1 MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT VIETNAM NATIONAL UNIVERSITY OF FORESTRY NGUYEN PHUC THO RESEARCH ON WATER RETENTION EFFICIENCY OF FO
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MINISTRY OF EDUCATION AND TRAINING MINISTRY OF AGRICULTURE AND RURAL DEVELOPMENT
VIETNAM NATIONAL UNIVERSITY OF FORESTRY
NGUYEN PHUC THO
RESEARCH ON WATER RETENTION EFFICIENCY OF FOREST FOR PAYMENT FOR ENVIRONMENTAL SERVICES FOR
HYDROPOWER RESERVOIRS IN VIETNAM
SUMMARY OF DOCTORAL DISSERTATION
Major: Silviculture Code: 9.62.02.05
HA NOI - 2020
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The dissertation has been completed at:
VIETNAM NATIONAL UNIVERSITY OF FORESTRY
Supervisors:
1 Assoc Prof Dr Tran Quang Bao
2 Assoc Prof Dr Nguyen Dinh Duong
Examiner 1:………
Examiner 2: ………
Examiner 3: ………
The dissertation will be defended before the University Board of Examiners
Venue: Meeting Room E, Building A3 Vietnam National University of Forestry, Xuan Mai, Chuong My, Ha Noi
Time: At………… Date……… Month…… Year 2020
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LIST OF PUBLICATIONS
1 Nguyen Phuc Tho, Tran Quang Bao (2011) The potential and solutions to
increase ecological economic values of natural forest in Vietnam Journal of
Economic Ecology Vol 38/2011, page 111- 117
2 Nguyen Phuc Tho, Tran Quang Bao (2017) Evaluate the water retention
efficiency of forest in hydropower reservoirs by bio-physical indicators Journal
Agriculture and Rural Development, Vol 11/2017, page, 116-124
3 Nguyen Phuc Tho, Tran Quang Bao (2017) Determining the value of forest
environmental services for hydropower reservoirs in Vietnam Journal
Agriculture and Rural Development, Vol 15/2017, page 145-152
4 Nguyen Phuc Tho, Tran Quang Bao, Nguyen Hong Hai (2019) Flow
Characteristics of Hydropower Reservoirs in Vietnam Journal Agriculture and
Rural Development, Vol., 07/2019, page 130-136
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5 The general structure of the dissertation 7
1.1 Some related concepts 81.2 National and international research situation 8
2.1 Research contents 9
2.1.2 Determining water retention capacity for hydroelectric reservoirs
2.1.3 Determining the water retention value range of forests in
2.1.4 Proposal the amount of payment for forest environmental services
2.2 Methods 9
3.1 Characteristics of the basins 15
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3.3.2 Range of water retention value of the forest 193.3.3 Range of water retention value per hectare of forest 193.3.4 Range of water retention value per kWh of electricity 203.3.5 Range of water retention value of forest per one cubic meter of
3.4 Proposal the amount of payment for forest environmental services for hydropower plants 203.4.1 Principles for determining the number of payments for forest
3.4.2 The estimation of the range of payment for forest environmental services for hydropower plants per kWh of electricity 203.4.3 The estimation of payment for forest environmental services for
4.1 Conclusions 234.2 Existence and recommendations 24
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INTRODUCTION
1 Significance of the Study
Payment for forest environmental services has contributed greatly to raising social awareness about the value of forest environment, benefits, rights and obligations of those who are paid and have to pay (both of payee and payer)
The policy of payment for forest environmental services (PFES) has been applied effectively in life and has brought many positive aspects However, the implementation of PFES policy has not been thoroughly resolved, the determination of PFES value and level is still not scientific and not sufficient to convince PFES users as well as forest owners The scientific basis for determining the value of PFES directly affects the effectiveness of the advocacy and policy implementation process The lack of basis leads to reduction of the policy value of the forest environment
So far, although there have been legal documents issued and applied in practice; there is no detail, specific and comprehensive research confirming the exact role and value of keeping the water of the forest to satisfy the parties involved in PFES, especially PFES for hydropower reservoirs From the
urgent issue, the topic “Research on water retention efficiency of forest for
payment for environmental services for hydropower reservoirs in Vietnam"
is conducted as necessary, great scientific and practical implications."
The research object of the study is the ability of forests to retain water
in some hydroelectricity plants in Vietnam
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the dry season for hydropower plants
4 New contributions of the study
4.1 The theoretical and scientific basis
- Supplementing the scientific basis for the selection of methods to study the water retention capacity of forests;
- Contributing to providing a scientific database of policies for payment
of forest environmental services in hydroelectric lakes in Vietnam
4.2 The results and conclusions
- Identify characteristics of basins;
- Identify the role and value of water retention of forests in the dry season;
- Establish a range of the amount of forest water retention services according to forest origin, forest types and forest status in hydropower
reservoirs;
- Propose the amount of PFES for some hydropower plants in Vietnam
4.3 The practice
Supporting managers in planning and calculating the amount of PFES
in compliance with local conditions to improve the effectiveness of forest
protection and development in Vietnam
5 The general structure of the dissertation
The outline of the dissertation as following:
- Along with the introduction, the main part is presented, including 3 chapters:
+ Chapter 1: Literature review
+ Chapter 2: Research contents and Methods + Chapter 3: Results and Conclusions
- References including English documents and Vietnamese documents;
- 38 tables are numbered in order; and
- 18 images are numbered in order
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CHAPTER 1 LITERATURE REVIEW 1.1 Some related concepts
The dissertation cited relevant concepts through legal documents Such concepts include (1) Forest environment; (2) Forest environmental services; (3) Payments for forest environmental services; (4) Water retention capacity
of the forest
1.2 National and international research situation
In this section, the dissertation has summarized all the national and international research on issues related to the study including: (1) Amount of forest value; (2) Water retention capacity of the forest (including conditions affecting water retention capacity of the forest, mechanism of them, evaporation and flow characteristics in basins); (3) Payment for forest environmental services
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CHAPTER 2
RESEARCH CONTENTS AND METHODS 2.1 Research contents
2.1.1 Study on characteristics of basins
2.1.2 Determining water retention capacity for hydroelectric reservoirs in the dry season
- The effect of water retention on forest per hectare;
- The effect of water retention on forest per kWh;
- The effect of water retention on forest per cubic meter of water;
2.1.3 Determining the water retention value range of forests in hydropower reservoirs
- The water retention value range of forest per hectare;
- The water retention value range of forest per kWh;
- The water retention value range of forest per cubic meter of water
2.1.4 Proposal the amount of payment for forest environmental services for hydropower plants
- Principles for determining the payment rates for forest environmental services;
- Proposal for payment of forest environmental services for hydropower plants;
- Determine the payment rates for forest environmental services for hydropower plants
2.2 Methods
2.2.1 The methods of data collection
2.2.1.1 Research methods of hydrological indicators
In the world, there are three main groups of methods to study hydrological indicators in relation to influencing factors In this topic, the
dissertation uses research methods on many basins that are not similar
2.2.1.2 Identify biophysical criteria
To study this content, the topic has experimented with 6 methods that have been and are being applied in practice, including Method using test yards, method using wooden stakes, method using erosion barrier, method of using erosion trap, method using hydrographic observation station and method using mathematical model with eight evaluation criteria for each method In which, there are some important criteria that are evaluated by weight factor Based on that, the study has selected the most optimal and effective method, which is the method using the hydrographic observation station with the highest total evaluation score
This method is implemented as follows: Constructing hydrographic stations to investigate the flow in the output section of many basins with different characteristics, thereby analyzing the effects of vegetation cover and
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factors to the water output at the point of discharge of the basin
(1) Information needs to collect
a The general information:
General information includes boundary, area, elevation, the average slope of the basin, area of forest status, precipitation transported in the basin, flow and sediment of 66 basins (including 17 basins with national observation stations) distributed in regions across the country
Area and boundary of basins: The research basins have boundaries and
areas that are entirely within the territory of Vietnam The boundaries of the research basins are determined by the Digital Elevation Model (DEM) with the help of ArcGIS software and verified by analyzing the distribution of contour lines on the 1: 50000 topographic map
The area of the basins is determined by the map boundary and the CartesianArea function of Mapinfo software
- The average elevation of the basin: the average elevation of the basin is
determined by the Digital Elevation Model (DEM) with an equal distance between elevation points of 30m
- The average slope of the basin: the average slope of the basin is also
determined through the DEM model and the slope function of ArcGIS
software follows these steps: Spatial Analysis Tools Surface Slope
- The area of forest status in the basin: for small and medium basins
where flow and sediment flow were directly investigated in 2012, 2013, this forest status map is reviewed and supplemented by using LANDSAT 8 satellite image with a resolution of 15m Landsat satellite images are free to download at the website: https://earthexplorer.usgs.gov/ The area of the forest statuses in the basin is determined on the forest inventory map for the period of 2013 - 2016 published by the Ministry of Agriculture and Rural
Development
- Precipitation:
Precipitation is measured by udometer in 49 basins without a national monitoring station along with the flow and sediment monitoring periods The location of the measuring station shall not exceed 2 km from the point of measurement of flow and sediment
Measurement time: at 7 o’clock and 19 o’clock daily (a new day from
19 o’clock)
- Flow, the height of water level:
Concrete sluices (cylindrical and box) with the system of blocking soil and sediment to stabilize the flow
Time of investigation:
For temporary observation stations, the survey time is conducted once or
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twice depending on the weather of the survey Specifically,
+ Investigate 1 time on a sunny day at 7-8 o’clock, 2 days after rain; + Investigation 2 times: a rainy day at 7-8 o’clock and 17-18 o’clock, less than 2 days after the rainy day The time for measurement is from 46 to
76 days during the transition period from the beginning to the middle of the rainy season
The height of water level: is determined by the measure of water before and after the sluices
Flow rate: measured by foam float, drifting from front to back of drain, made three times in a row for each survey point
For 17 basins have national observation stations:
The hydrographic survey at national hydrographic stations is conducted according to the general procedure which is twice a day at 7 AM and 7 PM For this content, the dissertation has monitored the flow in 49 basins and used the flow monitoring data of the Vietnam Meteorological and Hydrological Administration in 17 other basins The observed data for the national hydrographic stations are for the whole year 2007, with other stations starting from July or August and lasting from 1.5 to 2.5 months in 2012 and
2013 This is the transition period from the beginning of the rainy season to the highest rainfall period of the year The catchment areas range from a few hectares to hundreds of thousands of hectares
b Methods for determining the amount of water retained by the forest during the dry season
- Determine the flow volume for 6 months in the dry season:
In this study, each hydrological station is considered an outlet point to collect water from a hydroelectric reservoir The amount of water through the hydrographic monitoring station is determined by analyzing the process flow Based on the rainfall distribution by months of the year, it is possible to determine the dry season months for each place (6 consecutive months with the lowest rainfall)
- Determine the total amount of additional flow due to the forest:
Using empirical equations with impact factors to calculate the total amount of water for different forest cover levels will determine the total additional flow due to the influence of the forest
- Determine the standard forest area:
The standard forest area and the area ratio are determined according to the water holding capacity of forest statuses
The standard forest area is the forest area that has been modified to retain water equivalent to the status with the highest water holding efficiency - natural forest
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The number of cubic meters of water retained by the forest for supply during the dry season is determined by changing the standard forest cover from 0 to 100% in the empirical equation between these quantities and the influencing factors
c Converting the value of forest environmental services in the hydroelectric area from biophysical criteria to money
Using the market price method: the value of the forest water holding service is calculated by the amount of water retained by the forest for hydroelectricity in 6 months of the dry season multiplied by the water price of the irrigation charge
d Study on the method of determining the adjustment coefficients of payment for forest environmental services K
Determine the coefficient K for payment of forest environmental services based on forest origin, rich and poor level, protection level by the comparative method Accordingly, the coefficient K of a forest status will
be determined by the ratio of the environmental value of the forest state to the environmental value of the forest status with the best environmental efficiency
The coefficient K will be determined individually according to each criterion that affects decisively on the value of forest environmental services, including forest type (protection forest, special-use forest, etc.), forest origin (plantation forest or natural forests), forest status (rich, medium or poor forests, etc.) For a specific forest plot, there will be 3 adjustment coefficients
of payment for forest environmental services: K1 by forest type, K2 by forest origin and K3 by forest status
(1) Principle of determining the coefficient K
The principles for determining the correction factor K are as follows + The coefficient K must change according to the environmental efficiency of the forest
+ The coefficient K must be easy to apply in practice
+ The coefficient K should support the promotion of community rights and responsibilities sharing in forest protection and development