Impacts of Climate Change on Water Resources of Nepal [Elektronische Ressource] : The Physical and Socioeconomic Dimensions / Narayan Prasad Chaulagain. Universität Flensburg

User1

Sujets

• Reisen

Informations

• Publié par: universitat_flensburg
• Publié le: 01 janvier 2006
• Nombre de lectures: 19
• Langue: English
• Poids de l'ouvrage: 1 Mo

Extrait

Impacts of Climate Change on Water Resources of Nepal
The Physical and Socioeconomic Dimensions













Dissertation
Zur Erlangung des Grades:
Doktor der Wirtschaftswissenschaften (Dr. rer. Pol.)
an der Universität Flensburg








von

Narayan Prasad Chaulagain, M. Sc.
Nepal












Flensburg, 2006






















Gutachter :

1. Prof. Dr. Olav Hohmeyer (Betreuer)
Universität Flensburg
Internationales Institut für Management
Energie- und Umweltmanagement

2. Prof. Dr. Stephan Panther
Universität Flensburg
Internationales Institut für Management

3. PD Dr. Sc. Alfred Becker
Potsdam Institute for Climate Impact Research
iiContents

List of tables vi
List of figures vii
Acronyms and abbreviations ix
Acknowledgement xi
Abstract xii

1 Problem statement and objectives of the study 1
1.1 Background of the study and problem statement 1
1.2 Objectives 5
1.3 Organisation of the report 6

2 State-of-the-art review and development of hypotheses 7
2.0 General 7
2.1 Global climate change 7
2.1.1 Global temperature change 8
2.1.2 Change in precipitation and atmospheric moisture 10
2.2 Climate change in the Himalayan region and Nepal 11
2.2.1 Climate change in the Himalayas 11
2.2.2 Climate Change in Nepal 13
2.2.2.1 Change in temperature 14
2.2.2.2 Change in precipitation 14
2.3 Physical impacts of climate change 15
2.3.1 Impacts on water resources and hydrology- a global perspective 15
2.3.2 Impacts of climate change on water resources – the Himalayan perspective 17
2.3.2.1 Snow and glacier 17
2.3.2.2 River discharge 19
2.4 The socioeconomic impacts 20
2.4.1 Effects on the water withdrawals 21
2.4.2 Agriculture and food security 21
2.4.3 Effects on the hydropower potential 23
2.4.4 Effects on extreme events 24
2.4.4.1 Changes in flood and drought frequency 24
iii2.4.4.2 Glacier lake outburst floods 25
2.5 Projected future climate 27
2.5.1 Future global climate 27
2.5.2 Climate change scenarios for Nepal 27
2.6 Open questions 28
2.7 Development of hypotheses 29

3 Research methodology 30
3.1 Study design and context
3.2 Source of data 30
3.3 Detecting the climate change 31
3.3.1 Testing for significance 32
3.4 Estimating the physical impacts of climate change 34
3.4.1 Impacts of climate change on river runoff: the Water Balance Model - WatBal 34
3.4.2 Impacts on glacier mass balance in the Nepal Himalayas 36
3.4.2.1 Empirical glacier mass balance model 37
3.4.2.2 Application of the empirical glacier mass balance model 38
3.4.2.3 Sensitivity of the glaciers in the Nepal Himalayas to temperature rise 39
3.5 Estimating the socioeconomic impacts of climate change 40
3.5.1 Impacts on the total water availability in Nepal 41
3.5.2 Impacts on the hydropower potential 41
3.5.3 Impacts on the water balance situation 42
3.5.3.1 The FAO Penman-Monteith method 43
3.5.4 Climate change impacts on agricultural production, poverty and food security 44
3.5.5 Impacts on extreme weather events 44
3.6 Limitations of the study 45

4 Empirical findings on climate change in Nepal 46
4.0 General 46
4.1 Temperature change
4.1.1 Empirical findings on temperature change 46
4.1.2 Discussion of empirical findings on temperature change 48
4.2 Precipitation change 51
4.2.1 Empirical findings on change in precipitation amount
iv4.2.2 Empirical findings on change in number of rainy days 52
4.2.3 Discussion of empirical findings on precipitation change 54
4.3 Conclusion 55
4.3.1 Summary of findings
4.3.2 Open questions 56

5 Empirical findings on the physical impacts 57
5.0 General 57
5.1 Impacts on evapotranspiration and moisture balance
5.1.1 Empirical evidence on impacts on evapotranspiration and moisture balance 57
5.1.2 Discussion about the impacts on evapotranspiration and moisture balance 60
5.2 Impacts on the river flows 60
5.2.1 Runoff modelling of the Bagmati River at Chovar 62
5.2.2 Runoff modelling of the Langtang Khola at Langtang 64
5.2.3 Synthesis of the runoff modelling of the Bagmati River and the Langtang Khola 65
5.2.4 Discussion of the empirical evidence on the impacts on the river flows 69
5.3 Impacts of a temperature rise on snow and glacier systems 70
5.3.1 General findings 70
5.3.2 Sensitivity analysis of glacier mass balance to temperature rise 72
5.3.3 Discussion about the impacts of climate change on snow and glaciers 80
5.4 Conclusion 83
5.4.1 Summary of findings
5.4.2 Open questions 84

6 Empirical findings on the socio-economic impacts of climate change 85
6.0 General 85
6.1 Impacts on the water balance, agriculture and food security
6.1.1 Impacts on the irrigation water requirement 85
6.1.2 Impacts on the water balance situation 87
6.1.3 Impacts on the agricultural production, food security and poverty 90
6.1.4 Discussion of the impacts of climate change on water balance, Agriculture
and food security 97
6.2 Impacts on the hydropower potential 99
6.2.1 Empirical findings of the impacts on the hydropower potential 99
v6.2.2 Discussion of impacts on the hydropower potential 103
6.3 Impacts on the extreme events 104
6.3.1 Impacts on the glacier lake outburst floods 104
6.3.2 Impacts on droughts, floods and landslides 108
6.3.2.1 Snow-covered area and the extreme floods 108
6.3.2.3 Droughts, floods and landslides caused by the changing precipitation pattern 111
6.3.3 Discussion of the impacts of climate change on the extreme events 114
6.4 Conclusion 116
6.4.1 Summary of the findings 116
6.4.2 Open questions 116

7 Conclusions and recommendations 118
7.0 General 118
7.1 Conclusions 118
7.2 Recommendations 119
7.3 Propositions for future research 121

Bibliography 123
Annex

viList of Tables
Table 2.1 GCM estimates of temperature and precipitation changes for Nepal 28

Table 3.1 Descriptions of reference meteorological stations 31

Table 4.1 Annual and seasonal mean temperature trends of reference stations 47
Table 4.2 Minimum, maximum and mean annual temperature trends 48
Table 4.3 Annual temperature trends of reference stations for 1988-2000 48
Table 4.4 Analysis of trends in annual precipitation records 51
Table 4.5 Fluctuations of number of rainy days at reference stations 52
Table 4.6 Trends in number of rainy days as per daily precipitation 53
Table 4.7 Analysis of precipitation at Rampur, Kathmandu and Daman 54

Table 5.1 Sensitivity analysis of atmospheric moisture to a temperature rise 58
Table 5.2 of soil moisture storage with a temperature rise at Kathmandu Airport 59
Table 5.3 Precipitation and runoff of the Langtang Khola and the Bagmati River 61
Table 5.4 Sensitivity of the river runoff to climate change at the Chovar station 63
Table 5.5 Sensitivity of the Langtang Khola runoff to climate change 65
Table 5.6 of monthly runoff to temperature and precipitation changes 67
Table 5.7 Summary of sensitivity analysis of glaciers at Langtang 74
Table 5.8 Glacier mass balance rates with different temperature change scenarios 76
Table 5.9 Sensitivity of glacier ice-reserve to a temperature rise in Nepal 77

Table 6.1 Sensitivity of potential evapotranspiration to a temperature rise 86
Table 6.2 of the irrigation water requirement to a warming 87
Table 6.3 Water supply and demand situation at Chovar 89
Table 6.4 Poverty analysis and measurement in Nepal 91
Table 6.5 Sensitivity of calorie supply to a warming for average population 95
Table 6.6 of calorie supply to a warming for different income groups 96
Table 6.7 All-Nepal average monthly and annual hydrograph 100
Table 6.8 Sensitivity of hydropower potential in Nepal with temperature rise 101


viiTable 6.9 Sensitivity of hydroenergy potential in Nepal with temperature rise 102
Table 6.10 Sensitivity of melt- and rainwater to temperature change in Nepal 105
Table 6.11 Snow-covered areas and the ratio of maximum to minimum instantaneous
flows in some selected hydrological stations 108
Table 6.12 Sensitivity of snowfall to temperature increases in the Nepal Himalayas 112
Table 6.13 Sensitivity of rainfall to temperature increases in the Nepal Himalayas 113


List of Figures

Figure 2.1 Variations of the earth’s surface temperature 9
Figure 2.2 Annual temperature trends for 1976-2000 9
Figure 2.3 Annual precipitation trends for 1900-2000 10
Figure 2.4 Temperature trend as a function of elevation on the Tibetan Plateau 12

Figure 3.1 Conceptualization of water balance for the WatBa