Flood plains

The Philippines is a country that is both largely dependent on marine resources for its people's socio-cultural and economic activities, yet also highly vulnerable to extreme weather events caused by climate change. Recognizing this, a Climate Change Adaptation Project, with support from the Norwegian Trust Fund, studied three coastal communities in three (3) different provinces in the Bicol region, widely known to lie in the so-called 'Philippine typhoon belt'. The project sought to establish a community-based adaptation strategy in pilot sites by providing guidance on setting appropriate policies, climate proofing livelihoods with adaptation measures, and institutionalizing science-based-decision support systems. The project also sought to develop a replicable template that can be used by and adapted to all other similar sites in the Philippines. The project had four major components: (1) policy and legislation, (2) vulnerability assessment, (3) bio-physical adaptation...

Waters of the United States" (WoUS) are regulated by the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act (33 U.S.C. 1344). The Corps lateral jurisdictional extent in Arid West stream channels is the upper level of the ordinary high water (OHW). The channel shape, fluvial textures, and vegetation patterns of these arid stream channels are heavily influenced by short-term, high-intensity or "flashy" events, which create distinctive physical features and vegetation responses. To determine vegetation and channel morphology responses, sequential aerial photos and stream gauge data for eight ephemeral and intermittent stream channels in the Arid West were analyzed. The observed patterns associated with various discharge event levels are consistent with the Corps OHW delineation manual. The use of remote sensing resources provides another critical component for aiding in the delineation of the extent of the OHW in Arid West stream channels.

: This technical note describes two alternatives for the reestablishment of floodplain functions on incised streams. The first is to reestablish the hydrologic connection with the historic floodplain by raising the water or bed level on the incised stream. The second alternative is the construction of pseudo-floodplains within the incised channel margin.

Philippines, as it is known to be a stopover for Pacific typhoons, is frequently threaten by flood and landslide that endangers the lives of many Filipinos. Great amount of monetary resources are being used up annually because of incidents by annual heavy downpour in this country. The population, their source of revenue and the area are the ones affected by these unfortunate events that causes the country for millions of peso every year. In this regard, there is an obvious need for methods and strategies that will alleviate adverse situations and which will protect human lives, properties and social infrastructure against disaster phenomena. Different important parameters in disaster risk management such as earth observations, Light Detection and Ranging (LiDAR) and Geographic Information System (GIS) were integrated and utilized in this study. This study dealt with mapping and assessment of buildings that might possibly be exposed and vulnerable to flooding based on the simulated flood maps at different rainfall scenarios in Patalan River Basin, Pangasinan, Philippines. The assessment was done through GIS overlay analysis of the CLSU PHIL-LiDAR 1 Project outputs, the 3D building GIS database and flood hazard maps. The 3D building GIS database was generated through processes and analysis of various datasets that include 1m resolution LiDAR Digital Elevation Models (DEMs), geo-tagged video captured data and high resolution images in Google Earth. The flood hazard maps with different hazard levels were generated with the use of flood models developed using the combined HEC HMS and HEC RAS. Results of this study were series of flood exposure maps and vulnerability maps with statistics at different rainfall scenarios. The number of houses, businesses and other types of building at risk of being flooded was quantified. It was observed that buildings exposed and vulnerable to flood are highest at 100 year return period. With the total of 129,800 building features extracted, results show that at 100 year return period there will be 61,377 buildings, 16,806 buildings and 23 buildings at low, medium and high hazards, respectively. Moreover, also at 100-year return period, a total of 12,569 buildings, 8,628 buildings and 17,795 buildings were identified that had high vulnerabilities to flood in terms of height at low, medium and high hazards, respectively. These produced maps can provide valuable information to the local government units and the communities around Patalan river basin in their flood disaster management through appropriate and riskconscious development in order to prevent further build-up risks. Through these maps, it is easier to disseminate information that is more realistic to the residents about the hazardous areas and to help them act on warning and evacuating measures.

This inventory of the vascular flora of Fort Greely in interior Alaska was conducted sporadically during summer 1996, 1997, and 1998. Fort Greely covers 0.66 million acres (267,763 ha) and is composed of five major subdivisions: 1) the large floodplains of Jarvis Creek, the Delta River, Delta Creek, and Little Delta River, 2) the surrounding lowlands associated with these rivers, 3) several glacial moraines, 4) two highland areas (Molybdemum Ridge and Dinosaur Ridge), and 5) the higher mountains of the Alaska Range (up to 2000 m in elevation) along the southern edge of the base. Habitats range from very dry south-facing slopes to for-

The UMRS encompasses the commercially navigable reaches of the Upper Mississippi River, as well as the Illinois River and navigable portions of the Kaskaskia, Black, St. Croix, and Minnesota Rivers. Congress has declared the UMRS to be both a nationally significant ecosystem and a nationally significant commercial navigation system. The mission of the LTRMP is to provide decision makers with information for maintaining the UMRS as a sustainable large river ecosystem given its multiple-use character. The long-term goals of the Program are to understand the system, determine resource trends and effects, develop management alternatives, manage information, and develop useful products.

Abstract : ELECTRONIC FILE CHARACTERISTICS: 21 files; Adobe Acrobat (.PDF) and JPEG image. PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in.; 93.2 MB. SYSTEMS DETAIL NOTE: IBM-clone PC-compatible. ABSTRACT: This report is concerned with mapping the Quaternary geology of an area comprising portions of approximately ten topographic quadrangles that cover an area of the Middle Mississippi River from St. Louis, MO, on the northern boundary of the study area, to Cape Girardeau, MO, on the southern boundary (Figure 1). The entire study area is within the U.S. Army Engineer District, St. Louis, extending from river mile 50 at Cape Girardeau to river mile 189 at St. Louis. Physiographically, the floodplain of the Middle Mississippi River is flanked by steep sedimentary bedrock uplands. At its widest point, the floodplain is no more than 19 km (12 miles) across but typically averages approximately 8 km (5 miles) in width. Throughout the valley, the Mississippi River generally flows along the base of either valley wall. The largest metropolitan area in the study area is St. Louis, MO. The purpose of this investigation has been to (a) determine the areal distribution and physical characteristics of the various alluvial deposits, (b)reconstruct the general geologic history of the area, (c) conduct subsurface stratigraphic correlation of various geologic environments of deposition as an aid in determining foundation and under seepage conditions, and (d) determine the depth and general nature of the Paleozoic deposits beneath the Holocene alluvium to the extent possible.

This study examined vertical, lateral, and downstream variations in the grain-size characteristics of historical (post-1830) overbank deposits in a watershed that has experienced high rates of accelerated flood plain sedimentation. More than 800 samples were collected from 53 cores along nine flood plain transects. Overbank deposits exhibit a coarsening-upward sequence attributed to historical changes in the sand content of source materials. The erosion of loess-capped soils increased the exposure, erosion, and transport of sandy parent materials. The average sand content of near-channel cores increases moderately downstream along two of the reaches because sandy source materials are increasingly exposed in larger main valleys in the northern part of the watershed. The two northernmost reaches are coarser overall, but do not display significant downstream trends. The sand content of surface and early historical overbank deposits generally decreases laterally as an exponential function of distance from the channel, suggesting transport by turbulent diffusion. The presence of sand throughout the transects and lateral coarsening at two of the transects, however, suggests that sediment transport by convection is also important.

A new method to calculate flow in compound channels is proposed: the interacting divided channel method (IDCM), based on a new parametrization of the interface stress between adjacent flow compartments, typically between the main channel and floodplain of a two-stage channel. This expression is motivated by scaling arguments and allows for a simple analytical solution of the average flow velocities

A new method to calculate flow in compound channels is proposed: the interacting divided channel method ͑IDCM͒, based on a new parametrization of the interface stress between adjacent flow compartments, typically between the main channel and floodplain of a two-stage channel. This expression is motivated by scaling arguments and allows for a simple analytical solution of the average flow velocities in different compartments. Good agreement is found between the analytical model results and laboratory data from the literature.

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Waters of the United States" (WoUS) are regulated by the U.S. Army Corps of Engineers under Section 404 of the Clean Water Act (33 U.S.C. 1344). The Corps lateral jurisdictional extent in Arid West stream channels is the upper level of the ordinary high water (OHW). The channel shape, fluvial textures, and vegetation patterns of these arid stream channels are heavily influenced by short-term, high-intensity or "flashy" events, which create distinctive physical features and vegetation responses. To determine vegetation and channel morphology responses, sequential aerial photos and stream gauge data for eight ephemeral and intermittent stream channels in the Arid West were analyzed. The observed patterns associated with various discharge event levels are consistent with the Corps OHW delineation manual. The use of remote sensing resources provides another critical component for aiding in the delineation of the extent of the OHW in Arid West stream channels.

The Arid West region is dominated by watersheds that have a high frequency of intermittent and ephemeral channels. These channels are influenced by watershed characteristics and the local hydrologic regime, which dictate the amount of sediment deposited and eroded in the channel. Over time, this sediment movement causes the geometry of the channel and the surrounding floodplain to evolve. For this study, 14 mountain, 18 foothill, and 17 basin ephemeral and intermittent channels within multiple watersheds were evaluated for specific characteristics, including geology, slope, watershed design, and floodplain geomorphology. We used multivariate analyses to explore patterns of similarities and differences among the channel and watershed characteristics. Using these results and characteristics, we devised a simple, artificial channel classification to evaluate OHW indicators to better understand watershed and intermittent and ephemeral channels across the landscape in the Arid West region. A total of 18 channel types were classified: 4 in the mountains, 8 in the foothills, and 6 in the basins. Our findings demonstrate that watershed and channel characteristics vary considerably across the landscape in the Arid West, suggesting that channel classification is potentially useful for evaluating the variability of occurrence of OHW indicators at a larger scale.