Effects of terracing practices on water erosion control in China: A meta-analysis

Abstract

A B S T R A C TTerracing has long been considered a strategy for soil and water conservation in many mountainous regions of the world. However, the effectiveness of terracing is limited by many factors, such as climate, soil properties, topography, land use, culture, demography and socioeconomic status. The aim of this critical review is to evaluate the roles of terracing on water erosion control in China. A meta-analysis of 601 runoff and 636 sediment observations involving a diversity of terrace structures was conducted. These 1237 observations involved level terraces, slope-separated terraces, slope terraces, zig terraces, fanya juu terraces and half-moon terraces, wide geographical locations within China, a diversity of land uses from forests to bare land, and a slopes ranging from 3°to 35°. The results confirmed that terracing significantly and positively affected water erosion control. In terms of different terrace structures, bench terraces were superior with respect to runoff and sediment reductions. Land use also played a crucial role in the efficiency of erosion control; terraces associated with tree crops and forests conserved the greatest amount of soil and water. In addition, a significant positive correlation between slope gradient (3°-15°and 16°-35°) and the effect of terracing on water erosion control was observed with the greatest decreases in water erosion occurred at slopes of 26°-35°and 11°-15°. This study revealed the effectiveness and variations of terracing with respect to water erosion control at the national scale and can serve as a scientific basis for land managers and decision makers. However with increasing urbanization, terrace abandonment increases as does the loss of place-based knowledge regarding terrace construction and maintenance.

Effects of minimum soil disturbance practices on controlling water erosion in China's slope farmland: A meta‐analysis

“…Theoretically, the sediment yield reduction might be synchronized with runoff reduction without the implementation of minimum soil disturbance practices, which means that the sediment yield reduction is approximately equal to the runoff reduction. For terracing practices, the sediment yield reduction is close to the runoff reduction (48.9% for runoff and 53.0% for sediment yield), which indicates that terracing controls water erosion by diminishing runoff and sediment yield synchronously (Chen, Wei, & Chen, ). Terracing practices reduce the velocity and total amount of surface runoff straightforwardly by reshaping the land‐surface morphology (Chen, Liu, & Chen, ).…”

“…for runoff and 53.0% for sediment yield), which indicates that terracing controls water erosion by diminishing runoff and sediment yield synchronously (Chen, Wei, & Chen, 2017). Terracing practices reduce the velocity and total amount of surface runoff straightforwardly by reshaping the land-surface morphology (Chen, Liu, & Chen, 2012).…”

Evaluación de los servicios ecosistémicos proporcionados por las terrazas agrícolas

“…The importance of the regulating ES is reflected in the large volume of research highlighting the effectiveness of terraces regarding erosion and flood reduction (e.g. Beach et al, 2002;Gebremichael et al, 2005;zhang & Li, 2014;Chen et al, 2017). Mekonnen et al (2015) identified terraces as sediment retention traps and Wheaton & Monke (1981) considered them the best measure for erosion control.…”

“…Hass et al, 1966;Hammad et al, 2004;Hammad & Børresen, 2006;Wei et al, 2016;Rashid et al, 2016Water Hass et al, 1966Thomas et al, 1980;Chow et al, 1999;Beach et al, 2002;Liu et al, 2004Liu et al, , 2011Schiettecatte et al, 2005;Rashid et al, 2016;Reynes Trias, 2006;Wei et al, 2016 REGULATING Erosion Thomas et al, 1980;Wheaton & Monke, 1981;Chow et al, 1999;Beach et al, 2002;Sharda et al, 2002;Dorren & Rey 2004;Hammad et al, 2004;Gebrernichael et al, 2005;Reynes Trias et al, 2006;Romero Díaz et al, 2007;Chen et al, 2012;Pietsch & Mabit, 2012;Kagabo et al, 2013;Dumbrovsky et al, 2014;zhang & Li, 2014;Arnaez et al, 2015;Mekonnen et al, 2015;Kovár et al, 2016;Rashid et al, 2016;Wei et al, 2016;Arévalo et al, 2017;Chen et al, 2017 Water Thomas et al, 1980;Sandor & Eash, 1995;Chow et al, 1999;Beach et al, 2002;Liu et al, 2004…”

“…The scientific interest in terraces is also shown by the many international conferences on this subject, such as the series of World Conferences on Terraced Landscapes (Mengzi, Yunnan, China in 2010;Cusco, Peru in 2014;Padua, Italy in 2016;Canary Islands, Spain in 2019), and by the various special issues of journals (Balbo & Puy, 2017;Varotto et al, 2019) and review articles (Dorren & Rey, 2004;Stanchi et al, 2012;Tarolli et al, 2014;Arnaéz et al, 2015;Wei et al, 2016;Chen et al, 2017).…”