Adhikari B, Verhoeven R, Troch P
Department of Civil Engineering, Hydraulics Laboratory, Ghent University, Ghent 9000, Belgium.
Water Sci Technol. 2009;59(8):1505-13. doi: 10.2166/wst.2009.150.
This paper attempts to find a strategy to provide year-round irrigation for cultivating three crops per year in the southern plains of the country taking a case study of the Babai basin. Despite having enough flows during the summer for growing rice in total 27,000 ha area, the dry season flows of the Babai river can irrigate only 6,300 ha in winter and 4,000 ha in spring limiting the cropping intensity to 138.50%. It is proposed to irrigate the 7,500 ha southern dry area at the right bank bringing water from a large snow-fed river: the Karnali. Water balance study of the three irrigation regions to be irrigated from the Babai source preserving their existing water rights showed that the year-round irrigation at the west with the proposed arrangement will fall short of only 13.9 million m(3) water volume. At the east side, the head reach area and the tail portion will fall short of 19.4 and 66.4 million m(3) of water to insure a cropping intensity of 250%. The deficits can be fulfilled by means of capturing the excess river water of rainy season in local reservoirs and by making conjunctive use of groundwater. The proposed solution is financially, environmentally and socially viable being a cost effective, user friendly and should be the linchpin towards attaining a sustainable year-round irrigation in the region.
本文以巴巴伊流域为例，试图找到一种策略，为该国南部平原每年种植三季作物提供全年灌溉。尽管夏季流量充足，可在总计27000公顷的面积上种植水稻，但巴巴伊河的旱季流量在冬季仅能灌溉6300公顷，春季仅能灌溉4000公顷，这将种植强度限制在了138.50%。建议从一条由大量雪山融水补给的大河——卡纳利河引水，灌溉右岸7500公顷的南部干旱地区。对将从巴巴伊水源灌溉的三个灌溉区域进行的水平衡研究表明，在保留其现有水权的情况下，按照提议的安排，西部全年灌溉仅缺水1390万立方米。在东部，源头区域和尾部将分别缺水1940万立方米和6640万立方米，以确保250%的种植强度。这些缺水可通过在当地水库储存雨季多余的河水以及联合使用地下水来弥补。提议的解决方案在经济、环境和社会方面都是可行的，具有成本效益、方便用户，应该成为该地区实现可持续全年灌溉的关键。
