The monitoring indexes of soil and water conservation in a small watershed includes rainfall, water level, flow rate and flood sediment (suspended sediment). In this study, two methods, including rain gauge and automatic rain recorder, were used to measure rainfall amount in the watershed. Three rainfall stations were established in the central, upper and lower reaches of the watershed, respectively. The simultaneous measurement of rain gauge and automatic rain recorder were checked with each other and the mean value taken as the watershed rainfall. Water-level observation is one of the basic measurements at the runoff station, and is the basis of flow estimation. Water level was measured by water gauge, and the flow rate from the watershed outlet was calculated using a flume weir flow formula39. The basic requirements of water-level observation at the basin outlet are: the daily water level was measured at 0800 and 2000 (local time) during normal water-level periods, and the flood level was measured by points of flood rising, falling and water-level changing at different short intervals40. Observation accuracy was ±1 cm. Sediment was analysed by collecting runoff samples. The observation of suspended sediment is carried out by artificial observation method. In the process of runoff yield, the turbid water samples were collected artificially by a sampling bottle at a certain time interval, the sediment content was measured by drying in the laboratory, the sediment yield of the whole basin was then calculated41. The volume of the sample bottle is 1000 mL. Sampling times were 3, 6, 12 and 30 minutes after runoff yield during one rainstorm.