The Spatio-temporal Dynamics And Mechanism Of Domestic And Industrial Water Use In Lancang-mekong River Basin

Countries in Lancang-Mekong River basin depend on water resources in soico-economic development.With the great development,the competition among countries for water resources has gradually intensified.Demand for domestic and industrial water has increased due to a rapid growth in population and economic that futher exacerbated the tension,which should to be focused.However,the records of domestic and industrial water use in Lancang-Mekong River basin are incomplete,which brings in a hard comprehension of past water use situation and a constructive plan for future water use.The study calculates domestic and industrial water use data in the Lancang-Mekong Basin from year 2000 to 2019 based on multiple data.Also,it wants to reveal the spatial and temporal patterns of domestic and industrial water use on the basin scale,national scale,and provincial scale.Furthermore,it tries to explore how human activities affect the changes,with the attempt to provide a unified standard for water use allocation in the basin countries.Results showed:(1)The domestic water use increases every year.On the basin level,total domestic water use of the basin grows from 15.84×10~8 m~3to 22.72×10~8 m~3in year 2000-2019.On the national level,from the three perspectives of water use scale,growth rate and growth intensity,Thailand part belongs to the first grade.Vietnam and Cambodia part belong to the second grade.China and Lao and Myanmar part belong to the third grade.All countries have a lower urban domestic water use than rural areas but a higher growth rate.On the provincial level,the growth rate of domestic water consumption in each province slows down before 2007 and the growth intensity was low.The hot spot of high growth rate switches from Northern Highland to Korat Plateau.After 2007,the growth rate of domestic water consumption in each province shifts from fluctuating to steady and the gap between provinces narrows in growth intensity.(2)The industrial water use increases every year.On the basin level,industrial water use increases from 13.59×10~8 m~3to 42.27×10~8 m~3in year 2000-2019.On the national level,the industrial water use in Thailand section is the largest and fluctuated upward.The growth rate in Vietnam section decreases gradually.The growth rate in China section firstly increases and then decreases.The growth rate in Laos section turns low to high.The Cambodia section experienced a process of‘low total volume and fast growth rate to high total volume and slow growth rate’.The Myanmar section changed fluctuately before 2010 and increased significantly after 2010.On the provincial level,the industrial water use of each province is distributed in a circular pattern,with a pattern of"high-low-high"from provinces in Thailand outward.The growth rates of downstream provinces are generally higher than those of upstream.The changes in industrial water consumption of each province in the same country are mostly at the same level.(3)The coupling relationship between domestic and industrial water consumption in the provinces gradually increases.Details are as follows.(1)2000-2003 is the stage of insignificant coupling,the distance between the two centers of gravity first decreases and then increases,but they move in opposite directions.(2)2003-2006 is the stage of significant coupling.Both of centers of gravity move northwest to southeast and the two are closer.(3)2008-2013 is the phase of weakening coupling and the distance between centers of gravity expands.(4)2013-2016 is the phase of insignificant coupling.Although the distance between the two shortens,the direction and speed of movement are quite different.(5)2016-2019 is the stage of significant coupling,both types of centers of gravity move from northwest to southeast as a whole.(4)Industrial water use is the dominant factor that influences the total water consumption and they change simultaneously.The domestic water consumption has a weaker impact than industrial water consumption.In terms of specific factors,economic scale is the primary driver of water use growth in all countries except for Cambodia part.The China,Thailand and Vietnam part effectively suppresses the growth of total water use due to a lower industrial water intensity,while the enhancement of industrial water use intensity in the Cambodia and Laos part increase total water consumption.Industrial structure,population scale,urbanization level and domestic water use intensity all contribute to the growth of total water use.Though the cumulative contributions are relatively small,but its driving effect is profound in the long future and it should be taken into water planning considerations in advance.Therefore,Therefore,the basin and countries could reduce the water use intensity to control water consumption.What’s more,it’s necessary to incorporate the possibility of rapid growth of domestic water into future regional water resources planning,and formulate plans in advance to cope with water supply pressures.