The Water Pricing Model At The Grid Scale

With the increasingly severe situation of water resources,mankind has begun to seek appropriate methods for the rational allocation of regional water.As an effective development and utilization method,water resources management has gradually become one of the key research issues in the academia.There are many methods for water resources management,but the improving market economy system has made the role of price mechanism in water resources management more apparent,and water prices have also become one of the important factors affecting the use of water resources.Advances in science and technology have led to a shift from macroscopic research to microscopic research in water resources management.The traditional way of water price constitution based on administrative boundaries is no longer able to meet the precision requirements of modern society.Therefore,in order to avoid such problems,based on the SHRD model established in the previous period,we used the 3 S techniques and the water price data of all counties and cities in the Hanjiang River basin to establish a new precision water pricing system.The main content of this article includes:(1)We collect and collate the current water price data and analyze its pricing method.In combination with the SHRD model established and revised in the previous period,we establish the water pricing model at the grid scale(WPG model),which calculate water price at each grid in the study area.The results show that the most important difference between the current water price and the water price at the grid scale is the availability of water resources.The new water pricing model fully takes into account the difficulty in taking water at spatial grid points;it also changes the traditional pricing of regional water resources with administrative boundaries to the price at grid scale,and improve the precision of water resources in space.(2)We download remote sensing images and nighttime lights for preprocessing respectively,calculate the normalized differential vegetation index(NDVI)and interpret images to obtain several land types including artificial surface.We use NDVI to correct the nighttime lights and the results were superimposed on the artificial surface so that the ideal built-up area is finally obtained.Based on this,a built-up area extraction model(NLVI model)at grid scale is established,and the scope of the built-up area of the Hanjiang River basin is calculated as the charging range of urban residents' domestic water use.Then,the scope of the irrigation and gravity irrigation in agricultural irrigation can be calculated.The NLVI model changed the ambiguity of the boundary between different categories of water tariffs when traditional fees were charged.(3)In combination with water price model at grid scale(WPG model)and the built-up area extraction model(NLVI model),two types of water price for urban residents' life and agricultural irrigation can be calculated separately.It is found that the pattern of the water price of different types at the grid scale in the Hanjiang River basin is similar,with the maximum value appearing in the area of the main stream or near the main stream.Higher values appear in the northeast and central regions,while low values mainly appear in the northwestern region of the basin.However,due to the current water price in the study area,topography,land type,and river network distribution,microscopic differences in water charges still exist.The empirical research shows that the water price at the grid scale based on the WPG model and NLVI model is compatible with the living conditions and irrigation of the residents of the Hanjiang River basin and irrigation conditions in agriculture,so the study is feasible and scientific.