1 水资源概况上蔡县地处豫中南的淮北平原,为北亚热带和暖温带过渡地带,有明显的季节型气候特点,其自然地理位置和气候特色客观上造就了水资源对当地社会经济发展不利的自然特色。全年降水大都集中在6～9月份,这期间降水形成的地表径流约占全年径流总量的70%～80%,且常以暴雨形式出现。降水年际变化大,丰水年与枯水年降水量相差2—3倍,极易发生旱涝灾害。 1 Water resources overview Shangcai County is located in the Huaibei Plain of Central Henan Province, which is a transition zone between North Subtropics and warm temperate zone. It has obvious seasonal climate characteristics. Its natural geographical location and climatic features have objectively created water resources on the local social and economic development Unfavorable natural features. The annual precipitation is mostly concentrated in June-September. During this period, the surface runoff formed by precipitation accounts for about 70% -80% of the annual total runoff, and often occurs in the form of heavy rain. The annual variation of precipitation is large, and the difference between the annual rainfall and the dry year is 2-3 times, which is prone to drought and flood disasters.