Changing Vegetation Patterns in Yobe State Nigeria: An Analysis of the Rates of Change, Potential Causes and the Implications for Sustainable Resource Management

The exploitation of natural resources for timber production, fuelwood use and conversion to agricultural land is increasing to such an extent that the sustainable use of many areas of the world is in doubt. This paper examines three decades of freely available Landsat satellite images of the northeastern part of Nigeria using a supervised classification based technique to create maps of vegetation change in Yobe State. The maps are then used to examine the temporal and spatial aspects of changes which have occurred in the context of previous evidence and literature. The results indicate that the vegetation of the area has drastically reduced since the 1970’s. However, as this study shows, the pattern of these changes is complicated and cannot be explained by any single physical or anthropogenic causal factor. Similarly, evidence from ground truthing investigation indicates the importance of fuelwood collection to the deforestation process within the region. This article shows the value of an existing remote sensing and image processing methodology for the assessment of vegetation change in developing countries in relation to the sustainable management of natural resources. The study also discusses the overall change within the study area and discusses several potential causative factors of the observed patterns of change.

Peasant Household Oriented Land Circulation from the Perspective of State Governance

Based on the state governance background of peasant household oriented land circulation,I analyzed characteristics of peasant household oriented land circulation.The characteristics mainly include uncertain definition of rural land circulation,significant off-media feature of land circulation,long-term land circulation contract,farmers' preference of peasant household oriented land circulation,and progressive path of land circulation.The essential feature is the progressive mode of land circulation.Under the existing property right,it realizes the perfect combination of modern production factors and traditional agricultural,and the combination of traditional family safeguarding function and modern social mutual growth spirit.Thus,it shows relative independence and manifests the idea of common prosperity.The opportunity cost of peasant household oriented land circulation is minimal,institutional cost will increase circulation risk,and what's more,the cost for state governance of peasant household oriented land circulation is minimal.It comes to conclusion that building proper and harmonious land circulation mechanism is responsibility of central government and favorable for healthy development of peasant household oriented land circulation.

Experimental Determination of the Landé g-Factors for 5s^2 ^1S and 5s5p ^3P States of the ^87Sr Atom

We present an experimental determination on the Lande g-factors for the 5 s^2 ^1 S0 and 5 s5 p ^3P0 states in ultra-cold atomic systems, which is important for evaluating the Zeeman shift of the clock transition in the ^87Sr optical lattice clock. The Zeeman shift of the 5 s5 p ^3 P0-5 s^2 ^1 S0 forbidden transition is measured with the π-polarized and σ^±-polarized interrogations at different magnetic field strengths. Moreover, in the g-factor measurement with the σ^±-transition spectra, it is unnecessary to calibrate the external magnetic field. By this means, the ground state 5 s^2 ^1 S0 g-factor for the ^87Sr atom is-1.306（52） ×10^-4, which is the first experimental determination to the best of our knowledge, and the result matches very well with the theoretical estimation. The differential g-factorδg between the 5 s5 p^3 P0 state and the 5 s^2 ^1 S0 state of the ^87Sr atoms is measured in the experiment as well,which are-7.67（36） ×10^-5 with π-transition spectra and-7.72（43） X 10^-5 with σ^±-transition spectra, in good agreement with the previous report [Phys. Rev. A 76（2007） 022510]. This work can also be used for determining the differential g-factor of the clock states for the optical clocks based on other atoms.

Timberland Investing and Private Property Rights in the United States of America

Investments in rural land for agriculture, timber, and other natural resource purposes occur frequently and globally. Fundamental principles of liberty and property found in the United States of America’s (“US”) legal system, from its origins to recent US Supreme Court decisions, continue to positively benefit holders of real estate in the Southern US, through a deep-rooted public policy of supporting private property rights and rural economic development. This stable rule of law enhances the long-term adaptability and sustainability of timberland as an asset class. This article is a commentary. It combines legal research methodology with the observations and conclusions of the authors. Its purpose is to demonstrate that the existence of alienable, documentable ownership, and related property rights create inherent stability and security. These principles form the basis of a culture that is defined by the rule of law and is “open for business.” This business mindset is particularly prevalent in the Southern US.

Impact of Land Reclamation on the Vegetal Cover of Bayelsa State, Nigeria

The study examined the impact of land reclamation on vegetal cover in Bayelsa State.For the purpose of this study,both quantitative and quali­tative research methods were adopted.Field observations,questionnaire survey and landsat imagery of land cover changes in the year 1986 and 2018 were generated from the global ground cover facility stream.The time series study design and supervised classification of the image processing were adopted to determine the impact of land reclamation on vegetal cover of the study area.It was therefore recommended that recovery of land will make strategic urban planning initiatives sustainable in overcrowded areas and institutions should also put in place laws and strategies to regulate rec­lamation activities across the region and also geo-spatial skills should be put in place to help quantify the dynamics,trends and rate of reclamation induced land cover change in the environment.

Comparison and Analysis of Agricultural and Forest Land Changes in Typical Agricultural Regions of Northern Mid-latitudes

The northeastern China, the United States, and the western Europe are important agricultural regions both on the global and regional scales. The westem Europe has a longer history of agricultural land development than the eastem United States. These two regions have changed from the deforestation and reclamation phase in the past to the current land abandonment and reforestation phase. Compared with the two regions, large-scale land exploitation has only been practiced in the northeastern China during the last century. After a short high-intensity deforestation and reclamation period, agricultural and forest lands are basically in a dynamic steady state. By comparing domestic and international agro-forestry development and considering the ecological environment and socio-economic bene- fits that can be derived from agro-forestry, this paper suggests that large area of reforestation would be inevitable in future though per- sistent and large agricultural demand in coming decades even more. And local reforestation at slope farmland with ecological vulner- ability should be imperative at present to avoid severer damage. At the same time, from the perspective of Land Change Science, the results demonstrate that the research on land use change in the agro-forestry ecotone is typical and critical, particularly those dealing with the analysis of spatial and temporal characteristics and the simulation of climate, hydrology, and other environmental effects.

Driving Factors for Forest Fire Occurrence in Durango State of Mexico:A Geospatial Perspective

Forest fire is one of the major causes of forest loss and therefore one of the main constraints for sustainable forest management worldwide.Identifying the driving factors and understanding the contribution of each factor are essential for the management of forest fire occurrence.The objective of this study is to identify variables that are spatially related to the occurrence and incidence of the forest fire in the State of Durango,Mexico.For this purpose,data from forest fire records for a five-year period were analyzed.The spatial correlations between forest fire occurrence and intensity of land use,susceptibility of vegetation,temperature,precipitation and slope were tested by Geographically Weighted Regression(GWR) method,under an Ordinary Least Square estimator.Results show that the spatial pattern of the forest fire in the study area is closely correlated with the intensity of land use,and land use change is one of the main explanatory variables.In addition,vegetation type and precipitation are also the main driving factors.The fitting model indicates obvious link between the variables.Forest fire was found to be the consequence of a particular combination of the environmental factors,and when these factors coexist with human activities,there is high probability of forest fire occurrence.Mandatory regulation of human activities is a key strategy for forest fire prevention.

Trajectory Tracking of Vertical Take-off and Landing Unmanned Aerial Vehicles Based on Disturbance Rejection Control

We investigate the trajectory tracking problem of vertical take-off and landing (VTOL) unmanned aerial vehicles (UAV), and propose a practical disturbance rejection control strategy. Firstly, the nonlinear error model is established completely by the modified Rodrigues parameters, while considering dynamics of the servo actuators. Then, a hierarchical control scheme is applied to design the translational and rotational controllers based on the time-scale property of each subsystem, respectively. And the linear extended state observer and auxiliary observer are used to deal with the uncertainties and saturation. At last, global stability of the closed-loop system is analyzed based on the singular perturbation theory. Simulation results show the effectiveness of the proposed control strategy. © 2014 Chinese Association of Automation.

Trophic Status of Shallow Lakes of La Pampa (Argentina) and Its Relation with the Land Use in the Basin and Nutrient Internal Load

Phosphorus and nitrogen are essential nutrients for living organisms. Their concentration in the water of an aquatic ecosystem is one of the factors responsible for the trophic status of the lake and is related to the soils of the region and to the human activities carried out in their basins. These nutrients are also found in the bottom sediments, where they can either be retained or re-enter the water column. Since the information about the concentrations of nutrients in the water of some lakes of La Pampa (Argentina) is fragmentary, the aim of this study is to describe the trophic status of some shallow lakes of the semiarid center of Argentina and analyze its relation with the human activities in their basins, the concentrations of nutrients and organic matter and particle size distribution of sediments. To this end, we studied ten shallow lakes subjected to different anthropogenic influences (agriculture, agriculture and livestock and impacted by cities). All were hypertrophic and the concentrations of total phosphorus and total nitrogen were among the highest reported globally. Since some lakes had no fish, cladoceran grazing (top-down effect) led them have reduced concentrations of phytoplankton chlorophyll-a and high water transparency. This relativizes the use of these parameters to determine the trophic status. The sediments of seven of the studied lakes were predominated by fine sands, whereas three were predominated by silts. Nutrient and organic matter content were high, with higher concentrations in lakes with prevalence of fine particles. The reduced adsorption capacity of sediments, the resuspension by wind, the anthropogenic input and the accumulation favored by the arheic character of the basins would explain the high concentrations of nutrients in the water of these Pampean environments.

Comprehensive Evaluation of Unsafe State of Arable Land Resources:A Case Study of Chengdu City

We establish the unsafe state indicator system reflecting the unsafe state of arable land within the scope of the city. Using analytic hierarchy process and entropy method,we determine the weight of indicator; using linear weighted method,we conduct comprehensive evaluation of unsafe operation of arable land resource system in Chengdu City during the period 1999-2010. Through the unsafe state analysis,we draw the following conclusion: the share of arable land area in total land area,effective irrigation area,the area of low-yielding field,application rate of chemical fertilizer per unit area of arable land,and application rate of pesticide per unit area of arable land,are the key factors for easing the unsafe state in the short term. Finally we put forth the following recommendations: strengthening profound understanding of the seriousness of unsafe state of arable land; strengthening the basic arable land protection; continuing to tap the quality enhancement potential of arable land; consistently implementing the guideline and policy of " Combination of Use and Maintenance" .

Investigation of Climate and Land Use Policy Change Impacts on Food Security in Eastern Sudan, Gadarif State

The aims of this research were to investigate the impacts of climate variations on land use policies, food security and vegetation cover in Gadarif State (eastern Sudan) during 1961 to 2013. Analysis of precipitation and temperature time series revealed that the annual precipitation was decreasing while the temperature was increased in the study area. Precipitation was decreasing at a rate of −50.3 mm/10a, while the temperature was increasing at a rate of 0.02°C/10a. The result of both SPEI and SPI showed that the Gadarif State has been changed to a high frequency of drought during 1961-2013. Sorghum yield showed a significant positive relationship with precipitation during July and October (CC = 0.364 and 0.321, respectively), moreover, a significant positive relationship between Sesame yield and precipitation was observed during July (CC = 0.335). A significant negative relationship between Sorghum yield and mean temperature was observed during the rainy season (July to October) with CC = −0.278. The yield productivity of Sorghum and Sesame had decreased significantly (from more than 800 kg/ha in the 1960s to less than 200 kg/ha in 2000s for Sorghum, while 500 kg/ha in 1960s to 100 kg/ha in 2000s for Sesame). The Mechanized Rain-fed Agriculture (MRA) area of Sorghum and Sesame in the Gadarif State had been increased from 1,058,241 ha to 2,799,655 ha during 1961 to 2013. Thus, we ultimately suggest that in the Gadarif State, policy makers must strive for an increase in yield per unit area by using sufficient fertilizers along with the gradual increment in tendencies of grain production through expansion of the cultivated area.

The Spatial Organization Dialectics of the City ofJeriquara/SP, Brazil

The present paper aims to analyze and discuss the morphological formation of the city of Jeriquara, located in the countryside of the state of S o Paulo, Brazil. The importance of this study lays on its primary documentation, that is, the long lease deeds (cartas de aforamento). These deeds are part of the medieval legal system implemented in Brazil by the Portuguese. The long lease, perpetual lease or tenure, or fiefdom (in the Brazilian legal system, aforamento, enfiteuse or emprazamento) are synonyms of this legal institute that divides urban land between two holders: the Catholic Church and the civil individual. This article employs as research method the interpretive and descriptive analysis of such deeds, based on theoretical bibliography on the referred legal institute, civil law and the Brazilian forms of urbanization. Following the presentation of a case study there will be the discussion of the juridical issues at the core of the national colonization implemented by the Portuguese and which are at the genesis of several of the current conflicts. This study shows that the urban territory of many cities is still ruled by these past contexts and, without understanding them, we will not be able to efficiently interfere with city spaces.

An assessment of “fishing down marine food webs” in coastal states during 1950–2010

Mean trophic level of fishery landings（MTL） is one of the most widely used biodiversity indicators to assess the impacts of fishing. Based on the landing data compiled by Food and Agriculture Organization combined with trophic information of relevant species in Fish Base, we evaluated the status of marine fisheries from 1950 to 2010 for different coastal states in Pacific, Atlantic and Indian Oceans. We found that the phenomenon of ＂fishing down marine food webs＂ occurred in 43 states. Specifically, 27 states belonged to ＂fishing-through＂ pattern, and 16 states resulted from ＂fishing-down＂ scenario. The sign of recovery in MTL was common in the Pacific, Atlantic and Indian Oceans（occurred in 20 states）, but was generally accompanied by significantly decreased catches of traditional low trophic level species. In particular, 11 states showed significant declining catches of lower trophic levels. The MTL-based assessment of ＂fishing down marine food webs＂ needs to be interpreted cautiously.

Land,Markets and the Modernization of Rural Society:A Comparison of the Views of Fei Xiaotong and R.H.Tawney

Fei Xiaotong’s(Fei Hsiao-tung)works on rural economies and societies written in the 1940s were deeply affected by British economic historian R.H.Tawney.Through comparison,this article reveals at least two connections between their works.First,Tawney’s analysis of the transition from agricultural modernization to industrial modernization in Britain serves as a reference for Fei’s works on the economic transformation of the Yangtze Valley in Jiangsu and Lucun village in Yunnan.Second,Tawney’s“theory of gentry”also serves as the underlying view for Fei’s theory on the functions of the Chinese gentry.However,Fei does not simply follow Tawney’s steps.Instead,he offers unique insights into the issues of horticulture transformation and gentry types in China.Furthermore,in Fei’s social theory and practice,the role of“state”was considered to be less positive.The interrelations of the community,market,intellectuals and the state construct Fei’s modernization scheme of China.His idea about how China,a slower participant in the world system,can maintain economic autonomy was still valuable today.

Impact of Urbanization on Agricultural Land in Makurdi Local Government Area of Benue State,Nigeria

This study assessed the impact of urbanization on agricultural land in Makurdi local government area of Benue State.The data collected were population figures and land use for three Epoch(1997,2007 and 2017).The satellite images were sourced from the National Center for Remote Sensing and Geographic Information System,Jos.In the analysis,cross change detection analysis and overlay analysis using ArcGIS 9.0 was performed to detect where land-use change has occurred and which type of land use agricultural land has transformed too.The GIS analysis revealed that there is an increase in settlement and a decrease in Agricultural land from 1997–2017.It also revealed that 99.51ha of agricultural land use has been converted to settlement between 1997 and 2017.The results reveal that urbanization has significant effects on Agricultural Land in the study area and these effects include;decreasing agricultural land,decreasing agricultural activities and decrease in farm size.If the growth in the population of Makurdi LGA continues unchecked,agricultural land will be significantly depleted in the future.The study recommended that there should be effective law and policy to control population growth sustainably to minimize the negative impact of urbanization in the study area.Also,urban agriculture should be encouraged to sustain the food supply in urban areas.

Dynamic Spatial Evolution of Market-oriented Supply Level of State-owned Land

The purpose of this study is to analyze the characteristics of the spatial distribution and change trend of the marketing level of stateowned land supply so as to provide policy recommendations. Method of spatial autocorrelation analysis is employed. The results indicate that the spatial layout of the land supply marketing level is generally dispersed,but it does assemble in some specific area. The correlation between the marketing level of state-owned land supply and the economic development is not statistically significant. But their relations fluctuate obviously. The overall marketing level of state-owned land supply is increasing and spatially concentrated. The expansion rate of marketing has decreased first and then increased and stabilized now. The high-value cluster center of marketing level of state-owned land supply exists all over the country; however the existence probability of the cluster is bigger in undeveloped areas. It is concluded that spatial autocorrelation analysis is a good method to quantitatively analyze the spatial variation of marketing level of state-owned land supply in China. To grasp the spatial and temporal variations of the marketing level of state-owned land supply is also good to enhance running of the state-owned land market.

Evaluation of Mountain Land Ecological Security Based on DPSIR Model and Entropy Weight Method

In the Report of the 19 th National Congress of the Communist Party of China,it stated that we must put the ecological safety and green development in the first place.To achieve rural revitalization,ecological livability is the most important factor.Taking Luquan Yi and Miao Autonomous County(national level poor county)in Jinsha River valley of Yunnan Province as an example,using DPSIR(drivers,pressures,states,impacts,responses)model,this paper established an evaluation indicator system.Besides,using the entropy method,it determined the indicator weight.In addition,it evaluated the land ecological security of Luquan County since the implementation of targeted poverty alleviation policy(2013-2017)using multi-factor comprehensive evaluation method.This study shows that Luquan County has improved its ecological security in the past five years.The ecological status has gone through four stages,from sensitive state to severe state to critical safety to excellent ecology,and the value of the comprehensive index of land ecological security shows a rising trend.Through analyzing the ecological security value of each criterion hierarchy,it obtained the main factors affecting the ecological security of Luquan County.On this basis,it came up with feasible measures and recommendations for studying the ecological security of land in the region,so as to guide the rational use of land and sustainable economic development,provide a reference for the implementation of rural revitalization strategies,and promote the construction of regional ecological civilization.

Geographical Information System-Based Assessment of Ecological Security in Changbai Mountain Region

Ecological security defined as the creation of a condition where the physical surroundings of a community provide for the needs of its inhabitants without diminishing its natural stock,which is important for regional security and social stability.In recent years,land use patterns in the Changbai Mountain region have changed significantly with intensive human activities,and consequently led to increasing problems in regional ecological security.Based on the Pressure-State-Impact-Response(PSIR) model and the mathematical method of catastrophe progression supported by geographical information system(GIS),the ecological security situation of the study area under land use and cover change(LUCC) was evaluated.The results indicated that the ecological security in Changbai Mountain region varied nonlinearly,which got better from 1990 to 2000 but became worse from 2000 to 2007,the ecological security levels in Changbai Mountain region were mainly medium and medium to low during the past 17 years,with higher values of Ecological Security Index(ESI) in the central region and lower values in the east and west,the ecological security situation was more serious in the settlements and river valleys,where the LUCC was most remarkable.

Forecast of Dynamic Change of Land Use Based on Cellular Automata

Land use change is a very complex process of evolution.On the basis of the principle of cellular automata,this article presents a kind of method that we can first mine state transition rule from historical map data,and then conduct forecast by virtue of Monte-Carlo method,achieving spatial dynamic forecast from map to map.We interpret TM remote sensing image in Ji'nan City in 2004 and 2006 to get present land use map for empirical research,and forecast land use map in 2012 and 2016,respectively.Studies show that this method of using spatial data to mine state transition rule,has advantages of simpleness,accuracy,strong real-time characteristic etc.in the simulation of dynamic change of land use,the results of which are roughly in line with the actual results,therefore,it can provide reference for land use planning.

破解海岸带环境司法困境:基于陆海统筹原则

我国海岸带环境案件存在管辖权冲突、法律适用有争议、原告资格不明确、诉讼性质认定有争鸣、诉讼程序衔接未确定、司法执行机制不完善等环环相扣的问题,造成海岸带环境司法困境。究其根源,主要在于陆海“二分法”的分类思维影响较大,其与陆海统筹合为表里的内涵尚未得到全面、深入的理解。为破解海岸带环境司法困境,既要重视海岸带环境案件的特殊性,将其确立为类型化案件并由海事法院专门管辖,又要贯彻陆海统筹原则,实现司法规则内在融贯、法治环节协调一致。