Due to an abundant rainfall and frequent rainstorm, and geographical characteristics of mountain and hills, the potential erosive dynamics of soil erosion is strong. The low resistant erosion ability of ground substance, especially in granite weathering crust and purple rock and its soil are the inner causes of severe soil erosion. The utilization of natural resource of mankind was increased due to characteristics of social and economic environment of the province. The unreasonable land utilization caused vegetation destroy, which is the key factor of soil erosion.

豐沛的降雨和頻繁的暴雨，以及多山地丘陵的地形特征国产91色综合九九免费，為土壤侵蝕提供了強大的侵蝕潛在動力亚洲天堂在线观看免费；抗侵蝕性較弱的地面組成物質(zhì)一区二区视频在线导航，特別是花崗巖和紫色巖風化殼及其土壤国产又紧又粗又黄又爽视频网站，是造成土壤侵蝕特別嚴重的內(nèi)在原因直接看的av网站免费观看；而社會經(jīng)濟環(huán)境特點使人類利用自然資源強度增加，出現(xiàn)了一系列土地利用不合理現(xiàn)象国产激情高清视频，導致其中植被破壞，是造成土壤侵蝕的決定性因子久久国内精品。

Soil erosion is the most serious ecological environmental problem in Loess Plateau of China. Unreasonable land use practice is identified as one of the most important reasons for triggering and aggravating soil erosion, and the driving mechanisms for land use change and the relationship between land use spatial pattern and soil erosion are the important aspects for the study about soil erosion.

水土流失是黃土高原地區(qū)嚴峻的生態(tài)環(huán)境問題欧美大片免费久久精品三p，不合理的土地利用是引發(fā)和加劇水土流失的重要原因之一欧美性爱视频黑白配，土地利用變化驅(qū)動機制和土地利用空間格局與水土流失關系是其研究的重要方面。

It shows that runoff is closely correlated with the features of individual precipitation, and it is also affected by vegetation within a short period of time. Raindrop erosion, sheet flow erosion and rill erosion on the slope are the main soil erosion patterns; sediment yield occurs mainly in flood season. Human activity and individual precipitation are two important factors that control the soil erosion at a small watershed. Comprehensive management on the slope in a small watershed is an efficient measure of water and soil conservation.

分析表明亚洲日韩欧美精品，小流域的產(chǎn)流方式容易隨次降雨條件的變化而變化精品视频二区，植被因素在較小時間尺度內(nèi)就會影響產(chǎn)流；產(chǎn)沙主要來源于坡面上的濺蝕查找黄网站、片蝕和細溝侵蝕大黄片坐爱视频，時間主要集中在汛期；人類活動以及次降雨條件是控制小流域侵蝕產(chǎn)沙的重要因素欧美特黄性交片；在小流域內(nèi)進行坡面的綜合治理是水土保持的有效措施性色av一区二区三区V视界影院。

Surface erosion occurs mainly in farmland, sparse grassland and woodland, is the rainfall and runoff erosion on the surface is relatively uniform, including the raindrop erosion, sheet erosion and rill erosion .

面蝕主要發(fā)生在坡耕地、稀疏牧草地和林地熟女91九色地址，是降水和徑流對地表相對均勻的侵蝕方式人人摸人人草人人操，包括雨滴侵蝕、片蝕和細溝侵蝕日韩精品短片影院在线播放视频免费。

The main results were summarized as follows: 1 After forestland was destroyed into farmland, the main erosion type changed from sheet erosion to intensive rill and severe shallow gully erosion, accelerated soil erosion was severe and erosion intensity was hundreds to thousands times greater than those in the forestland prior to deforestation.

隨著開墾年限的增加免费色色的网站，單位降雨侵蝕力引起的侵蝕量呈加劇趨勢。在植被破壞15年的裸露休閑地淺溝集水區(qū)花蝴蝶免费视频高清版下载，侵蝕蝕強度隨坡長的增加而增加找一个黄色的网址能看毛片视频的，且淺溝槽侵蝕量大于淺溝間，切溝溝槽侵蝕量大于切溝間美国一级A片AAA欧美。

Quantitatively studying on the change of accumulated sheet and rill erosion amounts.Sheet erosion rate firstly gradually increased, then rapidly increased and finally remained stable with the rainfalls time, but the rill erosion rate increased more quickly than sheet erosion rate and the value of rill erosion rate was higher than of sheet erosionrate.

定量分析了次降雨條件下累積面蝕量亚洲图片国产精品一区二区、細溝累積侵蝕量及面蝕率、細溝侵蝕率隨時間的變化在試驗條件下在线观看午夜国产猫咪影院视频免费，隨著降雨的進行欧美日韩有码A，坡面面蝕率先緩慢增加趨勢后基本保持穩(wěn)定，而細溝侵蝕率具有隨降雨時間急劇增加現(xiàn)象日韩中文激情无码迅雷下载视频。

The means of expression on types of soil erosion and grading of intension is the paper medium long-term in soil erosion scopes. Quantitative study aims at the aspects of soil erosion mechanism and erosion quantity of small catchment or sidehill before. In the course of possession of the digital information on soil erosion figures, the integration of RS and GIS technique is used based on ARC/INFO.

在ARC/INFO軟件平臺的支持下717秋霞理论电影网good，采用遙感一地理信息系統(tǒng)一體化的土壤侵蝕強度等級制圖方法，獲取了土壤侵蝕的圖形數(shù)字信息在线播放欧美9797影院，運用圖形數(shù)字信息對土壤侵蝕景觀結構進行了計算强奸乱伦免费视屏。

Exhibiting angle unconformities or erosion unconformities in different part of the basin, these surfaces are obvious to be recognized on seismic profiles.T1 conformity, separating Eogene from Neogene, was formed during the whole basin uplifting and erosion by the end of Eogene.T1 unconformity denuded unbearing strata differently, and the deeper and thickest erosion lies on the southern margin of the basin, which reflects the activity of southern Jiangnan paleo-terrene. In conclusion, the major erosion belts extending along NW direction reflects NE-SW compression and slipping caused the Eogene basin uplift and strengthen the earlier NW direction extending low convex, and formed the NW direction extending depress and erosion belts.

古近系和新近系之間的T1不整合面形成于古近紀末期的盆地整體抬升，對下伏地層造成不同程度的剝蝕国产真实乱子精品视频，沿盆地南緣的剝蝕層位深Jizz国产精品网站，剝蝕量大，反映盆地南緣整體相對隆起久久青春国产精品毛片，與江南古陸的隆起作用有關国产一区二区三区91免费播放。T1界面剝蝕帶走向以北西向為主，反映了盆地在古近紀末受到了北東－南西向的擠壓或壓扭作用，該作用造成盆地整體抬升性感丝袜黄色网站免费在线A片，強化了北西向展布的低凸起国产精品igao视频网网址免费播放，產(chǎn)生了近北西向的洼陷和剝蝕帶。

The main contents are as follows:Firstly, starting with the general situation of soil erosion and the harms caused by it, the causes leading to the local soil erosion problem are analyzed comprehensively in the paper. And connecting with the measures taking place, sticking points towards the career of soil and water conservation are expatiated upon.Secondly, Back-Propagation Neural Network, One of Artificial Neural Network is used to set up a modal about the connection of the soil erosion modulus and seven factors impacts on it, such as, rainfall, rainfall largest intensity in 30 minutes, runoff coefficient, vegetation cover percent, rate of granule, rate of physical viscidity-clay, the rate of organic matter. Through the comparison with linear regression model, the second regression model, the Chinese Soil Loss Equation, it illustrated that BP Neural Network modal is more accurate than the other three modals in forecasting the mount of soil erosion, and the BP Neural Network will have some applicability in forecasting in soil erosion.

本文以霍山縣作為皖西大別山區(qū)的典型區(qū)域二区在线网站，主要研究了以下內(nèi)容：(1)從介紹霍山縣土壤侵蝕狀況以及所造成的危害入手人人摸人人爽一及片，全面分析了導致當?shù)赝寥狼治g發(fā)生的原因，并結合當?shù)夭扇〉乃帘３窒嚓P措施亚洲无码色色操，闡述了當?shù)厮帘３止ぷ鞯陌Y結所在无码一区二区三区av免费；(2)結合上土市水土保持試驗站多年實測資料和2005年實驗資料，應用BP神經(jīng)網(wǎng)絡理論免费黄色网站查询，建立了次降雨土壤侵蝕量與次降雨量黄片你懂的、最大30min雨強、徑流系數(shù)一级又黄又粗毛片视频、植被覆蓋度等因子之間關系的模型aaaaaa性欧洲，并通過BP神經(jīng)網(wǎng)絡的預測模型與一次回歸模型、二次回歸模型久久伊人精品免费视频、CSLE模型之間的對比分析国产天天在线视频，說明了建立的BP神經(jīng)網(wǎng)絡模型在土壤侵蝕預測可以取得較回歸模型和CSLE模型更高的精度，也說明了BP神經(jīng)網(wǎng)絡理論在土壤侵蝕預報中具有一定的適用性最新福利一区。

Although forest canopy layer could prevent splash erosion effectively, clay was taken away by overland flow and run off easily, the erosion amount became less after removing the forest canopy and surface soil, while the splash erosion still produced in the surface layer; the splash function weakened after having water current, the starting particles were less than bareland, so removing the surface disturbed soil made the erosion amount and clay less, silty sand more than bareland, but unsteady, the wear and tear energy used by raindrop splash and current function for overcoming sediments separating and starting were comparatively large, sediments were very difficult to be started and transported, it explained that forest root systems could increase anti-erosion capability of forest vegetation, make rainfall-current system splash and export finer particles than bareland.

雖然林冠層能有效防止濺蝕的發(fā)生成性交免费视频，但坡面流還是能帶走粘粒部分，粘粒還是容易流失小蝌蚪视频破解软件下载安装。去除林冠和表層土后欧美一级性爰，侵蝕量變得更少，但表層還是會被濺蝕在线播放免费黄色网页视频，有水流后狼友视频首，濺蝕作用減弱，顆粒起動的比裸地的少2区在线免费观看视频，所以99久久久码国产精品性，去除表層擾動土后，侵蝕量更少18禁止看网站，粉沙多女人高爱潮一级AA片视频下载，粘粒比裸地更少一些，但不穩(wěn)定免费超碰在线观看，雨滴擊濺和水流作用用于克服泥沙分離起動損耗的能量較大v黄片視頻，很難被起動輸移，這說明森林植被根系的作用增加了林地植被的抗蝕力国产一级A∨国产片免费，使降雨一水流系統(tǒng)僅能濺起輸出比裸地坡面更細小的泥沙顆粒欧美性爱在线三区。