Application of Geo-informations and universal soil loss equation for soil macro nutrient and carbon loss evaluation in Mae Chan watershed, Chiang Rai Province

Abstract

The application of Geographic Information Systems (GIS) and Universal Soil Loss Equation (USLE) to evaluate macro plant nutrient and carbon loss in Mae Chan watershed in Chaing Rai province had the following objectives: to determine the amount of soil loss by soil erosion, and classify level of soil loss in the Mae Chan watershed in Chaing Rai province. The study was done by using Universal Soil Loss Equation (USLE) criteria for soil erosion intensity classification, sediment delivery ratio (SDR), and soil sampling within the study area to analyze the amount of macro plant nutrients and carbon value, compared with the standard method in the laboratory. The result showed that the amount of soil loss in the Mae Chan watershed was 5,193,119 tons with an average of 12.85 tons/rai. The soil erosion was classified into five levels: very slight, slight, moderate, severe, and very severe and the results were 102.47 km2 (40.48%), 49.89 km2 (19.76%), 18.42 km2 (7.30%), 51.55 km2 (20.41%), and 30.19 km2 (11.96%), respectively. The loss of nitrogen, phosphorus, potassium, organic matter, and organic carbon were 10,689.30, 50.73, 676.74, 128,031.40 and 74,136.90 tons, respectively. The loss of macro plant nutrients was classified as the amount of fertilization loss of urea, super phosphate, and potassium chloride with the amount of 13,917.02, 290.63 and 1,358.21 tons, respectively. The amount of sediment yield was 800,732.069 tons and sediment yield of organic carbon was 9,740.542 tons while organic carbon loss from waterways was 4,410.946 tons.