Study On Regional Difference Of Production Water Footprint Of Main Crop Based On Cropwat In Shandong Province

Water resources problem is the focus of the world today. In recent years, along with thepopulation explosion and the rapid development of world economy, water resources is facinga serious situation of shortage. In terms of Shandong province, the contradiction betweensupply and demand of water resources is outstanding.Per capita water resources quantity inShandong Province is less than500cubic meters. As the traditional agricultural province,agricultural water accounts for more than75%of the total water consumption in Shandongprovince. The major food crops of winter-wheat and summer-maize production water inShandong province occupies a considerable proportion of agricultural water.The water useefficiency of winter-wheat and summer-maize not only connects with the agriculturalsustainable development in Shandong province,but also have an important effect on ourcountry’s food security problem.Based on the research achievements of agricultural function zoning in Shandongprovince, this article divides Shandong province into six sub areas:lubei yellow river floodplain area,luxinan yellow river flood plain area, luzhongnan hilly and mountainousarea,ludong hilly area, luzhong piedmont plain area, the Yellow River delta plain area. Inorder to represent different precipitation conditions,there level years are selected in thestudy:normal year(2010),wet year (2003), dry year (2002).Based on the water footprinttheory,cropwat is used to calculate crop water requirement of winter-wheat andsummer-maize in Shandong province,and then virtual water content of blue water, green water,gray water as well as blue, green, gray water production footprint are calculated.ArcGISsoftware is used to analyse and divide space division on production water footprint ofwinter-wheat and summer maize in Shandong province.The regional difference on virtualwater content and production water footprint is selectively analyzed.The main conclusions of this article are listed as follows:(1)The blue, green virtual water content of winter-wheat and summer-maize inluzhongnan hilly and mountainous area is the largest among the six sub areas.the The YellowRiver delta plain area has a smaller content,the lest four areas each has a middle level content. The Yellow River delta plain has the largest gray virtual water of major crops in Shandongprovince.The northern Yellow River flood plain has the smallest content of gray virtual water.(2)In normal year(2010), Yellow River delta plain area has the smallest content of bluevirtual water of winter-wheat in Shandong province,which is0.06m3/kg.The biggest contentof blue virtual water of winter-wheat is in eastern hilly area in Shandong province,which is0.11m3/kg. Compared with normal year, the content of blue virtual water of winter-wheat inShandong province in wet year is a little smaller.But in dry year,the content involved isobviously bigger.It shows that under the circumstances of less precipitation, irrigation waterdemanded in agriculture production is bigger. Unit area green water consumption ofwinter-wheat growth in Shandong province is closely associated with precipitation.In dry year(2002), the per unit green water consumption of winter-wheat growth in the whole province is398mm, however, in wet year (2003), that figure is716mm.The latter is80%more than theformer, suggesting that the green water consumption of winter wheat in Shandong province isdirectly constrained by precipitation. Because of summer-maize growth period in Shandongprovince is in flood season, which has effective rainfall to meet the demand of summer maizegrowth, rainfall changes have little influence on the content of green virtual water ofsummer-maize in Shandong province.(3)Distribution of the main crop production water footprint in the study area is listed asfollows:the production water footprint in south-central hilly and mountainous area andsouthwest Yellow River plain area is higher. The Yellow River delta plain area and the centralpiedmont plain area have a lower number. The lest two areas have the middle levelnumber.Winter-wheat in Shandong province has a balanced proportion of blue and greenwater footprint,however,the blue water footprint of summer-maize in Shandong province isslightly higher than the green water footprint of summer maize The production water footprintof summer-maize is higher than that of winter-wheat.(4)Gray water footprint constitute an important part in production water footprint ofmain crops in Shandong province. The content of gray water of winter-wheat andsummer-maize in Shandong province is high.Shandong province has much room forimprovement in improving the utilization ratio of nitrogenous fertilizer and controlling ruralnon-point source pollution field.(5)The virtual water flow amount of main crops in south-central hilly and mountainous area, eastern hilly area and southwest yellow flood plain area is bigger.Yellow River deltaplain area has the smallest virtual water flow amount. Virtual water flow amount ofwinter-wheat and summer-maize in Shandong province accounts for a large proportion of thetotal water resources. The water resources flowing through the consumption and production ofgrain can not be overlooked.