Land use management optimization for Abolabbas Watershed resources conservation

Environmental and economic impacts of soil erosion are due to improper land management in a watershed. Although it is impossible to stop soil erosion completely under natural conditions، there is a great need to control erosion for proper land use planning. According to the scarcity of literature in the area of soil nutrient evaluation with optimization models، the main objective of this research is determining the optimum level of land uses to minimize soil erosion and nutrients losses and maximize people incomes that live in a watershed. For this purpose، Abolabbas Watershed in the north-eastern part of Khouzestan Province was chosen for this research. A linear programming model was used in three different scenarios including current land use condition without land management، current land use condition with land management and standardized land use condition. Results demonstrated that the current land uses are not optimized for the least soil erosion and nutrient losses and high income. At optimized conditions، the area of forests and orchards increased by 1. 81 and 55. 7% respectively، rangelands with no changes، and irrigated and drylands decreased by 67. 5 and 31. 4% respectively. Also، results showed that land use optimization، in current land uses with no land management، decreases total soil erosion by 3. 2% and total nutrient soil losses by 2. 5 and increases total income by 29. 7%، in current land uses with land management، decreases total soil erosion by 35. 3% and total nutrient soil losses by 70. 2 and increases total income by 37. 2%، and in standardized land uses، total soil erosion by 47. 2% and total nutrient soil losses by 70. 4 and increases total income by 41. 8%. Sensitivity analysis، also، showed that the change in the area of orchards and Irrigated lands has the most effects on increasing income and decreasing soil erosion and nutrients losses in Abolabbas watershed.