沙地的

Ingredient analysis, grain size analysis and scanning electron microscope observation show that the sands of Huangyangtan sandy land come from the diluvium on Huangyangtan platform and the alluvium of Yanghe river.

对黄羊滩沙地进行物质成分分析、粒度分析和扫描电镜观察，结果表明：黄羊滩沙地的物质具有二源性特征，分别来源于黄羊滩洪积台地洪积物和洋河冲积物。

Based on the research, the quantity of sandlot"s dust samples is concentrated in 150cm height below, and primarily are the middle and lager particles, so sandlot"s transmission of small particles is less than the other three surfaces in 150cm height above.

2经测定，在150cm高度层以下沙地风蚀物含量较大，但由于沙地地表颗粒组成以中砂粒和细砂粒为主，因而在150cm高度层以上沙地的输沙量低于其它三种地表。

Gramineae and Compositae by the shifting sand to the fixed sandy land, the species of which changed greatly, that indicated they were playing a great role in the recovery of the sands. Asclepiadaceae plants could serve as a indicative plants to distinguish between the types of shifting sand and other sand; Portulacaceae and Bibgnoniaceae plants, which appeared only in the fixed sandy land, has become a landmark to determine the fixed sand plants. In addition to artificially plant Caragana spp. and Artemisia spp.

豆科和藜科植物作为流动沙地的先锋物种，表现出较强的适应能力；禾本科和菊科植物由流动沙地到固定沙地，其种类变化较大，表明其在沙地恢复中发挥着巨大的作用；萝摩科植物可作为区分流动沙地和其它沙地类型的指示性植物；马齿苋科和紫薇科植物仅在固定沙地中出现，已成为判断固定沙地的标志性植物。

Brought forward and reasoned the forming mechanism of Maowusu sandy land. Based on the analysis of the development of Holocene rivers and related loess and windsandy geomorphology, the paper put forward the forming mechanism of Maowusu sandy land as follows: while the climate became dry, the exterior channels extended backwardly and cut through the remained lake system of ancient Hetao lake. This resulted in the rapid discharge of underground water. The vegetation living on this water resource was destroyed completely. Then the sand began to form.

对毛乌素沙地的形成机制进行了新的探索基于对过渡地带全新世河流及其相关的黄土和风沙地貌发育、土地利用变化等分析，提出毛乌素沙地的形成机制：在气候变干的同时，外流河谷溯源延伸，切穿了长城以北河套古湖残遗湖系，使地表地下水迅速外泄，原靠湖系水资源维系的生长在河套古湖湖滨沙堤形成的沙地上的非地带植被的生存条件被彻底摧毁，而起沙。

The analysis of chorological and spatial changes of desertification indicates that expansion of desertification mostly takes place around the four main sandy lands: Keerqin, Hulunbeier, Hunshandake and Maowusu, while situation in the central part of sandy land is kept relatively steady, with some part of these areas tending to take a favorable turn.

通过沙漠化时空演变过程分析表明：沙漠化的发展主要集中在科尔沁沙地、呼伦贝尔沙地、浑善达克沙地和毛乌素沙地的边缘，而沙地的内部则相对稳定，部分地区有逆转的趋势。

At the edge of sand land, there lies a Caragana microphylla zone. From the fringe to the center of sand land, there are more mesic plant communities. A sandy environment which is different the local climate is constructed in the hinterland of the sand land, so there are more different ecological types of the plant communities.

在沙地与草原的过渡带上一般会有由小叶锦鸡儿群落组成的一个过渡带，从沙地的边缘到沙地的腹地，植物群落逐渐中生化，沙地在其腹地营造了一个超越当地气候特征的沙地环境，容纳了各类不同生态类型的植物群落。

The degradation process of the sandy rangeland expresses the change from fixed sand to semifixed sand.

沙地草场退化过程主要表现为固定沙地向流动沙地的演化。

Ulmus pumila open forest s have extensive distribution in the Otindag Sandy Land, which are important for lightening sandstorm.

榆树是浑善达克沙地的优势种，榆树疏林在浑善达克沙地成缀块状分布，对于该区域生态系统的整体性和多样性维持以及防风固沙等方面具有重要意义。

Ulmus pumila L. var. sabulosa is an indigenous plant in Hunshandake sandy land.

沙地榆是浑善达克沙地的乡土树种。

But at the same time,itexisted in the fact that the water environment was amended,showingthat many lakes and ponds such as Hong Jiannuo Lake appearing andexpanding in the end of Qing dynasty.4.The vegetation in Mu Su Desert passed through several phases inhistorical times,the main phases are:the species composition ofvegetation community was gradually simplified;xeromorphous and sandyplant increased;the status of desert vegetation rose evidently.However,the change of vegetation zonation means that forest plainchanged into drought plain did not occur.5.The main modality of Mu Su Desert land degenerating has beendesertification,it had occurred before human activities intervenedintensively.Two-thirds of land has been desertification at variousdegrees.

但与此同时，也存在着局部的水环境改善，突出表现为红碱淖等湖沼在清末民初的出现和扩大。4、毛乌素沙地的植被在历史时期经历了群落种类组成渐趋简单、旱生沙生资源植物增加、荒漠植被地位明显上升等变化，但是并不存在由森林草原到干草原的地带性植被变化。5、沙漠化是毛乌素沙地土地退化的主要表现形式，在人类活动强烈干预以前就存在着，秦汉以来，有大约2／3的土地发生了程度不同的沙漠化。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。