典型工程项目引领的现代学徒制人才培养模式实践探索

现代学徒制已成为时下高等职业院校人才培养模式改革的一种探索和尝试.本研究以高等职业院校测绘类专业人才培养为探讨对象,从现代学徒制的内涵、特点及要求出发,分析梳理了测绘类专业人才需求量大但高技术技能型人才供给不足的发展现状,测绘类专业人才培养中存在缺乏有效教育平台、企业参与课程建设不够、师资队伍欠缺及实训条件有待改进等问题,并以重庆工程职业技术学院为例,从人才培养平台打造、培养模式构建、师资队伍及校内外实习实训基地建设、校企合作培育等方面论述了丘陵山区典型工程项目引领的测绘类专业现代学徒制人才培养模式的实践路径.

基于区域分化下重庆市土地利用结构效率评价——综合运用信息熵和Malmquist指数

以重庆市38个区县的面板数据为基础,综合运用信息熵和Malmquist指数模型,对重庆市2004-2013年期间土地利用结构信息熵以及土地利用全要素生产率及其分解进行分析评价.结果发现:(1)2004-2013年重庆市的土地利用结构信息熵总体呈"平稳-下降-平稳"的变化趋势,空间上信息熵值由主城片区向两翼递减,各片区的发展方向不同是导致其空间分异主要原因.(2)2004-2013年重庆市的全要素生产率呈现微弱的递减趋势,技术效率的下降是其主要原因,各片区的全要素生产率表现出鲜明的空间分异特征,经济发展阶段的不同以及经济发展的局限等问题是形成差异的主要原因.研究发现各片区出现的问题不能"一刀切",需区别对待技术进步、土地配置效率以及集约利用等因素对于土地利用效率的影响.

生态约束下丘陵山区都市休闲农业发展布局及策略研究

发展都市休闲农业是实现生态保护和农业协调发展的重要途径。为探索丘陵山区生态保护与农业协调发展之径,用生态敏感性评价表征生态环境约束力,在分析综合生态敏感性的空间分布及区域特征基础上,提出生态约束下研究区都市休闲农业发展的空间布局规划,及其发展的对策建议,主要是强化基础设施,夯实农业发展基础、强化政策扶持,促进产业融合发展、明确用地政策,保障休闲农业项目落地、拓宽融资渠道,保障都市休闲农业发展资金、强化经营主体培训,培育不同专业型新型经营主体、强化"互联网+农业",拓宽农产品营销渠道。

基于兴趣点(POI)挖掘的重庆主城区农家乐空间分布特征

发展乡村旅游是实现乡村振兴战略的重要抓手之一。为了解重庆主城区农家乐的空间分布特征,以期对其进行布局优化,以从百度地图上抓取的564个农家乐兴趣点(POI)为研究对象,运用GIS空间分析技术和数理统计方法,从分布类型、均衡性和空间格局角度定量研究重庆主城区农家乐空间分布特征。结果表明,重庆主城区农家乐分布类型为凝聚型,地区分布不均衡,空间格局为“多中心集群分布”型,存在“U”型农家乐核心密度圈,基本形成集中连片的带状空间格局,以北碚区和南岸区为高密度聚集中心点。农家乐空间分布主要影响因素为地形地势、植被覆盖、交通条件、旅游资源、客源市场和经济密度。

基于AHP的农业主题公园综合评价——以川东低山丘陵区17个农业主题公园为例

农业主题公园是农旅融合新模式,科学地分析评价农业主题公园,是促进农业主题公园健康发展的重要手段.本研究在归纳总结有关农业主题公园建设标准和规范的基础上,运用层次分析法构建了农业主题公园综合评价指标体系,并以川东低山丘陵区17个典型农业主题公园进行实证研究.研究表明:(1)川东低山丘陵区农业主题公园综合评价等级集中于Ⅰ,Ⅱ,Ⅲ级,占比依次为17.65%,58.82%,23.53%.(2)政策规范是引导农业主题公园健康发展的关键因素,Ⅰ级农业主题公园相对集中于广安市,Ⅱ级农业主题公园相对集中于重庆市.(3)Ⅱ,Ⅲ级农业主题公园普遍存在农业文化缺失、产业发展不均、管理粗放、忽视品牌宣传等问题.应从及时出台政策规范、完善产业结构、深入挖掘特色文化、完善基础设施和提高服务水平等方面促进农业主题公园健康发展.

重庆市A级旅游景区空间格局特征及演变

基于重庆市2008年、2013年和2018年A级景区点位数据,从重庆市及四大片区两个视角出发,利用最邻近指数、核密度分析和标准差椭圆等空间分析方法研究了其空间格局特征及演变.结果表明:重庆市A级景区空间分布类型为凝聚型,总体布局“西南密,东北疏”;10年间主城片区以及渝东北片区景区分布先分散后极化,渝东南片区以及渝西片区景区不断聚集,并且聚集程度逐渐加深;随着旅游业的发展,景区分布的高密度区不断从主城片区扩散,基本形成覆盖主城片区及渝西片区的全域核心密度圈;景区分布重心从西南向东北方向略有偏移;地形地势、旅游政策、经济水平以及交通格局对A级景区的空间凝聚有着比较显著的影响.

基于PSR模型典型山区耕地集约利用及其驱动力研究——以四川凉山彝族自治州为例

耕地集约利用对地区特别是民族山区的粮食安全和社会稳定具有重要的现实意义.本文以凉山彝族自治州(以下简称为凉山州)为例,构建基于PSR模型的耕地集约利用评价体系对耕地集约利用进行评价,并通过SPSS20.0软件采用主成分分析法探讨耕地集约利用水平变化的驱动因素.结果表明:1)凉山州2005-2014年间的耕地集约利用水平变化较大,2011年后增幅逐渐增强,状态、响应、压力子系统依次对耕地集约利用产生不同程度影响,三大子系统也相互影响.2)耕地集约利用水平变化的驱动因素为:自然条件、工程政策措施、经济水平、人口与投入等因素.研究得出:凉山州耕地集约利用变化与PSR模型的三大子系统存在不同程度的相关性.所选指标较好体现凉山州耕地集约利用水平,耕地集约利用的驱动因素符合凉山州实际,证实PSR模型的普适性的同时体现出凉山州耕地集约利用的独特性与差异性.

重庆市北碚区耕地多功能评价及时空演变分析

从耕地多功能理论出发,构建耕地多功能评价指标体系,采用改进层次法的模糊优选模型对北碚区2009-2016年耕地功能变化进行研究.结果表明:1)在新时期背景下,耕地的内涵不断丰富,从基本的生产功能逐渐衍生到社会功能、生态维持功能及城镇阻隔功能等集为一体的复合功能.2)北碚区耕地多功能时空演变特征差异明显,生产功能、生态维持功能、社会功能及城镇阻隔功能都有不同程度的变化,生产功能和生态维持功能呈现先上升后下降再上升的“N”型趋势,社会功能变化呈现缓和下降趋势,城镇阻隔功能则逐年增强.3)总体上,北碚区耕地综合功能偏弱,可根据该区特点因地制宜地进行发展.

川西平原乡村聚落重构策略——基于宜居性评价

选取四川省广汉市为研究区域,运用GIS空间分析方法,定量识别广汉市宜居性空间特征和规律,并以此为依据对其乡村聚落进行空间重构。结果表明:①广汉市县域宜居性呈现以中心城区为高值中心,各乡镇场镇为副高值中心的圈层状分布态势。其中,生活保障功能呈现由中部向四周成圈层状递减态势,生活改善功能呈现分别以中心城区和各乡镇场镇为高值中心向外递减的两类特征,乡风净化功能呈现以中心城区为高值中心向西北和东南方向扩散递减态势。②广汉市乡村聚落空间格局可优化为城郊融合型、聚集提升型、特色发展型、撤并重组型。③川西平原乡村聚落的整治建设和保护规划仍存在总体规划布局单一化、同质化等缺陷,阻碍了川西平原传统文化延续和新农村人居环境改善。

城市周边永久基本农田布局合理性评价——以重庆市北碚区为例

为科学地探讨城市周边永久基本农田布局的合理性,本文以重庆市北碚区为研究区,从基本农田布局的适宜性和协调性两个方面建立综合评价体系,采用互斥矩阵分类法,将北碚区城市周边永久基本农田布局划分为5类:高度合理区、一般合理区、保留发展区、缩减调出区和不合理区,分别占总面积的19.11%,41.98%,27.36%,9.21%,2.34%,总体布局较为合理,并针对不同类型的区域提出了有效的管理措施.

紫色土旱坡地减磷配施有机肥的磷肥效应及磷素迁移特征

【目的】本文探索了长江上游紫色土旱坡地麦玉轮作系统减少农田磷素流失和有效提高磷肥利用率的最佳施肥模式,以期降低磷对水体富营养化的影响。【方法】2011-2015年,以紫色土旱坡地典型农作冬小麦和夏玉米为材料,在西南大学试验农场进行田间定点试验。试验采用随机区组设计,共设置7个田间小区试验,依次为不施用磷肥(P0)、优化施肥(P)、倍量施磷肥(2P)、优化施肥+秸秆还田(SP)、优化施肥+猪粪有机肥(MP)、优化施肥量磷肥减量20%+猪粪有机肥(MDP)、优化施肥量磷肥减量20%+秸秆还田(SDP)。测定了各处理土壤基础性质,以及0~20、20~40、40~60 cm土层土壤全磷和有效磷含量,调查不同生育期冬小麦和夏玉米各主要生长指标和产量。【结果】冬小麦季和夏玉米季都以2P处理作物磷吸收量为最高,但是磷素表观利用率却不高。小麦季SDP和MDP处理分别比P处理磷肥表观利用率高5.9%和4.2%。玉米季有机无机肥配施处理磷肥表观利用率也显著高于单施化肥处理(P<0.05)。坡上除了P0和P处理全磷含量有所减少外,其他各处理全磷含量都呈增加趋势;坡中、坡下的增长幅度要大于坡上。除了P0处理土壤有效磷含量降低外,其他处理坡上、坡中、坡下土壤中有效磷含量都呈增加趋势。【结论】紫色土旱坡地冬小麦和夏玉米适当减磷配施有机肥可以显著提高作物对磷肥的吸收利用,提高磷肥的利用率,秸秆和猪粪有机肥还田对土壤磷素有活化效果,可以促进磷素在土壤中的迁移,猪粪有机肥促进作用较强。

Tillage Effect on Organic Carbon in a Purple Paddy Soil

The distribution and storage of soil organic carbon (SOC) based on a long-term experiment with various tillage systems were studied in a paddy soil derived from purple soil in Chongqing, China. Organic carbon storage in the 0-20 and 0-40 cm soil layers under different tillage systems were in an order: ridge tillage with rice-rape rotation (RT-rr) > conventional tillage with rice only (CT-r) > ridge tillage with rice only (RT-r) > conventional tillage with rice-rape rotation (CT-rr). The RT-rr system had significantly higher levels of soil organic carbon in the 0-40 cm topsoil, while the proportion of the total remaining organic carbon in the total soil organic carbon in the 0-10 cm layer was greatest in the RT-rr system. This was the reason why the RT-rr system enhanced soil organic carbon storage. These showed that tillage system type was crucial for carbon storage. Carbon levels in soil humus and crop-yield results showed that the RT-rr system enhanced soil fertility and crop productivity. Adoption of this tillage system would be beneficial both for environmental protection and economic development.

Effect of four crop straws on transformation of organic matter during sewage sludge composting

A 45-d laboratory experiment was conducted to compare the effect of four crop straws on the transformations of organic matter （OM） during composting of sewage sludge. The four crop straws included rape straw, wheat straw, maize straw and rice straw. The following parameters such as temperature, OM, humic-like substances （HS）, fulvic-like acids （FA） and humic-like acids （HA） were determined. The degradation of OM and the formation of HS and HA could be described well by the first-order kinetic model, while the FA content fluctuated during composting. The maximal degradation rates of OM in the compost piles added with rape straw, wheat straw, maize straw and rice straw were 34.7, 46.9, 54.7 and 52.8%, respectively, and the final contents of HS were 118, 128, 141 and 134 g kg-1, respectively, while the humification indices were higher in the compost piles added with maize straw and wheat straw than in those with rice straw and rape straw. The results indicate that a higher hemicellulose content and a lower C/N ratio in crop straw can result in a higher rate of OM degradation and higher contents of HS, while a higher content of lignin can lead to a higher polymerization degree of humic substances in compost piles. The final compost piles added with maize straw has the highest contents of OM, total nitrogen and humus substance as well as the highest values of polymerization degree, while compost piles with rape straw have the highest potassium content and those with rice straw have the highest pH values.

Source-sink landscape spatial characteristics and effect on non-point source pollution in a small catchment of the Three Gorge Reservoir Region

The source and sink landscape patterns refer to landscape types or units that can either promote positive evolvement of non-point source(NPS) pollution process, or can prevent/defer the ecological process, respectively. Therefore, the role of a catchment landscape pattern in nutrient losses can be identified based on the spatial arrangement of source and sink landscapes. To reveal the relations between landscape spatial characteristics and NPS pollution in small catchment, a case study was carried out in a Wangjiagou small catchment of the Three Gorges Reservoir Region(TGRR), China. Google earth imagery for 2015 were processed and used to differentiate source and sink landscape types, and six subcatchments were selected as sample regions for monitoring nitrogen and phosphorus nutrients.Relative elevation, slope gradient and relative flow length was used to construct the Lorenz curves of different source and sink landscape types in the catchment, in order to assess the source and sink landscape spatial characteristics. By calculating the location-weighted landscape indices of each subcatchment and total catchment, the landscape spatial load characteristics affecting the NPS pollution was identified, with a further Pearson correlation analysis for location-weighted landscape indices and nitrogen-phosphorus monitoring indicators. The analysis of Lorenz curve has revealed that the obtained distribution trend of Lorenz curve and curve area quantified well the spatial characteristics of source and sink landscape pattern related to the relative elevation, slope gradient and relative flow length in small catchment. Results of Pearson correction analysis indicated that location-weighted landscape index(LWLI) combining of terrain and landscape type factor did better in reflecting the status of nitrogen and phosphorus loss than the indices related to relative elevation, slope gradient and relative flow length.

Assessing the Real Value of Farmland in China

The preservation of farmland is a growing concern in China because the fact that China possesses limited land resources and the world's largest population presents a clear contradiction. Only when the value of farmland is fully appreciated in commercial markets can farmland preservation be effectively achieved. The current study constructed a model to evaluate the economic, social, and ecological value of farmland in China according to the connotation of values. As a case study, the value of Chinese farmland was estimated in 1999, 2002, 2005, 2008, and 2011 using the established model. Although the amount of farmland was greatly reduced from 1999 to 2011 due to constructive occupation, agricultural restructuring, ecological restoration, and disaster destruction, the value of this farmland increased from 220.71×1012 to 736.26×1012 RMB Yuan as a result of the multifunctional nature and scarcity of farmland during the same period. The potential value of farmland in China was huge, but the value in the market was greatly underestimated, especially in regard to its social and ecological value. This study proposes a new method that integrates the discounted value of all future services provided by a natural resource(for the society and individuals) to evaluate the resource assets, provides a scientific foundation for the preservation and operation of farmland assets, and explores ways to increase farmers' property income.

Assessing effects of “source-sink” landscape on non-point source pollution based on cell units of a small agricultural catchment

Ascertaining the relationship between "source-sink" landscape and non-point source(NPS) pollution is crucial for reducing NPS pollution, however, it is not easy to realize this target on cell unit scale. To reveal the relationships between "sourcesink" landscape and NPS pollution based on cell units of a small catchment in the Three Gorges Reservoir Region(TGRR), the runoff and nutrient yields were simulated first by rainfall events on a cell unit scale based on the Annualized AGricultural Non-Point Source Pollution Model(AnnAGNPS). Landscape structure and pattern were quantified with "sourcesink" landscape indicators based on cell units including landscape area indices and locationweighted landscape indices. The results showed that:the study case of small Wangjiagou catchment highlighted a good prediction capability of runoff and nutrient export by the AnnAGNPS model. Throughout the catchment, the spatial distribution trends of four location-weighted landscape indices were similar to the trends of simulated total nitrogen(TN) and total phosphorus(TP), which highlighted the importance of spatial arrangement of "source" and "sink" landscape types in a catchment when estimating pollutant loads. Results by Pearson correlation analysis indicated that the location-weighted landscape index provided a more comprehensive account of multiple factors, and can better reflect NPS-related nutrient loss than other landscape indices applied in single-factor analysis. This study provides new findings for applying the "source-sink" landscape indices based on cell units in small catchments to explain the effect of "source-sink" landscape on nutrient export based on cell unit, and helps improve the understanding of the correlation between "source-sink" landscape and NPS pollution.

乡村振兴背景下灾毁耕地复垦潜力研究——以重庆市北碚区为例

为探究乡村振兴背景下灾毁耕地复垦潜力,推进乡村振兴战略,以重庆市北碚区灾毁农用地为例,野外调查灾毁农用地的数量、分布和类型,总结研究其现状特点,并构建灾毁耕地复垦潜力评价指标体系,对灾毁耕地进行复垦潜力评价研究。结果表明:Ⅰ级潜力类型的灾毁耕地经过相应的复垦措施,能够恢复成优质农田;Ⅱ级潜力类型的灾毁耕地有较好的农业发展基础,可因地制宜发展本地蔬菜种植;Ⅲ级潜力类型的灾毁耕地大多数地表破坏程度较严重,灌溉条件难以保证并且排水设施不健全,可适度发展牧草业;Ⅳ级潜力类型的灾毁耕地改造难度大,限制性因素较多,几乎不能复垦为耕地,可适度发展林业。研究表明,北碚区灾毁耕地复垦虽然受到一定因素限制,但该区降水充足、土壤水分状况较好、有机质含量较丰富,农业生产潜力较大。

LAND USE CHANGE AND ITS SOCIO-ECONOMIC DRIVING FORCES UNDER STRESS OF PROJECT IN OLD RESERVOIR AREA——Case Study of Linshui Reservoir Area of Dahonghe Reservoir in Sichuan Province

The old reservoir areas built in 1950s-1970s left behind many socio-economic problems, because of the administrative backward migration and little migration fund, and all these problems would be tied to land. Based on interviewing with peasant households, combining land use survey and socio-economic statistical index, this paper analyzed land use change and its corresponding driving forces in Linshui reservoir area of Dahonghe Reservoir. Results showed that land use change in the reservoir area was mainly embodied on low-lying land submergence and migration requisition land. The former changed the land use patterns, and the latter mainly reconstructed original land property and made land over-fragmented. Cultivated land per capita was 0.041ha in this area, below the cordon of cultivated land per capita enacted by FAO. Currently, there were still 30.25% of peasant households being short of grain in trimester of one year, and there were 35.27% of people living under the poverty line. The conditions of eco-environment in Linshui Reservoir Area were worse, and healthy and sub-healthy eco-environment accounted for less proportion, composed of green belt around the reservoir area and paddy field ecosystem, and economic forest and orchard ecosystem, respectively. The stress of the reservoir project was macroscopic background to analyze the driving factors of land use change, and real underlying diving factor of the land use change in the area was the change of cultural landscape under the stress of reservoir project. The rapid increase of population was the key factor to induce the change of man-land relationship in the reservoir area, the low level of rural economy was the crucial factor to decide how migrants input for production, and the belief of migrants, influencing the land use patterns in a certain extent, was the inducing factor to keep land use stable. The low-lying submergence and infrastructure construction accompanied the reservoir project were leading factors driving land use change in the area, while changes in land use patterns, after the reservoir being built, were the responses of peasant households’ behaviors to land use change.

Effects of Land Management Practices on Soil Water in Southwestern Mountainous Area, China

The effects of selected land management practices （cross-sloping tillage, ridge culture, organic manure, and straw mulch） on soil water conservation in a southwestern mountainous area, China, were studied during November 2002 to November 2004. The experimental field is divided into three parts based on soil layer depths, 0-60 cm （part Ⅰ）, 0-40 cm （part Ⅱ）, and 0- 20 cm （part Ⅲ）, and they all had the same slope azimuth （SE）, slope （10°）, and slope type （linear）. The experimental plots were subjected to the following treatments： cross-sloping tillage （CST）; cross-sloping tillage with organic manure （CST/ OM）; cross-sloping tillage with straw mulch （CST/SM）; contour ridge culture （CRC）; contour ridge culture with organic manure （CRC/OM）; and contour ridge culture with straw mulch （CRC/SM）, to identify the effects of management practices on soil water. Water contents were determined for soil samples collected, using a 2.2 cm diameter manual probe. Soil water was monitored once every five days from Nov. 20, 2002 to Nov. 20, 2004. The results indicated that, in the study stages, an integration of rainfall, evaporative losses, and crop transcription controlled the basic tendencies of profile （mean） soil water, while land management practices, to a certain extent, only modified its amount, distribution, and routing. Moreover, these modifications also mainly focused on the first 20 cm depth of topsoil layer. When each management practice was compared with control treatment, season changes of profile （mean） soil water were pronounced, while interannual changes among them were not significant. More comparisons indicated that, in the study stages, contour ridge culture had better effects than cross-sloping tillage. And under the same tillage, the combination of organic manure could achieve more than straw mulch. These management practices should be recommended considering the effectiveness of soil and water management techniques in the southwestern mountainous area, China.

AN INSIGHT ON DRIVERS OF LAND USE CHANGE AT REGIONAL SCALE

The studies of driving forces of regional land use change (LUC) are to reveal the real motivation behind the LUC and its interacting mechanism, so as to simulate and predict the process of LUC. Presently, studies rooting from different natural and socio-economic backgrounds and from different scales have deepened the people’s understanding and cognition to driving forces of regional LUC. Biophysical driving forces are relatively stable, and have the cumulating effects. Human driving forces are relatively active, and are main driving forces of short-term regional LUC. Existing regional LUC models can answer the three main problems: which contribution (why), which location (where) and what rate (when). But, regional land use system is defined as the self-organized system, usually affected by the cri- tical value area and sudden change, and controlled by different stages. To reduce the impact of critical threshold and break on land use system, the studies of LUC driving forces will aim at following priority areas: data linkage between remote sensing and no-remote sensing data; underlying driving force identification; driving factor quantification; driving factor scale dependence; and driving process integration simulation.