6. A conceptual reservoir model of the upper Xilin watershed consisting
of 5 zones: SD = sand dunes, Marsh = marshland, Grass = grassland,
T1 = tributary and H = headwater. P, E and T depict precipitation,
evaporation and transpiration, respectively. Precipitation, that falls as
snow (e.g. Marsh ), is modeled with an energy balance model. The snow
brown boxes represent multiple layers of the unsaturated zone (U)
which is modeled with the Richards Equation (RE). The arrows
represent water flow between the various storages (e.g. G1-5 =
groundwater storages 1-5), to the Xilin river (QX) and to the tributary


IV


(QT). The question marks (?) highlight the model processes to be
tested as hypotheses. ....................................................................................... 17
Figure 1-7. Land use and grazing intensities (a) of the base scenario and (b) of
the production scenario [after