Flood management consists many aspects such as hazard assessment, vulnerability assessment, exposure assessment, risk assessment, early warning system, damage assessment as well as risk mitigation planning. Conventional flood management are depending on the ground based monitoring of rainfall and river discharge. Many parts of the world are not covered by these sensor networks in one hand and these ground based systems are costly. Most of the tropical countries have high flood risk and low financial and institutional capacity to afford ground based system. While conventional flood management is time and cost intensive, spaceborne remote sensing provides timely and low-cost data in comparison to field observation, and is the obvious choice for most developing countries affected by flooding. Many aspects of flood management are being aided with the advancement of remote sensing technology. More precise and near real time flood detection, lead time in flood early warning system, accurate and advance inputs of hydrological models are now blessed by space technology. Many methods and approaches have been developed to overcome the constrains in the application of spaceborne remote sensing in flood management. Application of satellite remote sensing in flood hazard assessment is well documented, however, the application of space technology in other aspects of the flood management is also promising. Therefore, this review paper focuses on the applicability of spaceborne remote sensing and in most of the aspects in flood management.
Debris flow impact force is an important factor for controlling structural damage, and it is the key factor for engineering design and risk assessment. Variation laws of debris flow impact force play an important role in preventing check dam impact damage and providing technology, data and support for check dam construction. Many influencing factors exist in debris flow impact force with different influencing magnitudes. The three main factors, i.e. the debris flow bulk density, the drainage channel slope and the upstream surface gradient of the check dam, were selected to be analyzed. The purpose of the study was to analyze the influencing degree of the three factors. Three levels were set for each factor and nine text schemes were established based on the theory of orthogonal experimental design. What is more, the related miniaturized flume experiment was carried out to measure impact force of debris flow. Finally, taking the impact force mean values of key point as the evaluation index, the flume experiment results were analyzed in detail by extreme difference analysis and variance analysis. Research results indicate: among the three factors, the drainage channel slope has the most significant influence, the upstream surface gradient of the check dam is in the second place and the debris flow slurry density is the third. The form of impact force mean with the maximum value: the drainage channel slope is 15°, the debris flow bulk density is 18.1 kN/m3 and the upstream surface gradient of the check dam is 1:0. 相似文献