1 材料与方法
1.1 试验设计
1.1.1 试验装置
1.1.2 试验设置
1.2 测定方法
1.3 试验参数计算
1.3.1 平均流速
1.3.2 雷诺数
1.3.3 弗劳德数
1.3.4 阻力系数
1.3.5 平均粒径
1.3.6 计算径流剪应力
1.3.7 实测径流剪应力
2 结果与讨论
2.1 坡面流流速
表1 不同粗糙度下流速与流量、坡度回归关系Tab.1 Regression relationship between velocity, flow and slope under different roughness |
| 粗糙度/mm | 回归方程 | 决定系数R2 |
|---|---|---|
| 对照组 | v=1.284Q0.347S0.317 | 0.987 |
| 0.2~0.6 | v=0.733Q0.241S0.443 | 0.992 |
| 0.6~1.0 | v=0.668Q0.265S0.456 | 0.992 |
| 1.0~1.4 | v=0.644Q0.269S0.493 | 0.992 |
| 1.4~2 | v=0.615Q0.284S0.503 | 0.996 |
| 2~3 | v=0.552Q0.244S0.557 | 0.995 |
2.2 坡面流水深
2.3 坡面流流型、流态
表2 不同坡度和粗糙度下坡面流雷诺数Tab.2 Reynolds number of overland flow under different slopes and roughness |
| 粗糙度/mm | 坡度/(°) | 流量/(L·s-1) | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.15 | 0.3 | 0.45 | 0.6 | 0.75 | 0.9 | 1.05 | 1.2 | 1.35 | 1.5 | ||||
| 对照组 | 3 | 775 | 853 | 1 037 | 1 382 | 1 855 | 1 955 | 2 272 | 2 342 | 2 416 | 2 659 | ||
| 9 | 621 | 840 | 1 379 | 1 563 | 1 898 | 1 991 | 2 168 | 2 626 | 2 845 | 3 150 | |||
| 15 | 640 | 987 | 1 422 | 1 555 | 1 993 | 2 281 | 2 616 | 2 819 | 3 016 | 3 399 | |||
| 0.2~0.6 | 3 | 346 | 623 | 897 | 1 133 | 1 360 | 1 671 | 1 909 | 2 156 | 2 437 | 2 828 | ||
| 9 | 438 | 603 | 846 | 1 208 | 1 382 | 1 703 | 2 001 | 2 208 | 2 547 | 2 842 | |||
| 15 | 444 | 601 | 855 | 1 170 | 1 535 | 1 799 | 2 045 | 2 301 | 2 618 | 2 852 | |||
| 0.6~1.0 | 3 | 367 | 510 | 890 | 1 108 | 1 450 | 1 549 | 1 850 | 1 963 | 2 431 | 2 657 | ||
| 9 | 405 | 595 | 952 | 1 102 | 1 269 | 1 534 | 1 819 | 1 930 | 2 611 | 2 744 | |||
| 15 | 485 | 797 | 1 110 | 1 277 | 1 492 | 1 684 | 1 944 | 2 274 | 2 613 | 2 996 | |||
| 1.0~1.4 | 3 | 267 | 550 | 808 | 981 | 1 272 | 1 385 | 1 650 | 1 788 | 2 074 | 2 326 | ||
| 9 | 247 | 532 | 737 | 943 | 1 190 | 1 388 | 1 557 | 1 839 | 2 277 | 2 393 | |||
| 15 | 321 | 573 | 834 | 1 033 | 1 245 | 1 439 | 1 637 | 1 730 | 2 193 | 2 372 | |||
| 1.4~2 | 3 | 266 | 546 | 796 | 1 105 | 1 237 | 1 471 | 1 609 | 2 045 | 2 237 | 2 550 | ||
| 9 | 288 | 571 | 889 | 1 087 | 1 332 | 1 568 | 1 785 | 2 047 | 2 261 | 2 558 | |||
| 15 | 284 | 584 | 817 | 1 057 | 1 376 | 1 585 | 1 749 | 2 085 | 2 294 | 2 871 | |||
| 2~3 | 3 | 230 | 492 | 810 | 1 110 | 1 463 | 1 627 | 1 915 | 2 158 | 2 348 | 2 677 | ||
| 9 | 243 | 606 | 861 | 1 153 | 1 324 | 1 849 | 2 071 | 2 411 | 2 573 | 2 791 | |||
| 15 | 279 | 600 | 946 | 1 114 | 1 362 | 1 586 | 1 802 | 1 999 | 2 333 | 2 660 | |||
2.4 阻力系数
表3 不同粗糙度下坡面流阻力系数与雷诺数回归关系Tab.3 Regression relationship between overland flow resistance coefficient and Reynolds number under different roughness |
| 粗糙度/mm | 回归方程 | 决定系数R2 |
|---|---|---|
| 对照组 | f=1.215Re-0.340 | 0.770 |
| 0.2~0.6 | f=4.909Re-0.413 | 0.507 |
| 0.6~1.0 | f=21.428Re-0.554 | 0.530 |
| 1.0~1.4 | f=20.640Re-0.568 | 0.771 |
| 1.4~2 | f=51.960Re-0.648 | 0.839 |
| 2~3 | f=122.478Re-0.733 | 0.805 |
2.5 径流剪应力
表4 不同粗糙度下径流剪应力与流量、坡度的回归关系Tab.4 Regression relationship between runoff shear stress and flow and slope under different roughness |
| 粗糙度/mm | 回归方程 | 决定系数R2 |
|---|---|---|
| 对照组 | F=33.574Q0.766S0.825 | 0.964 |
| 0.2~0.6 | F=8.25Q0.716S-0.123 | 0.756 |
| 0.6~1.0 | F=12.459Q0.307S0.016 | 0.615 |
| 1.0~1.4 | F=166.265Q0.634S1.629 | 0.752 |
| 1.4~2 | F=5.214Q0.756S-0.518 | 0.891 |
| 2~3 | F=25.542Q0.818S0.195 | 0.607 |