Everything about N-OF01 Overflow Test (Reference) id;activity_name;activity_type;activity_descriptor;breaching;animal;erosion;temporary;levee_survey;prolonged;start_date;end_date;date_length_day;date_length_hour;date_other;levee_stretch;location_x;location_y;location_z;location_descriptor;location_other;objectif_important;objectif_knowledge;pre_condition;act_des;monitoring_process;monitoring_reasoning;limits;during_activity;post_activity;activity_result;results_conc;knowledge_desc;ref_links;wrk_1;wrk_2;wrk_3;key_info 63;N-OF01 Overflow Test (Reference);Strength test;The N-OF01 Reference overflow test has been executed on the landward side of a Dutch levee in the Hedwige-Prosper Polder. The test section is 2 m wide, sided by wooden boarding, and considered to be in a good condition without any visible anomalies. The vegetation state is considered in a state after normal maintenance, with grass lengths of ca. 20 to 30 cm and subject to normal Dutch maintenance methods. Note that the grass may have suffered from the extended dry period from April to September ’20.;False;False;True;False;False;False;2020-10-24 08:00:00;2020-10-28 17:00:00;5;;30.5 hours effective overflow time.;VI;51.34842843;4.22904;12.0;Landward slope of levee.;"Lambert'72 coordinates: X = 140226.0 m Y = 226526.0 m";Perform an overflow test on a Dutch levee in (visually) good condition. It is considered as a reference case for the Dutch levee in the Hedwige-Prosperpolder.;Impact of river overflow on a grass-covered levee.;Levee slope in visually good condition.;"29 blocks of overflow activity for a duration of 30.5 hours. Nominal discharge of 360 L/s. Measured discharge of 330 L/S.";"- Overhead cameras (4) - Acoustic water height sensors - Electromagnetic current velocity sensors - Discharge sensor (EM or acoustic)";"Description of the hydraulic conditions of the overflow. The setup is described in Vercruysse et al. (2022): ""Design and application of an overflow generator."" (Ref WL2022R20_047_1)";;During the test, it was observed that soil eroded slowly and exposed grass roots, without creation of any significant damage that would lead to imminent failure of the levee slope. Near the levee toe edge, a drainage layer became exposed and some of the gravel that was part of that drainage layer, got washed away.;The levee slope stayed in good condition apart from the slight erosion described during the activity. No critical damage.;A levee slope in good condition is able to withstand a 165 L/s.m discharge for at least 30 hours.;"Factual data report: https://stowanl-my.sharepoint.com/:w:/g/personal/llhpp_stowa_nl/EX5yYnuJ-EBBjoKAxAwg8LkBef8ra9V_-GHjzbkz0Was8g?e=pyaUSq Annexes: https://stowanl-my.sharepoint.com/:w:/g/personal/llhpp_stowa_nl/EWIzoxIhxopCryc6744YgHYBBWr_0fhoGpJ_1pSy0_tM2w?e=pY8Hc6";An integration report will be added later (February 2023) as knowledge document.;under development;True;False;False; All DATA concerning N-OF01 Overflow Test (Reference) data_type;data_descripion;date_date;data_find;data_media;data_media_find Timeseries;Timeseries of Discharge, Water Height and Current Velocity in different positions on the levee slope.;2022-06-15;https://stowanl-my.sharepoint.com/:f:/g/personal/llhpp_stowa_nl/ErTeMm0VuptOkW5eZeLVcvUBMQ5NzhHuMa8Dxezt9EXETA?e=3bhJsy;; Photo imagery;2 portals with in total 4 cameras are used to take surface photographs of the levee slope at different times during and in between overflow activity. The surface images in between overflow blocks show damage and vegetation evolution.;2022-06-01;https://stowanl-my.sharepoint.com/:f:/g/personal/llhpp_stowa_nl/ErTeMm0VuptOkW5eZeLVcvUBMQ5NzhHuMa8Dxezt9EXETA?e=3bhJsy;; All EQUIPMENTS concerning N-OF01 Overflow Test (Reference) equip_type;equip_usage Overflow generator.;"The setup is described in Vercruysse et al. (2022): ""Design and application of an overflow generator."" (Ref WL2022R20_047_1)" All SENSORS concerning N-OF01 Overflow Test (Reference) No sensors added