Global rainfall erosivity assessment based on high-temporal resolution rainfall records

Abstract

The exposure of the Earth’s surface to the energetic input of rainfall is one of the key factors controlling water erosion. While water erosion is identified as the most serious cause of soil degradation globally, global patterns of rainfall erosivity remain poorly quantified and estimates have large uncertainties. This hampers the implementation of effective soil degradation mitigation and restoration strategies. Quantifying rainfall erosivity is challenging as it requires high temporal resolution(<30 min) and high fidelity rainfall recordings. We present the results of an extensive global data collection effort whereby we estimated rainfall erosivity for 3,625 stations covering 63 countries. This first ever Global Rainfall Erosivity Database was used to develop a global erosivity map at 30 arc-seconds(~1 km) based on a Gaussian Process Regression(GPR). Globally, the mean rainfall erosivity was estimated to be 2,190 MJ mm ha−1 h−1 yr−1, with the highest values in South America and the Caribbean countries, Central east Africa and South east Asia. The lowest values are mainly found in Canada, the Russian Federation, Northern Europe, Northern Africa and the Middle East. The tropical climate zone has the highest mean rainfall erosivity followed by the temperate whereas the lowest mean was estimated in the cold climate zone.

A review of the (Revised) Universal Soil Loss Equation (R/USLE): with a view to increasing its global applicability and improving soil loss estimates

“…Panagos et al (2017) have used pluviographic data from 63 countries to calculate rainfall erosivity and spatially interpolated the results to construct a global rainfall erosivity map at 30 arc-seconds 30 resolution. Despite its coarse resolution, this global dataset can be used as a resource for rainfall erosivity in data-sparse regions.…”

Climate Change Impacts on Sediment Quality of Subalpine Reservoirs: Implications on Management

“…The erosive power of rainfall can be expected to change with increase of precipitation intensity [13,43,86,87]. Consequently, the increased erosion rates can elevate the sediment delivery from The PCA analyses also allowed finding relationships between physical-chemical characters of sediments (fine fraction < 2 mm, TOC, sedimentation rate and percent sedimentation) and morphometric features of reservoirs (altitude, surface area, maximum depth and volume) (Figure 3).…”

“…The erosive power of rainfall can be expected to change with increase of precipitation intensity [13,43,86,87]. Consequently, the increased erosion rates can elevate the sediment delivery from catchments [88] and lakes and reservoirs act as primary sink in the sediment cascade [89].…”

“…Figure 4a shows the predicted changes in rainfall erosivity for 2050 scenario [13]. Generally, the Alpine area is characterized by moderate (from 0 to 50 MJ mm ha −1 h −1 year −1 ) to high (from 300 to 500 MJ mm ha −1 h −1 year −1 ) increase of rainfall erosivity (R-factor), as well as our region of investigation, although slightly lower than in the northern slope of the Alpine chain (Switzerland).…”

“…Anthropic activities influence sediment dynamics in watercourses [1,8,9] and recent works are currently focusing on potential impacts of climate change on sediment loads [5,10]. In fact, increasing air temperature and altered rainfall rates will increase soil erosion and will affect the distribution of vegetation in catchments [11][12][13], leading, in turn, to increased sediment flows [5].…”