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Evaluation of land use to decrease soil erosion and increase income

100%

Khorsandi N.

Polish Journal of Environmental Studies

2014

tom 23

nr 4

Land use optimization is one of the most important issues that has a big effect on soil conservation. In this project in order to achieve minimum soil erosion and maximum profit of different land uses, including forest, orchard, range, irrigated and dry farming land use, linear programming was used in Qazvin plain watershed. Three different scenarios of land use were designed: 1) existing land use, 2) existing land use with some land management, and 3) optimum land use with suitable land management. By using Lingo software, the optimum statues were determined. The results showed that the area of orchards (45% increased), irrigated lands (58% decreased), and dry lands (53% decreased) have to changed for optimization land uses, but the area of forest and rangeland did not need any changes. Also, the amount of soil erosion in existing land use, existing land use with land management, and optimum land use with suitable land management declined 4%, 30%, and 39%, respectively, while their profit increased 30%, 39%, and 40%, respectively. In addition, the results of sensitive analysis indicated that orchard and irrigated land are the most sensitive land uses in solving the problem.

Comparison of different interpolation methods for investigating spatial variability of rainfall erosivity index

45%

Khorsandi N., Mahdian M. H., Pazira E., Nikkami D., Chamheidar H.

Polish Journal of Environmental Studies

2012

tom 21

nr 6

The objective of our study was to expand the R factor of the RUSLE model, erosivity index by its estimation from more readily available rainfall erosivity indexes and parameters in stations without rainfall intensity data, and to determine the most accurate interpolation method for preparing an erosivity index map. Among different erosivity indexes and parameters based on rainfall amounts, only the modified fournier Index (FImod) was highly correlated with EI30 in 20 synoptic stations. A local model was used for estimating EI30 from FImod in the other 66 stations without rainfall intensity data. The spatial variability of the calculated EI30 in all of the stations was different at an azimuth of 32º when compared to the other directions. Moreover, the nuggetto- sill ratio of the semivariogram (0.27) confirmed a strong spatial correlation of EI30. The inverse distance weighting (IDW), spline, kriging, and cokriging methods with elevation as a covariable were compared by a cross-validation technique. The root mean square error (RMSE) value of the cokriging method when compared to that of the IDW, kriging, and spline methods in the study area declined by 11%, 3%, and 4%, respectively. The output maps for all of the interpolation methods followed similar decreasing trends from west to east, with the highest erosivity index (1,450 MJ·mm·ha⁻¹·h⁻¹·y⁻¹) found in the west. This pattern corresponds with the pattern of climatic change from subhumid to semiarid.

Ograniczanie wyników

2 Polish Journal of Environmental Studies

2 Khorsandi N.

1 Chamheidar H.

1 Mahdian M. H.

1 Nikkami D.

1 Pazira E.

1 2014

1 2012

Wyniki wyszukiwania

Evaluation of land use to decrease soil erosion and increase income

Comparison of different interpolation methods for investigating spatial variability of rainfall erosivity index