The Ming And Qing Period Off The Distribution And Improvement Of The Regional Salinization Of The Soil

The paper discusses the distribution and improvement of salinate soil during the period of Ming and Qing dynasties to Minguo period in the Guanzhong region from the view of historical geography. This paper analyzes salinate soil distribution's spatiotemporal characteristics and cause of its formation by collecting of distribution about the salinate soil during Ming and Qing dynasties to the Minguo period in the Guanzhong area. Thereby, the improvement and utilization measures of the salinate are summarized. This paper divides into two parts, the first part is introduction and the second part is main body. This paper contains three chapters. The basic conclusion about this paper is as following:First, we discusses the main area of salinate soil during the period of Ming and Qing dynasties to the Minguo period, in terms of chronological order as longitude and spatial order as latitude based on the review of the salinate soil distribution in the Guanzhong area. We find that the previous distribution of salinate soil is similar to the situation we can learn until now based on the collecting of the documents. The salinate soil is mainly distribute in the east of Guanzhong areas, which are including Jinghuiqu Irrigation Area, the Pu county of Luohuiqu Irrigation Area, Fuping County, Hua County, Huayin County, the downstream of Wei river and the beach of the Wei river.Second, according to the standard if the salinate soil can produce salt or not, the salinate soil is dividing into two types:the one is the generally alkali-saline level; the other is the higher alkali-saline lever. The alkali-saline level of Fuping, Zhaoyi, Dali is more serious than other area which have seldom produce salt in all times. The distribution of alkali-saline soil, both have characteristic of time and space. Jinyang county, Sanyuan county, Gaoling county, Linwei area, which are all located in the Jinghe area. The salinate soil exists from Han dynasty before till to the Ming and Qing dynasty and Mingguo period. While, Chang'an, Hu county, Xingpin county are located along the Wei river, there is so many alkali-saline soil is formed cause the affection of the Wei river, and make a great influence of the local people's life. Dali, Chaoyi are located along with Yellow river, the change of Yellow river has the further and deeply influence of soil and alkali-saline. Hua county and Huayin county are located in the Yellow river's water back area. The flood and change of the Yellow river will influence the soil which distributes both sides of Yellow river. They are both have natural causes and artificial causes. The artificial causes main refer to non-reasonable means of irrigation, while, the natural causes are mainly including soil, geologic structure, dry climate, bad environment and so on. There are two reasons to make the salinate soil in this period, the one is dry climate, and the other is the change along the river. Based on these two reasons, the salinate soil area in Minguo period is widely than traditional Ming and Qing dynasty.Last, this paper discusses the improvement method of the salinate soil during the Minguo period based on the review of improvement of salinate soil of Guanzhong area. We find that the main measures are building water conservancy projects, growing rice, growing alkali proof plant and so on. Until in the Mingguo period, it has some certain of improvement of technology since the western technology is introduced during that time, at that time, even the new methods, new ideas and measure have been put forward. Such as chemical soil improvement and comprehensive treatment are combined.