An Artificial Neural Network-Based Response Surface Method for Reliability Analyses of c-φ Slopes with Spatially Variable Soil

This paper presents an artificial neural network（ANN）-based response surface method that can be used to predict the failure probability of c-φslopes with spatially variable soil.In this method,the Latin hypercube sampling technique is adopted to generate input datasets for establishing an ANN model;the random finite element method is then utilized to calculate the corresponding output datasets considering the spatial variability of soil properties;and finally,an ANN model is trained to construct the response surface of failure probability and obtain an approximate function that incorporates the relevant variables.The results of the illustrated example indicate that the proposed method provides credible and accurate estimations of failure probability.As a result,the obtained approximate function can be used as an alternative to the specific analysis process in c-φslope reliability analyses.

Approach of moving boundary and its application in 3D tidal current simulation of Changjiang (Yangtze) River Estuary based on ECOMSED model

Considering three-dimensional model ECOMSED can not simulate wetting-drying of shoal with its fixed boundary, an approach to represent moving boundary in the model is introduced here. This approach smoothly joints the internal and external mode by making use of wetting and drying technique and is verified by a numerical test which presents a good agreement with the previous test results obtained by other researchers. A three dimensional numerical model is established to simulate the hydrodynamics in spring tide in the Changjiang （Yangtze） River estuary by this modified ECOMSED model which is also validated through the observed field data, the simulation presents a good periodic tidal change. It also successfully simulates the tidal current of computational areas and reproduces the tidal flat intermittent appearance.

Effects of altitude and slope on the climate–radial growth relationships of Larix olgensis A.Henry in the southern Lesser Khingan Mountains,Northeast China

Background:The relationship between climate and radial growth of trees exhibits spatial variation due to environ-mental changes.Therefore,elucidation of how the growth–climate responses of trees vary in space is essential for understanding forest growth dynamics to facilitate scientific management with the ongoing global climate warming.To explore the altitudinal and slope variations of these interactions,tree-ring width chronologies of Larix olgensis A.Henry were analyzed in the southern Lesser Khingan Mountains,Northeast China.Results:The radial growth of L.olgensis exhibited significant 5-to 10-year periodic changes at three altitudes and two slopes,and the frequency change occurred mainly during the early growth stage and after 2000.The radial growth of L.olgensis was significantly negatively correlated with September precipitation only at low altitudes,but also with the mean temperature in July–August and the mean maximum temperature in June–August at high altitudes.The radial growth of L.olgensis at low and middle altitudes as well as on the sunny slope led to a higher demand for moisture,while temperature was the key limiting factor at high altitudes and on the shady slope.Conclusions:The climate–radial growth relationship of L.olgensis exhibits altitudinal and slope variability.This study quantitatively describes the spatially varying growth–climate responses of L.olgensis in the southern Lesser Khingan Mountains,which provides basic data for the management of L.olgensis forests and the prediction of future climate impacts on forest ecosystems.