| 透水係數 | Hydraulic Conductivity |
| 濕度儀 | Hygrometer |
| 撞擊式雨滴譜儀 | Impact Distrometer |
| 斜水尺 | Inclined Gage |
| 指標流速法 | Index-velocity Method |
| 間接流量測量 | Indirect Discharge Measurement |
| 土壤滲入計 | Infiltrometer |
| 滲入係數 | Infiltration Coefficient |
| 土壤滲入量 | Infiltration Flow |
| 儀器校正 | Instrument Correction |
| 等雨量線法 | Isohyetal Method |
| 同位素追蹤劑 | Isotopic Tracer |
| 地面撞擊式雨滴譜儀 | Joss-Waldvogel Distrometer, JWD |
| 鉛錘側線 | Lead Line |
| 氯化鋰露點儀 | Lithium Chloride Dew-point Meter |
| 蒸滲儀 | Lysimeter |
| 平均斷面法 | Mean-section Method |
| 量水堰 | Measuring Weir |
| 微波降雨雷達 | Micro Rain Radar, MRR |
| 中斷面法 | Mid-section Method |