ACKNOWLEDGEMENT With the consent of Vietnam National University of Forestry, Faculty of Forest resources and Environment Management, I carried out the thesis named “Floodplain development in Bui river due to land use change from 2004 to 2015 “ On the occasion of completing the thesis, I would like to express deep gratitude to Dr Bui Xuan Dung who has guided and helped me in the process of the implementation and the completion of this study I sincerely thank Dr Chu Ngoc Thuan in Global Institute for Water Security, University of Saskatchewan for his valuable and constructive suggestions during the planning of this research work His willingness to give his time so generously has been very much appreciated I wish to extend my thanks to express my heartfelt gratitude to Dr Chu Thi Binh and Msc Vu Xuan Dinh in Faculty of Economics and Business Administration for the encouragements and suggestions and for helping me to improve the quality of my study I would also like to express my gratitude to the staffs working in Chuong Mi People Committee and Luong Son People Committee for the enthusiastic help during my works I also place on record, my sense of gratitude to one and all who, directly or indirectly, have lent their helping hand in this venture Due to the limited knowledge and experiences, this report is not finalized yet I am looking forward to receiving feedback from teachers and friends to improve this thesis CONTENTS ABSTRACT I INTRODUCTION 1.1 Introduction 1.2 Literature review 1.2.1 Introduction of GIS, HECRAS and HEC-GeoRAS 1.2.2 Application of GIS, HECRAS and HEC-GeoRAS in modeling floods II GOALS AND SPECIFIC OBJECTIVES 2.1 Goals 2.2 Specific objectives III STUDY AREA AND METHODS 3.1 Selection of research site 3.1.1 Natural conditions 3.1.2 Socio characteristics 10 3.2 Methods 10 3.2.1 Secondary data collection 10 3.2.2 Fieldwork 11 3.2.3 Data processing 14 IV RESULTS AND DISCUSSION 18 4.1 Characteristics of hydrological conditions and land-use/cover change in Bui river basin 18 4.1.1 Characteristics of hydrological conditions in Bui river from 2004 to 2016 18 4.1.2 Situation of Land-use in Bui river basin from 2004 to 2016 20 4.2 Floodplain characteristics in Bui river for different flood events 23 4.3 Evaluation of the interactions between changes in land-use/cover, hydrological conditions and floodplain 26 4.4 Possible solutions to enhance corridor management for sustainable development 29 VI CONCLUSION AND RECOMMENDATIONS 31 6.1 Conclusion 31 6.2 Recommendations 31 REFERENCES 32 APPENDIX 35 LIST OF ABRREATION DEM: Digital Elevation Model HECRAS: Hydrologic Engineering Centers River Analysis System GIS: Geographic Information System TIA: Total impervious area TIN: Triangle Irregular Network LIST OF TABLE Table 3.1 Data collection 13 Table 4.1 Correlation of rainfall, water surface elevation, floodplain areas 25 LIST OF FIGURE Figure 1.2 GIS components Figure 3.1 Map of study area Figure 3.2 Vietnam rain gage 11 Figure 3.3 Sampling diagram 11 Figure 3.4 Example of cross-sectional measurement 12 Figure 3.5 Diagram of floodplain mapping process 14 Figure 3.6 Profile plots of water surface for five flood events: July 11 th 2006, June 21st 2010, August 23rd 2012, September 25th 2013 16 Figure 3.7 Triangular irregular networks (TIN) model of study site 17 Figure 4.1 The response of monthly rainfall and monthly discharge from 2004 to 2015 18 Figure 4.2 Relationship between annual rainfall and runoff in Bui river from 2004 to 2015 .19 Figure 4.3 Relationship between annual rainfall and runoff in Bui river from 2004 to 2015 .20 Figure 4.4 Land-use map of Bui river basin in 2005 21 Figure 4.5 Land-use map of Bui river basin in 2010 21 Figure 4.6 Land-use map of Bui river basin in 2014 22 Figure 4.7 Fluctuation of land use categories in Bui river basin in 2005, 2010, 2014 23 Figure 4.8 Model of floodplain in Bui river in different flood events: a) July 11 th 2006, b) June 21st 2010, c) August 23rd 2012, d) September 25th 2013 24 Figure 4.9 Fluctuation of width and water surface elevation in cross section 2,3,4 in four flood events 25 Figure 4.10 The relationship between experimental width and simulated width 26 Figure 4.11 The response of rainfall and water surface level in Lam Son station 28 Figure 4.12 The relationship between percentage of total impervious area and floodplain area in Bui river 28 ABSTRACT Floodplains are land areas adjacent to rivers that are subjected to recurring inundation Due to their continually changing nature, floodplains need to be examined in view of how it might be affected by land-use/cover change This study will focus on issues that arise in Bui river belonging to Hoa Binh province and Hanoi capital For finding out the impacts of land-use/cover change in floodplain, four different flood events that have equivalent rainfall are chosen during the period of 2004 - 2015 The extent of floodplain was determined by using Hydrologic Engineering Centers River Analysis System (HEC-RAS) coupled with HEC-GeoRAS which is an useful tool in ArcGIS Water surface profile data exported from HEC-RAS simulations were processed by HEC-GeoRAS for floodplain mapping The result shows that (1) there is a relationship between annual rainfall and annual runoff shown by the equation y = 0.6093x – 42.176 (x is annual rainfall and y is annual runoff) (R2 = 0.9948) (2)Bui river had witnessed the change in land-use within its basin: the built-up area which are impervious surface including residential area, industrial zone, transportation system and many public areas increased by 2.89%; the forest land also increased by 9.15%; however, the unused land and agricultural land decreased by 5.66% and 3.62% over the period (3) The total impervious area in Bui river basin has close relationship with floodplain area shown by the equation y = 4.9064x + 10.47 (x is % total impervious area and y is floodplain area) (R2 = 0.97 ≈ 1) Although the rainfall in four different flood events are nearly equivalent or even decreasing, the water surface elevation had increasing trend Correspondingly, it is evident to prove the impact of land-use change on floodplain in Bui river I INTRODUCTION 1.1 Introduction Vietnam has 2360 rivers and canals that have 220000 km in length Only about 19% (41900 km) is considered navigable and 7% (15436 km) has been placed under management (Luis C Blancas and M.Baher El-Hifnawi 2014) In terms of climate conditions, our country has tropical monsoon climate that brings frequently much of rain Therefore, floodplains play significant roles Floodplains are areas adjacent to rivers, ponds, lakes, and oceans that are periodically flooded by lateral overflow at different points in time Floodplains are hydrologically important, environmentally sensitive, and ecologically productive areas that perform many natural functions Although flooding occurs naturally along every river and coastal areas, floodplains are beneficial because of storage and conveyance, protection of water quality, and recharge of groundwater Not only that but it also provides a variety of habitats for fish and other animals There is a fact that land cover change can have adverse impacts on floodplains Land cover change is caused by human demand Floodplain wetlands of big rivers have been impacted by many anthropogenic activities, including draining, conversion, and chemical and physical alteration resulting from land and water management practice (James Kriz et al., 2007) For example, people clear land in the river banks in order to practice farming such as growing vegetables, raising animal husbandry They impact the adjacent areas of river by constructing infrastructures like bridge, building, etc Unexpectedly, due to the growth of population people need more land than before That is the reason in some cases they encroach the floodplains for their own purposes The floodplain development may be a threat to the water quality, the level of storage, conveyance and also destroys the habitat of many aquatic organisms In the viewpoints of economists and sociologists, the dynamics of floodplain can enhance the risk of flood hazard, especially in flooding season The unpredictable water level easily inundates the low areas and consequently, floodplain development may cause severe economic disruption and loss of human life in densely populated region In Vietnam, the situation of floodplain management gets difficulties One key reason is that there are not clear floodplain management strategies In Gia Vien district, Ninh Binh province, there are more than 10 yards used for manufacturing, trading and gathering building materials in the outer dike This action narrows Hoang Long river, causes traffic jam and threats the safety of floodplain, especially during the flooding seasons (Van Phuc and Tien Khanh 2016) Another illegal action occurs in Phu Tho province Not only did the Northwest Mineral Corporation build houses within floodplain without permission, they ignored the dismantling command of local administration (Bui Anh 2016) The examples show the lack of interests to floodplain management Bui river is a tributary of Day river It is 91 kilometers in length and has 1249 km2 of basin area (Nguyen Thuy Duong, 2016) It originates from Lam Son commune (Luong Son district, Hoa Binh province) and flows to Phuc Lam commune (Chuong Mi district, Hanoi) before unifying with Day river Through a long time, Bui river catchment has experienced significant change in land use and land cover As a consequence, flood regime and floodplain in Bui river also have been impacted However, up to now, there are not any studies on impacts of land use/cover change to hydrological condition and floodplain development in Bui river Therefore, I choose to carry out this study named “Floodplain development in Bui river due to land-use change from 2004 to 2015” 19 0.570 0.570 0.507 0.542 0.391 0.688 1.140 24.600 1.330 0.933 0.816 0.671 20 0.570 0.539 0.570 0.572 0.433 0.671 1.420 7.440 1.280 0.933 0.854 0.671 21 0.570 0.507 0.570 0.507 0.448 0.587 0.836 5.320 1.240 0.933 1.770 0.671 22 0.570 0.539 0.477 0.477 0.433 0.587 0.723 4.220 1.190 0.913 1.020 0.636 23 0.570 0.539 0.477 0.449 0.539 0.603 0.636 8.100 1.240 0.894 0.977 0.636 24 0.570 0.570 0.539 0.419 0.620 0.636 0.636 4.320 1.190 0.894 0.933 0.636 25 0.570 0.539 0.539 0.447 0.555 0.636 0.570 3.460 1.190 1.910 0.894 0.636 26 0.570 0.570 0.477 0.447 0.694 0.723 0.570 3.140 2.800 1.510 0.894 0.570 27 0.539 0.477 0.507 0.365 0.818 0.603 0.539 3.110 1.920 1.190 0.854 0.636 28 0.507 0.477 0.477 0.447 0.875 0.620 0.570 2.640 1.430 1.060 0.854 0.671 29 0.570 0.477 0.447 0.723 0.554 3.910 2.580 1.280 0.977 0.854 0.636 30 0.570 0.419 0.447 0.671 0.743 3.170 2.740 1.280 0.977 0.854 0.603 31 0.570 0.391 10.300 2.580 39.984 143.517 Total (m3/s) 18.566 Total (year) 421.346 15.304 15.779 0.636 13.353 17.708 21.272 66 0.955 52.900 34.015 0.636 26.807 22.141 2007 Tháng I II III IV V VI VII 0.636 0.570 0.539 0.419 0.462 0.636 0.705 0.636 0.570 0.507 0.447 0.447 0.587 0.636 0.570 0.477 0.447 0.365 0.636 0.539 0.477 0.447 0.636 0.507 0.507 0.636 0.570 0.636 VIII IX X XI XII 3.070 2.300 1.240 0.894 0.854 0.761 1.900 2.060 1.280 0.894 0.778 1.020 0.778 1.350 2.060 1.190 0.894 0.816 0.433 1.240 0.689 1.430 1.920 1.170 0.894 0.816 0.447 0.492 0.743 0.636 1.120 1.730 1.080 0.816 0.816 0.507 0.447 0.492 0.636 0.862 0.997 1.630 1.060 0.933 0.778 0.570 0.507 0.507 0.478 0.636 0.962 7.110 1.520 1.060 0.894 0.778 0.636 0.570 0.539 0.477 0.527 0.620 0.707 2.690 2.340 1.220 0.854 0.778 0.636 0.570 0.570 0.507 0.802 0.570 0.636 1.950 4.160 1.130 0.854 0.778 10 0.636 0.570 0.570 0.507 0.733 0.688 0.570 1.530 2.520 1.020 0.816 0.778 11 0.636 0.570 0.539 0.419 0.778 0.636 1.430 1.330 2.180 1.280 0.816 0.778 12 0.636 0.570 0.507 0.419 0.742 0.671 1.350 1.480 1.950 1.220 0.778 0.778 13 0.636 0.570 0.539 0.365 0.637 0.671 1.190 1.260 1.700 1.060 0.816 0.778 14 0.636 0.570 0.539 0.338 0.603 0.636 0.836 1.130 1.630 1.020 0.816 0.742 15 0.636 0.507 0.507 0.365 0.524 1.150 0.689 1.060 1.630 0.998 0.816 0.705 16 0.570 0.507 0.507 0.391 0.477 0.798 0.636 1.860 1.470 0.998 0.816 0.705 17 0.570 0.507 0.507 0.419 0.447 1.030 0.671 11.300 1.400 0.955 0.816 0.705 18 0.570 0.570 0.507 0.419 0.433 0.653 0.856 26.700 1.330 0.955 0.816 0.671 Ngày 67 19 0.570 0.570 0.507 0.542 0.391 0.688 1.140 24.600 1.330 0.933 0.816 0.671 20 0.570 0.539 0.570 0.572 0.433 0.671 1.420 7.440 1.280 0.933 0.854 0.671 21 0.570 0.507 0.570 0.507 0.448 0.587 0.836 5.320 1.240 0.933 1.770 0.671 22 0.570 0.539 0.477 0.477 0.433 0.587 0.723 4.220 1.190 0.913 1.020 0.636 23 0.570 0.539 0.477 0.449 0.539 0.603 0.636 8.100 1.240 0.894 0.977 0.636 24 0.570 0.570 0.539 0.419 0.620 0.636 0.636 4.320 1.190 0.894 0.933 0.636 25 0.570 0.539 0.539 0.447 0.555 0.636 0.570 3.460 1.190 1.910 0.894 0.636 26 0.570 0.570 0.477 0.447 0.694 0.723 0.570 3.140 2.800 1.510 0.894 0.570 27 0.539 0.477 0.507 0.365 0.818 0.603 0.539 3.110 1.920 1.190 0.854 0.636 28 0.507 0.477 0.477 0.447 0.875 0.620 0.570 2.640 1.430 1.060 0.854 0.671 29 0.570 0.477 0.447 0.723 0.554 3.910 2.580 1.280 0.977 0.854 0.636 30 0.570 0.419 0.447 0.671 0.743 3.170 2.740 1.280 0.977 0.854 0.603 31 0.570 0.391 10.300 2.580 39.984 143.517 Total (m3/s) 18.566 Total (year) 421.346 15.304 15.779 0.636 13.353 17.708 68 21.272 0.955 52.900 34.015 0.636 26.807 22.141 2008 Tháng Ngày I II III IV V VI VII VIII IX X XI XII 0.981 1.020 0.837 0.769 0.819 1.320 3.380 2.130 2.160 4.060 34.600 2.720 0.981 1.020 0.837 0.802 0.837 2.090 3.050 4.180 2.110 3.670 22.900 2.720 0.981 0.981 0.802 0.802 0.819 1.470 2.440 2.790 2.130 3.460 15.000 2.610 0.981 0.981 0.802 0.802 0.937 1.250 2.100 2.410 2.210 3.290 10.600 2.610 0.981 0.981 0.802 0.802 0.871 1.300 1.980 2.270 3.300 3.260 8.260 2.550 0.981 0.981 0.769 0.769 0.871 1.250 3.880 2.160 2.750 3.100 6.870 2.550 0.981 0.981 0.769 0.769 0.854 1.230 2.610 3.240 2.410 2.970 6.110 2.610 0.981 0.907 0.802 0.736 0.802 1.230 2.240 9.240 2.240 2.910 5.950 2.610 1.020 0.907 0.802 0.705 1.260 1.130 2.130 4.180 2.160 2.880 5.140 2.610 10 0.981 0.907 0.802 0.736 1.960 1.150 1.950 3.670 2.300 2.780 4.740 2.550 11 0.981 0.907 0.837 0.705 1.190 1.090 1.980 3.330 2.320 3.000 4.510 2.490 12 0.981 0.907 0.837 0.673 1.080 1.090 2.050 3.000 2.730 2.810 4.210 2.490 13 0.981 0.907 0.802 0.736 1.000 1.130 1.980 2.750 2.320 2.750 4.060 2.490 14 0.981 0.907 0.769 0.736 0.981 1.230 1.850 2.610 2.290 2.750 3.910 2.490 15 0.981 0.907 0.802 1.450 0.942 1.170 3.120 2.490 2.180 2.880 3.770 2.440 16 0.981 0.907 0.802 1.060 0.942 1.170 5.580 2.400 2.080 2.780 3.630 2.380 17 0.981 0.907 0.802 0.872 0.907 1.510 7.740 2.350 2.050 2.690 3.490 2.380 18 0.981 0.837 0.802 0.837 1.240 2.220 8.170 2.320 2.000 2.580 3.360 2.430 19 0.981 0.802 0.802 0.802 1.430 2.320 5.070 2.320 1.980 2.660 3.360 2.380 69 20 0.907 0.837 0.769 0.736 1.250 3.330 4.590 2.270 1.950 2.660 3.230 2.380 21 0.981 0.907 0.769 0.736 1.130 2.970 4.600 2.210 2.000 2.660 3.230 2.380 22 0.981 0.837 0.837 0.769 1.070 1.850 3.360 2.160 1.980 2.630 3.230 2.430 23 0.942 0.802 0.769 0.907 1.060 1.750 3.030 2.160 1.930 2.630 3.100 2.380 24 0.907 0.837 0.837 0.907 1.020 1.900 3.010 2.100 1.900 2.850 3.100 2.380 25 0.942 0.871 0.769 0.871 1.020 1.600 2.690 2.100 2.360 2.660 2.970 2.380 26 0.942 0.871 0.802 0.871 0.981 2.340 2.550 2.210 2.380 2.910 2.910 2.380 27 0.942 0.871 0.802 0.837 0.981 3.630 2.400 2.080 26.900 3.290 2.970 2.490 28 0.942 0.871 0.769 0.837 0.981 5.360 2.320 2.030 5.820 2.910 2.850 2.430 29 0.942 0.871 0.769 0.837 0.924 3.340 2.240 1.950 4.240 2.750 2.850 2.430 30 0.942 0.736 0.802 1.970 2.410 2.160 1.950 3.950 6.350 2.780 2.380 31 0.942 0.736 2.130 2.530 98.380 85.590 Total (m3/s) 29.990 Total (year) 890.134 26.229 24.643 2.140 24.673 34.269 70 56.830 54.200 99.130 145.780 2.380 187.690 76.930 2010 I II III IV V VI VII IX X XI XII 0.948 0.879 0.812 0.780 0.880 0.949 1.020 1.330 2.890 2.300 1.390 1.170 0.948 0.879 0.780 0.812 0.880 0.950 0.932 1.230 2.570 2.170 1.330 1.170 0.948 0.879 0.748 0.780 0.796 0.984 0.829 1.150 2.380 2.040 1.330 1.130 0.948 0.879 0.780 0.812 0.748 0.896 0.764 1.090 2.140 1.960 1.330 1.090 0.914 0.879 0.748 0.780 0.733 0.862 0.733 3.980 2.040 1.940 1.330 1.090 0.948 0.879 0.748 0.748 0.671 0.846 0.671 1.780 1.960 1.820 1.330 1.090 0.948 0.879 0.748 0.748 0.672 0.866 0.627 1.390 1.990 1.770 1.310 1.170 0.948 0.879 0.846 0.780 0.672 0.896 0.673 1.250 1.970 1.730 1.250 1.170 0.914 0.846 0.812 0.812 0.672 0.829 0.814 1.210 1.820 1.680 1.250 1.130 10 0.948 0.812 0.812 0.812 0.826 0.764 0.796 1.170 1.730 1.660 1.230 1.090 11 0.879 0.812 0.748 0.812 1.190 0.780 0.702 1.150 1.680 1.590 1.190 1.020 12 0.879 0.846 0.780 0.780 1.000 0.748 0.814 1.150 1.820 1.590 1.230 1.090 13 0.879 0.879 0.748 0.748 0.880 1.030 0.934 1.110 1.820 1.660 1.250 1.060 14 0.879 0.879 0.748 0.780 0.764 0.985 0.984 1.060 4.930 2.190 1.210 1.130 15 0.879 0.948 0.748 0.812 0.796 0.703 0.862 1.020 4.330 2.210 1.230 1.170 16 0.879 0.948 0.748 0.846 0.764 0.627 0.703 1.020 2.890 1.940 1.230 1.170 17 0.879 0.948 0.812 0.879 0.748 0.642 0.702 1.020 2.330 2.070 1.190 1.130 18 0.879 0.914 0.780 0.914 0.702 0.599 2.680 1.020 2.040 2.270 1.170 1.090 19 0.879 0.879 0.748 0.948 0.657 0.599 1.400 1.000 1.960 2.120 1.170 1.090 Tháng Ngày 71 VIII 20 0.846 0.879 0.748 0.948 0.627 0.613 1.130 0.966 1.890 1.940 1.170 1.090 21 0.984 0.879 0.748 1.020 0.827 1.320 1.000 1.950 1.820 1.800 1.170 1.090 22 1.210 0.846 0.748 1.020 0.748 1.130 0.948 2.520 3.140 1.700 1.170 1.060 23 1.380 0.812 0.748 1.020 0.733 0.984 0.966 4.240 2.220 1.610 1.170 1.060 24 1.060 0.812 0.748 1.020 0.686 0.862 0.948 5.300 2.060 1.590 1.170 1.090 25 1.020 0.879 0.748 0.914 0.686 0.812 1.760 9.190 6.210 1.570 1.170 1.090 26 1.020 0.846 0.748 0.879 1.530 0.764 2.490 4.390 5.800 1.500 1.230 1.090 27 1.020 0.879 0.748 0.812 1.190 0.613 1.830 7.340 4.070 1.500 1.250 1.060 28 0.948 0.846 0.717 0.812 1.040 0.687 3.040 19.500 3.470 1.430 1.250 1.060 29 0.948 0.717 0.812 1.250 1.300 3.130 6.510 2.710 1.410 1.230 1.020 30 0.948 0.686 0.812 1.090 1.360 1.820 4.500 2.460 1.410 1.170 0.984 31 0.948 0.717 1.550 3.410 38.252 94.946 Total (m3/s) 29.655 Total (year) 496.431 24.421 23.515 1.020 25.452 26.478 72 26.000 1.410 81.140 55.580 0.948 37.100 33.892 2011 I Tháng Ngày II III IV V VI VII VIII IX X XI XII 0.238 0.210 0.210 0.198 0.192 0.204 5.020 6.990 1.810 4.320 1.160 0.740 0.238 0.210 0.210 0.198 0.238 0.286 3.660 9.640 1.650 2.650 1.140 0.617 0.238 0.210 0.186 0.210 0.372 0.211 3.550 5.350 1.550 2.180 1.070 0.515 0.224 0.210 0.198 0.210 0.231 0.357 2.360 3.500 1.490 1.730 1.050 0.515 0.224 0.210 0.210 0.210 0.395 0.735 1.620 2.710 1.520 3.040 0.985 0.484 0.238 0.210 0.210 0.210 0.503 0.745 1.570 15.800 1.420 5.840 0.985 0.484 0.238 0.186 0.224 0.210 0.737 0.648 1.350 5.350 1.290 4.590 0.985 0.515 0.224 0.186 0.238 0.210 0.351 0.571 1.200 8.680 1.220 5.390 1.030 0.587 0.210 0.186 0.210 0.198 0.242 0.351 1.050 5.120 5.240 4.850 0.924 0.515 10 0.224 0.186 0.186 0.186 0.210 0.259 5.800 4.350 4.430 3.550 0.862 0.453 11 0.224 0.186 0.198 0.186 0.284 0.238 2.610 8.230 2.750 2.870 0.821 0.453 12 0.238 0.186 0.186 0.210 0.302 0.238 1.850 5.730 5.300 3.950 0.821 0.453 13 0.224 0.210 0.198 0.176 0.238 0.224 1.440 4.070 7.140 2.960 0.821 0.453 14 0.210 0.210 0.198 0.168 0.238 0.759 2.590 3.210 4.540 8.240 0.801 0.453 15 0.210 0.186 0.332 0.165 0.327 0.738 3.120 2.670 3.800 4.720 0.740 0.484 16 0.210 0.210 0.658 0.186 1.710 0.957 2.110 2.550 3.290 3.250 0.740 0.424 17 0.210 0.224 1.200 0.186 0.684 2.340 1.810 2.380 2.560 2.710 0.720 0.395 18 0.210 0.186 2.200 0.308 0.380 1.010 1.550 2.140 3.570 2.350 0.658 0.395 19 0.210 0.186 0.976 0.224 0.294 0.622 1.560 12.700 3.590 2.180 0.658 0.395 73 20 0.210 0.198 0.424 0.176 0.238 0.929 1.220 23.900 2.870 1.910 0.658 0.395 21 0.224 0.210 0.308 0.176 0.231 0.622 1.140 9.040 2.650 1.810 0.638 0.395 22 0.210 0.210 0.280 0.176 0.224 0.454 1.550 6.340 2.150 1.700 0.658 0.395 23 0.210 0.210 0.238 0.158 2.460 0.410 1.570 4.980 1.950 1.620 0.679 0.395 24 0.210 0.210 0.238 0.150 0.904 7.500 1.360 5.640 1.780 1.490 0.597 0.395 25 0.210 0.210 0.238 0.150 0.551 24.000 1.160 4.060 1.680 1.410 0.576 0.453 26 0.210 0.210 0.238 0.143 0.395 7.990 1.010 3.420 1.550 1.390 0.576 0.424 27 0.210 0.210 0.238 0.143 0.350 6.960 0.903 2.960 2.760 1.330 0.561 0.365 28 0.210 0.198 0.210 0.448 0.283 5.670 0.821 2.599 1.840 1.400 0.515 0.365 29 0.210 0.238 0.338 0.238 3.290 0.781 2.280 1.600 1.480 0.515 0.335 30 0.210 0.238 0.224 0.231 5.370 1.730 2.150 3.440 1.260 31 0.210 0.224 7.720 1.950 66.785 180.489 22.944 13.247 Total (m3/s) 6.776 Total (year) 574.097 5.654 11.340 0.210 6.131 14.243 74 74.688 1.200 82.430 89.370 2012 I II III IV V VI IX X XI XII 0.379 0.274 0.255 0.191 0.121 0.568 10.700 1.710 1.280 0.934 0.553 0.455 0.379 0.221 0.255 0.165 0.121 3.390 7.290 1.260 1.330 0.914 0.524 0.538 0.404 0.238 0.255 0.165 0.113 3.830 3.550 1.080 2.050 0.875 0.524 0.481 0.600 0.292 0.295 0.165 0.093 1.660 2.040 0.972 1.470 1.090 1.300 0.481 0.598 0.292 0.357 0.165 0.230 1.420 2.180 0.934 1.230 1.420 0.730 0.481 0.510 0.292 0.274 0.274 0.655 1.530 1.650 0.915 2.370 1.060 0.646 0.481 0.510 0.292 0.206 0.529 0.385 1.190 1.350 8.050 7.130 1.030 0.583 0.455 0.481 0.292 0.191 0.381 0.276 0.914 1.210 10.500 3.130 0.914 0.538 0.428 0.455 0.292 0.221 0.206 0.246 0.899 1.080 6.100 2.220 0.838 0.586 0.428 10 0.379 0.255 0.221 0.191 0.240 1.170 1.410 3.150 1.870 0.857 0.568 0.404 11 0.357 0.313 0.221 0.165 0.199 0.783 1.170 2.220 1.550 0.800 0.568 0.404 12 0.334 0.313 0.221 0.165 0.285 0.680 1.030 1.810 1.450 0.748 0.553 0.379 13 0.334 0.274 0.206 0.165 0.238 0.598 1.100 1.730 1.560 0.712 0.538 0.379 14 0.334 0.255 0.206 0.165 0.192 0.568 1.130 1.550 1.500 0.712 0.524 0.379 15 0.379 0.255 0.206 0.165 2.760 1.040 0.876 1.350 1.330 0.696 0.524 0.379 16 0.357 0.274 0.191 0.165 0.652 0.713 0.765 1.260 1.210 0.662 0.481 0.379 17 0.334 0.274 0.221 0.229 0.404 0.614 0.729 1.480 1.190 0.662 0.481 0.379 18 0.334 0.255 0.221 0.206 0.324 0.583 0.696 20.800 1.120 0.679 0.481 0.357 Tháng Ngày 75 VII VIII 19 0.292 0.255 0.221 0.206 0.312 0.554 1.270 6.280 1.120 0.646 0.481 0.334 20 0.292 0.255 0.221 0.165 0.293 0.599 0.819 3.870 1.190 0.598 0.468 0.357 21 0.334 0.255 0.191 0.295 0.238 0.568 0.748 2.830 1.050 0.583 0.428 0.357 22 0.334 0.255 0.191 0.238 1.430 0.524 0.663 2.380 1.140 0.598 0.416 0.379 23 0.334 0.255 0.191 0.191 1.770 0.618 0.696 5.460 1.010 0.583 0.404 0.379 24 0.334 0.255 0.191 0.178 1.510 0.510 0.646 2.940 0.992 0.583 0.416 0.357 25 0.334 0.238 0.191 0.154 3.600 0.442 0.819 2.280 0.953 0.538 0.428 0.334 26 0.334 0.221 0.191 0.154 3.920 0.416 0.915 1.900 1.570 0.553 0.428 0.334 27 0.334 0.238 0.165 0.124 1.780 0.416 3.270 1.680 1.120 0.568 0.538 0.379 28 0.334 0.255 0.165 0.117 1.170 0.456 2.330 1.810 0.972 0.650 0.648 0.379 29 0.334 0.255 0.165 0.117 0.839 0.693 3.520 1.470 0.914 0.979 0.553 0.379 30 0.334 0.165 0.124 0.788 0.481 4.410 1.350 0.953 0.679 0.495 0.357 31 0.313 0.178 2.640 1.300 62.702 102.421 Total (m3/s) 11.695 Total (year) 351.897 7.690 6.649 0.697 5.920 25.881 76 28.427 0.646 47.974 23.807 0.334 16.405 12.326 2013 I II III IV V VI VII IX X XI XII 0.323 0.261 0.225 0.225 1.260 0.412 1.560 2.680 1.380 2.250 0.960 0.483 0.302 0.261 0.208 0.225 2.010 1.190 1.040 2.490 1.270 2.120 0.920 0.483 0.302 0.261 0.208 0.225 0.576 1.150 0.840 16.000 1.190 1.810 0.880 0.483 0.347 0.261 0.194 0.244 0.483 0.599 0.739 8.480 2.330 1.640 0.820 0.483 0.371 0.302 0.194 0.159 0.347 0.488 0.664 3.860 6.070 1.590 0.758 0.453 0.323 0.302 0.169 0.138 0.677 0.594 0.594 2.790 4.120 1.520 0.739 0.423 0.323 0.225 0.148 0.158 0.809 0.934 1.210 7.850 2.620 1.380 0.682 0.423 0.323 0.225 0.138 0.148 0.412 0.629 1.090 23.400 5.770 1.250 0.701 0.423 0.323 0.410 0.138 0.138 0.302 0.483 0.968 19.700 3.720 1.250 0.758 0.423 10 0.323 0.410 0.158 0.169 0.280 2.640 0.920 8.660 2.640 1.230 0.839 0.423 11 0.302 0.410 0.159 0.169 0.261 1.510 0.760 5.540 2.250 1.150 1.110 0.423 12 0.323 0.410 0.138 0.180 0.225 0.860 0.722 3.960 4.430 1.080 0.820 0.423 13 0.323 0.410 0.148 0.169 0.194 0.629 0.720 3.000 3.040 1.080 0.739 0.423 14 0.303 0.410 0.138 0.158 0.169 0.527 0.612 2.470 2.420 1.060 0.682 0.423 15 0.280 0.261 0.138 0.138 0.164 0.468 0.542 2.220 2.040 1.210 0.664 0.453 16 0.280 0.280 0.138 0.148 0.144 0.423 0.527 1.960 1.860 1.060 0.682 0.577 17 0.323 0.261 0.158 0.140 0.125 0.384 0.597 1.660 2.390 2.850 0.682 0.453 18 0.302 0.241 0.148 0.169 0.166 0.371 0.594 1.840 1.760 4.320 0.647 0.423 19 0.280 0.225 0.130 0.138 0.180 0.412 0.962 2.170 1.660 2.680 0.611 0.423 Tháng Ngày 77 VIII 20 0.280 0.241 0.138 0.140 0.175 0.347 0.683 3.110 3.480 1.910 0.611 0.423 21 0.280 0.280 0.138 0.114 0.242 0.312 0.648 2.510 2.640 1.570 0.611 0.423 22 0.280 0.280 0.138 0.106 0.164 0.314 2.090 2.740 1.930 1.450 0.611 0.397 23 0.280 0.280 0.138 0.140 0.257 0.842 2.070 2.090 1.690 1.270 0.611 0.371 24 0.280 0.241 0.158 0.158 0.291 7.620 1.550 1.710 1.710 1.170 0.577 0.371 25 0.280 0.225 0.158 0.122 0.483 2.470 1.110 1.640 3.150 1.150 0.527 0.371 26 0.280 0.208 0.158 0.138 0.637 1.540 1.600 1.690 11.700 1.060 0.483 0.347 27 0.280 0.225 0.148 0.138 0.327 1.170 3.980 1.420 5.420 1.000 0.527 0.347 28 0.261 0.241 0.121 0.130 0.304 0.960 7.800 1.330 3.520 0.980 0.594 0.347 29 0.261 0.106 0.122 0.261 0.780 7.010 1.420 2.710 0.980 0.420 0.347 30 0.280 0.114 0.100 1.040 1.610 10.200 1.290 2.280 0.980 0.498 0.302 31 0.280 0.225 4.880 1.660 59.282 143.340 Total (m3/s) 9.298 Total (year) 449.580 8.047 4.815 0.728 4.646 13.693 78 32.668 0.940 93.190 46.990 0.280 20.764 12.847 2014 I II III IV V VI VII IX X XI XII 0.274 0.317 0.366 0.203 0.544 0.420 1.550 0.366 1.510 2.480 1.370 0.900 0.317 0.317 0.366 0.203 0.366 0.274 5.260 0.366 7.290 2.330 1.280 0.900 0.317 0.317 0.317 0.203 0.355 0.236 3.240 1.150 2.950 2.220 1.280 1.000 0.317 0.317 0.317 0.203 0.319 0.203 1.440 0.485 1.950 2.140 1.280 1.000 0.317 0.317 0.366 0.236 0.485 0.366 1.070 0.420 1.530 2.170 1.280 1.000 0.317 0.317 0.317 0.317 0.370 0.236 0.903 0.366 1.280 2.120 1.280 0.900 0.317 0.317 0.317 0.317 0.270 0.420 0.788 0.420 1.090 2.020 1.280 0.900 0.317 0.317 0.274 0.317 0.270 0.366 0.638 0.420 1.000 1.920 1.460 0.900 0.317 0.317 0.274 0.317 0.270 0.274 0.541 0.420 1.020 1.840 1.370 0.900 10 0.317 0.317 0.274 0.955 0.270 0.317 0.541 0.366 1.480 1.840 1.280 0.900 11 0.317 0.317 0.274 0.485 0.240 0.420 0.523 0.317 1.210 1.770 1.280 0.900 12 0.317 0.317 0.274 0.485 0.270 0.366 0.469 0.274 0.878 1.730 1.280 0.900 13 0.317 0.317 0.274 0.420 0.270 0.274 0.469 2.340 0.810 1.630 1.180 0.900 14 0.317 0.317 0.274 0.420 0.270 0.789 0.436 1.280 0.765 1.580 1.180 0.810 15 0.317 0.317 0.317 0.366 0.200 0.659 0.407 0.810 0.788 1.540 1.180 0.810 16 0.317 0.317 0.317 0.317 0.200 0.423 0.366 0.635 0.765 1.490 1.090 0.720 17 0.317 0.366 0.274 0.274 0.180 0.329 0.560 0.560 7.860 1.650 1.180 0.810 18 0.317 0.366 0.236 0.274 0.180 3.880 0.485 0.485 3.720 1.560 1.180 0.810 19 0.317 0.366 0.236 0.236 0.810 2.550 0.420 0.420 2.670 1.560 1.090 0.810 Tháng Ngày 79 VIII 20 0.317 0.366 0.236 0.274 0.370 1.020 0.900 0.485 2.960 1.460 1.090 0.810 21 0.317 0.366 0.317 0.274 0.270 0.659 1.170 0.420 41.400 1.460 1.090 0.810 22 0.317 0.366 0.366 0.274 0.240 0.579 1.000 0.366 9.230 1.750 1.000 0.810 23 0.317 0.366 0.366 0.236 0.200 0.560 0.635 0.366 5.790 1.560 1.000 0.720 24 0.317 0.366 0.420 0.277 0.160 0.673 0.485 0.380 4.180 1.460 1.000 0.635 25 0.317 0.366 0.366 0.274 0.160 0.410 0.420 0.415 3.830 1.460 1.000 0.720 26 0.317 0.366 0.274 0.296 0.160 0.439 0.560 0.730 3.380 1.460 1.000 0.720 27 0.317 0.366 0.274 3.190 0.200 0.380 0.560 0.600 3.140 1.460 0.900 0.720 28 0.317 0.366 0.236 0.733 0.420 0.428 0.420 0.773 3.140 1.840 0.900 0.810 29 0.317 0.236 0.393 0.240 0.409 0.420 9.170 2.810 1.750 0.900 0.810 30 0.317 0.236 0.570 0.240 0.354 0.420 3.520 2.670 1.840 0.900 0.720 31 0.317 0.203 0.420 1.920 27.516 31.045 Total (m3/s) 9.784 Total (year) 366.840 9.464 9.194 0.970 13.339 9.769 80 18.713 1.560 123.096 54.650 0.635 34.580 25.690 ... conditions in Bui river change from 2004 to 2015? 2) What are the changes of land- use/ cover in Bui river basin from 2004 to 2015? 3) Does land- use change have any influences on floodplain of Bui river? ... hydrological condition and floodplain development in Bui river Therefore, I choose to carry out this study named ? ?Floodplain development in Bui river due to land- use change from 2004 to 2015? ?? 1.2 Literature... to examine the impact of land- use/ cover change on floodplain in Bui river from 2004 to 2015 2.2 Specific objectives - To investigate the hydrological conditions and land use/ cover change in Bui