Prolonged droughts have also led to desertification.

长期的干旱会导致沙漠化。

The expansion of desertlike conditions into areas where they did not previously exist is called desertification.

沙漠化现象的扩大到以前不存在的方被称为沙漠化。

Desertification occurs when fertile farmland turns into desert.

沙漠化发生在肥沃的农田成沙漠时。

The aim is to create a natural shield against desertification.

其目的是建立一个天然屏障来抵御沙漠化。

So the process of places becoming deserts is called desertification.

因此，这些方成沙漠的过程被称为沙漠化。

Sandstorms in China appear to have increased in recent years as a result of desertification.

土壤的沙漠化使近年来中国的沙尘暴呈上。

For example, in some areas of northwest China desertification is also a serious problem.

例如，中国西北部某些方的沙漠化也是一个很严的问题。

There's a material called liquid NanoClay that aims to reverse desertification turning wasteland into fertile soil.

有一种叫做液态纳米粘土的材料，旨在逆转沙漠化，将成肥沃的土壤。

Population growth, urbanization and desertification triggered by increasing climate change have escalated the conflict.

如今气候化加剧，因此带来的人口增长，城市化，以及土沙漠化问题使这一冲突愈演愈烈。

But what is troubling is the increasing desertification in the region which is essentially pulling the Sahara desert south.

但令人不安的是，该区日益严的沙漠化实际上正在把撒哈拉沙漠往南拉。

In some regions, the increase in desert areas is occurring largely as the result of a trend toward drier climatic conditions.

在许多区，沙漠化问题主要是因气候干燥而起。

This is a process that happens when land becomes desert because of climate changes and because people cut down trees and dig up grass.

气候化以及人们砍树除草使土为沙漠这个过程就叫做土壤沙漠化。

Desertification is accomplished primarily through the loss of stabilizing natural vegetation and the subsequent accelerated erosion of the soil by wind and water.

沙漠已经占据了球表面积约四分之一，而且最近几十年正以惊人的速度扩张。沙漠化是指类似沙漠的环境漫延到原本并非沙漠的区域。据估计，球表面另外四分之一的方正面临沙漠化威胁。

Evidence of this ongoing force known as desertification comes from satellite photographs of once arable fields now abandoned. But not all of them moved away.

从卫星照片可以看出沙漠化，曾可耕种的田，如今弃置废。但并非所有方都改。

UN has the impact of desertification and drought on farmers is one of several factors causing the Sahel conflict in Burkina Faso Mali and Nigher.

联合国沙漠化和干旱对农民的影响是导致布基纳法索、马里和更晚萨赫勒冲突的几个因素之一。

The raising of livestock is a major economic activity in semiarid lands, where grasses are generally the dominant type of natural vegetation.

导致沙漠化的主要因素有四个：过度种植，过度放牧，过分砍伐，过度灌溉。由于人口密度增加，人们对粮食作物的种植已经扩展到日益干燥的区域进行。这些区域很有可能经常会发生干旱，所以农作物种植失败是很正常的事情。大多数农作物的种植需要事先移除天然植被，而农作物欠收后又会留下大面积，非常容易被风力和雨水侵蚀。草类通常是当的主要天然植被类型。

To the south encroaching desert, south of the Sahara, a group of Sahel countries have launched an ambitious great green wall initiative to plant hardy trees and grasses to fight desertification.

为应对撒哈拉沙漠以南的南侵沙漠，一些萨赫勒国家发起了一项雄心勃勃的" 绿色长城" 计划，种植耐寒的树木和草来防治沙漠化。

Even in the areas that retain a soil cover, the reduction of vegetation typically results in the loss of the soil's ability to absorb substantial quantities of water.

沙漠化主要通过以下过程实现：首先自然植被不断减少，随后风力和雨水加速了土壤的腐蚀。有的时候松散的土壤全部被风刮走，留下石质化的表层；其它情况下细小的沙粒可能会被吹走，而正常沙粒大小的砂子不断堆积，从而形成移动的沙丘或者沙脊。植被的减少通常也会导致土壤吸收大量水的能力丧失。

Your assignment for this week will be to read up on this research and write a report on how dust from damaged land may exacerbate drought conditions and lead to further desertification of arid areas.

你们这周的任务将是阅读这项研究并写一篇关于来自受损土的沙尘如何加剧干旱状况并导致干旱区进一步沙漠化的报告。

The extreme seriousness of desertification results from the vast areas of land and the tremendous numbers of people affected, as well as from the great difficulty of reversing or even slowing the process.

造成土沙漠化的最后一个主要人为因素在于人类过度灌溉导致土壤的盐碱化。灌溉多余的水渗透到下水位。假如没有排水系统的存在，那么下水位上，把溶解的盐分带到土壤表面。水分蒸发后，盐分留在了表面，形成白色的壳层，这一壳层阻止了空气和水接触底下的土壤。以及扭转甚至减缓这一过程的巨大困难。