Abstract: To quantitatively assess the impact of drought on water shortage and industrial loss in urban areas, the urban drought index (CWSI) is constructed based on the water balance principle to calculate the regional available water supply and water demand of different industrial types under varying water inflow frequency on a monthly scale. The Zhuzhou segment of Xiangjiang River with surface runoff as the water supply source is selected as the research area. The monthly regional water shortage and drought index (CWSI) of Zhuzhou segment from 1960 to 2018 were calculated from the perspectives of water shortage and water withdrawal difficulty. Moreover, the response relationship between water shortage and drought loss is obtained by using HARA (Hyperbolic Absolute Risk Aversion) function, which is commonly used in the field of economics, to reflect the relationship between economic benefits and water consumption. On this basis, a dynamic optimization model of water shortage allocation based on optimal benefits is constructed to calculate the water shortage allocation of various industries under different drought degrees. The drought quota method is used to verify the allocation results, and then the drought loss corresponding to water shortage is calculated. According to the change of CWSI, the drought loss of various industries under different drought degrees is calculated. Based on the curve of annual average drought loss, the dynamic drought loss curve of typical years can be acquired according to the current monthly water change and the previous water shortage. The results demonstrate that urban drought is of high marginal loss and low frequency, which conforms to the change law of water shortage and drought loss based on HARA function. The research findings offer theoretical basis for urban drought risk assessment, early warning and drought quota management.

Key words: urban drought, drought loss assessment, HARA function, drought quota, drought index