Analysis And Systematic Risk Assessment Of Water-Food Ties In Beijing-Tianjin-Hebei Region

Water resources and food,as the decisive basis of urban development and the necessary material for people’s life,have always been concerned about their development.Beijing-Tianjin-Hebei is located in the financial,aviation,political and cultural center of China.Ensuring the safety of water resources and food is the fundamental task of urban development.In recent years,in the context of global climate change,due to the rapid population growth and economic and social development,the structure of agricultural water use in the Beijing-Tianjin-Hebei region is also changing,which increases the pressure on the development of its water resources and food industry.However,at present,the single research results on the two are very rich,but often ignore the complex relationship between them.Understanding the mutual feeding mechanism of"water-food"system is not only of great significance for optimizing water resources supply and demand pattern and ensuring food security,but also can provide scientific support for alleviating resource tension and rationally and efficiently utilizing regional water resources and food endowment.Therefore,this article fully consider food,meat,eggs,milk,15 kinds of food,in order to"water-food"ties as the breakthrough point,first of all,the specific calculation of food production and consumption of green water and blue water and grey water footprint,explore Beijing-Tianjin-Hebei region in2000-2020 food balance between supply and demand situation,on this basis,from the perspective of water footprint,Using system dynamics simulation analysis the complex association between them and the simulation control,finally build in water and food as the main body,and the economic,social,and environmental risk assessment indexes of complex system,21 years can be divided into three periods,a comprehensive evaluation of Beijing-Tianjin-Hebei region"water and food"systemic risk and its change law,and put forward the corresponding development Suggestions.The main conclusions of this thesis are as follows:（1）From the perspective of food water footprint supply and demand balance,Zhangjiakou city（2000-2001）,Chengde City（2000-2003）and Cangzhou City（2017-2019）in Hebei Province have water footprint supply and demand gap.In The Beijing-Tianjin-Hebei region,the demand gap of food and water resources fluctuates greatly and shows an increasing trend.Beijing has the largest supply and demand gap of food and water footprint,followed by Tianjin.Hebei has almost no gap,and the annual average water resources gap is-16.263 billion m~3,-11.995 billion m3 and 53.836 billion m~3,respectively.In terms of space,the gap of water footprint is large in the northern region（except Tangshan city）,while the surplus is large in the southern region.There was a gap between supply and demand of rice and beans in all parts of Beijing,Tianjin and Hebei,and a surplus of vegetable water footprint in all parts.（2）From the perspective of"water-food"system dynamics modeling and simulation,the errors of all variables of the system dynamics model established are within 10%,and the model simulation effect is effective.In terms of the future development trend of Beijing-Tianjin-Hebei water-food system resources,the water footprint will continue to increase by 2030,while the supply-demand ratio will decrease.Food shows a steady increase in crop food production and a decrease in meat food production.Three different scenarios were set by adjusting the planting area of crops with high water consumption（vegetables）and the utilization coefficient of irrigation water.The simulation results showed that the utilization coefficient of irrigation water had a more significant effect on food production when the planting area of vegetables was reduced by 10%and the irrigation coefficient was increased by 10%.Both methods can effectively alleviate the shortage of water resources for food production under the condition of limited blue water resources.（3）From the risk assessment of the"water-food"system,the risk probability of the"water-food"system in The Beijing-Tianjin-Hebei region is decreasing over time,and the stability of the"water-food"system is improved.In recent 21 years,the overall risk level of"water-food"system in Beijing-Tianjin-Hebei region is levelⅲ,and the situation of agricultural water resources utilization is that the operation of food industry is hindered by water resources supply,and the optimal allocation of water resources in food industry is needed.The highest threat index was found in Handan city.The highest risk rate was agricultural irrigation water shortage rate（D₁）,Hebei province had the largest contribution rate（10.18%）,Followed by Beijing（9.16%）and Tianjin（9.26%）.The main risk bearing factor was water-saving irrigation degree(D₁₃)in Beijing,with a risk rate of 2.93%,and effective irrigation degree(D₁₄)in Tianjin,with a risk rate of 3.15%.In Handan,Baoding and Hengshui,the highest risk rate is the construction status of agricultural irrigation facilities(D₁₅),and the rest is the demand meeting rate of local water resources(D₁₂).