Water, Migration, and Development
3. W hat are the impacts of migration, where do they occur, and what are the broader implications for development? Cities, which are often the destination of migrants, are believed to be more resilient to water shocks than rural locations are. This report provides evidence against this conjecture, finding that water shocks can have significant impacts in urban areas. In this way, the report sheds light on how fluctuations in the availability of water determine mobility, the flow of human capital, and the process of economic development itself. Although much has been written and studied on these topics at the regional or local level, this report takes a step back and provides a global view of the issues with new findings. These questions are all the more salient as climate change worsens stresses on the water cycle. The increasing variability and uncertainty of rainfall can weigh heavily on communities and economies. Rainfall shocks—anomalies whereby precipitation is well below or above normal levels—are already becoming more frequent, and coping with them may present one of the most difficult challenges confronting humanity. Indeed, a large body of recent work at the development policy and humanitarian nexus has recognized and
BOX 1.2: Is Water a Locational Fundamental? Access to a reliable water source has historically been a fundamental necessity to sustain human settlements at any given location. Archaeological evidence suggests that populations migrated where there was adequate water availability; as a result, the geographic distribution of water remains one of the locational fundamentals that have shaped the spatial distribution of economic activity over the course of history (Gupta et al. 2006). Along some coasts, access to the rich bounty of the sea supported early coastal settlements, particularly in the lush delta regions of major rivers. Over time, these regions attracted more people, buoying economic growth and creating longlasting civilizations that persist even today (Dalgaard, Knudsen, and Selaya 2020). People have always located where there is access to water. Map B1.2.1 confirms this observation by plotting the locations of the largest cities and major rivers, with the size of the dots representing city size classes. The clustering of cities observed along major river basins reflects the integral role of water availability in determining where populations choose to settle. For instance, note the concentration of cities along the Ganges and Indus rivers, and in Sub-Saharan Africa. In contrast, note also the absence of cities in arid regions such as the Sahara and western China. In the same vein, the presence of water-yielding aquifers is also an important determinant of where housing is built and populations settle (Burchfield et al. 2006). box continues next page
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