南通市自然灾害时空分布规律及其防治

分析了南通市的地震、塌岸、水土流失、水灾、旱灾、雹灾、寒害和台风等8种自然灾害的时空分布特点;对地震、水灾等6种灾害的功率谱、集中度和集中期分析显示,南通市自然灾害具有2.2年的年际变化规律和春季多冰雹、寒害,夏季多旱涝、台风的年内分布规律;地震受新构造运动断裂分布的控制呈条带状分布,水土流失主要分布于高沙土区,塌岸主要集中于东南部的沿江沿海地带;气象灾害全市皆有分布,但具有北多南少、北重南轻的总体特点;提出了加强自然灾害预报预警系统、农田水利基础设施和江海岸坡防护工程建设等相应的防治对策。

Laws of time-space distribution of natural disasters and Its prevention measures in Nantong City

Taking earthquake, collapse, water and soil loss, flood, drought, hail, cold disaster and typhoon as study objects, the author gets the laws and characters about time-space distribution of natural disasters in Nantong city preliminarily. Applying the power spectral analysis, the laws of 2.2-year-periodicity can be found. With the method of the degree and time of concentration, we found that hails and cold disasters have a high frequency in spring and floods, droughts and typhoons often happen in summer. In spatial distribution, controlled by neotectonic fractures, earthquakes take on zonal distribution. Water and soil loss mainly distributes in soil with high-content sands. Collapse distributes in southeastern district, which verges on river and ocean. Meteorological disasters distribute all over the land and have general character of "be more and serious in north, be few and light in south". Based on these characters, the prevention measures have been given. Forecast and early warning of natural disasters, irrigation and water conservancy foundation project and protective engineering of riverbank and seacoast construction should be strengthened.