Identifying Scale-location Specific Control on Vegetation Distribution in Mountain-hill Region

The scale-location specific control on vegetation distribution was investigated through continuous wavelet transforms approaches in subtropical mountain-hill region, Fujian, China. The Normalized Difference Vegetation Index (NDVI) was calculated as an indicator of vegetation greenness using Chinese Environmental Disaster Reduction Satellite images along latitudinal and longitudinal transects. Four scales of variations were identified from the local wavelet spectrum of NDVI, with much stronger wavelet variances observed at larger scales. The characteristic scale of vegetation distribution within mountainous and hilly regions in Southeast China was around 20 km. Significantly strong wavelet coherency was generally examined in regions with very diverse topography, typically characterized as small mountains and hills fractured by rivers and residents. The continuous wavelet based approaches provided valuable insight on the hierarchical structure and its corresponding characteristic scales of ecosystems, which might be applied in defining proper levels in multilevel models and optimal bandwidths in Geographically Weighted Regression.

Multilevel Assessment of Spatiotemporal Variability of Vegetation in Subtropical Mountain-hill Region

The complex spatiotemporal vegetation variability in the subtropical mountain-hill region was investigated through a multi-level modeling framework. Three levels- parcel, landscape, and river basin levels- were selected to discover the complex spatiotemporal vegetation variability induced by climatic, geomorphic and anthropogenic processes at different levels. The wavelet transform method was adopted to construct the annual maximum Enhanced Vegetation Index and the amplitude of the annual phenological cycle based on the 16-day time series of250m Moderate Resolution Imaging Spectroradiometer Enhanced Vegetation Index datasets during 2001-2010. Results revealed that land use strongly influenced the overall vegetation greenness and magnitude of phenological cycles.Topographic variables also contributed considerably to the models, reflecting the positive influence from altitude and slope. Additionally, climate factors played an important role: precipitation had a considerable positive association with the vegetation greenness, whereas the temperature difference had strong positive influence on the magnitude of vegetation phenology. The multilevel approach leads to a better understanding of the complex interaction of the hierarchical ecosystem, human activities and climate change.

An Analysis on the Economic Benefit of Simplified Cultivation Technology for Longan in Hills and Mountains of Maoming City

According to the characteristics of longan cultivated in the hill and mountain regions of Maoming City,this paper analyzed the economic benefit of the simplified cultivation techniques. With 15-year-old Chuliang longan trees as materials,the economic benefit of four kinds of simplified cultivation technologies was compared and analyzed. After nine years of continuous technological application,it was found that the input costs increased by 1. 62%,and the output profits increased by 56. 10%; in input costs,labor cost decreased by 41. 33%,pesticide cost decreased by 24. 19%,and fertilizer cost increased by 33. 57%.

Elemental composition and its environmental significance for the varicolored hills in the northern foothills of the Qilian Mountains of Sunan Yugur Autonomous County,China

The varicolored hills in the northern foothills of the Qilian Mountains of northem China, in the Hexi Corridor of Gansu Province＇s Sunan Yugur Autonomous County, have given this region a unique geomorphology. In this paper, we describe the elemental composition, lithological characteristics, and source type of the sediments that formed the varicolored hills. We found that the major oxides that make up their sediments are SiO2, A12O3 and Na2O. These sediments had higher Fe2O3, MgO, CaO, and Na2O contents and lower SiO2, A12O3, K2O, and TiO2 contents than in the major Fangyan rock group of the Jianglang Mountains Danxia landform and the red paleosols that have accumulated in the Yaojia Formation of the Songliao Basin. The varicolored hills have developed their strong coloration as a result of oxidation or reduction of Fe. Our data suggest that the sediments developed from terrestrial detrital deposits.The varicolored hills in the northern foothills of the Qilian Mountains of northem China, in the Hexi Corridor of Gansu Province＇s Sunan Yugur Autonomous County, have given this region a unique geomorphology. In this paper, we describe the elemental composition, lithological characteristics, and source type of the sediments that formed the varicolored hills. We found that the major oxides that make up their sediments are SiO2, A12O3 and Na2O. These sediments had higher Fe2O3, MgO, CaO, and Na2O contents and lower SiO2, A12O3, K2O, and TiO2 contents than in the major Fangyan rock group of the Jianglang Mountains Danxia landform and the red paleosols that have accumulated in the Yaojia Formation of the Songliao Basin. The varicolored hills have developed their strong coloration as a result of oxidation or reduction of Fe. Our data suggest that the sediments developed from terrestrial detrital deposits.

Hill Dwellers Climb Cultural Mountain——Miao people record their identity and history in eco-museum

Instead of running away, she stood to attention with arms akimbo and gave a serious smile. The giant wooden basket on her back almost made her fall as she tried to straighten her body. When I raised the camera, Yang Jiaxiu was walking along a narrow, muddy mountain path in a virgin fir forest, carrying about 50 kilograms of water. She twisted her body to pour the water into a large tank when she finally arrived at her house. Then the Miao woman put down the

“森列”与“饾饤”:南宋园林假山营造的两种类型及其结合发展

现有中国园林史研究已经认识到南宋是园林中石假山营造得到重要发展的时期,然而南宋园林假山营造的具体方式及其形态特点尚未得到有效探讨。在深入研读相关文献与图像的基础上,结合历史来源与后世影响,探讨南宋园林假山营造的类型及其发展。首先从“置”与“叠”2种基本方式出发,在历史语境中探讨“森列”与“饾饤”这2类南宋常见的假山营造类型及其来源与影响;进而关注二者在仿“飞来峰”营造中的结合与发展,从而更清晰地认识南宋,乃至其后的石假山营造。这一研究将对其后中国园林假山发展的认识,乃至当代假山特点的理解提供坚实的历史理论基础。

基于模糊PID的丘陵山地灌溉控制系统设计

针对传统丘陵山地农业灌溉通常采用人工控制电磁阀进行灌溉所出现的水资源浪费、人工成本高等问题,设计了一套基于模糊控制和PID控制的丘陵山地农作物自动灌溉控制系统,将PID控制的稳定性和模糊控制的适应性相结合来控制灌溉时长。通过Simulink搭建的丘陵山地灌溉系统,分别用常规PID和模糊PID来控制该系统进行仿真实验。结果表明:模糊PID控制下的系统相比于常规PID控制,超调量和调节时间都明显降低,具有更高的稳定性、适应性和调节性能,可以用于丘陵山地农业自动灌溉系统中。

丘陵山地遥控履带割草机设计与性能试验

针对广西丘陵山地15°~25°坡地的经济作物种植园区坡度较大、地块分散、缺少机耕道,现有机械化割草机具难以进入并进行作业的难题,结合种植园区生草栽培的农艺技术,研发一种可遥控的履带割草机。根据园区作业环境的割草机工况要求,对整机及关键部件如履带行走系统、切割系统、变割草高度调节系统等进行计算分析与设计;设计并进行整机性能试验,实验结果表明,该割草机动力充足,最大纵向爬坡角度为36°,最大斜向爬坡角度为41°,在增程系统作用下,综合工况下作业时间由1.5 h延长至1.8 h;最小转弯半径为403.5 mm;对割草机的遥控操作性能做直线行走试验,测试路段试验最大偏驶角度不大于3°;倾翻试验台架测试纵向倾翻稳定角为48.9°,横向倾翻稳定角为64.4°;在广西某机械化茶园示范区进行割草试验,平均割草率为95%;可通过遥控实现割草机的行走、制动、转向和割草刀具高度调节,满足丘陵山地作物园区作业需求。

低山丘陵地貌类型林业生态建设与治理模式研究

低山丘陵地区存在严重的水土流失问题,原因包括过度放牧、乱砍乱伐和陡坡开荒等。针对这一问题,可采取小型流域综合治理为主的水土流失治理模式。治理措施包括山顶封禁治理管理、山腰退耕还林和坡改梯防治技术。封禁山顶地区,恢复植被生长,定期禁止砍伐、割草和放牧,并对裸露的土地进行覆盖和种植草木。在山腰地区实行退耕还林策略,种植经济果树,并采用坡改梯技术建设平整的农田。此外,还应注重水利工程建设,解决林间灌溉问题,并推广节水灌溉技术。这些措施有助于改善低山丘陵地区的水土流失问题,保护生态环境。

山地电动履带底盘设计与仿真分析

针对丘陵山区地形起伏大、地块碎小、土壤粘重等复杂的农机作业背景,以及现有农机作业对高效、安全、环保的履带底盘需求日益增长的现状,设计制造了一种山地电动履带底盘。通过Solidworks软件建立履带底盘模型,并借助Adams多体动力学仿真软件对底盘的爬坡、过沟和越障性能进行了动力学仿真。仿真结果表明,最大爬坡角度为25°,最大过沟宽度为400 mm,最大跨越垂直障碍物高度为200 mm,仿真试验验证了底盘在行驶过程中的可行性,为进一步优化丘陵山区农业机械底盘结构提供了参考。

丘陵山区茶园管理机车架设计与分析

设计了一款满足丘陵山区茶园一体化管理的机械设备,采用复合式结构设计,通过快速拆装接口,实现耕地、除草、开沟施肥和喷药的一体化作业。分别利用CATIA、理论力学、ANSYS Workbench对车架进行三维建模、载荷分析和有限元分析。结果表明,车架正常工况下最大变形量为7.773 mm,最大应力为87.87 MPa,安全系数为2.67,符合设计要求。

Landslide Hazard Zonation Mapping in Ghat Road Section of Kolli Hills, India

Landslides are the most common natural disaster in hilly terrain which causes changes in landscape and damage to life and property. The main objective of the present study was to carry out landslide hazard zonation mapping on 1:50,000 scale along ghat road section of Kolli hills using a Landslide Hazard Evaluation Factor(LHEF) rating scheme. The landslide hazard zonation map has been prepared by overlaying the terrain evaluation maps with facet map of the study area. The terrain evaluation maps include lithology, structure, slope morphometry, relative relief, land use and land cover and hydrogeological condition. The LHEF rating scheme and the Total Estimated Hazard(TEHD) were calculated as per the Bureau of Indian Standard(BIS) guidelines(IS: 14496(Part-2) 1998) for the purpose of preparation of Landslide Hazard Zonation(LHZ) map in mountainous terrains. The correction due to triggering factors such as seismicity, rainfall and anthropogenic activities were also incorporated with Total Estimated Hazard to get final corrected TEHD. The landslide hazard zonation map was classified as the high, moderate and low hazard zones along the ghat road section based on corrected TEHD.

从“海山仙馆”说起“仙山楼阁”意象图式的溯源与流变

中国人的山水观形成源于对自然之美的赞叹,古人在赞叹“天地有大美而不言”的同时将山水观念渗透到对其聚居环境的创造之中,这是一种“集体记忆”在长期人与景观互动中塑造的“地方认同”,并体现在古今营造活动中的某种空间结构。“仙山楼阁”的图景源自上古神话,体现了先民对自然的崇拜、敬畏和健康长寿的愿望,累世积淀,逐成为中国文学、绘画与园林创作的经典意象。本文将以位于珠江滨岸滩涂的历史名园“海山仙馆”研究为切入点,解读“仙山楼阁”意象的地域表达与演绎,探析其空间原型的萌芽、空间模式的确立及流变。引入意象图式的概念,有利于将物质实体转向空间结构逻辑认知,对探索传统空间模式的传承与当代转译具有启发性。

丘陵山地农业装备与坡地作业关键技术研究综述

丘陵山区先进适用农机装备的研发是目前国内农机装备研究的热点和难点问题之一。目前,我国丘陵山区农业生产存在“无机可用,无好机用”的现实问题,并且先进适用丘陵山地农机装备(简称山地农业装备)的研发缺乏必要的理论支撑。本文重点综述了国内外山地农业装备尤其是山地拖拉机及山地农机调平技术、山地拖拉机驱动与动力系统、山地农机具及其作业性能的研究现状,阐述了农机土壤压实与坡地土壤耕作侵蚀的研究进展,总结归纳了山地农机设计及山地农机-土壤互作机理研究的计算机辅助方法。展望丘陵山地农机装备及坡地作业技术的研究重点及发展方向:山地农机-坡地土壤-作物(养分)互作机理研究;山地农机总体设计与农艺及坡地作业场景深度融合;山地农机姿态调平机构与控制策略;山地农机动力高效传递与灵便转向驱动;山地农机作业机组的智能化监测与精确自主导航。以期为我国丘陵山区农机装备的研发设计提供借鉴参考。

植保无人机助推山区智慧农业发展的路径分析

随着新一代信息技术的不断成熟以及我国对于农业重视程度的不断提高,丘陵山区智慧农业市场呈现出需求大、热度持续走高的特点。其中,植保无人机在智慧农业市场中占据了较大份额,但其发展还存在许多阻碍。为了探明植保无人机的发展方向,扫清智慧农业发展道路上的阻碍,课题组从植保无人机、智慧农业的发展现状出发,分析了现阶段的市场现状和政策现状,提出当前植保无人机存在推广难度大、缺少系统监管、设备技术有待完善等问题。基于现存问题,对植保无人机助推丘陵山区智慧农业发展的路径进行了整合讨论,得出以下路径:构建符合山区实际情况的特色植保无人机监管模式、发展山区植保无人机信息化管理系统、确定山区植保无人机科技创新方向。对于增强山区智慧农业发展内生动力,奠定山区智慧农业及乡村振兴发展基础具有一定参考价值。

低山丘陵地形效应的三维有限元模拟

山地丘陵地形对地震动的分布有重要的影响,研究地形效应,有利于充分认识地震灾害风险,为减轻灾害损失做好防御措施。基于实际地形建立自贡西山公园观测台阵所在山体的三维有限元模型,研究开发黏弹性人工边界和SH波垂直入射前处理程序,开展动力学数值模拟;数值模拟结果与实际记录进行对比,并验证模型的合理性;研究分析低山丘陵山体对地震动强度及空间分布影响,以及峰值加速度与入射波频率、高程、坡度的关系。结果表明:低山丘陵山顶位置地震动峰值放大明显,而山脚凹陷位置地震动峰值存在削弱现象;地形效应与输入地震动频率密切相关,不同主频的输入地震动所造成的地表峰值加速度分布不同;较高主频的地震动可以凸显地形细节的影响;地表峰值加速度与高程具有较好的正相关关系,与坡度的相关关系较弱。综合高程和坡度拟合峰值加速度的效果优于仅使用高程或坡度的拟合,二元三次多项式拟合效果较好,可用于定量描述地形放大系数随高程和坡度的变化。

丘陵山地藜麦联合收割机设计与试验

我国藜麦多种植于高海拔、丘陵山区,种植地块小、坡度大、道路狭窄,为降低普通稻麦联合收割机收割藜麦损失大、含杂高、喂入不畅等问题,本研究针对藜麦种植农艺和茎秆特性设计了一种丘陵山地藜麦联合收割机。该机采用小行距扩口链齿喂入装置,配合下割刀、纹杆与杆齿组合式纵轴流脱粒滚筒、组合式分离凹板、双层往复式振动筛等装置,实现藜麦顺畅喂入、脱粒与分离、清选作业,对关键部件进行设计仿真,并进行田间试验。仿真结果表明:藜麦分禾喂入过程分禾角度较小,不会产生茎秆折损。试验结果表明:藜麦籽粒含水率14%、茎秆含水率为26%时,脱净率96.83%、含杂率4.30%、破损率0.15%、割台损失率1.54%、夹带损失率0.92%、清选损失率0.52%、总损失率2.98%。作业期间整机运行平稳,满足藜麦机械化收获要求与作业指标,可以作为丘陵山地藜麦联合收割机使用。本文可为藜麦联合收割机设计与试验提供一定参考。

一种增程式果园管理车辆的设计与分析

针对我国果园种植地区地形复杂多样,使用专用大型机械存在着生产效率低、能源利用率低、不能灵活地进行作业等问题,以山地丘陵地区为设计背景,设计一种小型、节能、灵活的增程式山地果园管理车辆。采用模块化、多功能、一机多用的农机设计理念,用CATIA软件对该车辆进行三维建模,对动力系统部件进行选型和计算,并进行动力系统的设计。最后得出该车辆可以稳定地完成行走、旋耕等工作。该车辆结构合理,相比于传统的果园旋耕机,提高了生产效率,并且可以使增程器维持在一个节能的工况,使得能源利用率有了很大的提高,符合国家提出的“双碳政策”,为山地果园管理车辆的设计提供了一种参考方案。

丘陵山地动力底盘发展现状与展望

动力底盘是丘陵山地移动式动力机械的重要组成部分,是决定丘陵山地机械化装备技术发展的关键。按底盘行走方式分类,阐述了几种底盘的结构和性能特点,提出了丘陵山地动力底盘与地面耦合机理、多功能轻量化、智能化和信息化的发展研究方向。

河南省丘陵低山区刺槐人工林立地分类及立地质量评价

为确定河南省丘陵低山区刺槐适宜的生长环境,为刺槐的经营管理和立地生产潜力提升提供参考。以河南省丘陵低山区106块1~26年生刺槐人工林为研究对象,采用典型抽样方法,调查样地内对树高生长有显著影响的环境因子,利用数量化理论Ⅰ分析各调查指标对刺槐生长的影响,对刺槐人工林进行立地类型划分与立地质量评价。结果表明,影响刺槐人工林立地质量的主要环境因子依次为土壤质地、海拔高度、土层厚度、坡向;复相关系数的t检验得t=14.96,复相关系数及各立地因子偏相关系数均达显著水平,此次所构建的数量化立地指数表适用于河南省丘陵低山区刺槐人工林。采用土壤质地、海拔高度、土层厚度、坡向4个主要因子的组合,划分为10个立地类型组、80个立地类型。将80个立地类型划分为好、中、差3个立地等级,对每个立地类型立地质量评价分析得出,研究区有75%的样地立地质量在中等以上。河南省丘陵低山地区刺槐人工林最适宜生长的环境为中厚(>30 cm)、壤土、小坡度、阴坡。