Spot gauged flows on the lower River Frome, Dorset, April-November 2022

Measurements were taken by dividing the river channel into at least 10 equally spaced transects, with the depth and flow velocity recorded at each vertical transect. For small streams (< 3 m width), 5-10 transects were used. The flow velocity was recorded at a depth of 40% above the riverbed. The cross-sectional area for each transect was determined by multiplying the width of the transect by the average depth of the two adjacent vertical transects. This was then multiplied by the average velocity of the two adjacent vertical transects to get discharge for each transect. The sum of all transects provided total stream discharge. To conduct the measurements, a Valeport mechanical flow meter was used. Flows are reported as m3 s-1. Due to time constraints only one flow recording could be taken at each site, on each survey date, i.e. no replicates.本次测量通过将河道划分为至少10个等间距条带（transect）开展，在每个垂向测线（vertical transect）处记录水深与水流流速。对于宽度小于3米的小型溪流，采用5至10个条带即可。流速测量点位设置在距河床40%水深处。单个条带的横截面积（cross-sectional area）通过该条带的宽度与相邻两个垂向测线的平均水深相乘得到；随后将该横截面积与相邻两个垂向测线的平均流速相乘，即可得到该条带的过水流量（discharge）。所有条带的流量之和即为溪流总流量。本次测量采用Valeport型机械式流速仪（Valeport mechanical flow meter）完成。流量单位以立方米每秒（m³ s⁻¹）计。受时间限制，每个监测点位在每次调查日仅能完成一次流量测量，未设置重复测次（replicates）。