小型地中式称重蒸渗仪系统的研制

Development of a small-scale local weighing lysimeter system

为进一步提高称重蒸渗仪的分辨率和准确度,通过配备高精度称重传感器和用于消除环境因素对称重影响的参考桶,研制了小型地中式称重蒸渗仪系统,并应用于水稻蒸发蒸腾量(ET)和棵间蒸发量(E)的观测中。结果表明:该称重蒸渗仪系统对ET和E的分辨率可达0.005和0.003 mm,对应的高峰ET和E观测时段可以实现1 min以内(ET和E可分别达到10和20 s)的水分消耗的识别,低通量阶段也可达到3~5 min/次;参考桶的配备将蒸渗仪系统的15 min、小时和日尺度的ET观测准确度分别提高了3.51%、2.17%和0.77%,E观测准确度分别提高了18.52%、11.81%和2.95%。研究结果表明该套蒸渗仪系统具有分辨率高、准确度好、数据可靠等优势,可用于农业、水文等领域的研究,特别适用于短时蒸发蒸腾和旱地生态系统空气凝结水等微小水量变化的测定。

To further improve the resolution and accuracy of weighing lysimeters,a small-scale local weighing lysimeter system equipped with high-precision weighing sensors and reference buckets which can eliminate the influence of environmental factors on the weighing was developed and then applied to observe rice evapotranspiration(ET)and inter-plant evaporation(E).The results showed that the resolution of ET and E measured by this system can reach 0.005 mm and 0.003 mm,respectively,and the corresponding observation time of peak ET and E are less than a minute(10 s and 20 s for ET and E,respectively)for the identification of the water consumption;moreover,it can still manage 3-5 minutes in the low-throughput phase.The observation accuracy of ET on 15 min,hourly and daily scale by this lysimeter system were improved by 3.51%,2.17%and 0.77%,and those of E were improved by 18.52%,11.81%and 2.95%,respectively.It shows that the lysimeter system can produce accurate,stable and reliable data with high resolution,it is applicable to the research of agriculture,hydrology and other related fields,especially for the measurement of small water changes such as short-term evapotranspiration and atmosphere condensed water of ecosystem in arid regions.