南通市地处长江口,南临长江、东濒黄海,境内地势平坦,地面高程一般在废黄河基面以上4.3米左右,最低里下河地区2.0米,最高如皋县高砂土地区6.0米,属平原河网地区,总面积8410.7平方公里,地理位置、自然条件都比较好。解放前因水利失修,旱、涝、风、咸、潮等自然灾害不断,农业生产低而不稳。建国三十多年来大搞水利,开挖骨干河道十二条,二、三、四级河道纵横交错,共开挖土方35亿多立方米,沿江沿海并港建闸50多座,初步形成了一个防 Nantong City is located in the mouth of the Yangtze River, south of the Yangtze River, the Yellow Sea east, the territory is flat, the ground elevation generally 4.3 meters above the waste Yellow River base, the lowest Lixiahe area 2.0 meters, the highest Rugao high sand area 6.0 meters, Plain river network area, with a total area of ​​8410.7 square kilometers, geographical location, natural conditions are better. Before the liberation of water due to disrepair, drought, waterlogging, wind, salt, tide and other natural disasters continue, low and unstable agricultural production. Over the past 30 years since the founding of the People’s Republic of China, water diversion has been carried out and 12 backbone channels have been excavated. The river channels of the second, third and fourth grade have been crisscrossed in a crisscross pattern. More than 3.5 billion cubic meters of earth have been excavated, more than 50 gates have been built along the coast and along the river, A defense