主讲人: Roland Bunch
活动: ECHO East Africa Highlands Symposium 2014 (2014-10-27)
A-frame levels can be used to trace contour lines for soil conservation, or irrigation ditches at ½ % slope. They are highly accurate, and cost nothing.
主讲人: Roland Bunch
活动: ECHO East Africa Highlands Symposium 2014 (2014-10-27)
A-frame levels can be used to trace contour lines for soil conservation, or irrigation ditches at ½ % slope. They are highly accurate, and cost nothing.