tailieunhanh - Drought Management and Planning for Water Resources - Chapter 3

Đất nước là một thành phần quan trọng thủy văn của lưu vực sông. Trung bình dòng chảy của sông thoát nước từ các mạch nước ngầm ở khu vực lục địa theo thứ tự 30% tổng lưu lượng dòng chảy, đó là điều cần thiết trong việc duy trì dòng chảy trong quá trình thời gian khô, cái gọi là cơ sở dòng chảy trong sông vĩnh viễn. Tầm quan trọng của tầng nước ngầm nạp tiền, số lượng thường lớn của nước được lưu trữ trong họ, yên thân của họ khai thác, và tổng thể nhiều chi phí thấp hơn của đất. | chapter three Strategies for the conjunctive use of surface and groundwater Andres Sahuquillo Universidad Politécnica de Valencia Spain Contents Methods of conjunctive Artificial Alternate conjunctive Stream-aquifer Comparison between artificial recharge and alternate Other aspects and Transformation of aquifer-river relationship due to ground water Use of karstic Alleviation of land drainage and salinization in irrigated areas and conjunctive Conjunctive use potential in developing Analysis of conjunctive use Methods of Conclusion and 49 Copyright 2006 by Taylor Francis Group LLC 50 Drought Management and Planning for Water Resources Introduction Ground water is an important hydrological component of watersheds. Average river flow drainage from aquifers in continental areas is in the order of 30 of total stream flow which is essential in sustaining stream flow during dry periods the so-called base flow in permanent rivers. Magnitude of aquifer recharge the usually big volumes of water stored in them easiness of their exploitation and the overall much lower cost of ground water development make their use very attractive. Wise use of the different and complementary characteristics of surface and subsurface components through conjunctive use of surface and ground water can achieve greater yields economic or functional advantages than separate management of both components. One complementary characteristic is the large volume of water stored in aquifers from tens to hundreds of times their annual recharge. In the same way volume of aquifer storage provided by a relatively small fluctuation of the piezometric head in unconfined aquifers considerably exceeds the available or economically feasible surface storage. That allows .