Physical Scarcity of Water in a Region

Abstract

This report builds a s-type curve model which defines the change of per capita water consumption following the change of GDP, and it defines the rate of per capita satisfaction of using water which is considered as the index to judge the ability of the region to provide clean water to meet the needs of its population. Under certain prediction, analyzing and function fitting, we can achieve to get the rate of per capita satisfaction of using water in the future by predicting rainfall capacity to determine other water resources. We build a general model to provide a measurement of the ability of a region to provide clean water to meet the needs of its population. Considering the ability of the region to provide clean water, it should satisfy the balance of both supply and demand in the region. In the condition that all the population are using clean water; per capita household water occupancy volume and the number of population both determine the ability of a region to provide clean water to meet the needs of its population. We need to define the rate of per capita satisfaction of using water to reflect the ability of a region to provide clean water to meet the needs of its population, the s-type curve of per capita water consumption and the occupancy rate of per-capita water consumption. The rate of per capita satisfaction of water consumption is that per capita water consumption with its ratio of per capita water consumption function with the region society condition. The bigger the rate of per capita satisfaction of using water is, the stronger the ability of a region to provide clean water to meet the needs of its population is. We can get per capita water consumption on arbitrary time and space by historical data. Per capita water consumption divides by the stable value at the s-type curve of the per capita water consumption to express the ability of a region to provide clean water to meet the needs of its population at the time in this region. We need to get total water consumption by historical data including surface water supply volume, underground water supply volume, other water supply volume, quantity of water diversion, water storage and so on. In the condition that people are not establishing new water conservancy project and not overly exploring, the ability of water storage, so the water-regulating capacity and the source of underground water are constant. Therefore, the dynamic change of the water supply quantity in the region are caused by the dynamic change of surface water resources and other water resources. We predict total water supply quantity and the occupancy rate of per-capita using water in the future several years by the time series prediction method. By predicting the number of people in the future several years by Logistic Model, we can Get per capita water consumption in the future several years by these prediction. We could also determine the ability of a region to provide clean water to meet the needs of its population in the future.