Analysis On Influencing Factors Of Grain Crops’ Water Footprint And Agricultural Water Efficiency In Qingtongxia Irrigation Area

Qingtongxia Irrigation Area is an important grain production base in Ningxia.The rational use of water resources can effectively alleviate the water pressure in irrigation areas.Water footprint is helpful to study the problem of water shortage.Therefore,this paper calculates the water footprint of food crops in Qingtongxia Irrigation Area and analyzes the changing characteristics of its water footprint.Through M-K test and AMOS path analysis,the effect of various factors on the water footprint of food crops in Qingtongxia Irrigation Area was discussed and analyzed,and the water footprint intensity of each area in Qingtongxia Irrigation Area was calculated to analyze the temporal and spatial variation of agricultural water use efficiency.Using spatial autocorrelation analysis of crop water footprint intensity values across irrigated areas to discuss their changing relationships.Finally,the system dynamics model is used to judge and analyze the key factors affecting agricultural water use efficiency in Qingtongxia Irrigation Area,set reasonable control parameters,and analyze changes in regional agricultural water use efficiency.The following main conclusions are obtained:(1)Through the calculation of the blue and green water footprints of the main food crops in Qingtongxia Irrigation District,we found that 2002 was the year with the largest green water footprint,while 2005 was the year with the highest blue water footprint in the Qingtongxia Irrigation District.The same food crop in the irrigated area has different blue and green water footprints,and the changing trends of the two are basically opposite.This means that when the water demand of crops is met,less irrigation water is used when there is more precipitation,and more irrigation water is used when there is less rainfall.At the same time,when calculating the water footprint,blue water accounts for a larger proportion of the total water footprint.This further indicates that crop planting in Qingtongxia Irrigation Area uses more irrigation water,and its production water presents a state of more blue water and less green water.(2)When only climatic factors are considered,rainfall has the greatest impact on the blue and green water footprints of grain crops in Qingtongxia Irrigation District.When comprehensively considering agricultural inputs and climatic conditions,the amount of pesticides applied,the total power of agricultural machinery and rainfall have a greater impact on the blue and green water footprint of food crops in irrigated areas.Rainfall is the climatic factor that has the greatest impact on the blue and green water footprint,whether or not agricultural input indicators are considered.(3)Before 2007,all regions except Yinchuan had a large decrease in the water footprint intensity value.From 2007 to 2017,the water footprint intensity decreased gradually in different places.After 2017,the water footprint intensity values of all regions except Wuzhong City tended to be stable,and the water footprint intensity values of Wuzhong during the study period were larger than those of other regions.(4)The change trend of the water footprint intensity of Qingtongxia Irrigation District from 2001 to 2020 was analyzed,and it was found that the water footprint intensity of food crops in adjacent areas was relatively clustered in different regions.From the LISA agglomeration map,it can be seen that Wuzhong City is a typical H-H agglomeration area,and its water footprint intensity value is relatively high.At the same time,the water footprint intensity level of its surrounding areas is also relatively high.Yinchuan City is a L-L agglomeration area,with high grain output value and high water use efficiency,while Pingluo County occasionally appears in a H-L agglomeration area,and the intensity of agricultural water footprint continues to decrease,which has a large space for development.(5)Based on the water footprint,a system dynamics model of agricultural water use efficiency in Qingtongxia Irrigation District was constructed.When the water consumption of blue water remains unchanged,the effective utilization coefficient and irrigation water utilization coefficient of Qingtongxia Irrigation District are adjusted differently.It was found that when the effective utilization coefficient and the irrigation water utilization coefficient increased,the yield of the main grain crops in the irrigated area showed an increasing trend,and the increase degree was different.It shows that the crop effective utilization coefficient and the irrigation water utilization coefficient have a certain degree of influence on the agricultural production in the irrigated area,and this method can put forward specific control measures.