Tjapku Bog
Tjapku Bog is a low bog about 12 km eastwards from Ludza on Mudavas lowland.
Area: 1,061 ha
The average depth of the peat layer is 1.2 m; the deepest layer is at 5 m.
Total deposit of peat: 12 mil. m3
Peat is medium and well decayed; under the peat there is sapropel. A part of the bog water outflows to the Ludza River, which flows along the north-western side of the bog. Open ditches dried 660 ha; the drainage system dried 95 ha. The drained area is occupied by forest. The eastern part of the bog is crossed by road Ludza–Aizpūre.
Latvijas daba. 5.sēj. – Rīga: Latvijas enciklopēdija, 1998. – P.222.