Study On Development And Change Of Warping Dams On Loess Plateau

Soil erosion and drought and little rain are two major restrictive factors for crop cultivation in the Loess Plateau.People cope with the constraints of drought and lack of rain by building water conservancy,planting drought-tolerant crops and adopting drought-resistant and moisture-conserving tillage techniques.Faced with soil erosion,the ancestors of Yusi have created many technical measures for soil and water conservation,such as terraces,dams dams,water cellars and waterlogging ponds.Inspired by the natural "Juhuang",people make full use of the water and soil resources lost in the Loess Plateau and build dams and weirs to retain water and soil in the ditches.These lost water and soil deposits will form a flat cultivated land.This land use pattern is called dam land by local people,and dams and weirs are called dams dams.As an important engineering measure to control soil and water loss in the Loess Plateau,dams dam has both the effect of damsing land and making land.It is a unique land use mode that suits local conditions.Its origin can be traced back at least to the Ming and Wanli years.After the mid-Qing Dynasty,the increasing population pressure in Shaanxi and Shanxi prompted the people to build dams Dams as one of the ways to expand the area of cultivated land and increase grain production,thus enabling dams Dams to develop to a certain extent.During the period of the Republic of China,the urgent need of the Yellow River harnessing made more and more experts and scholars realize that the safe flow of the Yellow River could not be separated from the water and soil conservation in the upper and middle reaches.As an important engineering measure of gully harnessing,dams dam experienced a leap from theoretical conception to concrete practice.In order to realize the self-sufficiency of military and civilian grain and cotton,the government of Shaanxi-Gansu-Ningxia Border Region,which seeks to survive between cracks,has established a mutual aid and cooperation organization in the form of "government-led and mass participation",and has launched a mass movement to build dams Dams in the border region.At the same time,the tradition of single-family dams dam construction is still continuing.In the era of collectivization,the construction of dams Dams in Suide County can be regarded as the epitome of the construction of dams Dams in the whole Loess Plateau area.Based on the continuation of tradition,the construction of dams dam in Suide County was put on the agenda in spring 1950.At first,it was only an attempt to call on some advanced villages such as Liuwan Village to build dams dam.In 1953,Suide Soil and Water Conservation Science Test Station selected Taoyuan Gully as the demonstration area of soil and water conservation,with a view to promoting the work of soil and water conservation in Suide County through typical demonstration and point-to-area way.The first harnessing measure of Taoyuan ditch is to build dams dam in ditch.Then,a series of scientific experiments and concrete practices of dams dam were carried out in Taoyuan ditch,and scientific experiments of site selection,construction,maintenance and flood control and harvest of crops on dam land were successfully completed,which accumulated relevant experience in dam land conservation.In the late 1950 s,Suide County launched a mass campaign for the construction of dams Dams throughout the county through leading the Party committee,typical demonstration and technology imparting.Especially in the 1960 s and 1970 s,dam land,as one of the three basic farmland in the Loess Plateau,has been greatly developed.In the era of collectivization,the construction of dams Dams has changed the ecological environment of the Loess Plateau to a certain extent,and has a far-reaching and lasting impact on local agricultural production.The implementation of household contract responsibility system leads to inadequate management and protection of silt dams.In addition,the defects of Silt Dams Built in the era of collectivization and the shortage of government funds for soil and water conservation make the vulnerability of Silt Dams increasingly prominent and the benefits of soil and water conservation and crop cultivation weakened.