| The rapidly increasing demand for water resources,the construction of various ecological restoration engineering measures,and the unstable supply of water resources caused by climate change will make the future regional water shortage problem more prominent,thereby increasing the consumption of natural ecosystems and the consumption of human socio-economic sectors.Water,especially the conflict between farmland irrigation and water consumption.In order to alleviate conflicts and ensure the sustainable development of natural and socio-economic systems,it is necessary to quantify the water consumption between different sectors from a holistic perspective,rather than dividing natural and socio-economic systems,especially natural ecosystems and farmland irrigation.Systematic segmentation to develop more scientific water management policies.How to quantify the water consumption of different departments on a large-scale long-term sequence remains to be further solved.This paper first proposes the crop water consumption model and ET decomposition algorithm to quantify the natural ecosystem water consumption,farmland rainwater consumption,farmland irrigation water consumption and human available water volume in the seven major river basins in China from 1982 to 2015,and clarify that different watersheds are different.The spatial and temporal dynamic characteristics of the department's water consumption,and further analyze the relative importance of human activities and climate change on the water consumption of different sectors,clarify the dominant factors,and provide a scientific basis for water resources management policies.The main conclusions of this paper are as follows:(1)The R~2 of the long-term sequence simulation of the model can reach 0.65,which indicates that the model can better simulate the rainwater consumption an farmland irrigation water consumption on the large scale,and it has become the overall analysis human-coupling system.The potential of a powerful tool for water allocation.(2)Between 1982 and 2015,the spatial pattern of farmland irrigation water consumption and farmland rainwater consumption showed a high in the south and a low in the north,mainly related to the cultivation methods of irrigated crops in the south.The natural ecosystem water consumption in each basin accounts for a large proportion,while the farmland rainwater consumption and farmland irrigation water consumption account for a relatively small proportion,mainly because the area of natural ecosystems is much higher than that of farmland ecosystems.The water resources in the seven major river basins were more severe,and precipitation,evapotranspiration,natural ecosystem water consumption and irrigation water consumption showed a significant upward trend,with increases of 1.9 mm,1.18 mm,1.17 mm and 0.25 mm,respectively.Farmland rainwater consumption showed a significant downward trend with a decrease of 0.24 mm(p<0.5).In each basin,the variation of water consumption variables in the Yangtze River Basin and the Yellow River Basin is more obvious,and the change trend is relatively consistent with the whole,while the water consumption variables of other basins are not significant.(3)Between 1982 and 2015,land use changed drastically,and the overall farmland and irrigated farmland showed a significant decline and a significant increase.The increase in irrigated farmland is mainly concentrated in the Yellow River Basin,the Yangtze River Basin and the Pearl River Basin.The climate is developing in the direction of warming and humidification,and the temperature,radiation and precipitation are both significantly increased.(4)The water consumption of natural ecosystems is mainly regulated by climate change,and the role of human factors is small.Irrigation water consumption is jointly regulated by human factors and climate change. |
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