12-8  Irrigation, Reservoirs, Flood Prevention, Water and Soil Conservation and Improvement of Saline-Alkaline Land
Item	1990	1995	2000	2005	2006	2007
Number of Irrigated Areas at year-end    (set)	5363	5562	5683	5860	5894	5869
33 000  Hectares and Over	72	74	101	117	119	120
20 000-33 000  Hectares	76	99	141	170	166	174
Effective Irrigated Area      (10 000 hectares)	2123.1	2249.9	2449.3	2641.9	2802.1	2834
33 000  Hectares and Over	604.7	631.4	788.3	1023	1052	1052
20 000-33 000  Hectares	189.6	244.4	344.0	408	409.2	414.9
Number of Reservoirs	83387	84775	85120	85108	85849	85412
Large Reservoir	366	387	420	470	482	493
Medium-sized Reservoir	2499	2593	2704	2934	3000	3110
Small Reservoir	80522	81795	81996	81704	82367	81809
Capacity of Reservoirs        (100 million cu.m)	4660	4797	5184	5624	5842	6345
Large Reservoir	3397	3493	3842	4197	4379	4836
Medium-sized Reservoir	690	719	746	826	852	883
Small Reservoir	573	585	594	602	611	625
Water-saving Irrigated Area (10 000 hectares)			1638.9	2133.8	2242.6	2348.9
Flooded or Waterlogged Area (10 000 hectares)	1933.7	2006.5	2098.9	2133.9	2137.6	2141.9
Area of Soil Erosion under Control	5300	6690	8096	9465	9749	9987
(10 000 hectares)
Improved Area of Saline-Alkaline Land	499.5	543.4	584.1	603.2
(10 000 hectares)
Total Length of Dikes                   (10 000 km)	22.0	24.7	27.0	27.7	28.1	28.4
Area of Land Protected by Dikes	3200.0	3060.9	3960.0	4412.0	4548.6	4551.8
(10 000 hectares)
a) The capacity of the large-scale reservoir is over 100 million cubic meters, while that of the medium-scale one is from 10 to 100 million cubic meters,
and that of the small-scale one is from 100 000 to 10 million cubic meters.