Aquatic systems and water security in the Metropolitan Valley of Mexico City
In megacities water quantity and quality are threatened by complex and interrelated processes caused by population growth, land use change, unsustainable agricultural practices, deforestation, erosion, destruction of ecosystems, lack of planning, laissez-faire policies, unsustainable water management, political conflicts, and increasingly also by the impacts of climate change. In the Metropolitan Valley of Mexico City (MVMC) located in the high plateau of Mexico City and on former lakes, the dry out policies during the last 300 years have been counterproductive, causing scarcity, pollution, health and environmental problems, subsidence and water conflicts, particularly affecting social vulnerable people. Megacities require an integrated management of water and aquatic systems — integral water resource management, rainwater harvesting, maintenance and replacement of infrastructure, restoration of ecosystems and urban planning. This implies investments and a water culture including a transparent administration and peaceful negotiation of conflicts regarding concessions, access, and reuse of water allocation. Socio-political and environmental processes are complex; besides technical factors and ecosystem recovery, socio-cultural changes must transform human settlements and power structures.
Perceived versus actual water quality: Community studies in rural Oaxaca, Mexico.
Compromised water quality risks public health, which becomes particularly acute in economically marginalized communities. Although the majority of the clean-water-deprived population resides in Sub-Saharan Africa and Asia, a significant portion (32 million) lives in Meso- and Latin-America. Oaxaca is one of the marginalized southern states of Mexico, which has experienced high morbidity from infectious diseases and also has suffered from a high rate of infant mortality. However, there has been a paucity of reports on the status of water quality of culturally diverse rural Oaxaca. This study follows community-based participatory research methods to address the data gap by reporting on water quality (chemical and microbiological) and by exploring social realities and water use practices within and among communities. Surveys and water quality analyses were conducted on 73 households in three rural communities, which were selected based on the choice of water sources (i.e., river water, groundwater, and spring water). Statistically significant variations among communities were observed including the sanitation infrastructure (p-value 0.001), public perception on water quality (p-value 0.007), and actual microbiological quality of water (p-value 0.001). Results indicate a high prevalence of diarrheal diseases, a desire to improve water quality and reduce the cost of water, and a need for education on water quality and health in all the surveyed communities. The complexities among the three studied communities highlight the need for undertaking appropriate policies and water treatment solutions.
An Internet-based Real-time Heavy Rainfall Display System
A new storm warning system, which can be accessed through the Internet and by cellular phones is described. At the time of a heavy rainfall for disaster prevention, it is important that every resident understand how heavy is that rainfall. A real-time heavy rainfall display system designed for all of Japan provides such information (http://www.disaster-i.net/rain/). In that system values for 1-hour precipitation, 24-hour accumulated precipitation, etc. are displayed at every observatory. Advantages are that not only the latest observations but differences from the historical highest records can be seen. Almost all information is displayed by characters so that users have easy access to the system even when the communication network is crowded. Access date for the six months after the system opened shows that the average daily number of accesses of the top page was 306, and the largest number 3078. The maximum number for daily access to all the pages was about 21,500. This is about 2% of the number obtained on the same day for a similar system operated by the Ministry of Land, Infrastructure and Transport (http://www.river.go.jp/).