| Month | 1877-78 Minimum Year | 1878-79 Maximum Year | Mean of 20 Years | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Blue Nile at Khar- toum. | Assuân. | Cairo. | Blue Nile at Khar- toum. | Assuân. | Cairo. | Blue Nile at Khar- toum. | Assuân. | Cairo. | |
| June | 1000 | 800 | 600 | 1000 | 500 | 250 | 1000 | 750 | 500 |
| July | 2800 | 2400 | 1100 | 3500 | 2000 | 900 | 2800 | 2200 | 1100 |
| August | 5300 | 5600 | 3900 | 8200 | 7900 | 5200 | 7000 | 7900 | 5300 |
| September | 4700 | 5900 | 4400 | 12500 | 12100 | 8600 | 8500 | 9200 | 7200 |
| October | 2500 | 4000 | 3900 | 8000 | 9300 | 10300 | 4500 | 6000 | 6900 |
| November | .. | 2400 | 2550 | .. | 4700 | 6500 | .. | 3300 | 3700 |
| December | .. | 1500 | 1600 | .. | 3200 | 3600 | .. | 2200 | 2300 |
| January | .. | 1200 | 1300 | .. | 2400 | 2600 | .. | 1600 | 1600 |
| February | .. | 800 | 800 | .. | 2100 | 2100 | .. | 1200 | 1200 |
| March | .. | 600 | 550 | .. | 1900 | 1900 | .. | 850 | 800 |
| April | .. | 500 | 400 | .. | 1600 | 1600 | .. | 700 | 620 |
| May | .. | 400 | 300 | .. | 1500 | 1500 | .. | 600 | 520 |
| Mean | .. | 2175 | 1783 | .. | 4100 | 3754 | .. | 3041 | 2645 |
Note.—The very high discharges at Assuân and Cairo in April and May 1879; the minimum discharge of that year was about 1500 cubic metres per second. There has never been any discharge like that since.
Appendix J.
DISCHARGE TABLES OF THE DIFFERENT GAUGES OF THE NILE AND ITS TRIBUTAIRIES.
Table XXVII.—Discharges table of the Victoria Nile at the Ripon Falls.
| Gauge. | Discharge m³ per second. | Remarks. |
|---|---|---|
| 0·0 | 380 | This discharge table is the mean of two alternative tables; one assuming that the width of thesill of the Ripon Falls was 127 metres as stated by Sir William Garstin, the other assuming that only half this width was theworking sill, the rest being more or less shallow water. The constant has been taken as ·57. Sir William Garstin makes thewidth of the sill 70 + 40 + 13 = 127 metres, while Chavanne gives it as 82 + 14 + 55 + 22 = 173metres. The wider the sill, the quicker is the rise of discharge from the measureddischarge at the gauge of ·51. |
| ·1 | 410 | |
| ·2 | 450 | |
| ·3 | 480 | |
| ·4 | 520 | |
| ·5 | 550 | |
| ·6 | 580 | |
| ·7 | 620 | |
| ·8 | 660 | |
| ·9 | 700 | |
| 1·0 | 740 | |
| ·1 | 780 | |
| ·2 | 820 | |
| ·3 | 860 | |
| ·4 | 900 | |
| ·5 | 950 | |
| ·6 | 990 | |
| ·7 | 1040 | |
| ·8 | 1090 | |
| ·9 | 1140 | |
| 2·0 | 1190 |
Table XXVIII.—Discharge table of the Albert Nile at Wadelaï.
| Gauge. | Discharge cubic metres per second. | Gauge. | Discharge cubic metres per second. | Gauge. | Discharge cubic metres per second. |
|---|---|---|---|---|---|
| 0·0 | 520 | 1·0 | 780 | 2·0 | 1090 |
| ·1 | 544 | ·1 | 810 | ·1 | 1104 |
| ·2 | 568 | ·2 | 840 | ·2 | 1118 |
| ·3 | 592 | ·3 | 870 | ·3 | 1132 |
| ·4 | 616 | ·4 | 900 | ·4 | 1146 |
| ·5 | 640 | ·5 | 930 | ·5 | 1160 |
| ·6 | 668 | ·6 | 962 | .. | .. |
| ·7 | 696 | ·7 | 994 | .. | .. |
| ·8 | 724 | ·8 | 1026 | .. | .. |
| ·9 | 752 | ·9 | 1058 | .. | .. |
Table XXIX.—Discharge Table of the Albert Nile at the Gondokoro gauge.
| Gauge. | Discharge cubic metres per second. | Remarks. |
|---|---|---|
| 0·0 | 550 | There is a scour of a metre and upwards at this gauge site during a high flood. The pit isapparently filled with sand during a low flood. |
| ·2 | 600 | |
| ·4 | 660 | |
| ·6 | 740 | |
| ·8 | 820 | |
| 1·0 | 900 | |
| ·2 | 1060 | |
| ·4 | 1220 | |
| ·6 | 1380 | |
| ·8 | 1540 | |
| 2·0 | 1700 | |
| ·2 | 1900 | |
| ·4 | 2100 | |
| ·6 | 2300 | |
| ·8 | 2500 | |
| 3·0 | 2700 |