Assessment of soil erosion under long-term projections of climate change in Poland

Abstract

Soil is a major natural resource fundamental for food production, and a habitat for living organisms. It is therefore extremely important to prevent its erosion. It is assumed that 50% of erosion at the global scale is caused by water. A relatively low number of studies model soil loss in Northern and Eastern Europe. Although that region currently contributes to total soil loss the least, the projected long-term climate change in Europe is likely to affect soil loss due to changes in rainfall characteristics. This study quantifies historical soil loss rates based on high-resolution datasets, and assesses the impact of the projected climate change on long-term average annual soil erosion rates in Poland, located in the temperate climate zone, using the Revised Universal Soil Loss Equation (RUSLE) model. The study investigates the projected changes for two future time horizons, namely: 2021-2050 (near future – NF) and 2071-2100 (far future – FF), under two different Representative Concentration Pathways (RCP) 4.5 and 8.5. To account for the uncertainty of individual climate models, an ensemble of nine EURO-CORDEX model scenarios was used. Based on the multi-model ensemble median, the average soil erosion rate in Poland for the historical period is 0.48 t ha−1 yr−1. The total annual soil loss in Poland is estimated at 14 Mt. The highest soil loss rate is observed in the south of Poland with mean annual erosion rate of 1.7 t ha−1 yr−1. Although it occupies only 16% of the territory of Poland, its share in total soil loss in the country is 62% (8.6 Mt year−1). The average projected potential soil erosion by water in the future increases gradually, reaching +7% (RCP4.5 NF), +8% (RCP8.5 NF), +13% (RCP4.5 FF), and +18% (RCP8.5 FF). The results of this study might be valuable for the development of the national soil conservation policy. The study fills the spatial gap in modelling of changes in soil erosion caused by climate in the Northern and Eastern part of Europe. Due to the lack of other national studies in the region, the directions of such changes could be transferrable to countries in the same climate zones, with a similar vegetation cover structure.