Table 1 Description of carbon variables and natural and anthropogenic factors.
From: Control factors and scale analysis of annual river water, sediments and carbon transport in China
Abbreviation | Name and unit | Description |
|---|---|---|
Size | Size (km2) | watershed, catchment or basin area in km2 |
L | Length (km) | river or basin length or characteristic slope length |
RD | Runoff depth (mm) | total annual runoff divided by basin area in mm |
QA | Annual average discharge (m3 s−1) | annual average water discharge divided by time (seconds) |
Rc | Runoff coefficient | runoff depth divided by annual rainfall Rc = RD/total rainfall |
Rainfall | Total rainfall (mm) | precipitation received during the period of trial, i.e., annual precipitation |
MAP | Mean annual precipitation (mm) | long-term mean annual precipitation - average precipitation over 30 years or more |
MAT | Mean annual temperature (°C) | long-term mean annual temperature - average temperature over 30 years or more |
S | Slope (%) | average slope gradient of the river basin |
LAT | Latitude (°) | latitudinal position of river or catchment/basin outlet |
LONG | Longitude (°) | longitudinal position of river or catchment/basin outlet |
Vc | Vegetation coverage (%) | average vegetation coverage percent of the basin; when not provided, this value was calculated from the available NDVI: coverage(%) = −4.337–3.733*NDVI + 161.968*NDVI*NDVI61 |
RSCI | Reservoir storage capacity index (%) | the ratio of the total reservoir water storage capacity to the annual average water discharge of the contributing catchment |
SOC | Soil organic carbon (%) | average soil organic carbon content of the basin; when SOM is indicated instead of SOC, then SOC = 0.58*SOM26,62 |
BD | Bulk density (g cm−3) | average soil bulk density; when not provided, this value was calculated as SOC: BD = −1.229ln(SOC) + 1.2901(for SOC < 6%) and BD = 1.3774e(−0.0413SOC)(for SOC >6%)26 |
TSSC | Total suspended sediment concentration (mg L−1) | average total suspended sediment concentration in the runoff |
TSSL | Total suspended sediment load (g·m−2·a−1) | total suspended sediment load of unit area; when not provided, this value was calculated as TSSL = TSSC × RD ÷ 1000 |
POCC | Particulate organic carbon concentration (mg L−1) | average concentration of particulate organic carbon in the runoff |
POCL | Particulate organic carbon load (g·m−2·a−1) | calculated or provided annual particulate organic carbon export unit area; when not provided, this value was calculated as POCL = POCC × RD ÷ 1000, where 1000 is the unit for conversion to a constant |
DOCC | Dissolved organic carbon concentration (mg L−1) | average concentration of dissolved organic carbon in the runoff |
DOCL | Dissolved organic carbon load (g·m−2·a−1) | calculated or given annual dissolved organic carbon export unit area; when not provided, this value was calculated as DOCL = DOCC × RD ÷ 1000, where 1000 is the unit for conversion to a constant |
TOCC | Total organic carbon concentration (mg L−1) | average concentration of total organic carbon in the runoff |
TOCL | Total organic carbon load (g·m−2·a−1) | calculated or given total annual organic carbon export unit area, TOCL = POCL + DOCL |
