Analysis On Pressure Assessment And Driving Forces Of Agricultural Water Resources In Shanxi Province Based On Water Footprint

Shanxi Province is located in arid and semi-arid regions with low precipitation and uneven spatial and temporal distribution.Water shortages have severely restricted agricultural production in Shanxi Province.Increasing water use efficiency is an important approach to deal with the development of agriculture in Shanxi Province.The concept of water footprint has broadened the traditional water resources evaluation system and provided a new perspective for the scientific evaluation of water resources use in agricultural production.This paper base on water footprint theory to analyse grain production water footprint and the characteristics of temporal and spatial changes in 11 cities in Shanxi Province from 2005 to2014,establish a general agricultural water resources pressure index system based on water footprint(GWSI)and water consumption(BWSI)and assess the water resources pressure in agricultural production,use Logarithmic Mean Divisia Index(LDMI)method to analyze different influencing factors of crop water footprint and reveal the driving force of crop water footprint in Shanxi Province.The main conclusion of this paper is as follow:Based on two methods,the CROPWAT and the actual water consumption in the region,to quantize the crop water footprint in Shanxi Province.The results showed that:(1)The crop water footprint which based on the actual irrigation water consumption calculation method is higher than CROPWAT.The CROPWAT quantifies the evapotranspiration of the crop under ideal conditions,but the water footprint calculation method which based on the actual irrigation water consumption considered that the loss of water distribution and field irrigation process,and it can more accurately reflect the utilization of water resources and the level of agricultural water in the crop production process in Shanxi Province.(2)From 2005 to 2014,the crop production water footprint,blue water footprint,and green water footprint in Shanxi Province had significant differences between crops and regions,and both showed a downward trend during the inter-annual period.The crop water footprint and the blue-green water footprint are generally characterized by northern high and southern low,the production water footprint is higher in Datong,Luliang and Taiyuan,but lower in Linfen and Jinzhong;From the perspective of the blue and green water footprints,the blue water footprint in Shanxi Province has a higher proportion in the crop production water footprint,and the spatial distribution of the blue water footprint ratio is basically the same as the spatial distribution of irrigation water.(3)From 2005 to 2014,the general agricultural water resources,crop water footprint and its composition in Shanxi Province had significant differences between crops and regions,and both showed an upward trend during the inter-annual period.The mean value of the general agricultural water resources in Shanxi Province for several years is 128.57×10~8m~3.Among the regions,there are more water resources in Yunan and Yuncheng,and less in Yangquan,Taiyuan,and Jincheng.Shanxi's green water resources occupy an important position in the available water resources,with an average of 73%for many years.The crop water footprint in Shanxi Province varies significantly between crops and regions,and shows a significant increase during the inter-annual period.The inter-regional trend shows an increase from north to south.Ten-year average of the total crop water footprint in Shanxi Province is 77.3×10~8m~3,green water footprint account for 69%.(4)The average annual values of BWSI and GWSI in Shanxi Province were 1.8 and0.48,respectively.The pressure on blue water resources was relatively high,and it declined during the past ten-year fluctuation,the water resources pressure of agricultural production was relieve but the proportion was low.The agricultural water resources in Shanxi Province still face the unsustainable crisis.Inter-regional Yangquan,Taiyuan,Zhangzhou and Yuncheng have greater pressure on water resources.(5)LDMI analysis shows that planting scale and population change are the main driving forces for the increase of crop water footprint in Shanxi Province.Urbanization,planting structure and water-saving technologies have inhibited the growth of crop water footprint in Shanxi Province.The effects of the five factors were different between crops and regions.Maize and wheat had a positive effect on the crop water footprint in Shanxi Province,while sorghum and millet had an negative effect on the water footprint.Taiyuan's population change among regions is the main driving force for the increase of crop water footprint in Taiyuan City,while in other regions,scale effect is the main driving force for the increase of water footprint.The water-saving technologies of Datong,Taiyuan,and Jincheng are drop behind others,but agricultural production should focus on improving water-saving technologies and adjusting planting structures.Therefore,considering the water-saving effect,maize is recommended as the best crop for agricultural production in Shanxi Province.