Comparing watershed soil erosion of Taiwan and Thailand

Abstract

Abstract. Tropical watersheds in Taiwan and Thailand face the same severe soil erosion problem that is increasing at an alarming rate. In order to evaluate the severity of soil erosion, we quantitatively investigate the issue using a common soil erosion model (Universal Soil Loss Equation, USLE) on the Shihmen reservoir watershed of Taiwan and the Lam Phra Ploeng basin of Thailand, and compare their respective erosion factors. The results show an interesting contrast between the two watersheds. Some of the factors (rainfall factor, slope-steepness factor) are higher in the Shihmen reservoir watershed, while others (soil erodibility factor, cover and management factor) are higher in the Lam Phra Ploeng basin. The net result is that these factors cancel each other out, and the amount of soil erosion of the two watersheds are very similar at 68.03 t/ha/yr and 67.57 t/ha/yr, respectively.

Soil Erosion Modeling and Comparison Using Slope Units and Grid Cells in Shihmen Reservoir Watershed in Northern Taiwan

“…The average R factor was 12,798 MJ-mm ha −1 hr −1 yr −1 , or 6.4 times the global average of 2000 MJ-mm ha −1 hr −1 yr −1 [23]. The K factor ranged from 0.004 to 0.042 t-hr MJ −1 mm −1 [24]. The C factor was converted from a land use survey in 2004 [25] and a conversion table between the land uses and the C factors [26], and the average C value was 0.016.…”

Comparing watershed soil erosion of Taiwan and Thailand

“…With the loss of precious topsoil, agricultural productivity is negatively impacted (in the case of Thailand) and reliable drinking water supply is jeopardized (in the case of Taiwan). To better identify and understand the different contributing factors of soil erosion in typical watersheds of Taiwan and Thailand, we continue a previous study [1] in this paper to quantitatively compare the characteristics of the watersheds of Taiwan and Thailand and their respective erosion factors.…”