THAI NGUYEN UNIVERSITY UNIVERSITY OF AGRICULTURE AND FORESTRY JOSE ALBERTO UMALI DUNCA SOIL EROSION MODELING USING GEOGRAPHICAL INFORMATION SYSTEM: RESEARCH STUDY IN BINH GIA DISTRICT, LANG SON PROVINCE BACHELOR THESIS Study Mode: Full-time Major: Environmental Science and Management Batch: 2012-2016 Thai Nguyen, 2016 i n Thai Nguyen University of Agriculture and Forestry Degree program Bachelor of Environmental Science and Management Full name Jose Alberto Umali Dunca Student ID DTN1353110554 Soil Erosion Modeling Using Geographical Information Thesis title System: Research Study In Binh Gia District, Lang Son Province Supervisor MSC. NGUYEN VAN HIEU Supervisor Signature Abstract: Land area is one major component in the progress of the world’s biophysical resources. Nowadays, soil erosion is an emerging topic regarding in the land’s degradation. Erosion whether by the subjects’ water, wind, or tillage; involves three (3) diverse actions – soil detachment, movement and deposition.
Soil erosion is not just an ecological issue in Vietnam in general; additionally flash flooding is a significant danger to human life and property. Binh Gia District is located75 kilometers far from the capital city of the province which is Lang Son City. It is located in the tropical monsoon climate, influenced by the general climate of the north; the climate is humid tropical monsoon. Average annual rainfall is 1,540 mm, and during the rainy season is 212 mm per month.
RUSLE is an erosion model designed average soil losses from sheet and rill erosion under specified condition and was developed by Wischmeier and ii n Smith in 1978. However, there are significant limitations due the model only estimates rill and inter-rill erosion, this means that no wind erosion was taken in consideration for the simulation.By the used of GIS technology, this method was adapted by the researcher in conducting a case study in Binh Gia District to model soil erosion. The result of the analysis showed that the amount of soil loss in the research area ranges from 0 to 5893. Furthermore the total soil loss in the area was about 80169 ton per year from 11.
Soil Erosion, RUSLE Method, Geographical Keywords Information System (GIS) Number of pages 59 Date of submission iii n Acknowledgements First of all I want to express my sincerest gratitude to my Research Adviser MSc. Nguyen Van Hieu to this support to my Bachelor’s Thesis, as well as for his patience, motivation, and great knowledge. His guidance has helped me from the beginning, from learning at first, and all throughout my research and for the writing of this thesis as well. My special thanks also to his assistants for their support to the completion of my paper.
Deepest thanks to Laguna State Polytechnic University Siniloan Campus, Siniloan, Laguna to their recommendation to us to study abroad, and also to Thai Nguyen University of Agriculture and Forestry to their acceptance to study full-time in their University with a 100% scholarship. Sincere thanks also to Nguyen Vu Tuan Anh, Jimlea Nadezhda Mendoza, Keraia Vince Geronimo, and Paul Ezekiel Losaria for always around to help, and share their knowledge for me to finish my study. Last but not the least, I want to thank God for everything he gave to us; for my family, my aunt and uncle, grandma and grandpa for their love, supports and their challenges for me to study hard and be a better student than before. And for my Dad, this is for you.
Thai Nguyen, 2016 Student Jose Alberto Umali Dunca iv n Table of Contents Table of Contents. v LIST OF FIGURES. 1 LIST OF TABLES. 2 LIST OF ABBREVIATION.
Background and rationale. Geographical Information System (GIS). Collecting and selecting data. The Revised Universal Soil Loss Equation (RUSLE).
The natural conditions and socioeconomic in research area (Binh Gia District). Area’s Climate and weather. Digital Elevation Model Map of Binh Gia District. Result of soil erosion map.
Rainfall Erosivity Factor (R). Soil Erodibility Factor (K). Slope length and Slope steepness factor (LS). Erosion Management Practice Factor (P).
Map editor (In ArcGIS 10. DISCUSSION AND CONCLUSION. 59 vi n LIST OF FIGURES Figure 3.1 Diagrams of RUSLE Method Figure 3.2 Diagrams of Calculating LS Factor Figure 4.1 Binh Gia District Map Figure 4.2 DEM of Binh Gia District Figure 4.3 Rainfall Erosivity Map (Factor R) Figure 4.4 Soil Erodibility Map (Factor K) Figure 4.5 Slope Map of Binh Gia District Figure 4.6 Slope Steepness (Factor S) Figure 4.7 Flow Directions and Accumulation Figure 4.8 Factor M and F Figure 4.9 Slope Lengths (Factor L) Figure 4.10 Topographic Map (Factor LS) Figure 4.11 Normalized Difference Vegetation Index Map Figure 4.12 Crop Management Map (Factor C) Figure 4.13 Soil Loss Map of Binh Gia Figure 4.14 Soil erosion chart Figure 4.15 Date Frame Tool Figure 4.16 Map Locator Figure 4.17 Other map elements Figure 4.18 Edited Soil Erosion Map of Binh Gia District 1 n LIST OF TABLES Table 3.1 K Factor Value in Northern Part of Vietnam Table 3.2 Coefficient of Vegetation in Vietnam Table 4.1 Soil Erosion Value in every commune 2 n LIST OF ABBREVIATION ADB: Asian Development Bank DBMS: Database Management System DEM: Digital Elevation Model ESRI: Environmental Systems Research Institute ETM: Enhanced Thematic Mapper FAO: Food And Agriculture Organization GIS: Geographical Information System IDW: Inverse Distance Weighted MNF: Minimum Noise Fraction MSEC: Management Of Soil Erosion Consortium NDVI: Normalized Difference Vegetation Index PLER: Predict And Localize Erosion And Runoff RUSLE: Revised Universal Soil Loss Equation SLR: Soil Loss Ratio SMA: Spectral Mixture Analysis SWAT: Soil And Water Assessment Tools TIN: Triangulated Irregular Network USLE: Universal Soil Loss Equation USPED: Unit Stream Power Erosion/Deposition WCP: World Climate Programme 3 n PART I. Background and rationale Land area is to be deliberated as the one important geographic sector in the progress advancement of the world's biophysical assets (Bakimchandra, 2011).
Impacts of soil erosion picking up the danger of lessening area accessibility and crisp water accessible per capita, in this way, nourishment security and manageable advancement are vital issues in the low accessible area per capita nations (Dercon et al., 2012), for example, in Vietnam. The essential reason of soil erosion are ecological debasement, for example, deforestation, heightened land use, and the expanding scene populace (Ahmed et al., 2010), atmosphere and morphological conditions, for occurrence high concentrated precipitation, steep hill slopes. Sometime ago in tropical locales, the top soil layer was regularly ensured by thick vegetation spread, root frameworks (Kefi et al. Soil erosion is not just an ecological issue in Vietnam in general; additionally flash flooding is a significant danger to human life and property.
Flash floods are characterized as remarkable floods delivered by extreme precipitation, over rapidly reacting of catchments and happen inside six hours of the causal precipitation occurrences. Binh Gia District is located in the hilly and mountainous part of Lang Son Province. Binh Gia’s population is 53 214 and covering land area of 1,091 km2. Binh Gia district is fragmented by rocky hills that have a slope of 25-300 or more.
The valley is narrow that annual crops are not much, leading to low revenue. It is located in the tropical monsoon climate, influenced by the general climate of the north; the 4 n climate is humid tropical monsoon. The districts have cold winter; and dry, hot, humid, and rainy summer. The average temperature is 20°c and the temperature ranges from -1°c to 37°c.
Surface water in Binh Gia is abundant. Bac Giang River is an important source of water irrigating the crops and water for the people in daily use. Research objective The researcher aim to calculate the rate of soil loss, and to model the soil erosion map of Binh Gia District by the use of ArcGIS software and RUSLE Method 1. The requirement - To classify and process spatial data - To know the rate of erosion in the research area - To be familiarized in GIS software in mapping and analyzing data 1.
The significance For learning and researching purpose: to apply the researching methods, ways to model the soil loss of the research area, to increase the knowledge about Geographic Information System as well as the ArcGIS software The practical significance: applying the ability on reality combine with collecting and analyzing data, assessing the loss of soil. Soil Erosion Soil erosion is a naturally occurring process that affects all landforms. Erosion, whether it is by water, wind or tillage, involves three distinct actions – soil detachment, movement and deposition. Topsoil, which is high in organic matter, fertility and soil life, is relocated elsewhere "on-site" where it builds up over time or is carried "off-site" where it fills in drainage channels.
Soil erosion reduces cropland productivity and contributes to the pollution of adjacent watercourses, wetlands and lakes (Ritter, 2015) Soil erosion can be a slow process that continues relatively unnoticed or can occur at an alarming rate, causing serious loss of topsoil. Soil compaction, low organic matter, loss of soil structure, poor internal drainage, salinization and soil acidity problems are other serious soil degradation conditions that can accelerate the soil erosion process. Soil erosion is a normally happening process on all area. Soil erosion might be a moderate procedure that proceeds generally unnoticed, or it might happen at an disturbing rate creating genuine loss of topsoil.
The loss of soil from farmland might be reflected in diminished yield generation potential, lower surface water quality and harmed waste systems. 6 n Causes of Soil erosion is controlled by the following factors: Rainfall Intensity and Runoff Both rainfall and runoff factors must be considered in assessing a water erosion problem. The impact of raindrops on the soil surface can break down soil aggregates and disperse the aggregate material. Lighter aggregate materials such as very fine sand, silt, clay and organic matter can be easily removed by the raindrop splash and runoff water; greater raindrop energy or runoff amounts might be required to move the larger sand and gravel particles.
Soil movement by rainfall (raindrop splash) is usually greatest and most noticeable during short duration, high-intensity thunderstorms. Although the erosion caused by long-lasting and less intense storms is not as spectacular or noticeable as that produced during thunderstorms, the amount of soil loss can be significant, especially when compounded over time. Runoff can occur whenever there is excess water on a slope that cannot be absorbed into the soil or trapped on the surface. The amount of runoff can be increased if infiltration is reduced due to soil compaction, crusting or freezing.
Runoff from the agricultural land may be greatest during spring months when the soils are usually saturated, snow is melting and vegetative cover is minimal. Soil Erodibility Soil erodibility is an estimate of the ability of soils to resist erosion, based on the physical characteristics of each soil. Generally, soils with faster infiltration rates, higher levels of organic matter and improved soil structure have a greater 7 n resistance to erosion. Sand, sandy loam and 2 loam textured soils tend to be less erodible than silt, very fine sand, and certain clay textured soils.
Tillage and cropping practices which lower soil organic matter levels, cause poor soil structure, and result of compacted contribute to increases in soil erodibility. Decreased infiltration and increased runoff can be a result of compacted subsurface soil layers. A decrease in infiltration can also be caused by a formation of a soil crust, which tends to "seal" the surface. On some sites, a soil crust might decrease the amount of soil loss from sheet or rain splash erosion, however, a corresponding increase in the amount of runoff water can contribute to greater rill erosion problems.
Past erosion has an effect on a soils' erodibility for a number of reasons. Many exposed subsurface soils on eroded sites tend to be more erodible than the original soils were, because of their poorer structure and lower organic matter.