Nghiên cứu khả năng tích lũy cacbon của một số loại hình sử dụng đất nông nghiệp tại huyện bố trạch, tỉnh quảng bình TT TIENG ANH

HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHAM QUOC TRUNG RESEARCH ON THE CARBON ACCUMULATION CAPACITY OF AGRICULTURAL LAND USE TYPES IN BO TRACH DISTRICT, QUANG BINH PROVINCE DOCTORAL DISSERTATION SUMMARY RESOURCES MANAGEMENT AND ENVIRONMENT Major: LAND MANAGEMENT Code: 9.85.01.03 Hue - 2022 HUE UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY PHAM QUOC TRUNG RESEARCH ON THE CARBON ACCUMULATION CAPACITY OF AGRICULTURAL LAND USE TYPES IN BO TRACH DISTRICT, QUANG BINH PROVINCE DOCTORAL DISSERTATION SUMMARY RESOURCES MANAGEMENT AND ENVIRONMENT Major: LAND MANAGEMENT Code: 9.85.01.03 SCIENTIFIC SUPERVISORS Assoc Prof Dr Nguyen Hoang Khanh Linh Assoc Prof Dr Huynh Van Chuong Hue - 2022 This dissertation has been completed at: University of Agriculture and Forestry, Hue University SUPERVISORS: Assoc Prof Dr Nguyen Hoang Khanh Linh Assoc Prof Dr Huynh Van Chuong Reviewer 1: Reviewer 2: Reviewer 3: This doctoral dissertation will be defended at Hue University’s dissertation defense committee meeting at………… on…………… This doctoral dissertation can be found at: TABLE OF CONTENT TABLE OF CONTENT INTRODUCTION 1 Statement of problem Research Objectives 3 Scientific and practical significance New contribution CHAPTER LITERATURE REVIEW 1.1 THEORICAL BASIS OF THE RESEARCH 1.2 PRACTICAL BASIS OF THE RESEARCH CHAPTER RESEARCH SITES, CONTENTS AND METHODOLOGY 2.1 RESEARCH SITES AND SUBJECTS 2.1.1 Research sites 2.1.2 Research subjects 2.2 RESEARCH CONTENTS 2.3 RESEARCH METHODOLOGY 2.3.1 Data 2.3.2 Surveying data 2.3.3 Remote sensing application method 2.3.4 GIS application method 2.3.5 Method of forecasting land use change using Markov chain 2.3.6 Data analysis method CHAPTER RESULTS AND DISCUSSION 3.1 CHARACTERISTICS OF SOCIO-ECONOMIC, NATURE AND LAND USE STRUCTURE IN BO TRACH DISTRICT 3.1.1 Natural characteristics 3.1.2 Socio-economic characteristics 3.1.3 Assessment of natural and socio-economic characteristics 3.1.4 Land use structure in Bo Trach district 3.1.4.1 The current status of agricultural land use 10 3.1.4.2 Changes in land use structure in the district 10 3.2.CHANGES IN LAND USE AREAS DURING THE PERIOD 20052018 IN BO TRACH DISTRICT 10 3.3 ASSESSMENT OF CARBON CARBONITY OF SOME TYPES OF AGRICULTURAL LAND USE IN BO TRACH DISTRICT 12 3.3.1 Characteristics of types of agricultural land use 13 3.3.2 Determination of biomass of actual land use types 12 3.3.3 Determination of biomass of some land use types from remote sensing images 13 3.3.3.1 Preprocessing image 14 3.3.3.2 Calculating indexes from remote sensing images for biomass calculation 13 3.3.4 Mapping biomass and carbon reserves of agricultural land use types in Bo Trach district 16 3.3.4.1 Determination of biomass value of different types of agricultural land use 16 3.3.4.2 Evaluation of the results of calculating the biomass of different types of agricultural land use in Bo Trach district 16 3.3.4.3 Establishing carbon maps in Bo Trach district, Quang Binh province 17 3.4 FORECAST FOR THE CHANGE OF AGRICULTURAL LAND USE TO 2030 OF BO TRACH DISTRICT, QUANG BINH PROVINCE 19 3.4.4.1 Application of automatic network and Markov chain to model land use change in Bo Trach district 19 3.4.4.2 Modeling land use change in Bo Trach district to 2030 20 3.4.5 Comparing forecast results with results of land use planning and socio-economic development orientation of Bo Trach district 20 3.4.5.1 Socio-economic development plan of Bo Trach district 20 3.4.5.2 Land use planning in 2030 Bo Trach district 21 3.5 PROPOSING SOLUTIONS TO USE LAND TO INCREASE CARBON ACCUMULATION IN BO TRACH DISTRICT, QUANG BINH PROVINCE 23 CONCLUSIONS AND SUGGESTIONS 24 CONCLUSIONS 24 SUGGESTIONS 24 INTRODUCTION Statement of problem Climate change is always a hot issue to argue It' s not just a matter of a country but a common problem of the whole society Climate change is the change of climate that exceeds the average state that has been maintained for a long time, often a few decades or longer [5] or According to Article of the United Nations Framework Convention on Climate Change [20]: "Climate change" means a change in the climate caused by human activity (directly or indirectly) changing composition of the global atmosphere and this change is added to the automatic observed climate change over comparable time It may be the warming of the earth, the rise of sea level due to ice melting, the shift in the intensity of the atmosphere, the cycle of circulation in nature The cause of climate change extremely varied It could be because of the changing nature of the natural environment, greenhouse effect rises in the atmosphere However, the biggest impact is by human beings Since population density is rapidly increasing, the demand for housing, food rises, a lot more factories are built Meanwhile, the forest is exploited and destroyed, many wild animals almost extinct The imbalance in the ecosystem has led to global climate changes Climate change is impacting the world Since a few years ago human has to face the threats of nature, natural disasters and epidemics that endanger human life The melting of two poles, tsunami, … of disasters occurring in many countries In the face of the effects of climate change, all sectors have to find ways to cope with this process Scientists around the world have discovered the fact that: Soil has an important, but little-noticed property "The ability to sequester carbon, reduce greenhouse gas emissions" [75] As we all know, there are about 830 billion tons of carbon in the air Every year, humans discharge about 10 billion tons more Soil can hold 4,800 billion tons, times more than air "We can significantly reduce the amount of carbon in the atmosphere by using land, using land management technology to reduce greenhouse gases", said co-author Johannes Lehmann of Cornell University [75] Therefore, understanding the relationship between carbon and some types of agricultural land use is a matter of great interest in the world in general as well as in Vietnam in particular It not only determines the amount of carbon accumulation in the soil, but also evaluates the type of land use for the best ability to accumulate carbon, thereby adjusting the planning in the direction of protecting the environment and combating climate change With carbon reserves of about 1500 billion tons, land is the second largest carbon sink in the world after the ocean, twice the amount of carbon in the atmosphere and about three times the amount of carbon accumulated in the plants of the world's ecosystems It is an important link in the global carbon cycle [4] In our country, along with participating in the REDD + program, scientists have conducted many studies to determine the amount of carbon accumulated in ecosystems, land use types to determine carbon accumulation in the environment and obtain financing from carbon sequestration environmental services [3] Although there have been many works, some guidelines on investigation and determination of carbon stocks at the national level, the studies only stopped at assessing the carbon sequestration capacity of forest soil, has not been determined carbon stocks of other agricultural land uses Currently, the world's new approach to climate change is to study adaptation measures, adapting to climate change not only at the global and regional scale, but also on the scope of climate change to propose measures to significantly reduce the amount of carbon in the atmosphere by land use, using land management technology to reduce greenhouse gases [77] Bo Trach district is a district of Quang Binh province that is on the rise, has a diverse land use structure, has Phong Nha - Ke Bang National Forest with a rich and diverse ecosystem, is a green lung that plays an important role in regulating and mitigating climate change According to the land inventory results as of December 31, 2019, the total natural area of Bo Trach district is 211,549.10 hectares with many types of land use [50] In order to serve the local socio-economic development in recent years, the conversion of agricultural land use types has taken place a lot, this process will affect the ability to accumulate carbon, increasing the impact of climate change Stemming from that fact, the research focuses on understanding the carbon accumulation capacity of agricultural land use types in Bo Trach district and at the same time learning about changes in agricultural land use in recent years; support for planning and land use planning in the coming time in order to improve the ability to accumulate carbon in the soil towards limiting climate change is an extremely necessary issue Research Objectives The study assessed ability to accumulate carbon of some types of agricultural land use and contribute to improving the efficiency of land use, limiting CO2 emissions, mitigating climate change in Bo Trach district, Quang Binh province Scientific and practical significance a Scientific significance The research results of the topic contribute to supplementing and perfecting the theoretical basis for climate change mitigation and adaptation In addition, the research results will contribute to a reference source for policy makers, improve technical capacity, manage land resources and build predictive models of land use processes The topic will create a deeper understanding of the relationship between carbon accumulation and land use change, contributing to the theory of the relationship between carbon accumulation, land use change and climate change b Practical significance The process of studying the carbon accumulation capacity of some types of land use in Bo Trach district, Quang Binh province contributes to an accurate assessment of the ability to accumulate carbon on the ground surface of each type of land use, which type of land use has the best ability to accumulate carbon With the obtained results, the thesis will support local authorities in developing a land use plan to 2030 as well as the annual land use plan during this period to ensure the availability of land for socio-economic development and at the same time to ensure climate change mitigation New contribution - The thesis has calculated the ability to accumulate carbon and built a map of the distribution of carbon stocks on some types of agricultural land use on the basis of fieldwork combined with GIS and Remote sensing technology From there, evaluate in general which type of soil has the best ability to accumulate carbon - Forecasting the change of agricultural land use by Markov chain to 2030 to assess the potential for carbon accumulation in the future in Bo Trach district, Quang Binh province CHAPTER LITERATURE REVIEW 1.1 THEORICAL BASIS OF THE RESEARCH The thesis has researched and clarified a number of issues related to the nature of the research object, including: Issues related to agricultural land use, biomass and carbon accumulation, total GIS and remote sensing in analysis of land use change, Modeling of land use change for prediction of land use Thereby, it can contribute to completing the theoretical basis for the research topics 1.2 PRACTICAL BASIS OF THE RESEARCH The study results reflect on the status of land use changes and carbon accumulation in land use types in the world and Vietnam from the past until the recent years It aims to clarify and provide more arguments on related issues for practical backgrounds 1.3 PREVIOUS PUBLICATIONS Research works related to the research field of the thesis are synthesized and analyzed from research results of prestigious scientists in many countries around the world and in many regions of Vietnam Research works in countries around the world are presented on a global scale, from continents, with a special focus on Asia, and some neighboring countries Research works in Vietnam are presented by region In general, through looking at research topics of domestic and foreign experts in the fields of land, agriculture, climate change, etc., it is found that the above topics are almost exclusively evaluated the carbon accumulation capacity of some trees on some specific land uses, the change of carbon biomass when changing land use purposes or the indicators of climate change which may be affected by land use dynamics, but there has not been a single study on the overall ability of carbon accumulation of some types of land use to mitigate and adapt to climate change On the other hand, not many studies specific to Bo Trach district, Quang Binh province have not been done Therefore, this thesis will focus on conducting research on the carbon accumulation capacity of some types of agricultural land use This is a new and correct research direction in line with the trend that focusing on economic efficiency has unintentionally pushed the environment into difficulties and challenges, but climate change is a matter of great concern The project after completion not only stops at the assessment of which crops, which land-use types have the best ability to accumulate carbon to fight climate change, but it also has a great impact on the land use planning scheme which is both economically efficient and mitigate climate change 10 crematoriums: 736.13 hectares, accounting for 0.35% of the natural area Land of rivers, canals, channels, streams: 2,459.48 ha, accounting for 1.16% of the natural area Land with specialized water surface: 313.80 ha, accounting for 0.15% of the natural area For unused land: 3,477.38 ha, accounting for 1.64% of the natural area In which: Unused flat land: 1,878.30 ha, accounting for 0.88% of the natural area Unused hilly land: 227.61 ha, accounting for 0.11 % of the natural area Rock mountains without forests: 1,371.47 hectares, accounting for 0.65% of the natural area Figure 3.2 Land use structure in 2018 of Bo Trach district 3.1.4.2 Changes in land use structure in the district Table 3.3 Structure and land area of Bo Trach district in the period 20052018 2005 2010 2018 Types of land Acreage Percent Acreage Percent Acreage Percent use (ha) (%) (ha) (%) (ha) (%) Agricul 192.641,00 90,74 195.987,47 92,27 196.673,24 92,97 tural land Nonagricult 10.123,84 4,77 11.568,57 5,45 113.98,26 5,39 ural land Unused 9.545,00 4,50 4.861,59 2,29 3.477,38 1,64 land Total 212.309,84 100,00 212.417,63 100,00 211.548,88 100,00 Thus, it can be seen that in a period of 13 years, Bo Trach district from 2005 to 2018, the process of urbanization has led to a clear change in the structure of land use in Bo Trach district, which manifests specifically, sharply reducing the proportion of agricultural land and unused land to convert to nonagricultural land to serve the urban development needs of the district 11 3.2.CHANGES IN LAND USE AREAS DURING THE PERIOD 2005-2018 IN BO TRACH DISTRICT Figure 3.3 Samples collected for interpretation Figure 3.4; 3.5; 3.6 Thumbnail image of land use cover map of Bo Trach district in 2005, 2010, 2018 respectively, built using eCognition software Table 3.5 Statistics on total area of land use changes in the period 2005-2010 Increase (+) Decrease (-) Types of land use 2005 (ha) 2010 (ha) Area (ha) 19.111,04 18.342,45 -768,59 Annual crop land Land for perennial crops 25.083,88 35.847,79 & Production forests 149.989,91 143.923,69 Natural forest land 17.364,05 13.434,95 Other land 10.763,91 -6.066,22 -3.929,10 12 Table 3.7 Statistics on total area of land use changes in the period 2010-2018 Increase (+) Decrease (-) Types of land use 2010 (ha) 2018 (ha) Area (ha) Annual crop land 18.342,45 17.169,15 -1.173,3 Land for perennial crops 35.847,79 40.818,64 & Production forests Natural forest land 143.923,69 137.739,6 -6.184,09 Other land 2.386,54 13.434,95 15.821,49 4.970,85 The results of analysis and general assessment of changes in area of land use types in the period 2005 - 2018 shows that the area of perennial crops and production forests increased the most, the area of forest natural decreased the most However, the trend only focused on the 2005-2010 period, and in the 2010-2018 period, besides the internal conversion of agricultural land groups, the conversion of agricultural land groups to other land groups increased sharply The purpose of the analysis of changes in agricultural land groups in the period 2005-2018 in Bo Trach district is to see which land groups have changed the most in recent years, which has the potential to affect the ability to accumulate carbon of the soil groups studied if there is a difference in the carbon accumulation capacity of these groups 3.3 ASSESSMENT OF CARBON ACCUMULATION OF SOME TYPES OF AGRICULTURAL LAND USE IN BO TRACH DISTRICT 3.3.1 Characteristics of types of agricultural land use 3.3.2 Determination of biomass of actual land use types Table 3.8 LAI ratio of land group for perennial crops and production forests Reality ratio (%) Type Min 40 Max 95 Land for perennial crops & Production forests Medium 71,632653 Standard deviation 10,963374 Table 3.9 LAI ratio of annual crops land Reality ratio (%) Type Min 50 Max 90 Medium 71,32653061 Standard deviation 10,04030991 Annual crop land 13 Table 3.10 LAI ratio of natural forest land Reality ratio (%) Min 80 Max 95 Medium 89,1176471 Type Natural forest land Standard deviation 2,43438927 From the results collected in the field, it shows that the difference between the natural forest land type and the LAI value is not too large which is due to the characteristics of the natural forest group with a relatively long development period, grows and develops in different areas, but it is an area less affected by human impact, so the coverage is quite high 3.3.3 Determination of biomass of some land use types from remote sensing images 3.3.3.1 Preprocessing image 3.3.3.2 Calculating indexes from remote sensing images for biomass calculation Figure 3.12 A thumbnail image of the NDVI vegetation difference index map Table 3.12 NDVI index information in standard cells Value NDVI on photo Min 0,311 Max 0,877 Medium 0,68007228 Standard deviation 0,11916429 14 Table 3.12 shows that the lowest NDVI value in Bo Trach district is 0.311 (for perennial crops and production forests in standard plot 10), the highest NDVI value is 0.877 (for natural forest land in standard plot 62), mean NDVI value is 0.69, standard deviation is 0.12 Figure 3.13 Miniature image of the LAI index map from sentinel satellite images in Bo Trach district Table 3.13 Ratio of leaf surface area of tree canopy to land surface area of annual plants growing in Bo Trach district Percent = Actual LAI Value Actual Value (%) LAI on Type difference difference / value photo LAI Land for Min 40,00 44,74 -15,63 -17,36 planting Max 95,00 85,85 31,08 77,70 perennial Medium 71,63 70,94 -0,69 -0,01 crops and Standard production 10,96 9,68 6,83 13,74 deviation forests Table 3.14 Ratio of leaf surface area of tree canopy to land surface area of perennial crops and production forests developed in Bo Trach district Actual Value LAI Value Percent = Actual LAI Type (%) on photo difference difference / LAI value Min 50,00 53,11 -5,47 -9,12 Max 90,00 87,45 23,04 46,08 Annual crop Medium 71,33 73,14 1,82 3,51 land Standard 10,04 7,80 6,58 11,28 deviation 15 Table 3.15 Ratio of leaf surface area of tree canopy to land surface area of natural forest type developed in Bo Trach district Actual LAI Percent = Value Value LAI on Actual Type (%) difference value photo difference / LAI Min 80,00 79,44 -6,19 -6,88 Max 95,00 95,11 10,11 11,89 Natura l forest land Medium 89,12 88,29 -0,83 -0,91 Standard 2,43 2,74 2,13 2,42 deviation Table 3.15 shows that the average value of LAI in field survey and LAI on image are relatively similar at 89.12% and 88.29%, respectively With the error ratio of calculating the actual LAI with the LAI on the image, the standard deviation error is about 2.42%, in other words, calculating the biomass can give an accuracy of up to 97.58% \ Figure 3.14 Thumbnail image of the fAPAR distribution map of Bo Trach district Table 3.16 Table of fAPAR indicators at standard plot points Value NDVI T on photo FAPAR Min 0,311 0,254 Max 0,877 0,863 Medium 0,693 0,665 Standard deviation 0,119 0,128 From Table 3.16, it shows that the average value of absorbed radiation for photosynthetic activity (FAPAR) for the whole study area is 0.665, which means that 66.5% of solar radiation in the visible light region is used to generate biomass Combined with the graph showing the relationship between NDVI index and FAPAR, there is a positive 16 correlation between NDVI and FAPAR with R2 = 0.5185 When the NDVI index has a high value, the FAPAR index also has a high value Figure 3.15 Correlation chart between NDVI index and fAPAR 3.3.4 Mapping biomass and carbon reserves of agricultural land use types in Bo Trach district 3.3.4.1 Determination of biomass value of different types of agricultural land use Figure 3.16 Thumbnails of biomass hierarchical maps of agricultural land use types in Bo Trach district Thus, from the results of analyzing and building the biomass value map of the land use types for annual crops, natural forest land, perennial crops and production forests, the research shows that the value of biomass of annual cropland is the smallest, of natural forest land is the largest, even some areas have absolutely no biomass (areas with negative values such as coastal white sand dunes, urban areas have concreting or ponds, lakes, rivers, streams, etc.) 3.3.4.2 Evaluation of the results of calculating the biomass of different types of agricultural land use in Bo Trach district The results show that the difference between the actual calculated biomass value and the biomass determined by remote sensing images has a mean square error of about 41.67 tons/ha The mean square error here is larger than that of other types because the biomass of natural forests is quite large, so it is easier to lead to errors The ratio of the error of calculating the 17 biomass on the image with the actual biomass has a standard error of about 10.35% or in other words, calculating the biomass on the remote sensing image can give an accuracy of 89.65% With the accuracy of the research method 89.65% is acceptable and it is possible to apply the method of using remote sensing images in the rapid assessment of biomass as well as carbon reserves for planning and conservation environmental protection 3.3.4.3 Establishing carbon maps in Bo Trach district, Quang Binh province Figure 3.17 Miniature image of Carbon maps in Bo Trach district Table 3.20 Carbon value of perennial crops and production forests Value Carbon (tons/ha) Min 14,45 Max Medium 36,95 28,79 Standard deviation 5,30 Table 3.21 Carbon value of annual crops land Value Carbon (tons/ha) Min 7,02 Max Medium 9,45 8,44 Standard deviation 0,55 Table 3.22 Carbon value of natural forest land Value Carbon (tons/ha) Min 152,45 Max 306,22 Medium 239,30 Standard deviation 26,93 Finally, by matching each type of carbon map according to the land use 18 boundary, the result is a carbon value map for the types of agricultural land use in Bo Trach district The results are shown in Figure 3.18 Figure 3.18 Miniature image of the carbon map of agricultural land use types in Bo Trach district Through the carbon value tables from Table 3.20, 3.21, 3.22 and the spatial distribution of carbon value of each type of agricultural land use in Figure 3.18, it shows that the carbon value of natural forest land is the largest, reaching from 152 45 tons/ha – 306.22 tons/ha, in average 239.30 tons/ha Next, land for perennial crops and production forests has the second highest value of carbon accumulation with values ranging from 14.45 tons/ha 36.95 tons/ha, in average 28.79 tons/ha The soil group with the lowest carbon value in the region is the land for growing annual crops, which is only 7.02 tons/ha - 9.45 tons/ha, with an average of 8.44 tons/ha Table 3.23 Statistics on the area of agricultural land use types and carbon value in Bo Trach district Average Area change value of Types of land use 2010 (ha) 2018 (ha) 2010-2018 Carbon (ha) (Ton/ha) Annual crop land 18.342,45 17.169,15 -1.173,3 8,44 Land for perennial 35.847,79 40.818,64 + 4.970,85 28,79 crops & Production Natural forest land 143.923,69 137.739,6 -6.184,09 239,30 Table 3.23 shows that, among the studied soil groups, natural forest land has the largest average carbon value (239.30 tons/ha) compared to other soil groups, but this soil group also has a damaged area decreased the most in the period 2010-2018 with more than 6,184.09 hectares of land Areas with large carbon reserves for natural forest land are mainly concentrated in Hung Trach, Thuong Trach, Son Trach and Tan Trach communes As is well known, forests are reservoirs of carbon absorbed 19 in the air, although there are some basic cycling cycles of this gas taking place on a daily basis One of the cycles (production) will return the carbon to the atmosphere, but some will enter the food chain or be retained in the soil Soil carbon usually remains stable in the soil for a long time Therefore, the protection of forests and forest cover plays an important role in carbon accumulation and climate change mitigation 3.4 FORECAST FOR THE CHANGE OF AGRICULTURAL LAND USE TO 2030 OF BO TRACH DISTRICT, QUANG BINH PROVINCE 3.4.4.1 Application of automatic network and Markov chain to model land use change in Bo Trach district 3.4.4.2 Modeling land use change in Bo Trach district to 2030 a Forecast of land use change to 2018 Based on the input data of Spot satellite images in 2005 and 2010, the CA - Markov model allows to forecast the land use change of Bo Trach district up to 2018 With the use of appropriate hierarchical maps and a map restricting development zoning as the limiting threshold of the process of changing land use class in Bo Trach district, the project has obtained the modeling results shown in Figure 3.22 Figure 3.22 Miniature image of land use forecast map of Bo Trach district in 2018 Table 3.30 Check the model prediction results with the numerical results of the classification and land use system (Unit: ha) Forecast Land cover Land Types of land use results 2018 classification 2018 statistics 2018 Annual crop land 18.617,78 17.169,15 17.147,22 Land for perennial crops 41.086,1 40.818,64 39.265,96 & Production forests Natural forest land 137.078,1 137.739,6 139.348,12 Other lands 14.766,9 15.821,49 15.787,58 b Forecast of land use change to 2030 20 Figure 3.27 Thumbnail image of the map of land use change forecast in Bo Trach district in 2030 Table 3.33 Statistics on total area of land use types in 2005 and forecast in 2030 Types of land use 2005 (ha) Annual crop 19.111,04 land Land for perennial crops & 25.083,88 Production forests 2005-2018 2018-2030 2005-2030 Forecast Increase (+) Increase Increase (+) Forecast results Decrease (-) (+) Decrease (-) results 2018 2030 Decrease (-) 18.617,78 16.801,08 41.086,10 -493,26 -1.816,7 -2.309,96 36.614,0 16.002,22 -4.472,1 11.530,12 Natural forest 149.989,91 137.078,10 137.012,6 -12.911,81 -65,5 -12.977,31 landland 17.364,05 14.766,90 21.121,2 -2.597,15 6.354,3 3.757,15 Other 3.4.5 Comparing forecast results with results of land use planning and socio-economic development orientation of Bo Trach district 3.4.5.1 Socio-economic development plan of Bo Trach district The forecast results of land groups up to 2030 is quite consistent with the district's 5-year development orientation (2021-2025), according to the forecast results, that agricultural land groups tend to decrease by 2030 is consistent with the development plan of the district with the goal of reducing the proportion of labor in this field to less than 50% In addition, according to the model, the area of land planted with production forests tends to increase, while the district's development plan is to increase the forest cover to nearly 70%, especially planted forests The service and industrial sectors 21 tend to increase in proportion to the increasing trend of non-agricultural land The topic provides a forecast model to 2030 in line with the development trend and progress of the district, it can be seen that the district's 5-year development plan to 2025 is also in the development process, in line with the forecast of the district model to 2030 3.4.5.2 Land use planning in 2030 in Bo Trach district Table 3.34 Comparison of forecast results and land use planning of Bo Trach district in 2030 Deviant Forecast results Zoning plan to acreage 2030 2030 Types of land Increase No use (+) Acreage Percent Acreage Percent (ha) (%) (ha) (%) Reduction (-) Annual crop land 16.801,08 7,94 13.537,00 6,48 +3.264,08 Land for perennial crops 36.614,0 17,31 61.953,91 29,65 -25.339,91 & Production forests forest 137.012,6 64,77 111.186,41 53,20 +25.826,19 Natural land Other land 21.121,2 9,98 22.307,03 10,67 -1.185,83 Total 21.1548,88 100 20.8984,35 100 +2.564,53 Table 3.35 The relationship between the forecast results and the mean carbon value of agricultural land uses in Bo Trach district Forecast Forecast Change in Average value of carbon in Types of land use results results area 20182018 (Ton/ha) 2018 2030 (ha) 2030 (ha) Annual crop land 8,44 18.617,78 16.801,08 -1.816,7 Land for perennial 28,79 41.086,10 36.614,0 -4.472,1 crops & Production forests Natural forest land 239,30 137.078,10 137.012,6 -65,5 Through the results of the forecast of land use change in Bo Trach district, the group of perennial crops & production forests to have is forecasted to 2030 the largest reduction in area, while the research results on the potential carbon accumulation capacity of this group of soils is of great value, ranking second after natural forest land Thus, if it is forecasted in the future the area of that this land resource tends to decrease alot, it will more or less affect the carbon accumulation capacity of perennial crops & production forests Besides, as the research results have shown, the group of annual crops is also one of the soil groups with the ability to accumulate carbon quite well However, like the group of land for perennial crops & production forests, 22 the area for annual crops is forecasted to decrease sharply compared to 2018 However, the area of natural forest land which is forecasted to reduce very little compared to the other soil groups, this is very meaningful for limiting climate change and protecting land resources when the carbon accumulation capacity of natural forest land is very high 3.5 PROPOSING SOLUTIONS TO USE LAND TO INCREASE CARBON ACCUMULATION IN BO TRACH DISTRICT, QUANG BINH PROVINCE - The group of natural forest land is the group of land with the ability to accumulate the largest amount of carbon biomass, but the research results show that in the period from 2005 to 2018 the area of this group of land decreased the most, the reason is that poor forests were converted to afforestation to exploit raw materials, rubber trees, fruit trees, to bring higher economic efficiency in order to improve the living standards of people living in communes with lots of land forests, live by forestry, minimize logging, destroy forests for a living However, although the area of natural forest land has decreased, Quang Binh province in general and Bo Trach district in particular need to improve the quality of forests with the policy of closing forests and allocating forests to organizations and individuals for zoning and protection Thereby, improving the carbon accumulation capacity of this soil group, while ensuring the district's socio-economic development orientation - The group of land for planting production forests and perennial crops is a group of soil with good carbon accumulation capacity, just after natural forest land Although the amount of carbon accumulation is not as much as that of natural forests, this group of soils occupies a rather large area in mountainous areas The State influences through the land lease policy, so land users are more interested in the economic value per unit area, which has focused on renovating and investing in advanced science and biotechnology; the main crops included rubber, acacia, melaleuca and fruit trees This group of trees has high carbon accumulation capacity to increase biomass accumulation, and at the same time contributes to stable economic growth based on commodity agriculture and deep processing industry - Group of land for annual crops: Selection of land cover crops, crop rotation, reduced cultivation, use of organic fertilizers or manure This solution has low sequestration potential, but is much more advanced than a standard carbon emission solution like annual farming Building a system of agroforestry, integrating tree planting with agricultural production This solution can combine growing annual crops, raising livestock with perennial crops Some systems combine timber or fruit trees and annual crops with appropriate spacing to minimize competition for growth, which in turn enhances carbon accumulation In fact, if implemented correctly, many 23 systems can out-produce monocultures, allowing more food crops to be grown and reducing deforestation pressures (the main driver of soil carbon accumulation minimisation) CONCLUSIONS AND SUGGESTIONS CONCLUSIONS The results were obtained from this research as follows: 1) The results show that there is a strong variation in land use types in Bo Trach district From 2005 to 2010, the area for perennial crops & production forests increased the most at about 10,763.91 The results of the change in the area of land use types in the period 2010-2018 show that the area of perennial crops and production forests increased the most at about 4,970.85 hectares, the area of natural forests decreased sharply about 6,184.09 This reflects the region's economic development orientation as a priority for agricultural development The economic restructuring has changed the current land use status and is the main cause of land use change 2) The results of the assessment of carbon accumulation capacity of agricultural land uses in Bo Trach district show that the carbon value of natural forest land is the largest, reaching from 152.45 tons/ha to 306.22 tons/ha, average 239.30 tons/ha Next, land for perennial crops & production forests has the second highest value of carbon accumulation with value from 14.45 tons/ha to 36.95 tons/ha, averaging 28.79 tons/ha The soil group with the lowest carbon value in the region is the land for growing annual crops, which is only 7.02 tons/ha - 9.45 tons/ha, with an average of 8.44 tons/ha The determination of biomass and carbon stocks of perennial crops not only contributes to reducing emissions and responding to climate change, but also provides a scientific basis and facilitates the adjustment of land use planning land use in the future to improve the ability to accumulate carbon in the soil towards limiting climate change 3) The results of forecasting the trend of land use change in the period 2005-2030 in Bo Trach district show that the type of natural forest land use tends to decrease sharply, the variation decreases by 12,977.31 hectares, in which land for planting perennial crops and production forests tends to increase sharply, with an increase of 11,530.12 The type of strong and relatively complicated fluctuations is other lands (including residential land, transportation, irrigation, trade, services, land of rivers, streams, canals, streams, unused land ) The results of the model have been verified with the results of the district's land statistics, with the classification results from the images, with the district's socioeconomic development plan and compared with the results of the land use planning to the end of the year The year 2030 shows similarities and is consistent with the development orientation of the district 24 4) From the research results, groups of solutions to increase the capacity of carbon accumulation according to each type of land use and each specific region in Bo Trach district have been proposed With these solutions, Bo Trach District People's Committee will have a basis to use land effectively to increase the ability to accumulate carbon to cope with climate change SUGGESTIONS - The State should have strict regulations to minimize the conversion of agricultural land, especially the area of specialized rice cultivation with high productivity and economic efficiency, to non-agricultural purposes It is necessary to minimize the change of land use purpose The conversion of agricultural land use purposes to non-agricultural land requires strict control, compliance with the Land Law and approved plannings and plans - The District People's Committee regularly updates the annual land change on the map and makes an annual change schedule to monitor and manage the land more closely and effectively - For the People's Committee of Quang Binh province in general and Bo Trach district in particular, it is necessary to improve the quality of forests with the policy of closing forests and allocating forests to organizations and individuals for zoning and protection Thereby, improving the carbon accumulation capacity of this soil group, while ensuring the district's socio-economic development orientation LIST OF PUBLICATIONS Pham Quoc Trung, Nguyen Hoang Khanh Linh, Huynh Van Chuong, Truong Thi Huong Dung (2018), Accessing land cover change in Bo Trach district, Quang Binh province based on high-resolution satellite imagery based on object-oriented perspective, Journal of Vietnamese Environment, No 9, Vol 1-5, 2018 Pham Quoc Trung, Nguyen Hoang Khanh Linh, Huynh Van Chuong, Dinh Vu Long (2018), Accessing land cover change in Bo Trach district, Quang Binh province based on high-resolution satellite imagery, Journal of Ecological Economy, Vietnam, No 55, pp 99- 110 Pham Quoc Trung, Nguyen Hoang Khanh Linh, Huynh Van Chuong, Nguyen Van Tien (2018), Measuring carbon storage capacity of perennial crop by gis and remote sensing technology in Bo Trach district, Quang Binh province; Hue University Journal of Science: Agriculture and Rural Development ,Vol 127, No 3A, 2018, pp 49-66 Pham Quoc Trung, Nguyen Duc Hoang, Nguyen Quang Tan, Nguyen Hoang Khanh Linh, Huynh Van Chuong (2019), ”Dyna-Clue application for modeling land use change: A case study in Bo Trach District, Quang Binh province, VietNam”, 2019 Joint International Conference on Science, Technology and Innovation, Mandalay by IEEE ... Khanh Linh Assoc Prof Dr Huynh Van Chuong Hue - 2022 This dissertation has been completed at: University of Agriculture and Forestry, Hue University SUPERVISORS: Assoc Prof Dr Nguyen Hoang Khanh... People's Committee regularly updates the annual land change on the map and makes an annual change schedule to monitor and manage the land more closely and effectively - For the People's Committee of... INTRODUCTION Statement of problem Climate change is always a hot issue to argue It' s not just a matter of a country but a common problem of the whole society Climate change is the change of climate