A cyber-enabled spatial decision support system to inventory Mangroves in Mozambique: coupling scientific workflows and cloud computing

Mangroves are an important terrestrial carbon reservoir with numerous ecosystem services. Yet, it is difficult to inventory mangroves because of their low accessibility. A sampling approach that produces accurate assessment while maximizing logistical integrity of inventory operation is often required. Spatial decision support systems (SDSSs) provide support for integrating such a sampling design of fieldwork with operational considerations and evaluation of alternative scenarios. However, this fieldwork design driven by SDSS is often computationally intensive and repetitive. In this study, we develop a cyber-enabled SDSS framework to facilitate the computationally challenging fieldwork design that requires the efficacious selection of base camps and plots for the inventory of mangroves. Our study area is the Zambezi River Delta, Mozambique. Cyber-enabled capabilities, including scientific workflows and cloud computing, are integrated with the SDSS. Scientific workflows enable the automation of data and modeling tasks in the SDSS. Cloud computing offers on-demand computational support for interoperation among stakeholders for collaborative scenario evaluation for the fieldwork design of mangrove inventory. Further, this framework allows for harnessing high-performance computing capabilities for accelerating the fieldwork design. The cyber-enabled framework provides significant merits in terms of effective coordination among science and logistical teams, assurance of meeting inventory objectives, and an objective basis to collectively and efficaciously evaluate alternative scenarios.     

Vertical distribution of soil moisture and surface sandy soil wind erosion for different types of sand dune on the southeastern margin of the Mu Us Sandy Land, China

Soil moisture is a critical state affecting a variety of land surface and subsurface processes. We report investigation results of the factors controlling vertical variation of soil moisture and sand transport rate of three types of dunes on the southeastern margin of the Mu Us Sandy Land. Samples were taken from holes drilled to a depth of 4 m at different topographic sites on the dunes, and were analyzed for soil moisture, grain-size distribution and surface sediment discharge. The results show that: (1) The average soil moisture varies in different types of dunes, with the following sequences ordered from highest to lowest: in the shrubs-covered dunes and the trees-covered dunes the sequence is from inter-dunes lowland to windward slope to leeward slope. The average moisture in the bare-migratory sand dunes is sequenced from inter-dunes lowland to leeward slope to windward slope. (2) Vegetation form and surface coverage affect the range of soil moisture of different types of dunes in the same topographic position. The coefficient of variation of soil moisture for shrubs-covered dunes is higher than that of other types of dune. (3) The effect of shrubs on dune soil moisture is explained in terms of the greater ability of shrubs to trap fine-grained atmospheric dust and hold moisture. (4) The estimated sand transport rates over sand dunes with sparse shrubs are less than those over bare-migratory dunes or sand dunes with sparse trees, indicating that shrubs are more effective in inhibiting wind erosion in the sandy land area.     

Diurnal and inter-monthly variation of land surface heat fluxes over the central Tibetan Plateau area

Summary The energy and water cycle over the Tibetan Plateau play an important role in the Asian monsoon system, which in turn is a major component of both the energy and water cycles of the global climate system. Using field observational data observed from the GAME/Tibet (GEWEX (Global Energy and Water cycle Experiment) Asian Monsoon Experiment on the Tibetan Plateau) and the CAMP/Tibet (CEOP (Coordinated Enhanced Observing Period) Asia-Australia Monsoon Project (CAMP) on the Tibetan Plateau), some results on the local surface energy partitioning (diurnal variation, inter-monthly variation and vertical variation etc.) are presented in this study.The study on the regional surface energy partitioning is of paramount importance over heterogeneous landscape of the Tibetan Plateau and it is also one of the main scientific objectives of the GAME/Tibet and the CAMP/Tibet. Therefore, the regional distributions and their inter-monthly variations of surface heat fluxes (net radiation flux, soil heat flux, sensible heat flux and latent heat flux) are also derived by combining NOAA-14/AVHRR data with field observations. The derived results were validated by using the ground truth, and it shows that the derived regional distributions and their inter-monthly variations of land surface heat fluxes are reasonable by using the method proposed in this study. Further improvement of the method and its applying field were also discussed.     

Desertification Reversion in Relation to Land Use Change and Climate in Naiman County, Inner-Mongolia, China

Analyses of desertified land and land use change in Naiman County of Inner-Mongolia showed that there was a fluctuated in-crease of rain-fed cropland in the period from 1951 to 1960, then decreased until the middle of the 1990＇s, then increased again, while irrigated cropland consistently increased. The woodland and build-up land consistently increased while grassland area de-creased. The area of water body increased from 1975 to 1995 and then decreased while river beach decreased. Wetland change fluctuated with a maximum of 303.53km2 in 1995 and a minimum of 62.08 km2 in 2002. Invasion of cropland into river beach does not only change land coverage on the beach, but also the hydrological process of the river systems and deeply influence wa-ter availability. The correlation between cropland and underground water table is negative and significant. Increase of irrigated cropland is the primary cause of water availability reduction. Water table reduction is negatively correlated to cropland. The total desertified land has decreased since 1975. A rapid increase occurred before 1959, but it is difficult to assess the change of deserti-fication due to lack of data from 1959 to 1975. Changes of different types of desertified lands were different. There is no signifi-cant correlation between land use and different types of desertified land, but there is a significant negative correlation between woodland and total desertified land. The correlation between grassland and total desertified land is positive and significant. There is a significant correlation between different land cover and key factors such as water body and annual precipitation, river beach and runoff, area of shifting dune and annual precipitation, and cropland and underground water table. Desertification reversion in Naiman County is fragile and will be even much more fragile due to population growth, rapid land use and climate change. This will lead to continued invasion of irrigated cropland into more fragile ecosystems and reduction of water availability.     

科尔沁沙地沙质草地与固定沙丘植物群落结构对极端干旱的响应

为了探究沙地植物群落结构特征对极端干旱的响应,通过野外模拟试验开展了极端干旱(生长季减雨60％与干旱60 d)对沙质草地和固定沙丘植物群落丰富度、地上生物量和叶性状等群落结构特征影响的研究.结果表明:(1)生境变化对植物群落地上生物量和叶干物质含量(LDMC)具有显著影响(P＜0.05),草地地上生物量和LDMC显著高...     

EFFECTS OF DCMU ON CHLOROPHYLL FLUORESCENCE RATIO F685/F735 IN MARINE RED,BROWN AND GREEN ALGAE

The chorophyll fluorescence ratio F685/F735 in vivo can be a useful indicator for stress detection inhigher plants and seaweed. DCMU [3 - (3, 4 - dichlorophenyl ) - 1, 1 - dimethylurea] treatment influencesthis ratio. Th effects of DCMU on F685/F735 of marine red, brown and green algae under excitationlight of different wavelengths were investigted. In the brown algae, Laminaria japonica and Undariapinnatifida,DCMU did not increase this ratio under blue light excitation but increased the ratio slightlyunder excitation by green light. For the red algea, Halymenia sinensis, DCMU increased the ratiomarkedly under both blue and green ligh excitation. The percentage increase could reach 50% (undergreen light excitation) and was due to unequal enhancement at the two emission maxima by DCMU. Afraction of chlorophyll which contributed to fluorescence in the 735 nm region was less sensitive toDCMU and was likely from photosystem I of red algae. In the green alga, Ulva pertusa, DCMU causeda slight increase in F685     

FRACTAL ANALYSIS APPLIED TO SPATIAL STRUCTURE OF CHINA＇S VEGETATION

Based on the fractal theory, the spatial structure of China＇s vegetation has been analyzed quantitatively in this paper. Some conclusions are drawn as the following. 1） The relationships between size and frequency of patch area and patch shape index exist objectively for China＇s vegetation. 2） The relationships between perimeter and area exist objectively for China＇s vegetation. 3） The fractal dimension of evergreen needleleaf forests on mountains in subtropical and tropical zones is the largest, while the smallest for deciduous broadleafand evergreen needleleaf mixed forests in temperate zone, reflecting the most complex spatial structure for evergreen needleleaf forests on mountains in subtropical and tropical zones and the simplest for deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone. 4） The fractal dimensions of China＇s vegetation types tend to decrease from thc subtropics to both sides. 5） The stability of spatial structure of deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone is the largest, while the smallest for double-cropping rice, or double-cropping rice and temperate-like grain, and tropical evergreen economic tree plantations and orchards, reflecting the steadiest for deciduous broadleaf and evergreen needleleaf mixed forests in temperate zone and the most unstable for double-cropping rice, or double-cropping rice and temperate-like grain, and tropical evergreen economic tree plantations and orchards in spatial structure. 6） The stability of spatial structure of China＇s vegetation tends to decrease from the temperate zone to both sides, it is significantly pertinent to understand the formation, evolution, dynamics and complexity rule of ecosystem of vegetation.     

Spatiotemporal variations of cultivated land use efficiency in the Yangtze River Economic Belt based on carbon emission constraints

In this study,the carbon emissions(CEs)from cultivated land(CL)were included as an undesirable output in the utilization efficiency of such land.A slack-based model was used to calculate the CL use efficiency(CLUE)for 11 provinces and cities in the Yangtze River Economic Belt(YREB)from 2007 to 2016,and then a kernel density estimation map was drawn to analyze the spatiotemporal variations of CLUE.The Tobit model was also employed to analyze the factors affecting the CLUE.The results show the following.1)In the YREB,the CEs from CL showed a rising and then a slowly decreasing trend.In this paper,we calculate CEs by carbon emission factors and major carbon sources,and the CEs from CL in the YREB totaled 25.2354 million tons in 2007.By 2014,the value had increased gradually to 28.4400 million tons,and by 2016 it had declined to 27.8922 million tons,suggesting that the carbon-emission reduction measures of the government had an impact.2)The CLUE of various provinces and cities in the YREB showed an upward trend in the time dimension,while for the spatial dimension,the kernel density was high in the east and low in the west,and the areas with high kernel density were mainly located in the Yangtze River Delta.3)The per capita gross domestic product,the primary industrial output,and the number of agricultural technicians per 10,000 people had positive effects on the CLUE.The CL area per capita and the electrical power per hectare for agricultural machinery had significant negative impacts on CLUE.In addition,every 1%increase in the number of agricultural technicians increased the CLUE by 0.057%.     

信息化对旅游经济效率的影响及其作用机制研究

基于31个省（市、区）的平衡面板数据,利用DEA模型测度各研究单元的旅游经济效率,并分别考察信息基础设施与信息技术消费对于提升旅游经济效率的作用。研究发现：① 信息化并未从整体上提升中国旅游经济效率,这初步证实了“索洛悖论”和“戈登效应”在旅游部门的存在性;② 信息化对旅游经济效率的促进作用主要得益于信息基础设施的驱动,但信息技术消费对旅游经济效率产生显著的抑制作用,旅游经营主体对信息技术的应用不足是主要原因;③ 中国三大地区的旅游经济效率依然存在东部＞中部＞西部的梯度特征,规模效率在空间上以胡焕庸线为分界线,东侧地区的效率值整体高于西侧,总体表现出与地区经济发展水平一致的空间分布规律,且空间分异不断扩大,西部地区应着重提高信息技术消费对旅游经济效率的促进作用。     

The Relationship between the Magnetic Cloud Boundary Layer and the Substorm Expansion Phase

The magnetic cloud boundary layer (BL) is a disturbance structure that is located between the magnetic cloud and the ambient solar wind. In this study, we statistically analyze the characteristics of the magnetic field B _z component (in GSM coordinates) inside the magnetic cloud boundary layers as well as the relationship between the magnetic cloud boundary layers and the magnetospheric substorms based on 35 typical BLs observed by Wind from 1995 to 2006. It is found that the magnetic field B _z components are more turbulent inside the BLs than those inside the adjacent sheath regions and the magnetic clouds. The substorm onsets are identified by the auroral breakups that are the most reliable substorm indicators by using the Polar UVI image data. The UVI data are available only for 17 BLs. The statistical analysis indicated that 9 of the 17 events triggered the substorms when BLs crossed the magnetosphere and that the southward field in the adjacent sheath region is a necessary condition for these triggering events. In addition, the SF-type BLs, which are named by their features of the B _z components inside the BLs and adjacent sheath regions, can easily trigger the substorms during their passage of the magnetosphere. SF-type BLs are characterized by sustained strong southward magnetic fields persisting for at least 30 minutes in the adjacent sheath regions and at least one change in the polarity of the B _z component inside the BL. In this study, 7 out of 8 such SF-type BL events triggered the substorm expansion phase, suggesting that the SF-type BLs are another important interplanetary disturbance source of substorms.