黄淮海平原灌溉农业对地下水依赖程度与保障能力

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。     

FOST PALEOZOIC FORMATIONS OF THE MN YIN AND LAI WU VALLEYS OF SHANTUNG.

INTRODUCTION. I was appointed to accompany Dr. J. G. Andersson to take a trip incentral Shantung. especially in Men Yin (蒙阴) and Lai Wu (莱芜),valleys,for the purpose of collecting fossils and observing the post-Palaeozoic forma-tions. We came back to Peking in December, 1922. The conclusion     

A COMPREHENSIVE STUDY OF MUD CRACKS AND OTHER SIMILAR STRUCTURES

In text-books of geology and in most papers dealing with geologicstructures, mud cracks seem to have been regarded as merely one kindof structures developed only in soft sediments, such as muds or clays. Itseems also that the studies of mud-crack structure have been mostly     

冀中山前平原农业区浅层地下水位对连年少雨响应特征与机制

冀中山前平原农业区浅层地下水是当地农田灌溉的主要水源,已处于超采状态。依据冀中山前平原不同农业区长观孔浅层地下水位动态监测资料,对浅层地下水位响应连年降水偏枯的变化规律进行了研究。结果表明:降水连年偏枯(少雨)时段的春灌期大规模集中开采浅层地下水,是冀中山前平原农业区浅层地下水位不断下降的主要动因;春灌期农业区浅层地下水位降幅与前一年和当年1月到6月降水量密切相关;当年降水量小于当地多年平均降水量(528.4mm)时,随着降水量减小,农业用水开采对浅层地下水位下降的影响增大;当年降水量大于当地多年平均降水量尤其大于620mm时,农业用水开采对浅层地下水位下降的影响显著减弱;合理调控农业区浅层地下水开采强度是缓解冀中山前平原农业区浅层地下水超采情势的重要举措。     

海河流域平原浅层地下水消耗与可持续利用

通过对海河流域平原区地下水储量消耗过程、空间分布及机理研究,揭示了区内地下水系统与相邻层圈之间水分通量因人为活动影响而发生剧变的规律,并在现状开采与补给条件下警告性预测了地下水资源可持续利用前景.     

ON THE SINIAN SYSTEM OF THE LIAOTUNG PENINSULA AND ITS EQUIVALENTS IN OTHER PART OF THE NORTH CHINA

The Sinian stratigraphy of the Liaotung peninsula was studies by many Chinese and Japanesegeologists. In this paper three sections of Sinian period in Lioatung peninsula and three sectionsof Lower and Middle Sinian period in Lioahsi area are discussed and several stratigraphical termsare assigned.     

Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14 million years ago

~~Geomorphologic evidence of phased uplift of the northeastern Qinghai-Tibet Plateau since 14 million years ago~~