Rain Garden Cross-Section: Water Layer by Layer

A cutaway perspective of a bioretention facility. The image simultaneously shows the ground surface and underground: the surface is a planted depression about twenty centimeters lower than the surrounding area, planted with sedges, irises, and shrubs that are both moisture-tolerant and drought-tolerant, with a surface covered in coarse gravel; there is an opening at the curb allowing road runoff to flow in, with energy-dissipating pebbles at the entrance. Cutting downwards reveals a layered structure—the upper layer is a sandy infiltration medium, the middle layer is a coarse sand filter layer, the lower layer is a graded gravel storage layer, and at the very bottom there is a perforated drain pipe and an overflow outlet. Each layer has a different thickness and distinctive color differences. Plant roots extend downwards through the medium layers. Avoid: only drawing the surface without showing the structure, making the layered thicknesses and materials indistinguishable, eliminating the inlet and overflow outlet, using water-intolerant ornamental plants.

Translated from Chinese by AI.

一個生物滯留設施的剖切透視。畫面同時呈現地面與地下:地表是低於周邊約二十公分的植栽窪地,種著耐濕耐旱兩相宜的莎草、鳶尾與灌木,表面覆蓋著粗礫石;路緣有一個開口讓路面的逕流流進來,入口處鋪著消能的卵石。往下切開可以看見分層構造——上層是砂質的滲透介質、中層是粗砂過濾層、下層是級配礫石的貯留層,最底部有一根穿孔的排水管與一支溢流口。每一層的厚度不同並有標示性的顏色差異。植物的根系向下延伸穿過介質層。避免:只畫地表看不到構造、讓分層的厚度與材料看不出差異、消除進水口與溢流口、使用不耐水的觀賞植栽。