Estimation of soil loss by an integrated approach of USLE and geospatial techniques—a case study of Kumulur watershed

Autor: Nagarajan Madasamy, Lalitha Rajangam, Mercy Backiyam Joshua
Rok vydání: 2020
Předmět:
Zdroj: Arabian Journal of Geosciences. 13
ISSN: 1866-7538
1866-7511
Popis: A study was conducted to estimate soil loss by an integrated approach of USLE and geospatial techniques from Kumulur watershed, Trichy district, Tamil Nadu, India, located at 10° 56′ 41.50″–10° 55′ 57.85″ N latitude and 78° 50′ 4.34″–78° 50′ 4.58″ E longitude with an areal extent of 848,694 m2. The factors in USLE were prepared as different thematic layers using GIS. The R factor was calculated using 28 years of rainfall data (1991–2018), and the average R factor was found to be 1862.892 MJ mm ha-1 h-1 yr-1. The K factor was generated through textural classes of soil by collection of soil samples. The high-accuracy digital elevation model (DEM) (4-m resolution) was created using hand-held GPS instrument and Google Earth. The contour, aspect, and slope maps were derived from DEM. The slope classes revealed to be moderately steep sloping having 32.248 and 17.873°, and the LS factor was found to be 0 to 219.33. The C and P factors were obtained from different land uses, viz., barren rocky, built-up area, fallow land, open forest, and water bodies prepared from Google Earth image (2-m resolution—2018 image). The average annual soil loss was estimated as 4.927 t/ha/year which ranged between 0 and 1.469 t/ha/year for each grid cell. To arbitrate the soil loss, the surface runoff of the watershed was also estimated by the SCS-CN method. The runoff depth (2018 rainfall) for CN I, II, and III was found to be 52.19, 120.09, and 664.46 mm, respectively, which shows moderately high runoff potential and moderately low infiltration rate.
Databáze: OpenAIRE
Externí odkaz: