A STUDY ON THE APPLICATION OF REGIONAL PARAMETERS IN REMOTE SENSING DIGITAL THEMATIC MAPPING

The present paper discusses the implications and drictions of the roponalparameters used in image recognihon, classification and mapping. lt is indispensablefor improving the accuracy of image classification and mapping quality. It focuseson the discussion of the theory and methodology for the detenninahon of ndonalparameters for spatial information including method for analysis of aukiliary datorelevan to geography and Anowledge-based roponal parameter research method.Applied researches on roponal parameters are also catried out in combination withpattem recoguhon and typological mapping of saline-alkali soils.

Fault-tolerant control systems design via subdivision of parameter region

This paper presents a linear matrix inequality （LMI） approach to solve the fault-tolerant control （FTC） problem of actuator faults. The range of actuator faults is considered as a parameter region and subdivided into several subregions to achieve a certain desired performance specification. Based on the integral quadratic constraint （IQC） approach, a passive fault-tolerant controller for the whole fault region and multiple fault-tolerant controllers for each fault subregion are designed for guaranteeing stability and improving performance of the FTC system, respectively. According to the estimation of parameters by FDI process, the corresponding subregion controller is chosen for the stability and optimal performance of closed-loop systems when the fault occurs. The case of incorrect estimation is also considered by comparing the performance index between the switched controller and the passive fault-tolerant controller. The proposed design technique is finally evaluated in the light of a simulation example.

Parameter regionalization of the FLEX-Global hydrological model

Global hydrological models(GHMs) are important tools for addressing worldwide change-related water resource problems from a global perspective. However, the development of these models has long been hindered by their low accuracy. In order to improve the streamflow simulation accuracy of GHMs, we developed a GHM—the FLEX-Global—based on the regionalization of hydrological model parameters. The FLEX-Global model is primarily based on the framework of the FLEX hydrological model coupled with the HAND-based Storage Capacity curve(HSC) runoff generation module to calculate net rainfall, and uses the global river-routing Ca Ma-Flood model to calculate river network routing. This new model allows for streamflow simulation at a spatial resolution of 0.5°×0.5° and a temporal resolution of 1 day in global catchments. To validate FLEX-Global accuracy, the FLEX-Global-simulated streamflow of 26 major rivers distributed in five different climate zones was compared with the observed data from the Global Runoff Data Center(GRDC). Next, the model performance of FLEXGlobal was further verified by comparing it with that of seven existing GHMs with varying accuracy in the five climate zones.Multi-metric evaluation indicated that the streamflow simulation accuracy was improved by the FLEX-Global model with regionalized parameters, especially in the tropical and dry climate zones. This newly-developed GHM with regionalized parameters can provide scientific support for the assessment of climate change impact, optimization of global water resource mangement, simulation of Earth's multi-sphere coupling, and implementation of the Inter-Sectoral Impact Model Intercomparison Project(ISIMIP).

Comparison of three regionalization techniques for predicting streamflow in ungaged watersheds in Nebraska,USA using SWAT model

This study compared three approaches,regional averaging,nearest neighbor,and donor techniques,to regionalize parameters in the Soil and Water Assessment Tool(SWAT)on eleven watersheds located in the Dissected Plains,Plains,and Rolling Hills Landforms in the eastern portion of the State of Nebraska,USA.Within the Rolling Hills Landform,three watersheds were randomly selected as calibration watersheds while two were randomly selected as validation watersheds.Two watersheds were randomly selected as calibration watersheds while one was randomly selected as a validation watershed within each of the Dissected Plains and Plains Landforms.The seven calibration watersheds were used to provide the necessary calibrated parameter sets to execute each of the regional approaches,while the four validation watersheds were used to assess the impact of applying each of these approaches to an uncalibrated watershed.Percent Bias(PBIAS)and the Nash Sutcliffe Coefficient of Efficiency(NSE)were used to assess model performance.Test results of this study show that all three methods performed poorly,since the majority of watersheds among each method tested exhibited PBIAS values greater than ±25% and/or NSE values less than 0.50,which were considered to be unsatisfactory in terms of model performance.The average regionalization,nearest neighbor and donor methods resulted in only four(two calibration and two validation),zero and one satisfactory set of simulated watershed results,respectively.The findings from this study indicate that although each watershed was successfully calibrated with NSE values ranging from 0.51 to 0.84,none of the three regionalization methods provided suitable calibration data sets to define parameter values for performing satisfactory simulations on ungaged watersheds across the eastern Nebraska landscape.