4.3. Limitations of this study
This study was carried out in quite a detail including, literature review, geospatial data collection, calculation of RUSLE factors, implementation of RUSLE at the national scale, and spatial analysis conducted to the best of the authors’ knowledge and experience. There may be some flaws, errors, or uncertainty in data that may affect results and methodology, so there are some limitations of this study.
For the estimation and monitoring of annual soil erosion over Pakistan, all the globally produced spatial datasets and comprehensive literature reviewed estimated values were utilized. Unfortunately, Pakistan is data-scarce, indeed medium spatial resolution (10 - 30 m) geospatial datasets are freely available to produce basic products (e.g. LCLU maps, soil characteristic maps) but unavailable at the national scale due to several reasons e.g. lack of willingness, technological lacks, and financial constraints. Although across Pakistan nearly 50 meteorological stations are installed most of the time rainfall data is unavailable, those are available are in hardcopy and confidential for the public and researchers.
Although in this study we tried to validate our soil erosion estimates with the previously conducted local/ small scale studies, we noticed that all the five studies were conducted in one big region (i.e. Potohar plateau).
Despite these limitations, spatially explicit and temporal soil erosion provided in this study is essential for various purposes, including the soil conservation and management practices, environmental impact assessment studies, among others.
5. Conclusions
This study presents a spatial quantitative evaluation of decadal (2005 - 2015) annual soil erosion change on the national and subnational levels of Pakistan using freely available remotely sensed data and easy-to-perform RUSLE. It provides baseline information about soil erosion intensities on seven administrative units of Pakistan. There was a lack of a scientific study in Pakistan on soil erosion dynamics and a current approach is a viable option as compared to field-based assessments and evaluations.
The results of this study would be utilized to identify the soil erosion prone areas and conversion of LCLU at the national scale that would help in planning the watershed management activities. International and national reporting on soil and LCLU change dynamics in Pakistan can be drawn from these results. Reported soil erosion and soil change dynamics on highly prone latitude windows would help planners, policy and decision-makers to devise mechanisms to control/ reduce soil erosion and to set conservation priorities. A bivariate analysis between soil erosion change and LCLUC (2005 - 2015) was assessed in this study which is an indication of the need for soil erosion control measures on a national scale.
References
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