Such programs are much needed because in many arid lands there is only a vague idea of the extent of groundwater resources.

这样的计划是非常必要的，因为在许多干旱地区，我们并不清楚其地下水资源的范围。

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Regularly flowing rivers and streams that originate within arid lands are known as "endogenous".

起源于干旱地区的流动性河流和溪流通常被称为“内源河流”。

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The United Nations Environment Programme and the World Bank have funded attempts to survey the groundwater resources of arid lands and to develop appropriate extraction techniques.

美国国家环境总署和世界银行开始拨款并着手调查干旱地区的地下水资源，以开发合适的开采技术。

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These wranglers double as tour guides, leading horseback rides through the surrounding arid lands, with views of the red rock mountains of nearby Sedona.

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The programme, which provides a UNESCO Global Network on Water and Development Information for Arid Lands was established in 2004 to strengthen the global capacity for management of water resources in arid and semi-arid regions.

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In the vast, arid lands of the north, even most Western armies with all their modern technology might struggle to find small bands of rebel and Islamist forces who can simply disappear into the landscape.

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