This data set is the daily water surface evaporation of Yangjiagou, dongzhuanggou and 18 Mu stations in Nanxiaohegou basin from 1981 to 1990. The model of observation instrument is HY.AM3 The diameter of the dish is 20cm, and the observation accuracy is 0.1mm. Observe at 8:00 a.m. every day, and observe once every five days during the freezing period. The evaporation capacity of the evaporating dish is observed with the same specification rainfall cup or special platform scale..
Instrument continuous observation Manual timing observation
1) If the calculated evaporation is negative, it will be recorded as "0.0 +". 2) Since the evaporating dish freezes in the specified observation time, and the observation is carried out at a non icing time, a "B" symbol should be added to the right side of the evaporation value. 3) During the icing period, if the total amount of evaporation is observed once a few days, the total amount should be recorded in the grid of the observation day, and the symbol "↓ B" should be filled in the grid of each day when the observation is stopped. However, for those who cross the month, the evaporation allocated to the previous month should be calculated according to the proportion of the number of days, and recorded in the doomsday grid of the month. Then, the total evaporation amount minus the evaporation amount of the previous month is used to calculate the evaporation allocated to the next month. When it is recorded in the observation day grid, the two values are added with the column symbol "Φ", and the rest days are filled with "↓ B". 4) If the observation data is missing, interpolation can be carried out, but the time of interpolation shall not exceed 3 days within 10 days. 5) During the non icing period, if the evaporation of all the missing days is included in the observation value of the subsequent observation day, no icing sign is added. 6) If there are combined and broken down values in a month, they are still regarded as complete data, and monthly evaporation is not bracketed. 7) If there is a combined value in a month, the average daily evaporation of the period is calculated by dividing the total amount of each merger period by the corresponding total number of days, and the selection of the maximum and minimum of each month is taken. If it is selected as the maximum and minimum, brackets shall be added; if other values are selected as the maximum and minimum instead of the average value, brackets shall be added generally; only if it can be determined that they are the maximum and minimum of a month, they shall not be bracketed. 8) The dates of the first and last ice in the evaporating dish during the period from July 1 of the previous year to June 30 of this year are recorded in the columns of the first and last ice formation in the pan. The date of the first freezing in the pan from July 1 to the end of this year is recorded in the ice date column at the beginning of this winter.
The self recording rain gauge is calibrated before the beginning of flood season every year. In the process of observation, when there is an abnormal value in the self recording rain gauge, the observed value of the ordinary rain gauge is used for interpolation. In the process of integration and input of observation data, there are four levels of manual verification, which are tabulation, primary calibration, recalibration and audit, to ensure the data quality.
This work is licensed under
CC BY 4.0 (Creative Commons Attribution 4.0 International License).
CSTR:11738.11.ncdc.HWXFZhan.2020.71
10.12072/ncdc.HWXFZhan.db0009.2020
