Effects of "Political Cycle" on Land Use Planning in China

As an explanation to economic cycle, political cycle theory has been widely used, and political factor has been gradual y recognized as an important fac-tor in influencing economy but not simply exteranl factors. However, there is stil a lack of enough research combining political factor and land use. Based on the exist-ing literature, we analyzed the mechnism and performance of howe political cycle with Chinese characteristics influence land use plannning in China, and specific so-lutions were put forward by combining the influences with the airm to promote bet-ter implementation of the planning goals.

Space range estimate for battery-powered vertical take-off and landing aircraft

A novel method for estimating the space range of battery-powered vertical take-off and landing(VTOL) aircraft is presented. The method is based on flight parameter optimization and numerical iteration. Subsystem models including required thrust, required power and battery discharge models are presented. The problem to be optimized is formulated, and then case study simulation is conducted using the established method for quantitative analysis. Simulation results show that the space range of battery-powered VTOL aircraft in a vertical plane is an oblate curve, which appears horizontally long but vertically short, and the peak point is not located on the vertical climb path. The method and results are confirmed by parameter analysis and validations.

Problems and Barriers Impeding the Implementation of MagLev Assisted Aircraft Take-Off and Landing Concept

Nowadays, the success of the new technology development and deployment process depends not only on technical, technological solutions, but also on solving the non-technological problems and crossing the societal and psychological barriers. A large international European projects, GABRIEL1 had developed a maglev assisted aircraft take-off and landing, that was applied to conceptual design of aircraft and required on-board and ground systems, had analysed all impacts (effects of concept deployment on effectiveness, safety, security, noise, emissions) and had demonstrated the safe applicability by concept validation. The applied methodology, used methods and the results of the Gabriel projects had been described and discussed by 55 project deliverables. This paper has a special goal: investigating the problems and barriers of possible implementing of the radically new technology, aircraft MagLev assisted take-off and landing. The study was started by identification and classification of the problems and barriers. After it, the problems were systematically analysed by use of special methodology containing the understanding (description) of the problems, investigation of the possible solutions and discussing their applicability (mainly by use of the Gabriel project results). The paper has three major sections: 1) description of the Gabriel concept and project results, 2) introducing some related thoughts on general aspects of new technology developments, and 3) discussion on the problems and their solutions. The major classes of the problems are the 1) technical, technological problems as developing a radically new solution, landing the undercarriage-less aircraft on the magnetic tracks, 2) stakeholders’ problems as decision makers kicking against supporting the developments of so radically new technologies and 3) society barriers like society worrying on and fear of future passengers on flying by aircraft have not conventional undercarriage systems. The paper will show that these problems have safe and cost-effective solutions.

Impact of Teak （Tectona grandis Linn.） Thinning Out and Peacock-plume [Paraserianthes falcataria L. （1. Nielsen）] Harvesting on Mineral Cycle, Pod Rot Incidence, Changing of Cocoa Yield, and Land Productivity in Indonesia

In 2009, Indonesia was included in a group of the ten biggest countries emitting greenhouse gases, and forest sector contributes 85%. This forest exploitation should be stopped, and by this research the industrial wood species with special planting pattern was used as cocoa shade trees. The experiment was conducted in East Java, Indonesia, altitude 45 m above sea level using four planting patterns, i.e. （A） cocoa-Tectona grandis Linn. 3 m x 6 m, （B） cocoa-T, grandis 6 m x 4.2 m ~ 4.2 m （triangle）, （C） cocoa-Paraserianthesfalcataria L. （I. Nielsen） 3 m ~ 6 m, and （D） cocoa-Leucaena sp. 3 m ~ 6 m （control）. Cocoa was planted in 3 m ~ 3 m distance; between rows of teak and Paraserianthes was planted. Cassia surithensis of 3 m distance in the row, as reserve shade trees. At 6 year old, Paraserianthes was harvested, and at 7 year old, teak trees were thinned out 50% population for A and 66.7% for B treatments. The result showed that cocoa agroforestry by using timber trees in regular planting pattern and accurate spacing did not decrease cocoa yield but improved land productivity. Paraserianthes harvesting produced 0.71 m3 timber and the price was US$38.0-US $40.0 per tree, while teak thinning out produced 0.07 m3 wood per tree and it cost was US$5 per tree. From 108 Paraserianthes trees harvested, 81 cocoa trees were affected, 11.9% were seriously damage, 6.85% were medium damage, and 5.36% were light damage. On the other hand, teak spacing did not cause serious damage on cocoa trees. Biomass of harvested Paraserianthes and teak supplied back to soil 543 g and 250 g per tree respectively for equalities to total urea, SP 36, KC1, Kieserite and Dolomite. Paraserianthes harvest and teak thinning out made microclimate to be warmer, humidity to be lower, so pod rot incidence become lower and pod yield was improved, namely 71% and 27.25% for Paraserianthes plot and teak plot, respectively. Harvesting of Paraserianthes produced benefit/cost plot of 43.63, and teak thinning out of 3.60. The revenue obtained from timber sales easily offset the costs of damage of the cocoa crop. It is concluded that by using accurate planting pattern, cocoa area could produce industrial timber without sacrifying cocoa production and exactly improve land productivity.

The Influence of Climate Change and Variability on Aircraft Take-off and Landing Performance;a Case Study of the Abeid Amani Karume International Airport-Zanzibar

Climate change (CC) and variability have been world widely reported to pose number of risks in aviation industry including accidents, astray, and other operational difficulties. The impact of weather on landing and take-off performances has been several times experienced at Abeid Amani Karume International Airport (AAKIA);however, the influence of climate change and variability to the aircraft performance needs to be assessed. Thus, this study investigated the influence of climate change and variability on aircrafts take-off and landing performances. Specifically, the study investigated;i) the influence of climate change on Take-off Distance Required (TODR) and Maximum Take-off Mass (MTOM) for different types of aircraft;ii) the influence of climate variability to the aircraft landing performance on light, medium and heavy aircraft and lastly, iii) the study investigated the seasonal and annual variability on aircraft landing performance due to climate variability. The datasets used in this study include the eight years (2014-2021), aircraft operational records (diversion and missed approach events) and Aviation Routine Weather Reports (METAR) records which were utilized as the indicators for landing performance, the long-term (1990-2020) annual maximum temperatures (Tmax) which was used to determine the TODR and MTOM. Statistical tools including mean, percentage changes, correlations, regression, and the chi-square test were used for analysis and hypotheses testing. The results revealed that light and medium aircraft categories were significantly most affected on diversion events as compared to the heavy categories;however, for the missed approach events the impact was vice versa. Moreover, the seasonal and annual variability on diversion and missed approach events were significantly different (at p ≤ 0.001). As for the take-off performance, results show that the TODR and MTOM were significantly increasing and decreasing (at p ≤ 0.001), based on increasing air temperatures. Therefore, the study concludes that the changing climate has significantly affected aircraft by increasing the TODR and decreasing the MTOM, while the climate variability has significantly affected landing performance by influencing the diversion and missed approach events. Thus, the study recommends (i) further research works including the feasibility study on runway extension for the safety of future aircraft operations at the AAKIA and (ii) proper maintenance and improvement of the Instrumental Landing Systems (ILS) as an adaptation measures to the landing aircraft during bad weather events.

The effect of the feedback cycle between the soil organic carbon and the soil hydrologic and thermal dynamics

Biogeochemical feedback processes between soil organic carbon (SOC) in high-latitude organic soils and climate change is of great concern for projecting future climate. More accurate models of the SOC stock and its dynamics in organic soil are of increasing importance. As a first step toward creating a soil model that accurately represents SOC dynamics, we have created the Physical and Biogeochemical Soil Dynamics Model (PB-SDM) that couples a land surface model with a SOC dynamics model to simulate the feedback cycle of SOC accumulation and thermal hydrological dynamics of high-latitude soils. The model successfully simulated soil temperatures for observed data from a boreal forest near Fairbanks, and 2000 year simulations indicated that the effect of the feedback cycle of SOC accumulation on soil thickness would result in a significant differences in the amount of SOC.

Daily Activity of Ground Rivers Cycle

This article describes a 24-hour daily activity of ground water cycle. It first proves the existence of vapour up-flux using a custom-made reflective carpet. At high grounds of equatorial altitudes above 1500 meter (less than that for other latitudes), water vapour is thought to be condensed forming fresh water within mountains. An evidence of this was found in several sites in Saudi Arabia, where fresh water down-streams from these mountains and pops-out of mountain sides or up from ground surface. Photos of such streams are presented. Another evidence of these rivers is presented in photos of green coastal regions in Saudi Arabia. The paper urges researchers to make concise annual water-budget studies for major known rivers in the world, to prove that rainfall in the basin of each of them runs severely short to explain the annual river flow quantity.

Responses of biomass to the addition of water, nitrogen and phosphorus in Keerqin sandy grassland, Inner Mongolia, China

The effects of water, nitrogen and phosphorus on productivity of sandy grassland were investigated with a fully factorial experi- ment to find out the main factors limiting natural restoration of grassland productivity in the southeastern Keerqin sandy land. In total, eight treatments were designed as water addition （W）, nitrogen fertilizer addition （N）, phosphorus fertilizer addition （P）, water ＋ nitrogen fertilizer addition （WN）, water ＋ phosphorus fertilizer addition （WP）, nitrogen fertilizer ＋ phosphorus fertilizer addition （NP）, water ＋ nitrogen fertilizer ＋ phosphorus fertilizer addition （WNP） and control （CK）. Each treatment was replicated six times and randomly assigned to 48 plots （4 m × 4 m） that were separated by a 2-m buffer. Results show that restoration of productivity is only limited by nitrogen factor for sandy grassland of Keerqin sandy land and not limited by water and phosphorus. Relative to CK plots, the biomass and the aboveground net primary productivity （ANPP） of all the plots added with nitrogen fertilizer were significantly enhanced （P 〈 0.05） in 2005 growing season. Grass root mass is dominant in underground biomass. The present study possibly underestimates net primary productivity of grassland in northern China, due to limitation of underground biomass measurements.

CO flux of soil respiration in natural recovering karst abandoned farmland in Southwest China

To estimate carbon sequestration potential in the karst area,soil respiration in a natural recovering karst abandoned farmland in Shawan,Puding,Guizhou,southwest China was continuously and automatically monitored for more than two years.The results show that the CO2flux of soil respiration(2.63±1.89 lmol m^-2s-^1)is higher in the karst area than in non-karst areas under similar conditions but that regional value(1.32 lmol m-2s-1)is lower because of larger rock fragment coverage(~50%).A the same time,the temperature sensitivity of soil respiration(Q10)in this study area is significantly higher than that of non-karst areas under similar conditions.Soil respiration has an obvious temporal variation,which is reflected in a significant exponential relationship between soil respiration and soil temperature,but the relationship between soil respiration and soil moisture is very complex.Especially soil respiration has an obvious spatial variation,which is likely affected by different diffusion or water-rock reaction processes.

The integration of nitrogen dynamics into a land surface model. Part 1: model description and site-scale validation

Nitrogen cycling has profound effects on carbon uptake in the terrestrial ecosystem and the response of the biosphere to climate changes.However,nutrient cycling is not taken into account in most land surface models for climate change.In this study,a nitrogen model,based on nitrogen transformation processes and nitrogen fluxes exchange between the atmosphere and terrestrial ecosystem,was incorporated into the Atmosphere–Vegetation Interaction Model(AVIM)to simulate the carbon cycle under nitrogen limitation.This new model,AVIM-CN,was evaluated against site-scale eddy covariance–based measurements of an alpine meadow located at Damxung station from the FLUXNET 2015 dataset.Results showed that the annual mean gross primary production simulated by AVIM-CN(0.7073 gC m^-2 d^-1)was in better agreement with the corresponding flux data(0.5407 gC m^-2 d^-1)than the original AVIM(1.1403 gC m^-2 d^-1)at Damxung station.Similarly,ecosystem respiration was also down-regulated,from 1.7695 gC m^-2 d^-1 to 1.0572 gC m^-2 d^-1,after the nitrogen processes were introduced,and the latter was closer to the observed vales(0.8034 gC m^-2 d^-1).Overall,the new results were more consistent with the daily time series of carbon and energy fluxes of observations compared to the former version without nitrogen dynamics.A model that does not incorporate the limitation effects of nitrogen nutrient availability will probably overestimate carbon fluxes by about 40%.

Phylogeny and evolution of charophytic algae and land plants

Charophytic algae and land plants together make up a monophyletic group, streptophytes, which represents one of the main lineages of multicellular eukaryotes and has contributed greatly to the change of the environment on earth in the Phanerozoic Eon. Significant progress has been made to understand phylogenetic relationships among members of this group by phylogenetic studies of morphological and molecular data over the last twenty-five years. Mesostigma viride is now regarded as among the earliest diverging unicellular organisms in streptophytes. Characeae are the sister group to land plants. Liverworts represent the first diverging lineage of land plants. Hornworts and lycophytes are extant representatives of bryophytes and vascular plants, respectively, when early land plants changed from gametophyte to sporophyte as the dominant generation in the life cycle. Equisetum, Psilotaceae, and ferns constitute the monophyletic group of monilophytes, which are sister to seed plants. Gnetales are related to conifers, not to angiosperms as previously thought. Amborella, Nymphaeales, Hydatellaceae, Illiciales, Trimeniaceae, and Austrobaileya represent the earliest diverging lineages of extant angiosperms. These phylogenetic results, together with recent progress on elucidating genetic and developmental aspects of the plant life cycle, multicellularity, and gravitropism, will facilitate evolutionary developmental studies of these key traits, which will help us to gain mechanistic understanding on how plants adapted to environmental challenges when they colonized the land during one of the major transitions in evolution of life.

Optimization and Control in the Low-carbon Reclamation of Damaged Land in Mine Areas

The process of exploiting mining land is the process of carbon increasing. The goal of top-level design of the mine land reclamation is not clear, which causes the reducing of carbon sink capacity. The mine land reclamation program targeted poorly, which is bad for the control of overall carbon resource and emission. According to the requirements in regional division of encouraged, restricted and prohibited development, in various regions, multiple objectives were set as to maximize economic benefits and not to reduce the carbon sinks level of mine area, using Markov process optimization land-use structure, and based on the land type and characteristics, by floating changing, increasing or decreasing, land exploitation structure was adjusted to meet the need of low-carbon mine land exploitation.

我国沿海滩涂盐碱地改良与综合利用现状与展望

沿海滩涂盐碱地是我国重要的后备土地资源,其生态生产力价值是沿海“蓝碳”的重要组成部分。针对长期以来沿海地区盐碱地综合利用效率低下和经济、生态、社会效益不高等问题,本文通过梳理沿海滩涂开发的历史和现状,总结不同改良方式主导的滩涂盐碱地利用方式的转变,评估滩涂盐碱地的生态生产力价值,分析滩涂盐碱地利用亟需解决的问题,以期为新时期我国沿海滩涂盐碱地的改良与综合利用提供参考。

考虑水土互馈关系的区域水土资源联合优化配置

针对水土资源空间不匹配、水资源总量不足及土地资源利用程度不高等问题,以二元水循环理论为基础,构建考虑水土互馈关系的区域水土资源联合优化配置模型。该模型包括产水模块、水土联合配置模块和土地模拟模块,以GDP最大和基于生态绿当量的区域植被覆盖率(EGE-RVC)最高为目标函数,并提出了一种耦合约束法、逐次逼近法和非线性规划的三层嵌套算法进行求解。以河南省洛阳市为例对模型和方法进行验证,结果表明,洛阳市可利用水量增加了4463万m^(3),GDP提高了12.5%,EGE-RVC增加了2.6%,各用地类型缺水率不同程度下降。研究成果能够为区域水土资源优化配置研究提供新的思路和技术参考。

面向土地立体化管理的二三维地籍数据联动技术研究

城市化进程的加快和人口的爆炸式增长,造成城市土地资源日趋紧缺,人地矛盾逐渐凸显,推动城市由外延式扩张向纵向立体化发展转变,逐渐显现土地立体化利用的形态。本文分析了从规划选址阶段、土地审批阶段、土地供应阶段、不动产登记阶段等建设工程全周期的土地立体化管理所面临的技术挑战,研究并分别提出对应升维的建设思路,满足三维确权的不动产登记要求,为二维平面向三维立体转变提供建设性参考,有效支撑土地立体化管理。

基于陆气耦合模式的降雨径流模拟研究进展

基于陆气耦合模式的降雨径流模拟是变化环境下水文循环过程研究的重要内容之一。围绕陆气耦合降雨径流模拟,分析基于陆气耦合模式的降雨径流模拟框架,对比基础输入资料、天气模式和陆面水文模型各方面的优缺点,回顾基于该框架的发展历程,从集合预报、数据驱动、陆面水文模型与天气模式3个方面介绍了陆气耦合降雨径流模拟技术的发展,提出多尺度转换、双向耦合、不确定性问题及误差修正4个热点关键技术问题,并对未来研究进行展望,以期为推进基于陆气耦合模式的降雨径流模拟研究提供参考。

多情景下中型航空公司碳排放预测研究

在国际国内减碳的大背景下,文章选择国内某中型航空公司作为研究对象,首先利用ICAO碳排放计算法,依据航班进程的两个阶段(LTO和CCD阶段),对2015—2019年的碳排放量状况进行计算分析,再通过设置不减碳情景、基础减碳情景、快速减碳情景和理想减碳情景4个民航发展情景,使用基于Python语言的蒙特卡洛模拟方法,以2021年为基准,对该航空公司2022—2035年内的碳排放进行仿真预测。结果表明:由于中型航空公司的发展需求,4种情况下都无法完成碳排放总量达峰,但其每万架次碳排放量明显降低,表明碳减排措施的有效性。最后从国内外理论研究和现实应用的角度出发,为中型航空公司提出了多条低碳发展建议,以助力我国民航业早日实现碳达峰、碳中和的重要目标。

“一码管地”机制下全覆盖地籍调查体系建立与研究

本文针对当前调查工作缺乏协同、技术标准不一、成果难以共享等问题,研究构建全覆盖地籍调查体系,形成全覆盖地籍调查“一张图”,提出“分级更新,逐级覆盖”的更新模式,探索“一码管地”的全生命周期管理机制。结合研究成果,推动“一码”业务关联、“一码”信息共享、“一码”过程管理,及“一码”申请可办,很大程度提升了工作效率。

变化环境下汉江流域水循环要素响应规律

汉江是长江第一大支流,也是南水北调中线工程和引汉济渭工程的水源地,具有重要的战略地位,科学评估气候变化和人类活动等变化环境下其水循环的响应,对流域水资源的可持续利用和制定适宜的管理政策有着重要意义。本文以汉江流域为研究区域构建了校准后的VIC分布式水文模型,随后基于降尺度后的全球气候模式数据和不同时期土地覆盖遥感数据设置不同情景的模拟,全面分析变化环境下流域水循环要素响应规律,并量化了气候变化和土地利用对径流变化的贡献率。结果表明:不同气候变化情景下,年均降水中上游增加显著,年内降水更加集中于夏秋季节丰水期,各月实际蒸散发整体增加且年内分布更加均匀化;丹江口入库流量和流域出口断面流量在RCP8.5情景呈显著增加趋势,流域年内枯水期流量减少,丰水期流量全年占比最大增加了8.51%,未来月流量更加集中于丰水期,发生干旱和洪涝灾害的概率将会增加。汉江流域的部分稀树草原和有林地在21世纪以来转化为郁闭度更高的落叶阔叶林,土地利用的变化没有使得流量的年际变化趋势有较大改变,但使得流量整体降低了。不同时期气候变化和土地利用对丹江口入库流量变化的贡献率分别为80%~88%和12%~20%,对流域出口断面流量变化的贡献率分别为72%~88%和12%~28%,气候变化是汉江流域径流变化的主要驱动力。

Land use changes and their relations with carbon cycles over the past 300 a in China

Land use and land cover in China have changed greatly during the past 300 a, indicated by the rapid abrupt decrease of forest land area and the rapid increase of cropland area, which can affect terrestrial carbon cycle greatly. The first-hand materials are used to analyze main characteristics for land use and land cover changes in China during the study period. The following conclusions can be drawn from this study. The cropland area in China kept increasing from 60.78×106 hm2 in 1661 to 96.09×106 hm2 in 1998. Correspondingly, the forest land area decreased from 248.13×106 hm2 in 1700 to 109.01×106 hm2 in 1949. Affected by such changes, the terrestrial ecosystem carbon storage decreased in the mean time. Car-bon lost from land use and land cover changes mainly consist of the loss from vegetation biomass and soil. In the past 300 a, about 3.70 PgC was lost from vegetation biomass, and emissions from soil ranged from 0.80 to 5.84 PgC. The moderate evaluation of soil losses was 2.48 PgC. The total loss from vegetation and soil was between 4.50 and 9.54 PgC. The moderate and optimum evaluation was 6.18 PgC. Such carbon losses distribution varied spatially from region to region. Carbon lost more significantly in Northeast China and Southwest China than in other regions, because losses of forest land in these two regions were far greater than in the other regions during the past 300 a. And losses of carbon in the other regions were also definite, such as Inner Mongolia, the western part of South China, the Xinjiang Uygur Autonomous Region, and the Qinghai-Tibet Plateau. But the carbon lost very little from the traditional agricultural regions in China, such as North China and East China. Studies on the relationship between land use and land cover change and carbon cycle in China show that the land use activities, especially those related to agriculture and forest management, began to affect terrestrial carbon storage positively in recent years.