This is a map of flood control features in Los Angeles as of the late ’70s from . There are hundreds of miles of concretized flood control channels, a handful of flood control basins and dams, and dozens of debris basins. Winter is coming and when the rain starts (well, if there’s rain in the first place), we’re going to start seeing mud slides and flooding on the news pretty soon.
One of the arguments that Ian Gregory makes in the chapter “Using Geographical Information Systems to Explore Space and Time in the Humanities” is that GIS can perform an analysis over a broad study area, both spatially and temporally, adding a new capability to humanities research. Previously, scholars could approach a phenomenon either spatially or temporally (which could lead to similar but irreconcilable theories, e.g., Cronon’s and Turner’s theories of urbanization), or focus on a smaller study area that theoretically represented what was happening in a larger area. The benefit of GIS is that by integrating space and time over large areas and spans of time, scholars can now reevaluate orthodoxies that previous studies may have led to. However, one weakness of GIS is that they are not as detailed and thus have less explanatory power. A possible methodological implication of GIS’s strengths and weaknesses is that scholars will use it as a preliminary step in research projects. After a broad overview is established with GIS, scholars would then do an in-depth case study to come up with an explanation or theory of the phenomenon.
The complementary relationship between GIS analyses and case studies reminded me of something I read about the flooding of the Los Angeles River. In the article “Flood Control Engineering in the Urban Ecosystem,” Jared Orsi writes about how “[m]oderate storms in 1978 and 1980 surprised flood controllers by triggering severe flooding, even in areas they had thought were protected” (148). The engineers were surprised, Orsi explains, because their theory of flood prediction was too generalized. If a fifty-year flood is only supposed to happen once every fifty years, why do they happen more often than that? The explanation is that the specific geographies of mountain ranges interact with complex storms in an uneven manner. One area may only get a drizzle while another may get a heavy downpour. While the average rainfall is not too bad, it is the smaller problem areas that you have to be careful about. This example from civil engineering illustrates why small study areas and case studies are an important part of research in the humanities, even though they are not sufficient.