论文部分内容阅读
河北省近一亿亩耕地中旱地约有5 000万亩,有一定灌溉条件,但水源无保证的占2 000万亩。若保持现有灌溉面积5 500万亩,一般年份保浇需水251亿立米,偏枯年需298亿立米,加上工业及生活用水22亿立米,按供需平衡计算,一般年缺水82亿立米,偏枯年缺水近160亿立米。近年来,由于降雨少,井灌区、部分渠灌区大量开采利用地下水,由于开采量大于补给量,导致地下水位普遍下降,机泵被迫更新换代。水量在减少,粗食要生产,农田要灌
Nearly 100 million hectares of arable land in Hebei Province are about 50 million hectares of dry land, with some irrigation conditions, but 20 million mu are not guaranteed by water sources. If the existing irrigation area is to be maintained at 55 million mu, there will be 25.1 billion cubic meters of water required for normal irrigation in spring and 29.8 billion cubic meters in dry year and 2.2 billion cubic meters of industrial and domestic water. According to the balance of supply and demand, the average annual water shortage will reach 8.2 billion cubic meters In the dry years nearly 16 billion cubic meters of water shortage. In recent years, groundwater has been exploited extensively in well irrigation areas and some drainage irrigation areas due to less rainfall. Since the amount of extraction is greater than the recharge rate, the water table generally drops and the pump is forced to be replaced. Water is reducing, crude food to be produced, farmland to irrigation