黄淮海平原灌溉农业对地下水依赖程度与保障能力

Groundwater Safeguard Capacity and Dependency Degree of Agricultural Irrigation on Groundwater in the Huang–Huai–Hai Plain

在我国北方粮食主产区,尤其黄淮海平原农业区,地下水是农业灌溉的重要水源,地下水超采状况与灌溉农业对其依赖程度和地下水保障能力密切相关。本文通过农业灌溉用水强度与降水量和农作物播种强度之间关系研究,以及灌溉农业用水对地下水依赖程度和对地下水超采影响特征研究,创建灌溉农业的地下水保障能力相应理念和评价理论方法,应用表明:(1)灌溉农业开采是黄淮海平原农业区地下水超采的主要因素,主要发生在小麦主灌期,且灌溉农业对地下水依赖程度愈高、灌溉前几个月份降水愈少农业超采愈严重;(2)农业超采区地下水位在主灌期呈"厘米"级(大于1.0 cm/d)下降、非灌溉期呈"毫米"级(小于1.0 cm/d)上升的"强降-弱升"规律;(3)采用灌溉农业用水对地下水依赖程度(A)、地下水对灌溉农业用水保障程度(B)和灌溉农业的地下水保障能力(C)的评价理论方法,能够客观阐明灌溉农业用水对地下水依赖状况、地下水保障能力的区域分布特征及其成因。结果表明黄淮海平原西北部灌溉农业的地下水保障能力较弱,尤其河北平原已处于"难以保障"或"无法保障"状态,黄河以南地区的地下水保障能力较强。

Groundwater is an important water source for agricultural irrigation in the main grain production region in North China, especially in the Huang-Huai-Hai Plain. The over-exploitation situation of groundwater is closely related to the dependence degree of irrigation agriculture on groundwater and the water support capacity （such as the safeguard capacity） of groundwater in this region. With the Huang-Huai-Hai plain as an example, the authors studied the relationship between the agricultural irrigation water, the precipitation and the crops planting intensity, the dependence degree of the agricultural irrigation on groundwater and the influence characteristics of the over-exploitation situation of groundwater and, on such a basis, proposed the corresponding concepts and methods for evaluation. The results of the application of the evaluation methodology are as follows： （1） Agricultural exploitation mainly in the irrigation period of wheat is the major factor of groundwater over-exploitation in the Huang-Huai-Hai Plain. The higher the dependence of irrigated agriculture on groundwater and the less the precipitation before irrigation period, the more serious the over-exploitation will be; （2） The shallow groundwater level in the agricultural exploitation area declines by more than 1.0 cm/d during the irrigation period and rises by less than 1.0 cm/d during non-irrigation period; （3） The regional characteristics, the situation and the causes of the dependence degree of irrigation agriculture on the groundwater and the safeguard capacity of the groundwater can be objectively clarified dependence degree of irrigation water on groundwater water （B）, and the safeguard capacity （C）. According to by using the evaluation methodology which includes the （A）, the supply extent of the groundwater to irrigation the results obtained, the groundwater safeguard capacity for agricultural irrigation is poor in the northwest area of the Huang-Huai-Hai Plain, especially in the Hebei Plain, the groundwater can hardly or even unable to guarantee the agricultural irrigation; in contrast, the safeguard capacity is stronger in the south area of the plain.