Effects Of New Soil And Water Conservation Measures On "Water-energy-food" System On The Loess Plateau,China

Water,energy and food are the three basic elements on which human beings depend for their survival,while the current shortage of freshwater resources,fluctuations in food supply and increasing demand for energy have become bottlenecks that constrain economic and social development.In recent years,exploration of the "water-energy-food" coupling has become a hot topic of widespread concern.The Loess Plateau region is ecologically fragile,with a shortage of water resources and a prominent contradiction between supply and demand,poor farming conditions,and at the same time is an important energy production base in China.Weighing the relationship between the three systems of food,energy and water,and exploring the impact of soil and water conservation on the local "water-energy-food" system is of great practical significance for ensuring resource security and achieving sustainable regional development.Based on the theoretical framework of "water-energy-food",this paper constructs a coordinated evaluation system of "water-energy-food" system coupling,and conducts quantitative evaluation and spatio-temporal evolution characterization of the level of coordination of "water-energy-food" system in seven provinces and regions of the Loess Plateau(Qinghai Province,Gansu Province,Ningxia Hui Autonomous Region,Inner Mongolia Autonomous Region,Shaanxi Province,Shanxi Province and Henan Province)based on three evaluation indicators: comprehensive development index,coupling degree and coupling degree.Based on the current status of soil erosion management in the study area,the impact of new soil and water conservation measures on the changes in the coupling coordination of the "water-energy-food" system is analyzed,the development trend of the coupling coordination in the next five years is predicted and countermeasures and recommendations are given.The main studying contents are as follows:(1)The comprehensive evaluation index of the "water-energy-food" system in the study area showed an increasing trend over the study period,from 0.118 to 0.193,with significant spatial differences.The provinces in the Northwest have seen the least amount of change,with the highest combined development index in the first period and lagging behind other regions in the second.The rate of development of the provinces in North China was fast in the early stage and stabilized in the late stage.In Central China,the rate of development of the provinces in the latter part of the year increased,with the highest overall evaluation index.(2)The composite evaluation index of water resources and food systems in the study region is increasing.The IWRA index is subject to fluctuations due to rainfall.The composite evaluation index of the food system grew at the fastest rate,with an overall fluctuating growth pattern.The composite evaluation index of the energy system showed a decreasing trend over the study period due to the existence of contradictions in energy supply and demand.(3)The "water-energy-food" system coupling in the study area has a tendency to increase before decreasing in volatility,and is currently at a high level of coupling,with geographical differences between provinces.The coupling degree of the system varies greatly among provinces and regions in the early period,the coupling level is relatively high in the provinces of the northwest region,the coupling degree of the provinces in the north China region does not change steadily,and the difference gradually decreases in the late period.(4)During the period 2007-2017,the coupling degree of the "water-energy-food" system in the study area increased steadily,from 0.314 to 0.426,from moderate dysregulation to near-coupling,and the spatial development of the coupling degree varied widely.At this stage,except for the Inner Mongolia Autonomous Region,which is in a mild dislocation,all other provinces and regions are in a near dislocation stage.(5)For the value of the system coupling degree of coordination increase,the northwest Qinghai,Gansu and Ningxia provinces and regions have the greatest impact on the area of new grass planting,the north China Inner Mongolia and Shanxi has the greatest impact on the new dam and terraces two kinds of engineering measures,Henan has the greatest impact on the area of new water conservation forest.Additional water conservation measures are mainly positively correlated with the value added of the Integrated Water Resources and Food Systems Assessment Index and negatively correlated with the energy system.