Towards groundwater security in coastal East Africa

东非沿海地区地下水安全

• 批准号: NE/L001888/1
• 负责人: Jean-Christophe Comte
• 金额: $ 10.88万
• 依托单位: Queen's University Belfast
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2013
• 资助国家: 英国
• 起止时间: 2013 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FL001888%2F1
• 关键词: Towards; groundwater; security; coastal; East

Groundwater resources in the coastal zone of EA are at risk. Increased demand, linked to rapid population growth in the coastal margins, has led to unsustainable and ill-planned well drilling and abstraction. Sea water intrusion into formerly freshwater aquifers frequently occurs as recharge from rainfall is insufficient to support the rate at which water is extracted. Wells supplying domestic, industrial and agricultural needs have, in many areas, become too saline for use.Climate change is expected to exacerbate this problem. Rising sea levels in the Indian Ocean region are projected to cause inundation of saltwater along the coastal zone, which is dominated by highly-permeable rock, while altered precipitation patterns and temperature change will affect the amount of water replenishing the aquifer through infiltration and recharge. Local communities across the region are already reporting changing tidal and rainfall patterns. The multiplicity of hydrological and demographic driving factors makes this a very challenging issue for management. At present the state of coastal aquifers in the EA region is not well constrained and past practices which may have exacerbated the problem have not been clearly identified. This project will bring together teams from Kenya, Tanzania and the Comoros Islands to address this knowledge gap; collaborating and working towards achieving water security in their respective areas. An integrative approach, combining the expertise of hydrogeologists, hydrologists and social scientists, will target selected sites along the coastal zone in each country. Hydrogeologic observatories will be developed where focussed research will identify the current condition of the coastal aquifers and identify future threats based on projected demographic and climate change scenarios. Water supply and monitoring needs will be identified through consultations with end-users and local authorities and optimum strategies for addressing these sought.An initial step will be to survey and bring together all existing data on well installations, abstraction, groundwater gradients and the salinity of existing wells at each pilot site. Understanding where wells are located, how deep they are, how much water is abstracted, what the flow directions are and what the salinity is, provides an overview of the state of the aquifer. Local data on hydraulic properties, such as the permeability, porosity, and storativity of the aquifer will be investigated and synthesised. Targeted electrical geophysical surveys, which provide relevant spatial information on both the aquifer structure and the saltwater distribution, will be undertaken.Similarly data is needed on the hydrological drivers in the system; to understand how much of annual rainfall infiltrates to replenish groundwater reserves (compared to the amount abstracted for human use) and how this might be impacted by changes in rainfall intensity or frequency. Land use and land use change is also important; controlling the proportion of incident rainfall which reaches the soil and subsequently groundwater. Recharge modelling will be an important tool for investigating different scenarios for climate and land use change and evaluating groundwater vulnerability. The social and political aspects of water use and development will be incorporated to assess the compatibility between the evolution of the availability of coastal freshwater resources and those of society and water politics. Researchers will engage with local community and stakeholder groups in each area and work together towards understanding the issues most affecting the communities with regards accessibility to water supply. A two-way exchange of knowledge between researchers and community members is essential in working towards feasible solutions to existing problems and ensuring preparedness for the changes in demographics and environment in the future.

EA沿海地区的地下水资源处于危险之中。需求增加，与沿海边缘的人口迅速增长有关，导致了不可持续且计划不足的良好钻井和抽象。海水侵入以前的淡水含水层经常发生，因为降雨的充电不足以支撑提取水的速度。在许多领域，供应国内，工业和农业需求的井已经变得过于盐水，无法使用。预计将加剧这个问题。印度洋地区的海平面上升预计会导致沿海地区淹没盐水，沿海地区以高度可渗透的岩石为主，而降水模式的改变和温度变化将影响通过浸润和补偿来补充含水层的水量。整个地区的当地社区已经报告了改变潮汐和降雨模式。水文和人口驱动因素的多样性使这是管理中非常具有挑战性的问题。 目前，EA地区的沿海含水层状况尚未得到很好的约束，过去可能加剧了该问题的实践尚未被清楚地确定。该项目将汇集来自肯尼亚，坦桑尼亚和科莫罗斯群岛的团队，以解决这一知识差距。合作并致力于在各自地区实现水安全。一种综合方法，结合了水文地质学家，水文学家和社会科学家的专业知识，将针对每个国家沿海地区的选定地点。将开发水文地质观测站，重点研究将确定沿海含水层的当前状况，并根据预计的人口统计和气候变化情景确定未来的威胁。供水和监测需求将通过与最终用户和地方当局的咨询以及解决这些寻求的最佳策略来确定。首先，将调查并将所有现有数据汇总到每个试点站点的井安装，抽象，地下水梯度以及现有井的盐度。了解井的位置，它们的深度，抽象的水量，流向是什么以及盐度是什么，可以概述含水层的状态。将研究和合成有关含水层的液压特性的局部数据，例如含水层的渗透率，孔隙率和储藏率。将进行有关含水层结构和盐水分布的相关空间信息的有针对性的地球物理调查。要了解每年降雨浸润以补充地下水储量（与人类使用的数量相比），以及这可能会受到降雨强度或频率变化的影响。土地利用和土地利用变化也很重要；控制到达土壤和随后地下水的事件降雨的比例。充电建模将是研究气候和土地使用变化和评估地下水脆弱性不同方案的重要工具。将纳入用水和开发的社会和政治方面，以评估沿海淡水资源的可用性与社会和水政治的供应发展之间的兼容性。研究人员将与各个领域的当地社区和利益相关者群体互动，并共同努力理解影响社区的问题，对供水的可及性。研究人员与社区成员之间的知识交流对于为现有问题的可行解决方案而努力，并确保将来的变化为现有问题做好准备。

项目成果

Geophysical methodological tests for the set up of water boreholes on the island of Grande Comore

在大科摩罗岛上打水井的地球物理方法测试

• 发表时间: 2013
• 作者: Join J.-L., Comte J.-C., Bourhane A., Soule H.

Modelling the impacts of climate change on fresh groundwater availability in low-lying coastal areas

模拟气候变化对低洼沿海地区地下水供应的影响

• 发表时间: 2016
• 作者: Comte J.-C.

Towards groundwater security in coastal East Africa: initiating a regional research network and integrated hydrogeologic, climatic and socio-economic observatories in coastal aquifers of the Comoros Islands, Kenya and Tanzania

实现东非沿海地下水安全：在科摩罗群岛、肯尼亚和坦桑尼亚沿海含水层启动区域研究网络和综合水文地质、气候和社会经济观测站

• 发表时间: 2014
• 作者: Comte J.-C., Cassidy R., Obando J. Et Al.

British Institute in Eastern Africa Annual Report 2013-2014

英国东非研究所年度报告 2013-2014

• 发表时间: 2014
• 作者: Cassidy, R

Modelling the response of fresh groundwater to climate and vegetation changes in coral islands

模拟珊瑚岛地下水对气候和植被变化的响应

• DOI: 10.1007/s10040-014-1160-y
• 发表时间: 2014
• 期刊: Hydrogeology Journal
• 影响因子: 2.8
• 作者: Comte J