Analysis of the spatial and temporal variation characteristics of hail events and damaged cotton in the Ogan-Kuchar River oases of southern Xinjiang during 1970-2013
Ogan-Kuchar River oases are one of the major production bases of cotton in southern Xinjiang. Due to climate change and expanding cotton plant area, cotton production suffers more and more hail damage. In this paper, based on 44-year hail data from 4 meteorological stations and 33-year hail disaster information from departments of local civil administration, the hail damage area and temporal variation of the hail hazards, hail intensity, hail activity pattern, damaging and controlling factors are analyzed. It is found that hail events in northern mountain areas are more than that in southern plains, but the damage area in northern mountain areas is less than that in southern plains; hail events are characterized by short period and distinct seasonality; there are 80% hail events with the intensity above average; hail events are occurring frequently and powerfully. Hail frequency has negative correlation with air temperature and positive correlation with precipitation. Shayar County, located in the south nearby desert area, is extremely damaged by hail, where intensity and damage of hail disaster, as well as the crop area and type, closely relate to seasonal and geographical features. The county has greater probability of cotton damage.