　

13-10 Irrigation, Reservoirs, Flood Prevention, Water and Soil Conservation and Improvement of Saline-Alkaline Land


Item
	1990	1995	2000	2002	2003


Number of Irrigation Areas at the year-end (set)	5363	5562	5683	5691	5729
33 000 Hectares and Over	72	74	101	110	112
20 000-33 000 Hectares	76	99	141	168	169
Effective Irrigated Areas (10 000 hectares)	2123.1	2249.9	2449.3	2503.0	2524.4
33 000 Hectares and Over	604.7	631.4	788.3	915.8	938.1
20 000-33 000 Hectares	189.6	244.4	344.0	407.2	408.4
Number of Reservoirs	83387	84775	85120	85288	85153
Large	366	387	420	445	453
Medium-sized	2499	2593	2704	2781	2827
Small	80522	81795	81996	82062	81873
Capacity of Reservoirs (100 million cu.m)	4660	4797	5184	5595	5658
Large	3397	3493	3842	4229	4278
Medium-sized	690	719	746	767	783
Small	573	585	594	597	597
Water-saving Irrigated Area (10 000 hectares)			1638.9	1862.7	1944.3
Flooded or Waterlogged Area (10 000 hectares)	1933.7	2006.5	2098.9	2109.7	2113.9
Area of Soil Erosion under Control	5300	6690	8096	8541	8971
(10 000 hectares)
Improved Area of Saline-Alkaline Land	499.5	543.4	584.1	528.3	586.5
(10 000 hectares)
Total Length of Dikes (10 000 km)	22.0	24.7	27.0	27.4	27.8
Area of Land Protected by Dikes	3200.0	3060.9	3960.0	4286.2	4387.5
(10 000 hectares)


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.