| 1. | The effective irrigation area is 72 . 74 million mu
农业有效灌溉面积479万公顷。 |
| 2. | The irrigated area amount to20000ha
灌溉面积共达二万公顷。 |
| 3. | The longest river is the yangtze , which is 6 300 km . longand drains a basin of over 1 800 000 sq . km
最长的河流是长江，它有6300公里长，有着1800000平方公里的灌溉面积。 |
| 4. | By the end of 1992 , the enclosed pastures of the autonomous region amounted to 544 , 500 hectares with an irrigated area of 174 , 000 hectares
到1992年底，全自治区草场围栏4 87公顷、灌溉面积17 |
| 5. | Future research may provide quantitative estimates of the amount of land irrigated and methane generated through this 5 , 000 - year interval
未来的研究应该可以为这5000年间灌溉面积与甲烷的产生做量化的估计。 |
| 6. | The paper assesses the two key factors , supplying and demanding status of water resources , that supports economy development
对水资源供需状况、有效灌溉面积两个支撑经济发展的关键因素进行了分析评价，提出了若干适宜指标。 |
| 7. | Some soils are affected by salinity - alkalinity : about 15 % of irrigated area suffer from varying degrees of salinity and sodicity and about 10 % from water logging
一些土壤受盐碱影响：约15 %的灌溉面积有不同程度的盐化和苏打碱化，约10 %的土壤受淹水之苦。 |
| 8. | Wells irrigated 80 % ~ 90 % infield . since irrigating and drinking all depended on wells , wells became an important factor that determined the distributing and scale of villages
二十世纪上半叶的华北，灌溉的水源几乎全靠水井，水井灌溉面积占全部灌溉面积的80 %一90 % 。 |
| 9. | Families could invest as little as $ 3 to buy a kit that irrigated a 40 - square - meter kitchen garden , then reinvest some of the 300 percent annual return it generated to expand the system ' s coverage up to an acre or more
农家只要投资三美元，购买一套足以灌溉40平方公尺菜圃的组件，便可使年收益增加三倍；然后再将这些额外增加的年收益，拿出一部份来扩充系统，使灌溉面积增加到0 . 4公顷以上。 |
| 10. | Ningxia yellow river irrigation area is a big famous irrigation area in china and has over 2 , 000 years history , there are 17 main canals ( 1540 km length ) and 6 , 450 , 000 mu area , it plays a very important role in development of ecnomic and social of ningxia autonomous region
宁夏引黄灌区是我国著名的大型古老灌区，具有两千多年的灌溉历史。现有干渠17条，长1540km ，实际灌溉面积645万亩，是自治区经济和社会发展的重要基础。 |
