Urban Floods in Lowlands—Levee Systems, Unplanned Urban Growth and River Restoration Alternative: A Case Study in Brazil

Abstract

Abstract:The development of cities has always had a very close relation with water. However, cities directly impact land use patterns and greatly change natural landscapes, aggravating floods. Considering this situation, this paper intends to discuss lowland occupation and city sustainability in what regards urban stormwater management, fluvial space, and river restoration, aiming at minimizing flood risks and improving natural and built environment conditions. River plains tend to be attractive places for a city to grow. From ancient times, levees have been used to protect lowland areas along major watercourses to allow their occupation. However, urban rivers demand space for temporary flood storage. From a systemic point of view, levees along extensive river reaches act as canalization works, limiting river connectivity with flood plains, rising water levels, increasing overtopping risks and transferring floods downstream. Departing from this discussion, four case studies in the Iguaçu-Sarapuí River Basin, a lowland area of Rio de Janeiro State, Brazil, are used to compose a perspective in which the central point refers to the need of respecting watershed limits and giving space to rivers. Different aspects of low-lying city planning are discussed and analyzed concerning the integration of the built and natural environments. OPEN ACCESSSustainability 2015, 7 11069

Urban Growth and Flood Disasters in the Coastal River Basin of South-Central Chile (1943–2011)

“…The latter has translated into the growth of flood risk zones for human settlements and infrastructure due to a greater concentration of people and structures [5,6]. Recent urban growth has not taken into consideration the space that rivers require to temporarily store flows during floods [3]. Global efforts have focused more on implementing flood control infrastructure such as dykes, dams, and channelization, but despite these efforts, modern cities remain vulnerable to flood risk [7].…”

“…Floods are natural processes in river systems [1,2]; however, humans have occupied and urbanized floodplains for their urbanization attractiveness due to planar morphology and water availability [3,4]. The latter has translated into the growth of flood risk zones for human settlements and infrastructure due to a greater concentration of people and structures [5,6].…”

Unraveling the impact of built-environmental self-modification of the local inhabitants in their attempt to reduce the urban flood impact in Grogol, Sukoharjo*

“…The spatial areas that are located on flood-risk locations such as riverbanks are commonly inherent in the aforementioned quality. [15] Therefore, the risks of flood increase according to the occupation of land along riverbanks for residential and industrial areas. [16] Since these areas usually experience a decrease in economic value, these locations attract an expansion of lowincome settlements which leads to uncontrolled expansions of disorganized covered land and chaotic settlements.…”

“…[16] Since these areas usually experience a decrease in economic value, these locations attract an expansion of lowincome settlements which leads to uncontrolled expansions of disorganized covered land and chaotic settlements. [15] response can reduce the vulnerability of the disaster-victim communities to the impact of extreme weather such as the escalation of urban floods. [17] However, the growth of urbanized land in developing countries such as Indonesia generally takes two different growth patterns; the planned urbanized land and the spontaneous and unplanned.…”

Urban Flood Simulation Using MODCEL—An Alternative Quasi-2D Conceptual Model

“…This model was called MODCEL. Some applications of this model can be found in the literature (see, for instance, [44][45][46][47]). …”