Development of an adolescent coping model in seasonal flood-prone areas:a qualitative feasibility study

Objective:The aim is to develop and verify the feasibility of an adolescent coping model in seasonal flood-prone areas.This coping model supports mental health nurses'practical application to adolescents in flood-prone areas.Methods:We developed the adolescent coping model based on the processes established in three integrated theories:self-care management for vulnerable populations,coping approaches,and coping with disaster.We conducted semi-structured interviews with 15 participants to explore their perspectives and experiences with flood disasters.We used purposeful sampling for maximum diversity.Data were collected through face-to-face,in-depth interviews.Data were transcribed verbatim,followed by qualitative content analysis.The coping model of adolescents in flood-prone areas was analyzed qualitatively and inductively from the viewpoint of acceptability.Results:The following five categories were identified:(1)coping process post-disaster;(2)coping approach;(3)community power;(4)vulnerability;and(5)self-potential.These domains formed a model for coping model adolescents in seasonal flood-prone areas.Accordingly,our findings showed that the model could be practical for mental health community nursing.Conclusions:Mental health nurses can use the coping model for disaster mental health nursing in adolescents in flood-prone areas.The application of this model will help adolescents increase self-efficacy.

Discussion on applying an analytical method to optimize the anti-freeze design parameters for underground water pipelines in seasonally frozen areas

Adopting the quasi-three-dimensional （Quasi-3D） numerical method to optimize the anti-freeze design parameters of an underground pipeline usually involves heavy numerical calculations. Here, the fitting formulae between the safe con-veyance distance （SCD） of a water pipeline and six influencing factors are established based on the lowest water temper-ature （LWT） along the pipeline axis direction. With reference to the current widely used anti-freeze design approaches for underground pipelines in seasonally frozen areas, this paper first analyzes the feasibility of applying the maximum frozen penetration （MFP） instead of the mean annual ground surface temperature （MAGST） and soil water content （SWC） to calculate the SCD. The results show that the SCD depends on the buried depth if the MFP is fixed and the variation of the MAGST and SWC combination does not significantly change the SCD. A comprehensive formula for the SCD is estab-lished based on the relationships between the SCD and several primary influencing factors and the interaction among them. This formula involves five easy-to-access parameters： the MFP, buried depth, pipeline diameter, flow velocity, and inlet water temperature. A comparison between the analytical method and the numerical results based on the Quasi-3D method indicates that the two methods are in good agreement overall. The analytic method can be used to optimize the anti-freeze design parameters of underground water pipelines in seasonally frozen areas under the condition of a 1.5 safety coefficient.

Study on preventing frost heave methods for highway foundation in seasonal frozen area

In order to resolve the frost-heave problem of highway foundation,firstly,the author discussed the law to frost heave of highway roadbed and gave an analysis on its influencing factors,such as soil,water and temperature.Meanwhile,sand clay and silt are given a classification according to frost heave ratio.Secondly,the roadbed frozen damage shows to frost heave and froze boiling based on the frost heave law and its influencing factors.In addition,taking some highway as an example and some principle suggestion was given through the theory on providing frostbite methods for highway foundation frost heave in seasonal frozen area.Specially,an effective method,STYROFOAM extruded polystyrene foam was introduced.

Root structure of slope protection plants in a high-grade highway

Root length and root length density of Lespedeza bicolor,Amorpha fruticosa,and Sea buckthorn were investigated in a country highway-TongSan highway（Tongjiang to Sanya） in Heilongjiang Province,China.The root lengths were divided into five root orders according to Pregizter sequence classification method.Results show that sea buckthorn roots are dominated by coarse roots in the horizontal growth,while L.bicolor has a large proportion of fine roots in vertical conical growth and A.fruticosa is in depth growth.Root length density of L.bicolor in all the root sequences is higher than that of sea buckthorn and A.fruticosa.On the basis of the root structure,it is inferred that L.bicolor roots mainly absorb the surface soil moisture for its normal growth;in contrast,A.fruticosa has good uptake ability to deep soil water.The root structure of sea buckthorn implies that it has a strong drought resistance.

ROLE IN MOISTURE TRANSPORTATION OF SEASONAL MEAN AND INTRASEASONAL OSCILLATIONS IN ASIAN SUMMER MONSOON AREA——LONG-TERM AVERAGE CHARACTERISTICS

By use of the May—September 1980—1986 ECMWF daily data of u,v,r and T at 850 hPa,a comparative analysis is performed of basic features of moisture transportation at seasonal mean,quasi-40-day,-biweekly,and-weekly oscillations,indicating that the seasonal mean transfer plays a decisive role in the moisture flux over the Asian monsoon region,displaying the integer of the monsoon systems there in character;that the transport related to these tropical intraseasonal oscillations are of equal importance in the monsoon period except the difference in their behaviors,i.e.,the transfer shows considerable relative independence in the South-and East-Asian systems;and that the transport at all these intraseasonal oscillations is found to be feeble at equatorial latitudes with little or no influence on each other for both hemispheres.

Simulating and validating the effects of slope frost heaving on canal bed saturated soil using coupled heat-moisture-deformation model

The lining canals in seasonal frozen soil areas can be severely damaged by frost heaving.The freezing and thawing contributes to the continual change of the temperature field and moisture field beneath lining canal,which will seriously affect the safe operation of the canal.In order to study the frost heaving damage mechanism of lining canal and to solve the associated engineering problems,the permafrost body was regarded as an elastomer,and a three-field,coupled,partial differential equation describing the temperature,moisture and deformation fields for a saturated two-dimensional canal bed was derived and established based on the Harlan model.The coupling equations were discretized using the finite element method in space and the finite difference method in time.The parameters were simplified appropriately based on compliance with the actual conditions and were simulated using finite element software.The results of a sample simulation showed that the simulated results and test results were basically consistent with variation laws,which proved the correctness of the numerical simulation theory and solution methods and the reliability of the calculation.The model can simulate the water,heat and deformation issues in the side slope of saturated canal bed soil in a seasonally frozen area and forecast freezing damage in the canals.

Detecting surface freeze/thaw states in Northeast China with passive microwave data using an improved standard deviation method

Passive microwave remote sensing datasets are widely used to observe surface freeze/thaw(F/T)states.However,current algorithms are highly affected by snow cover and complex land cover types,compromising their performance.Therefore,this study proposes an improved algorithm for daytime detection of diurnal F/T states by using Advanced Microwave Scanning Radiometer 2 data.In the daytime F/T discrimination algorithm,a microwave spectral gradient index is applied to divide the surface into snow-covered and snow-free areas.In the snow-free area,the surface temperature index is optimised to improve the accuracy of the standard deviation method(SDM)in evaluating the accuracy of the F/T state.For the nighttime dataset,the microwave standard deviation index difference values between day and night are used to detect the F/T states based on the daytime results.The accuracy of the improved algorithm reaches 88.6%and 84.5%in the daytime and at nighttime,respectively.Compared with the SDM,the accuracy is improved by 10.2%in the daytime and 5.4%at nighttime.The results demonstrate that the proposed model is able to effectively distinguish the F/T states of snow-covered surfaces.Optimising the surface temperature index can significantly improve the accuracy of the SDM.The results reveal that the proposed surface F/T detection algorithm can be applied to regions with complex land cover types.