جستجوی مقالات مرتبط با کلیدواژه "bare soil" در نشریات گروه "آبخیزداری، بیابان، محیط زیست، مرتع"

Gully erosion is one of the most important phenomenons in land degradation and desertification, which upsets the balance of environmental resources and its sustainability. The aim of this study was to determine the effective factors on creation of gully erosion using data mining methods in Bayan Watershed in the north of Fars Province. K-Means clustering algorithms and CART decision tree were used to model gully erosion. The estimated accuracy based on the parameters affecting the creation area in the final model is 100% for the educational data set and 71.43% for the experimental data set. Results from measuring different variables from 40 selected gullies, including a target variable (creation area) and twelve predictive variables, like creation slope, vegetation, bare soil, surface gravel, surface litter, EC, pH, SAR, OM, clay, silt and sand in field and laboratory operations and the use of data mining techniques, showed that the creation of gullies in this watershed is a function of silt, acidity, bare soil, gravel and organic matter. These results showed the effect of vegetation and consequently, the presence of adequate organic matter in the soil as the most appropriate method for controlling gullies and the destructive and intensifying effect of bare lands without vegetation in intensifying gully erosion. Therefore, it is necessary to establish and establish permanent and compatible vegetation, to stabilize and improve soil structure and increase organic matter, and control and management programs, in lands with more silt, to be operated more carefully.

Gully erosion is one of the main types of water erosion and is known as one of the destroying forms of land degradation and soil loss in the world. Therefore, knowing the most effective factors on extending this type of erosion is utmost important. Beside, management and control of gully erosion require knowing the most effective factors on gullies extension. So, the present study was performed to determine the most effective factors on gullies in Khorrambid Watershed, North of Fars Province through measuring the permanent gullies during 13 years (2004-2016). Results showed that the average of gully length extension was 21.67 m throughout this period. This data indicated that the length of gully extension was 1.67 m per year. Further, it is determined that the length expansion of permanent gullies in this region was a function of bare soil and saturated electrical conductivity, using SPSS and backward multivariable regression. In conclusion, it is suggested different management solutions to increase the soil resistance against the erosion be prioritized in management and implementation plans such as increasing adoptable cover vegetation for the natural condition of the region and exclude the area to restore vegetation cover and pay more attention to control erosion in gully head cuts.

Due to soil degradation and abundant of sediment production, the exact recognition of affecting factors on gullies erosion, and the impact of various factors on gully’s formation and development, require a more accurate study. In this regard, in the present study the length of gully, the area above headcut, headcut slope, percent of closed grain, bare soil, cover vegetation, litter, saturated electrical conductivity, pH, percent of organic matter, sodium absorption ratio, and percent of clay, silt and sand were measured in 30 gullies in 2018. Factor analysis with SAS software (version 9.1) was performed to determine the factors affecting the samples classification. Backward regression method in SPSS software (version 16) was used to determine the affecting factors on extension length of gullies, considering the length of gullies as dependent variable and other measured parameters as independent variables. The results of this study showed that the saturated extract electrical conductivity, the area above headcut and the percentage of bare soil factors play the most important role on the length extension of gullies in the Ghazeian watershed, located in the north of Fars province. Therefore, it is recommended to control erosion at headcut and through establishing the adaptable and resistance canopy copy cover, reduces the uncover area and increases the roughness coefficient. Also, it is essential to have a watershed in different part (climate) of the country having gully erosion to perform accurate research on soil particles, canopy cover, type and rate of rainfall, runoff height, shear stress, flow velocity, morphological characteristics, type of slope and its cover, mechanism of creation and expansion of gullies, and the gully erosion control methods.