12-9 IRRIGATION, RESERVOIRS, FLOOD PREVENTION, WATER AND SOIL CONSERVATION AND IMPROVEMENT OF SALINE-ALKALINE LAND |
|||||
Item |
1985 |
1990 |
1995 |
1996 |
1997 |
Number of Irrigation Areas (year-end) |
5281 |
5363 |
5562 |
5608 |
5579 |
33 000 Hectares and Over |
71 |
72 |
74 |
75 |
77 |
20 000-33 000 Hectares |
66 |
76 |
99 |
108 |
115 |
Effective Irrigated Areas (10 000 hectares) |
2077.7 |
2123.1 |
2249.9 |
2206.2 |
2249.5 |
33 000 Hectares and Over |
599.6 |
604.7 |
631.4 |
615.0 |
640.8 |
20 000-33 000 Hectares |
167.0 |
189.6 |
244.4 |
266.5 |
286.2 |
Number of Reservoirs |
83219 |
83387 |
84775 |
84905 |
84837 |
Large |
340 |
366 |
387 |
394 |
397 |
Medium-sized |
2401 |
2499 |
2593 |
2618 |
2634 |
Small |
80478 |
80522 |
81795 |
81893 |
81806 |
Capacity of Reservoirs(100 million cu.m) |
4301 |
4660 |
4797 |
4571 |
4583 |
Large |
3076 |
3397 |
3493 |
3260 |
3267 |
Medium-sized |
661 |
690 |
719 |
724 |
729 |
Small |
564 |
573 |
585 |
587 |
587 |
Total Area Liable to Flooding or Waterlogging (10 000 hectares) |
2420.7 |
2446.7 |
2442.5 |
2458.2 |
2458.2 |
Flooded or Waterlogged Area Under Control (10 000 hectares) |
1858.4 |
1933.7 |
2006.5 |
2027.9 |
2052.6 |
Percentage to Total Area Liable to Flooding or Water-logging (%) |
76.8 |
79.0 |
82.2 |
82.5 |
83.5 |
Total Area of Soil Erosion (10 000 hectares) |
12920.0 |
13600.0 |
16300.0 |
18266.4 |
18266.4 |
Area of Soil Erosion Under Control (10 000 hectares) |
4640.0 |
5300.0 |
6690.0 |
6932.1 |
7224.2 |
Percentage to Total Area of Soil Erosion (%) |
35.9 |
39.0 |
41.0 |
38.0 |
39.5 |
Total Area of Saline-Alkaline Land (10 000 hectares) |
769.3 |
753.9 |
765.6 |
772.5 |
772.5 |
Improved Area of Saline-Alkaline Land (10 000 hectares) |
456.9 |
499.5 |
543.4 |
551.3 |
561.2 |
Percentage to Total Area of Saline-Alkaline Land (%) |
59.4 |
66.3 |
71.0 |
71.4 |
72.6 |
Total Length of Dikes (10 000 km) |
17.7 |
22.0 |
24.7 |
24.8 |
25.1 |
Area of Land Protected by Dikes (10 000 hectares) |
3106.0 |
3200.0 |
3060.9 |
3268.6 |
3414.6 |
|
|
|
|
|
|
a)The capacity of the large reservoirs is over 100 million cubic meters, while that of the medium ones is from |
|
|
|
|
|
10 million to 100 million cubic meters, and that of the small ones is from 100 000 to 10 million cubic meters. |
|
|
|
|
|