The study region of the IATI-SGD project is situated in Southern Oman and extends from the Dhofar mountains into the Salaah coastal plain. Several watersampler units were set up along an elevational gradient to investigate the isotopic signatures of the monsoon precipitation, that recharges the groundwater resources of the costal plain.

Autosampler at rain station Alob, Oman

Autosampler an farm in Gogub, Oman

Autosampler at rain station Qairoon Hairiti, Oman

Autosampler at rain station Qairoon Hairiti, Oman

Autosampler an restaurant in Ittin, Oman

Autosampler at restaurant Al Makan, Oman

Stable water isotopes are a powerful analysis tool for data driven modeling of flow and retention times of water. To monitor the event specific dynamics of retention time watersamplers will be deployed throughout the Bode catchment, where both rainfall as well as runoff samples for isotope analysis will be sampled at high temporal resolution. The watersampler is part of the flexible and mobile monitoring system for earth observation MOSES - Modular Observation Solutions for Earth Systems. Their use in the framework of MOSES aims at automated sampling for the investigation of transport processes of dynamic hydrological events (e.g. floods, high and low waters).

In addition to the first field experiments in the Gondwanaland (Zoo Leipzig) and in Southern Oman, the device was installed in a climate controlled cabinet to comparable numbers regarding the evaporation reduction. The climate controll test were conducted at the TU Darmstadt and are part of a proof-of-concept publication (in preparation).

In the framework of a project on green roofs, Prof. Dr. Andreas Zehnsdorf (UFZ, UBZ) currently has two watersamplers built by the UFZ workshop for the automatic sampling of rain- and runoffwater.

The watersampler has already been presented at conferences and project meetings. A publication that has been selected as a HESS highlight article includes a detailed description of the watersampler as well as laboratory results demonstrating the evaporation prevention mechanism. Interested colleagues that would like to fabricate their own watersamplers can find the required technical drawings, microcontroller code, manuals, as well as a detailed bill of materials below:

Bill of materials - the bill of materials provides all parts required to assemble the distribution and control units. Links to manufacturers that ship to Germany have been added but are only exemplary.

• Bill of materials bill_of_materials.pdf (53.6 KB)

Technical drawings - based on these drawings you or workshops can manufactor the distribution unit and using the circuit digram the microcontroller can be assembled

• Distribution unit (technical drawings) distribution_unit.pdf (210.3 KB)
• Circuit diagram microcontroller_circuit_diagram.pdf (64.8 KB)

Microcontroller code - the microcontroller is an off-the-shelf product that requires code to control the stepper motor withion the distribution unit.

• Microcontroller code raincollector.zip (1.7 MB)

Manuals - the manuals include an opertaion manual that details how to operate the watersampler in the field as well as a manual on how to upload the microcontroller code onto the device.

• Operation manual operation_manual.pdf (1.7 MB)
• Manual for software upload manual_software_upload.pdf (278 KB)

References:

Michelsen, N., Laube, G., Friesen, J., Weise, S. M., Bait Said, A. B. A., and Müller, T.: Technical note: A microcontroller-based automatic rain sampler for stable isotope studies, Hydrol. Earth Syst. Sci., 23, 2637-2645, https://doi.org/10.5194/hess-23-2637-2019, 2019.

Michelsen, N., Laube, G., Friesen, J., Al Mashaikhi, K., Mueller, T. (2017) A microcontroller-based automatic rain sampler for stable isotope studies, EGU Leonardo Conference 2017. Michelsen_etal2017_EGU_Leonardo (1.3 MB)