The Environment Change Of Mu Us Desert In Historical Period

According to its characters of climate,geomorphology,vegetation andagricultural production,Mu Us Desert respectively belongs to semi-aridregion,border region of desert and loess,transition region fromgrassland to barren land and ecotone of agriculture and pasture husbandry.It is located at an exceeding transition zones,therefore,Mu Us Desertis no doubt a sensitive region to the environmental changes.It has afar-reaching significance for this region to argue and correct someviewpoints and to develop this region and to have a sustainabledevelopment for this region aftertime to researching into the course ofenvironmental changes and its influencing factors and discovering itsrules of environmental changes and inside and outside driving forces.In this paper,many information is gathered which is related toenvironmental changes of Mu Us Desert by the way of various kinds ofmeasures,including stratigraphy and archaeology,archaeologized intothe ancient cities environment,consulting historical literatures,investigating historical toponyms,and analysing local products,etc.Having Summarized all these information,the characters and its changecourses of environment in this region in the historical times werediscussed.The factors which include the courses of environmental changeand climatic change,the way and intensity of human activities have beensynthesized each other,and then those possible factors which couldinfluence the environment of this region are distilled and the effect ofthese factors have on the change course of environment in Mu Su Desertare determined.Main conclusions are as follows:1.Seeing the water system in the east of Mu Su Desert from therecordation of the book named Shui Jing Zhu(Commentary on the waterwayClassic) in volume 3,Sheyan water system is Wuding River today,Diyuanwater system is Yuxi River today,Zhuci water system is Tuwei Rivertoday,Yin water system is Kuye River today.Straight Road built inQin dynasty crossed the east of MuSu Desert from south to north.QinGreat Wall built in Zhanguo dynasty was basically located in boundarybetween southeast of Mu Su Desert and east of this region.Those 44fastnesses which were built by general Meng Tian in Qin dynasty arethought to be military cities built along the Yellow River.Moreover,there have also some ancient cities which were built in Qin and Handynasty along the line of water system in Henan province,they may bepossibly Gusuai (ancient fastnesses).2.According as the recordation of historical literatures,this paperdid textual research on some ancient cities which were distributedalong the line of water system,Straight Road was built in Qin dynastyand Qin Great Wall built in Zhanguo dynasty in Mu Su Desert.These ancient cities are located at ShangJun State including Sheyan County,Qiuci County,Fushi County,Baitu County and Xihe State includingHongmen County,Huojing ancestral temple,Humeng County,Yuxi Fastness,etc.Other twenty ancient cities ascriptions are determined accordingto historical literatures and discovering of archaeology,such asYangqiaopan ancient city was Yangzhou County in Qin and H an dynasty,but it also was Longyan City,Nanxiazhou City and Ningsuo City in Suiand Tang dynasty.Corresponding relations between Liuhu State and someancient cities in Tang and Song dynasty in southwest of Mu Su Desertwas basically made clear.3.The surface water environment in Mu Su Desert has had obvious changessince Qin and Han dynasty which existed 2000 years ago,basicallyputing up the shrinking and disappearing of lakes and natural ponds,the backward position of rivers chopping down and it's flux of waterdiminishing,and some perennial rivers becoming seasonal rivers,manymouth of springs were disappearing,etc.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.The courses of desertification have obvious phase characters,for the first time,it occurred in Donghan dynasty until Nanbei dynasty;the second time,it occurred in the end of Tang dynasty until Song andXia dynasty and occurred in Ming and Qing dynasty at the third time.The most serious desertification occurred in southeast of MuSu Desert,then appeared inferior degree in midst,north,south and east,anddegression degree in other directions.6.The changes of environment in Mu Su Desert in historical times havebeen controlled by climatic changes in temperature and drought-wetwithin hundreds or thousands years.At present,it came into being suchspatial structure and environmental characteristics fordesertification land because of being relative to other naturalgeographic characters and human activities.In all that,physiognomyand hiemal wind are the driving factors.The sandy matter in stratumis the physical fountain factor.The depravation of surface water inthis region is one of representations of environmental changes, meanwhile,it is also the factor which leads to the degradation ofvegetation and desertification.On the whole,human activity has actedupon these natural elements,becoming a dominant factor in the regionalenvironment changes since Ming and Qing dynasty.7.Influencing of human activities on the environment of Mu Su Deserthad occurred before Qin dynasty,and its intensity of earlier influencewas so slight that it could not cause a large scope and long timeenvironmental changes.But the intensity of human activities had beengradually increased since Ming and Qing dynasty,and had begun to bringinto play dominant role in terms of controlling and changing theregional environment.Especially the influence of rebuilding watersystem was more intensive.The action human act on environment ispossibly not only constructive but also devastating,moreover,nomatter which action is,its behind environmental effect is verycomplicated,the previous achievement made from rebuilding biologyenvironment could possibly induce soil salinization anddesertification afterward.Therefore,ecology construction ought tobe established in learning accurately its cause of formation.ReinventingMuSu Desert environment is not advisable,as well as usinga great deal groundwater to irrigate desert.To protect and amelioratewater system is a key point being used to resume Mu Su Desertenvironment.In this paper,multifold means were used to deduct reversely theenvironment of historical times,which is an effective method to discoverthe relation between human and land in this region and its deductive course.Whether ancient cities,toponym,products,literature or achievement ofarchaeology and recording of stratigraphy,useful information that we canget from each of them is restrictivist,only colligating them can reflectall-sided courses of environmental changes in this region,also can makecertain the cause of environmental changes in science and make researchingtheories have more reliability.