Responses of Runoff and Soil Loss to Rainfall Regimes and Soil Conservation Measures on Cultivated Slopes in a Hilly Region of Northern China

Abstract

Cultivated land plays an important role in water and soil loss in earthy/rocky mountainous regions in northern China, however, its response to soil conservation measures and rainfall characteristics are still not fully understood. In the present study, 85 erosive rainfall events in 2011–2019 were grouped into three types, and the responses of runoff and soil loss to soil conservation measures and rainfall regimes on five cultivated plots with different slopes in the upstream catchment of the Miyun Reservoir were evaluated. Results found that mean event runoff depths and soil loss rates on the five plots ranged from 0.03 mm to 7.05 mm and from 0.37 t km−2 to 300.51 t km−2 respectively, depending on rainfall regimes, soil conservation measures, and slope gradients. The high frequency (i.e., 72.94%) rainfall regime A with a short rainfall duration (RD), low rainfall amount (P), and high mean rainfall intensity (Im) yielded a lower runoff depth and higher soil loss rate. Rainfall regime B with a longer RD, and a higher P and Im, however, produced higher a runoff depth and lower soil loss rate. Terraced plots had the highest runoff and soil loss reduction efficiencies of over 96.03%. Contour tillage had comparable sediment reduction efficiency to that of the terraced plots on gentle slopes (gradient less than 11.0%), while its runoff reduction efficiency was less than 13.11%. This study implies that in the Miyun Reservoir catchment and similar regions in the world, contour tillage should be promoted on gentle slopes, and the construction of terraced plots should be given ample consideration as they could greatly reduce water quantity and cause water shortages in downstream catchments.

The Effects of Land-Use Change/Conversion on Trade-Offs of Ecosystem Services in Three Precipitation Zones

“…Land use influences carbon sequestration [56] and soil conservation directly [57], and it also influences water yield by hydrologic processes [58]. Similarly, precipitation is the key factor for carbon sequestration [59], soil conservation [60], and water yield [61]. Soil properties affect plant growth [62], soil erosion [63], and hydrologic processes [64], and they are also important factors for these three ESs.…”

The Effect of Soil Conservation Measures on Runoff, Soil Erosion, TN, and TP Losses Based on Experimental Runoff Plots in Northern China

“…The catchment covers an area of 33 km 2 . It has a temperate territorial monsoon climate with annual precipitation ranging from 300 mm to 700 mm, 70% of which falls from June to August [21].…”

“…The sandy loam soil contains around 60.9% particles that are larger than 0.05 mm in diameter, 18.22% particles that are 0.05-0.005 mm in diameter, 9.22% particles that are 0.005-0.001 mm in diameter, and 14.88% particles that are less than 0.001 mm in diameter [22], leading to a higher soil saturated hydraulic conductivity of around 77 cm/day. The dominant lithology is gneiss, scattered with granite and limestone [21]. The main land use types are forest, including economic forest orchard, followed by grass and cultivated land.…”