Benefits Analysis Of Water Use And Evolution Of Water Consumed Structure

Driven by the problems such as imbalance between water supply and demand, water environmental degradation and frequency of floods and droughts generated in the process of water resources utilization, the cognizance and utilization of water are constantly evolving and moreover the water function and benefits. In this paper, the marginal benefits, ecological service benefits and regional integrated benefits are analyzed and assessed based on conventional and unconventional water utilization. And the evolution of water consumed structure is discussed. The main research results are summarized as follows:(1) Defination of water use benefitsThree benefits of water resources utilization are defined according to conventional water and floodwater utilization. Firstly, the agricultural, industrial and domestic marginal benefits are calculated to quantitatively analyze contribution of water to the growth of different industries. Secondly, emphasizing on the water ecological service functions, the goods production, water and gas regulation, recreation and culture benefits are analyzed in monetary terms. Finally, considering the integrity of regional water utilization, the integrated economic, ecological and social benefits are assessed via built the benefits indices system of water utilization.(2) Analysis of water use and calculation of marginal benefits in Baicheng regionBaicheng region situated in the north-west Jilin province is the commodity grain base and classical drought region of China. The agricultural water consumption is accounted for85%-95%of the total water consumption, and water consumed structure maintains in a lower orderly state which means the singleness of water consumption in Baicheng region.The contributions of water to agricultural, industrial and domestic outputs are33.6%,22.8%and42.3%, and ratio of the corresponding marginal benefits is1:15:15. The results showed the conflicts between water inputs and outputs. Although the water outputs are related to the industrial intensity, the unreasonable of local water consumed stricture and water allocations is obviously.(3) Wetland evaluation of floodwater utilizationWetland is a multi-functional ecosystem, and most wetlands are subjected to water shortage and area shrinkage. Take Momoge wetland and Xianghai wetland in Baicheng region as example, the floodwater diverted from Nenjiang and Tao'er River is399million cubic meter from2003to2009, which translates into a monetary benefits of about1.52billion RMB in2009price, and the ratio of economic benefit, eco-environmental benefit and social benefit is1:12:2. The huge eco-environmental value verifies the environmental regulation function of wetland as "Earth's Kidneys" and the replenishment of floodwater to wetlands in the condition of water shortage.(4) Construction and evaluation of regional floodwater utilizationThe utilization of small and medium frequency of floodwater has remarkable benefits when conventional water supply is scarce relative to its demands. The concepts and categories of regional floodwater utilization benefits are defined according to flood loss analysis and conventional water path, and then the benefits indices system containing direct economic benefit, eco-environmental benefit and economic social benefit is built and assessed by the variable fuzzy pattern recognition model. The assessment results of benefits indices system of floodwater utilization in Baicheng region illuminates the feasibility of floodwater utilization in arid regions and there has a highly correlation between the benefits and floodwater utilization volume, and floodwater has more significant replenishment in the more water shortage areas and years.(5) Assessment and forecast of water useFor the Baicheng region, the sound evolution of water consumed structure is forced by floodwater utilization. Avoiding the particularity of specific region, the marginal benefits and the dynamic change of national water consumption are analyzed in a macro point of view. The industrial marginal benefits are advanced from1997to2010, and the ratio of agricultural marginal benefit, industrial marginal benefits and domestic marginal benefits is1:25:50. The results can explain the decrease of agricultural water consumption and the increase of industrial and domestic water consumption and the growth rate of domestic water consumption greater than industrial water consumption, which illuminates the benefit-orientation of water flow among industries. National water consumption from2010to2020is forecasted which shows the positive development trend and then the water consumption benefits will be more marked correspondingly.