农业、食品和资源经济系“，为粮食安全政策的未来创新实验室提供饲料

拜曼·h·哈木都和汉布罗·恩戈马，2019年。气候变化对赞比亚水资源可用性的影响:对灌溉发展的影响。喂养未来创新实验室的粮食安全政策研究论文146。bob体育登录东兰辛:密歇根州立大学。BOB体育

水资源对任何国家当前和未来的社会经济发展都至关重要。要以可持续的方式管理水资源，就需要很好地了解当地目前和未来这些资源的可用性:有多少水可用，在哪里可用，什么时候可用?本文评估了水资源的时空分布以及预计气候变化对水资源可用性的影响，并得出了对赞比亚灌溉发展的影响。与以往国家层面的研究不同，本研究是在流域层面进行的。本文利用水文建模框架中的水平衡模型和政府间气候变化专门委员会对未来气候情景的统计降尺度，模拟了从当前时期到本世纪末(2100年)气候变化对赞比亚主要河流流域水资源可用性的影响。主要结果表明，到2050年和2100年，赞比亚的气温预计将分别升高1.9摄氏度和2.3摄氏度。预计到本世纪中叶，全国降雨量将减少约3%，到本世纪末仅略微减少约0.6%。然而，不同地区之间存在很大差异，与北部地区相比，南部、西部和东部地区预计受到的影响要大得多。在全国范围内，这些降雨和温度的变化将使可用水量从目前(观测到的)约97立方公里减少约13%，到本世纪末减少到约84立方公里。在流域一级，与赞比亚南部和西部地区相比，北部流域的水资源可能保持不变或略有增加。 In particular, Zambezi, Kafue, and Luangwa River Basins are projected to have less water resources available due to reduced rainfall and higher temperatures . These findings have implications for smallholder irrigation development in Zambia. First, this implies that contingent on costs, current and future irrigation schemes will need to adopt more water efficient technologies such as overhead irrigation systems (e.g., center pivots and drip irrigation) as opposed to the prevalent surface irrigation methods. Second, reduced water availability will increase access and irrigation costs, which in turn may reduce its profitability among smallholder farmers as they tend to have limited capital and capacity to adapt to higher cost structures. Third, competition for the reduced available water resources will disadvantage the smallholder farmers. Policies to protect them against the large scale users are required. Options for bulky water transfer from low-demand, high-water areas in the north to the high-demand, low-water areas in the south should be explored. Fourth, water resources management and regulation need to be strengthened, for example by ensuring that water user rights and fees become mandatory, even among smallholder farmers. There is also need to improve rain water harvesting and storage by investing in more efficient reservoirs. How these reservoirs should be managed to ensure equitable access to water resources and to reduce water loss due evapotranspiration requires further thought.