Research On Water Resource Carrying Capacity Of Sandy Desertification Region In Northwestern Shanxi

The imbalance between supply and demand of water resources is a major issue that should be solved urgently in many cities of China.It is critical to exploit and use water resources rationally,which will maintain social stability and ensure economic development.The ecological environment was destroyed seriously in northwest Shanxi,such as vegetation deterioration,soil erosion and serious sandy desertification,because most of the water resources were used to industry and agriculture,but little to ecological water requirement.The only way to prevent ecological environment from worse further was the priority of ecological water requirement.This study took Youyu County as the study area,based on the daily meteorological factors(e.g.temperature,atmospheric pressure,precipitation)from 2004 to 2013 and land use/cover change of different periods,the ecological water requirement model was used to estimate the evapotranspiration and the ecological water requirement.Then the water resources carrying capacity of the study area could be calculated by using the multi-objective optimization mode and principal component analysis(PCA)method.The following conclusions can be drawn from the present study:(1)Mean daily reference evapotranspiration in the study area roughly showed a normal distribution pattern,the minimum value of reference evapotranspiration appear at the beginning and ending in a year.The inter-annual variations of the monthly reference evapotranspiration fluctuated greatly.The maximum value of average monthly variation of reference evapotranspiration appeared in growing season(May,June&July)and the minimum value can be seen in non-growing season(January&December),which is closely related to the local climate characteristics.(2)Comparing the ecological water requirement of the three land types in growth season,we can conclude that the ecological water requirement of grassland is minimum,about 1x10~8 m,and the value of dry land is maximum,close to 4×10~8 m~3.Although the woodland ecological water requirement per unit area was maximum,close to 560 mm and the dry land ecological water requirement per unit area was merely 400 mm.,the dry land ecological water requirement was higher than the woodland just because of the total area of dry land was more than that of woodland.(3)According to water resources condition,industrial and agricultural production scale and population,water resource carrying capacity of the study area exceeded standard seriously,especially the overproof rate of population upped to 52.91%.There were three main influences for water resources carrying capacity of the study area,including demographic situation,socio-economic status and the level of exploitation and utilization of water resources.The water resources carrying capacity in the study area had obvious fluctuation from 2003 to 2007,water resources carrying capacity of the study area was on the increasing tendency from 2008 to 2011,the population and economic scale had been expending,but the total water consumption was significantly lower than the previous five years,which showed that water resources utilization rate improve significantly.In order to prevent the ecological environment from worse further and to guarantee the stable and healthy development of economy,water resources can be reasonable artificial regulation by building water conservancy facilities,which will provide plenty of water for the cultivated land,forest and grass in northwestern Shanxi timely.In addition,the study area should carry out the inter-basin water resources scheduling on the basis of optimal allocation of water resources.