Stable water isotope monitoring network of different water bodies in Shiyang River Basin, a typical arid river in China
Data set of isotopes of different water bodies (precipitation, surface water, groundwater,soil water, and plant water) in the Shiyang River basin from 2015 to 2020. A total of 53 monitoring points were set up in the Shiyang River Basin , among which 35 were upstream, 6 in the midstream, and 12 in the downstream. 6,756 samples have been obtained, including 1,206 precipitation samples, 1,101 surface water samples, 161 groundwater samples, 3,779 soil water samples, and 509 plant water samples.
Steps to reproduce
In order to collect precipitation, 16 weather stations were set up in Shiyang River basin, which included rainfall barrels for precipitation observation and sampling. The rainfall barrels are placed in an open place outside and composed of rain carriers, funnel, water storage bottles, and rain cups. The diameter of the rain carrier is 20 cm, and the port of the device is horizontal. The height of the rain-bearing mouth of the instrument is set as 70 cm from the ground plane. The rain gauge is used to observe precipitation and collect precipitation samples. The collected liquid precipitation is transferred to a 100 ml high-density sample bottle immediately after each precipitation event. Polyethene bottles are used to collect surface water (rivers, lakes, reservoirs) and groundwater samples. When collecting water samples, stratified sampling is carried out at different depths (surface layer, middle layer, bottom layer). The bottle of the sample is sealed with parafilm film and then frozen until the experiment. Meanwhile, a label is pasted on the polyethene sample bottle, telling the date, sampling point, sampling depth of the sample and the stream and tributary stream. The collected water samples should be placed in places where the sunlight is not direct so as to avoid evaporation of water, which would affect the validity of the data.The samples were taken back to the refrigerator in the laboratory within 10 hours.Soil samples were collected at a depth of 100 cm. Soil samples were drilled into layers of 0-5 cm, 5-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 30-50 cm, 50-60 cm, 60-70 cm, 70-80 cm, 80-90 cm and 90-100 cm in the sample plot using soil drills. The soil samples collected were divided into two parts, one part of which was put into a 50 ml glass bottle. The bottle mouth was sealed with parafilm membrane and transported to the observation station within 10 hours after the sampling date was marked for cryopreservation to test stable isotope data. The other part of the sample was placed in a 50 ml aluminium box and by using the drying method to test the soil moisture content. Plants sample collection: sampling scissors collected the xylem stem of vegetation, the bark was stripped and put into a 50 ml glass bottle, sealed, and frozen until the experimental analysis.All the collected water samples were analyzed by liquid water isotope analyzer (dlt100, Los Gatos research, USA) in the Stable Isotope Laboratory of Northwest Normal University. Each water sample and isotope standard sample were injected 6 times continuously, to eliminate the memory effect of isotope analysis, the first two injection values were discarded and the average values of the last four times were used as the final determination results. In order to ensure the accuracy of the measurement results, a parallel sample was collected for each sample, and the average value of the two determination results was taken as the final value.