Optimizing land use pattern to reduce soil erosion

Abstract

Soil erosion hazard is one of the main problems can affect ecological balance inwatersheds. This study aimed to determine the optimal use of land to reduce erosionand increase the resident's income of Qushchi watershed in West Azerbaijan province,Iran. Income and expenses for the current land uses were calculated with field studies.Damages resulting from the soil erosion were estimated by soil depth equal to thespecified land uses. For three different options including the current status of land useswithout and with land management, and the standard status of land uses, multiobjective linear programming model was established by LINGO software. Then theoptimization problem of the land use was solved by simplex method. Finally, the bestoption of land use was determined by comparing erosion rate and its cost in eachscenario. Then the circumstances and the recommended conditions were compared.The results indicated that the current surface area of current land uses is not suitable toreduce erosion and increase income of residents and should change in the optimumconditions. At the optimum level, there should change horticulture area of 408 to 507(ha), irrigated land area of 169 to 136 (ha) and dry farming of 636 to 570 (ha), whileconversion of rangeland area not indispensable. In addition, the results showed that incase of the optimization of land use, soil erosion and the profitability of the whole areawill decrease 0.75% and increase 3.68%, respectively. In case of land managementpractices, soil erosion will decrease 42.27% and the profitability increase 21.39% whilein the standard conditions, soil erosion will decrease 60.95% and profitability willincrease 24.20%. The results of the sensitivity analysis showed that the changes in thehorticulture and range land areas have the greatest impact on the increasingprofitability and reducing soil erosion of Qushchi watershed. So, it is recommendedusing Education and Extension to promote the importance of land management tounderstand how proper use of the land.