Soil Erosion and Deposition in a Taiwanese Watershed Using USPED

Walter Chen,Kieu Anh Nguyen,Wu-Hsun Wang

doi:10.3390/su14063397

Abstract

Soil erosion is a global problem that has been exacerbated in recent decades by global warming and the increased frequency of extreme weather events. It is also a global issue addressed by the United Nations’ Sustainable Development Goal #15 that seeks to recover degraded land and create a world free of land degradation by 2030. In this study, we used the Unit Stream Power-based Erosion Deposition (USPED) model to investigate the distribution of soil erosion and deposition in an important reservoir watershed in Taiwan, which is known to have a high risk of sediment hazard. We found the average soil erosion rate to be 136.4 Mg/ha/year using the model’s recommended m = 1.3 and n = 1.2 empirical coefficients for a combined occurrence of sheet and rill erosion. Additionally, we selected the Sule sub-watershed and the Kala area as examples to illustrate the pattern of soil erosion and deposition and their relationship to rivers, roadways, and anthropogenic activity, and 3D terrain was employed to further enhance visualization of the model output. It was estimated that 12.6% of eroded soil was deposited with a 200 m buffer of the rivers in the watershed and might be swept into the river system by the next typhoon, torrential rain, landslide, or earthquake. In comparison to previous USLE- and RUSLE-based soil erosion modeling in the same research area, our USPED modeling is unique in that it included the amount and distribution of soil deposition. This successful implementation of USPED in Taiwan establishes a new modeling alternative in addition to the widely used USLE and RUSLE models. The findings can be used to direct future erosion pin placement in the research area, allowing for improved monitoring of sediment movement and avoiding sediment hazards.

Highlights

Accepted: 12 March 2022Soil erosion is a global problem that has been aggravated by global warming and the increased occurrence of extreme weather events in the last several decades
The revised universal soil loss equation (RUSLE) are the most common models used by researchers around the world, accounting for 13.9% and 17.1% of the literature published between 1994 and 2017 in the Scopus database, respectively [1]
USLE or RUSLE can only model the amount of soil erosion in watersheds; they cannot simulate the movement of sediments and where the soil is deposited in the watersheds

Summary

Introduction

Accepted: 12 March 2022Soil erosion is a global problem that has been aggravated by global warming and the increased occurrence of extreme weather events in the last several decades. The loss of valuable soil is associated with a reduction in the functioning of the ecosystem as well as an increase in CO2 levels in the atmosphere. When analyzing soil erosion in a watershed, the universal soil loss equation (USLE). The revised universal soil loss equation (RUSLE) are the most common models used by researchers around the world, accounting for 13.9% and 17.1% of the literature published between 1994 and 2017 in the Scopus database, respectively [1]. The predominant use of USLE and RUSLE is true in Taiwan for soil erosion analysis [2–11]. USLE or RUSLE can only model the amount of soil erosion in watersheds; they cannot simulate the movement of sediments and where the soil is deposited in the watersheds

Objectives

Methods

Results

Discussion

Conclusion