Advances in Quantifying Impact and Extent of Water-Land-Food Nexus for Food Security in Africa

Food systems have the potential to promote human health and enhance environmental sustainability;yet most African countries have decadal starvation and malnourishment due to unstable food systems lacking basic nutritional profiles. To understand the key questions of the African food production and food security crisis, it is important to evaluate the past and the present balance of food production and consumption quantitatively and comprehensively and identify resource constraints. This continental study analyzed water-land-food (WLF) nexus in recent decades (1997-2017) and accessed whether these resources cope with different population growth projections, dietary changes and agricultural water management. The findings revealed that in 2017, total production in Africa for the four major crops was 83.3, 34.1, 21.0 and 26.7 million tons for, respectively, maize, rice, sorghum and wheat. Together with the imported food, 38 countries experienced an increase in kcal by food supply, while 7 countries encountered a decrease. However, only 6 countries were above the 1500 kcal∙capita−1∙day−1—the global average food consumption from the four major crops. The study also found that in the context of food production and out of the total African population, 268 million (21.6%) have enough land and water, 310 million (25.0%) is without enough land and water, further 279 million (22.5%) have enough water but not enough land, and 381 million (30.8%) encounter enough land but not enough water. This is the first WLF nexus study for the African continent and emphasizes the need for efficient and rapid changes in the food systems of the African population, both in production and consumption, in order to provide sustainable and secure food systems, and ultimately approach the first three Sustainable Development Goals.

Water Resources Conflict Management of Nyabarongo River and Kagera River Watershed in Africa

In the process of exploiting and using water resources of river basin, the benefit conflict problems among upper and lower river districts and among different departments restrict to sustainable exploiting and using water resources of river basin. In this paper, the water resources conflict management of Nyabarongo River and Kagera River watershed is studied. The Nyabarongo is a major river in Rwanda, begins in Nyungwe Forest, and flows up to the north-western part of the country, then down through the center to the south-east, eventually forming the main tributary of the Kagera River watershed, the main affluent of Lake Victoria, which drains into the Nile River. The basin is shared among 11 riparian states. This trans-boundary character of the Nile presents a great challenge of water conflicts;national interests have historically been promoted at the expense of regional interests. The framework of this paper is as follows: the water resources bulletin is firstly described, and then the cooperation and regional conflicts are discussed;finally a sustainable framework for governing the water resources is proposed to meet water management in riparian states.

Prospects of eco-hydrological model for sponge city construction

Introduction:Understanding complex urban eco-hydrological processes through models is an important approach in sponge city construction.However,the research on this has not kept pace with the urgent need for sustainable development of urban water resources,which makes the current construction efficiencies unsatisfactory.Outcomes:This review highlights the importance of establishing a multi-scale urban distributed eco-hydrological model by analyzing the connotations of sponge city construction.Hydrological models that can be configured for sponge city construction were selected.Traditional models have limitations in coupling ecological and hydrological processes,multi-scale and landscape-based simulations,refined simulations,and computational efficiency.By contrast,cellular automaton has a discrete data structure in space,time,and states,is capable of bottom-up computing,and provides a new conceptual framework for simulating complex urban eco-hydrological processes.Discussion and Conclusion:Future model development may focus on the conduction of multi-scale simulation systems,the simulation of coupled urban eco-hydrological processes,the quantification of eco-hydrological responses to land cover composition,spatial configuration and low impact development practices,and improving simulation accuracy.