Water resource developments in Ethiopia: potential benefits and negative impacts on the environment, vector-borne diseases, and food security

Abstract

To satisfy the growing demand for electricity, Ethiopia plans to increase its electricity production five-fold between 2010 and 2015, mainly through the construction of dams. A literature review shows that while dams can boost power and agricultural production, promote economic development, and facilitate flood control, they can also lead to environmental, ecological, and socioeconomic changes. Several case studies show that dams may alter the composition and density of vectors and intermediate host species, increase the incidence of malaria schistosomiasis and possibly lymphatic filariasis, and lead to eutrophication of reservoirs, soil erosion, and earthquakes. There is evidence that dams and commercial irrigation schemes can increase soil and water degradation, vulnerability to drought, and food insecurity in riverine and lacustrine areas downstream of dams. It appears that dams in Ethiopia are also vulnerable to high soil erosion rates and earthquakes. Consequently, the current and proposed large-scale dam construction program in Ethiopia requires in-depth research to improve our understanding of the unintended negative effects of projects and to guide the location, design, and implementation of appropriate preventive and remedial programs.Résumé : Les auteurs présentent une revue de littérature montrant qu'en dépit du fait que les barrages peuvent favoriser les productions d'énergétiques et agricoles, promouvoir le développement économique et faciliter la maitrise des inondations, ils peuvent également provoquer des changements environnementaux, écologiques et socio-économiques. Plusieurs études de cas montrent que les barrages peuvent modifier la composition et la densité d'espèces hôtes vectrices et intermédiaires, augmenter l'incidence de la schistosomiase de la malaria et possiblement la filariose lymphatique, en plus de conduire à l'eutrophisation des réservoirs, à l'érosion du sol et aux tremblements de terre. Il y a des preuves à l'effet que les barrages et les systèmes d'irrigation commerciaux peuvent augmenter la dégradation de l'eau et des sols, la vulnérabilité à la sécheresse et l'insécurité alimentaire dans les régions riveraines et lacustres en aval des barrages. Il semble que les barrages en Éthiopie seraient également vulnérables à des taux élevés d'érosion du sol et aux tremblements de terre. Conséquemment, le programme actuel de construction de barrages à grande échelle en Éthiopie nécessite des recherches approfondies afin d'améliorer notre compréhension des effets négatifs collatéraux des projets et de guider la localisation, la conception et la mise en place de programmes de prévention et de remédiation.

Fasciolosis in sheep and goats slaughtered at abattoirs in Central Ethiopia and associated financial losses

“…There are also large-scale dam constructions for the improved power supply and food production to support economic development. However, the implementation of such irrigated agriculture and dams might lead to environmental and ecological changes that might modify the distribution and density of vectors intermediate host species, resulting in the occurrence and increased incidence of tropical vector-borne diseases of both animals and humans such as the fasciolosis, malaria, schistosomiasis, and filariasis ( Yewhalaw et al, 2014 ). Consequently, there is a need to plan intervention strategies in parallel to reduce the risk if it occurs.…”

Joint Bayesian modeling of time to malaria and mosquito abundance in Ethiopia

“…Several studies have investigated the effect of dams on malaria prevalence and incidence [ 23 – 25 ]. In general, dams can have profound effects on the survival, density, and distribution of disease vectors and parasites by altering the local ecology and habitats, and the altered vector/parasite ecology modifies the transmission of vector borne diseases such as malaria and its incidence [ 26 ]. Kibret et al (2009) investigated the association of Koka reservoir and Anopheles mosquito density and malaria risk.…”

The Health of the Water Planet: Challenges and Opportunities in the Mediterranean Area. An Overview

“…The MENA region's age-old water scarcity challenges are exacerbated by the growing water demands, inter-sectoral competition, and urbanization. Against this background, poor, broken, or obsolete infrastructures represent an obstacle that negatively influences water storage capacity, further causing water losses and limiting access to its use [120].…”

“…Several case studies show that dams can alter the composition and density of different pathogenic micro-organisms in freshwater, increasing the incidence of water-borne diseases, soil erosion, and eutrophication of water basins. Furthermore, water supply methods are not enough to meet the growing population [120][121][122].…”