Evaluation Of The Risk Of Water Resources For The Production Of Main Crops In Shandong Province Based On GIS And Water Footprint Theory

Increasing socio-economic activities and the rapid growth of population have greatly increased water demand in recent years,and the shortage of water resources is becoming increasingly prominent.The spatial and temporal distribution of water resources in Shandong Province is uneven,and the total amount is seriously insufficient.As a traditional agricultural province,agricultural water use accounts for about 75%of the total water use,and the production of wheat,maize,cotton and peanuts occupies a considerable proportion of agricultural water use in Shandong Province.In addition,under the dual influence of climate change and human activities,the contradiction between water supply and demand of water resources is intensifying.Therefore,it is urgent to study the risk assessment of water resources for main crops in Shandong Province based on the water footprint theory in order to provide a theoretical basis and realistic guidance for the sustainable utilization of water resources and food security.In this study,water footprint for the main crops and the composition of green and blue water were calculated in 17 regions in Shandong Province from 1990 to 2016 based on the CROPWAT 8.0 software.The temporal and spatial characteristics of water footprint,green and blue water footprint,and total water footprint for main crops were analyzed based on GIS and other technologies.The risks of water use for crop production in Shandong Province and various regions were assessed combined with the Water Resources Bulletin of Shandong Province.The main conclusions of this thesis are as follows:(1)The ETc,water footprint,green and blue water footprint for the four crops showed a downward trend in Shandong Province from 1990 to 2016.The water footprint,green and blue water footprint differed greatly in various precipitation types,and the amounts in dry and extremely dry years were greater than that in normal and wet years,and exhibited obvious spatial differences.(2)The total water footprint for wheat,cotton,and peanuts showed a downward trend in Shandong Province,while the total water footprint for maize increased significantly from 1990 to 2016.The total green and blue water footprint for wheat,cotton,and peanuts showed a downward trend,while the green and blue water footprint for maize exhibited an upward trend.The spatial difference of total water footprint,green water and blue water footprint is significant in Shandong Province.And the spatial pattern of water footprint for cotton shows a trend of decreasing from west to cast in different precipitation types.Generally.the total water footprint for peanuts is decreasing from east to west.(3)The total agricultural water footprint,green and blue water footprint showed a decreasing trend and the mean values were 406.22×108 180.51×108 m3 and 225.73×108 m3 in Shandong Province from 1990 to 2016,respectively.The spatial distribution pattern of total agricultural water footprint in Shandong Province showed the values were higher in the western and southern regions than that in the eastern,central and northern regions.Moreover,the total blue water footprint was higher in the western and eastern regions than that in the central region.The pressure index of the blue water resources was greater than 0.4 in 94%years of the study period in Shandong Province from 2000 to 2016,which indicating that the situation of water shortage in Shandong Province is not optimistic.The blue water resources pressure index is more different than the pressure index of water resources in 2015 and 2016 in Shandong Province.Agricultural production is facing the threat of water shortage in most regions.In particular,the drought conditions are serious in Qingdao during the past two years and the agricultural production risks are very high.