水土

Forest and Jinseng compound ecological system can obtain relatively high economic benefit, but soil erosion, soil crusting and deterioration and species reduction are main eco-environmental problems of Jinseng exploitation in Changbai Mountain region.

文摘：林、复合生态系统能够获得较高的经济效益，而水土流失，土壤板结、化及物种的减少是长白山地区人参开发所产生的主要生态环境问题。

These indicate that both soil and water in this irrigation area are in the process of progressively desalinized.

那么，灌区水土盐量演化走势究竟若何，在盐化还是在淡化，抑或稳定在一定的水平上。

The slop soil loss observation was stared in 1987 in Beijing, and the slope runoff plots were completed and improved in 2000, the entire seven mountain districts have emplaced the slop runoff stations.

北京的坡地水土流失观测始于1987年，2000年对坡地径流场又进行了系统的补充完善，在全市7个山区区均布设了坡地径流场。

The vegetation roots play a very important role in reducing soil erosion by means of being embedded in, entangled in and enwrapped in soil.

植物根系在土壤中穿插、缠绕和网络，与土壤形成了一种天然的复合材料，对防止水土流失具有重要作用。

The area of our cropland will decrease,and will harm the food security;The needed quantity of farming land by the year of 2020 is discussed in the article under the four fallow patterns :the seriously polluted faming land;the farming land with low output;the farming land of soil erosion and follow by crop rotation.

休耕会使耕地面积减少，对我国的粮食安全造成不利影响；文中阐述了在污染严重的耕地休耕、中低产田休耕、水土流失严重的耕地休耕以及采用轮作休耕4种不同模式下到2020年我国所需要的耕地保有量。

When water is added in increasingamounts to the normal soil,there is no increase in pH values of the suc-cessive filtrates and the pH of the distilled water is easily obtained,whilstthe pH value of the alkali soils falls very gradually to a ...

水土比例增大时，普通土壤各次滤液的pH 值并不增大，且易于达到蒸馏水的pH 值，反之，碱土的pH 值很慢的降低至pH 7.5。

A view of grid spatial data in 1998 and 2004, the landscape is fragmentized very much in the whole research area.

因此，农田也是水土流失治理的关键。

In 2003,the index of the landscape fragmentation has rised and the degree of the landscape fragmentation has changed seriously; the landscape of the soll and water loss has developed more and more multiple and fragmentized.

景观斑块个数增加，斑块平均面积出现不同程度的减少，景观斑块平均面积减少了5.7hm^2，景观破碎化指数1987年为0.914，2003年为0.922。破碎化指数增加，景观破碎程度加大。水土流失景观向多元化及破碎化方向发展。

This change may brought tremendous benefits to the economy of zoology:① the forest land renew as elements of Kai county landscape, the cover ratio of forest increase obviously to 66.29% from 22.55% now, gain double. At the same time, the scale and intension of the soil erosion will control efficiently with the disappearances of the steep slope which use for furrowing; and it don't exist converse succession, it also make the whole landscape ecosystem system enter into virtuous circle.

这种变化将产生巨大的生态经济效益：①有林地重新恢复为开县景观的基质，森林覆盖率显著增加，将由目前的22.55%增至66.29%，净增2倍，同时，陡坡耕地全部消失，水土流失规模和强度将得到有效控制，现有不少嵌块体的逆向演替将不复存在，使整个景观生态系统进入良胜发展。

Analysing the worsened geneses of water and soil losses can onlyinvolve the fundamental question of erosion caused by human beings.

剖析水土流失加剧的成因，不能不涉及人为侵蚀这个根本问题。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。