永久基本农田保护的实施评价与政策启示--以我国东部地区XX地级市为例

基于“三调”数据分析我国东部地区XX地级市永久基本农田保护变化,从流失去向与流失空间分布两个方面深入分析了其真实境况,从而提出切实的保护政策建议。结果表明:①流失去向包括农业结构调整、建设占用和自然损毁,其中农业结构调整占用为主导。②城市圈内比圈外占用普遍严重,尤其是城乡建设占用了大量基本农田。③永久基本农田存在空间错配现象,未做到“应划尽划”。据此,提出构建农户补偿机制、县级保护任务量与存量建设指标相挂钩、协同基本农田—生态—城镇空间布局,实施圈内基本农田动态监测机制等系列措施,以提升保护效果。     

ArcGIS技术在县域退耕还林决策分析中的运用——以江西省于都县为例

运用ArcGIS技术,结合江西省于都县耕地的数量与空间分布状况、坡度、人口等因素对该县退耕还林工作进行辅助决策分析,深入分析到乡镇以确定该县退耕还林区和退耕还林的实施措施,为于都县的退耕还林决策工作提供科学参考。     

Residential Preferences for River Network Improvement: An Exploration of Choice Experiments in Zhujiajiao,Shanghai, China

River networks have both ecological and social benefits for urban development. However, river networks have suffered extensive destruction as a result of urbanization and industrialization, especially in China. River restoration is a growth business but suffers poor efficiency due to a lack of social understanding. Assessing the benefits of river system restoration and recognizing public preferences are critical for effective river ecosystem restoration and sustainable river management. This study used a choice experiment with a multinomial logit model and a random parameter logit model to assess respondents’ cognitive preferences regarding attributes of river networks, and their possible sources of heterogeneity. Results showed that riverfront condition was the attribute most preferred by respondents, while stream morphology was the least preferred. Results also illustrated that the current status of each of three river network attributes was not desirable, and respondents would prefer a river network with a “branch pattern,” that is “limpid with no odor,” and “accessible with vegetation.” Estimated willingness to pay was mainly affected by household monthly income, residential location, and whether respondents had household members engaged in a water protection career. The assessment results can provide guidance and a reference for managers, sponsors, and researchers.     

RIPARIAN ZONE CLASSIFICATION FOR MANAGEMENT OF STREAM WATER QUALITY AND ECOSYSTEM HEALTH1

ABSTRACT: Riparian zones perform a variety of biophysical functions that can be managed to reduce the effects of land use on instream habitat and water quality. However, the functions and human uses of riparian zones vary with biophysical factors such as landform, vegetation, and position along the stream continuum. These variations mean that “one size fits all” approaches to riparian management can be ineffective for reducing land use impacts. Thus riparian management planning at the watershed scale requires a framework that can consider spatial differences in riparian functions and human uses We describe a pilot riparian zone classification developed to provide such a framework for riparian management in two diverse river systems in the Waikato region of New Zealand. Ten classes of riparian zones were identified that differed sufficiently in their biophysical features to require different management. Generic “first steps” and “best practical” riparian management recommendations and associated costs were developed for each riparian class. The classification aims to not only improve our understanding of the effectiveness of riparian zone management as a watershed management tool among water managers and land owners, but to also provide a basis for deciding on management actions.     

Road effects on abundance and fitness of Galápagos lava lizards (Microlophus albemarlensis)

Vehicle collisions with wildlife have the potential to negatively impact species everywhere roads divide natural habitats; this is especially true in areas where roads are a recent addition to the landscape (e.g., in the last decade) and/or where expansion of a road network is underway. This study addresses the impact of traffic fatalities on lava lizards, Microlophus albemarlensis, on the island of Santa Cruz, Galápagos. The main road bisecting the island north to south was added to the island beginning in 1974 but not fully paved until 2000. We assessed impacts occurring due to traffic and vehicle speeds on the island. This study adds impacts to lizard populations to those conducted on birds on Santa Cruz, providing a means to create multi-species recommendations. To quantify impacts to lizard populations, we assessed lizards on randomly chosen transects perpendicular to the road. We used Poisson regression to analyze those data and found a 30% increase in lizard abundance per 100 m distance from the road across vegetation zones. We compared incidence of prior tail loss of road-killed lizards and live animals to comment on additional energetic costs of occupying near-road territories. Tail condition could not be assessed in some road-killed lizards; among those that we could assess, 29% showed evidence of prior tail loss. That rate declined to apparent baseline conditions of only 1% beyond 200 m from the road. By traveling the length of the 40-km road, we identified hot spots for fatalities of both lizards and birds to provide necessary information for developing management and remediation strategies. We offer guidance on Best Management Practices, such as testing overpasses, fencing and underpasses, which might reduce vehicle impacts to lizards from drivers on the current road. This information is essential because of a planned increase in the Santa Cruz road network in areas where lava lizards are most abundant.     

区域绿地概念形成脉络与深层发展研究

《城市绿地分类标准》(CJJ/T 85-2017)中区域绿地概念是构建区域生态安全格局的重要"生态源"与"锚固点",目前被视为提升人类福祉的重要环节。总结国内外相关研究进展,本文从宏观、中观、微观三个尺度,梳理国内外具有区域绿地类型特征的生态用地起源与形成脉络。根据我国区域绿地所处的发展阶段,分析今后我国区域绿地的发展方向,从三个方面探讨区域绿地深层发展方向:①依据区域绿地类型划分保护的优先级,建立完善的保护政策;②深化研究区域绿地空间形态与功能的耦合协调机制,促进区域绿地最优效能发挥;③统筹多类型的区域绿地,维系区域一体化可持续发展。     

Scientist and Policy-Maker Response Types and Times in Suburban Watersheds

Differences between scientist and policy-maker response types and times, or the “how” and “when” of action, constrain effective water resource management in suburbanizing watersheds. Policy-makers are often rushed to find a single policy that can be applied across an entire, homogeneous, geopolitical region, whereas scientists undertake multiyear research projects to appreciate the complex interactions occurring within heterogeneous catchments. As a result, watershed management is often practiced with science and policy out of synch. Meanwhile, development pressures in suburban watersheds create changes in the social and physical fabric and pose a moving target for science and policy. Recent and anticipated advances in the scientific understanding of urbanized catchment hydrology and pollutant transport suggest that management should become increasingly sensitive to spatial heterogeneities in watershed features, such as soil types, terrain slopes, and seasonal watertable profiles. Toward this end, policy-makers should encourage funding scientific research that characterizes the impacts of these watershed heterogeneities within a geopolitical zoning and development framework.     

Selecting Sites for Converting Farmlands to Wetlands in the Sanjiang Plain, Northeast China, Based on Remote Sensing and GIS

Wetlands in the Sanjiang Plain are rich in biodiversity and natural resources in the northeast of China. However, this wetland area has decreased in size and deteriorated in quality owing to expanded agricultural activities since the 1950s. Converting farmlands to wetlands is necessary to improve these conditions. Using Remote Sensing (RS) and Geographic Information Systems (GIS) technologies, we derived farmland productivity data and hydrology data for the Sanjiang Plain. The farmland productivity data were derived from land use and net primary productivity (NPP) data of the MODIS products. We obtained three productivity farmland classes (low, medium, and high) through the NPP anomaly percentage method. We were only concerned with the low-productivity farmland. Hydrology data were modeled with a wetness index, which was derived from Digital Elevation Model (DEM) data. Based on these two data layers, we identified and prioritized sites for the conversion of farmlands to wetlands. The areas with low farmland productivity and medium or high wetness values have potential to support the conversion of farmlands to wetlands. Potential sites were prioritized in terms of patch size and proximity to natural wetlands and water bodies. We obtained three priority classes, among which the high-priority class would be used as the areas for the recent conversion of farmlands to wetlands. The area of this class was 75,888 ha and accounted for 1.3% of the total farmland area.     

如何完善河长制——基于与流域综合管理比较的视角

当前,河长制已成为我国进行河湖管护的综合协调平台,但其面临一系列问题,制约了我国河湖管护效果的进一步提升。世界主要国家的跨部门、跨利益相关方河湖管理协调政策主要是流域综合管理。河长制与流域综合管理都是针对所面临的河湖管理问题,经过长期的演变,逐渐形成的跨区域、跨利益相关方的协调政策,这都是符合所在国家实际情况的。基于公共政策学的基本原理,本文构建了以"政策目标—政策执行者—政策工具"为导向的三维河湖管护协调政策比较框架。通过此框架,分析了河长制存在的主要问题,以及河长制与流域综合管理的主要差异。针对河长制存在的主要问题,基于比较结果提出了相关对策,主要包括:科学设定政策目标,推进多元共治的河湖管护模式,创新运用市场化和信息化政策工具。     

Modeling Change-Pattern-Value Dynamics on Land Use: An Integrated GIS and Artificial Neural Networks Approach

The use of spatial methods to detect and characterize changes in land use has been attracting increasing attention from researchers. The objectives of this article were to formulate the dynamics of land use on the temporal and spatial dimensions from the perspectives of the Change-Pattern-Value (CPV) and driving mechanism, based on multitemporal remote sensing data and socioeconomic data. The Artificial Neural Networks were used to identify the factors driving changes in land use. The Pearl River Delta Region of southeast China, which was experiencing rapid economic growth and widespread land conversion, has been selected as the study region. The results show that from 1985 to 2000 in the study region (1) the most prominent characteristics of change in land use were the expansion of the urban land at the expense of farmland, forests, and grasslands, (2) the land-use pattern was being optimized during this period, (3) in an analysis of value, built-up land can yield a return of more than 30 times that of farmland, water area, and forests lands, and (4) rapid economic development, growth in population, and the development of an infrastructure were major driving factors behind ecological land loss and the nonecological land expansion.     

Characterizing the Extent of Spatially Integrated Floodplain and Wetland Systems in the White River,Indiana, USA

Floodplain delineation may inform protection of wetland systems under local, state, or federal laws. Nationally available Federal Emergency Management Agency Flood Insurance Rate Maps (FIRMs, “100‐year floodplain” maps) focus on urban areas and higher‐order river systems, limiting utility at large scales. Few other national‐scale floodplain data are available. We acquired FIRMs for a large watershed and compared FIRMs to floodplain and integrated wetland area mapping methods based on (1) geospatial distance, (2) geomorphic setting, and (3) soil characteristics. We used observed flooding events (OFEs) with recurrence intervals of 25‐50 to >100 years to assess floodplain estimate accuracy. FIRMs accurately reflected floodplain areas based on OFEs and covered 32% of river length, whereas soil‐based mapping was not as accurate as FIRMs but characterized floodplain areas over approximately 65% of stream length. Geomorphic approaches included more areas than indicated by OFE, whereas geospatial approaches tended to cover less area. Overall, soil‐based methods have the highest utility in determining floodplains and their integrated wetland areas at large scales due to the use of nationally available data and flexibility for regional application. These findings will improve floodplain and integrated wetland system extent assessment for better management at local, state, and national scales.     

Impacts of Transportation Routes on Landscape Diversity: A Comparison of Different Route Types and Their Combined Effects

A comparison of different transportation route types and their combined effects on landscape diversity was conducted within Tiaoxi watershed (China) between 1994 and 2005. Buffer analysis and Mann–Kendall’s test were used to quantify the relationships between distance from transportation routes (railway, highway, national, and provincial road) and a family of landscape diversity parameters (Simpson’s diversity index, Simpson’s evenness index, Shannon’s diversity index, and Shannon’s evenness index). One-way ANOVA was further applied to compare influences from different route types and their combined effects. Five other landscape metrics (patch density, edge density, area-weighted mean shape index, connectance index, and Euclidean nearest neighbor distance) were also calculated to analyze the associations between landscape diversity and landscape pattern characteristics. Results showed that transportation routes exerted significant impacts on landscape diversity. Impact from railway was comparable to that from highway and national road but was more significant than that from provincial road. The spatial influential range of railway and national road was wider than that of highway and provincial road. Combined effects of routes were nonlinear, and impacts from different route types were more complex than those from the same type. The four landscape diversity metrics were comparably effective at the buffer zone scale. In addition, landscape diversity can be alternatively used to indicate fragmentation, connectivity, and isolation at route buffer scale. This study demonstrates an applicable approach to quantitatively characterize the impacts from transportation routes on landscape patterns and has potential to facilitate route network planning.     

Integrated emergy,energy and economic evaluation of rice and vegetable production systems in alluvial paddy fields: Implications for agricultural policy in China

China is the largest rice producing and consuming country in the world, but rice production has given way to the production of vegetables during the past twenty years. The government has been trying to stop this land-use conversion and increase the area in rice-vegetable rotation. Important questions that must be answered to determine what strategy is best for society are, “What is the reason behind this conversion?”; “Which system is more productive and which is more sustainable?”; and “How can economic policy be used to adjust the pattern of farmland use to attain sustainable development?” To answer these questions, a combined evaluation of these agricultural production systems was done using emergy, energy and economic methods. An economic analysis clearly showed that the reason for this conversion was simply that the economic output/input ratio and the benefit density of the vegetable production system were greater than that of rice. However, both energy and emergy evaluations showed that long-term rice was the best choice for sustainable development, followed by rotation systems. The current price of rice is lower than the em-value of rice produced from the long-term rice system, but higher than that of rice produced from the rotation system. Scenario analysis showed that if the government increases the price of rice to the em-value of rice produced from the long-term rice system, US$0.4/kg, and takes the value of soil organic matter into account, the economic output/input ratios of both the rice and rotation systems will be higher than that of the vegetable system. The three methods, energy, emergy and economics, are different but complementary, each revealing a different aspect of the same system. Their combined use shows not only the reasons behind a system’s current state or condition, but also the way to adjust these systems to move toward more sustainable states.     

Effects of Land‐Use and Land‐Cover Change on Evapotranspiration and Water Yield in China During 1900‐20001

Abstract: China has experienced a rapid land‐use/cover change (LUCC) during the 20th Century, and this process is expected to continue in the future. How LUCC has affected water resources across China, however, remains uncertain due to the complexity of LUCC‐water interactions. In this study, we used an integrated Dynamic Land Ecosystem Model (DLEM) in conjunction with spatial data of LUCC to estimate the LUCC effects on the magnitude, spatial and temporal variations of evapotranspiration (ET), runoff, and water yield across China. Through comparisons of DLEM results with other model simulations, field observations, and river discharge data, we found that DLEM model can adequately catch the spatial and seasonal patterns of hydrological processes. Our simulation results demonstrate that LUCC led to substantial changes in ET, runoff, and water yield in most of the China’s river basins during the 20th Century. The temporal and spatial patterns varied significantly across China. The largest change occurred during the second half century when almost all of the river basins had a decreasing trend in ET and an increasing trend in water yield and runoff, in contrast to the inclinations of ET and declinations of water yield in major river basins, such as Pearl river basin, Yangtze river basin, and Yellow river basin during the first half century. The increased water yield and runoff indicated alleviated water deficiency in China in the late 20th Century, but the increased peak flow might make the runoff difficult to be held by reservoirs. The continuously increasing ET and decreasing water yield in Continental river basin, Southwest river basin, and Songhua and Liaohe river basin implied regional water deficiency. Our study in China indicates that deforestation averagely increased ET by 138 mm/year but decreased water yield by the same amount and that reforestation averagely decreased ET by 422 mm/year since most of deforested land was converted to paddy land or irrigated cropland. In China, cropland‐related land transformation is the dominant anthropogenic force affecting water resources during the 20th Century. On national average, cropland expansion was estimated to increase ET by 182 mm/year while cropland abandonment decreased ET by 379 mm/year. Our simulation results indicate that urban sprawl generally decreased ET and increased water yield. Cropland managements (fertilization and irrigation) significantly increased ET by 98 mm/year. To better understand LUCC effects on China’s water resources, it is needed to take into account the interactions of LUCC with other environmental changes such as climate and atmospheric composition.     

Determinants of deforestation in Nepal's Central Development Region

The process of deforestation in the Central Development Region (CDR) of Nepal is diverse in space and time, with rapid deforestation still occurring in areas outside the national parks and wildlife reserves. This paper identifies the spatial driving forces (SDFs) of deforestation in the CDR for 1975–2000 using satellite data of 1975 (MSS), 1990 (TM), and 2000 (ETM+) along with socio-demographic and socioeconomic variables. Radiometrically calibrated satellite images are individually classified into seven distinct classes and merged together to cover the entire CDR. Classification accuracies are also assessed. Areas of land use and cover within the areas of each Village Development Committee (VDC) and municipality represented by GIS polygons are calculated from the classified images by overlaying vector files of 1845 polygons representing sections of VDCs and municipalities in 30–1199 m, 1200–2399 m, 2400–4999 m and >5000 m elevation levels. These elevation levels were estimated from the DEM compiled from 24 ASTER scenes taken on different dates. Only the first three elevation levels are used in the analysis because area >5000 m is under permanent snow cover where human related forestry activities are almost negligible. A transition matrix is generated for 1975–1990 using classified images of 1975 and 1990 and then this product is used to further develop another transition matrix for 1990–2000 with the classified ETM+ 2000 images as the final stage. The GIS polygon layer is overlaid on the transition matrices to calculate deforestation areas for 1975–1990 and 1990–2000. Biophysical and socioeconomic information collected from various sources is then brought into a GIS platform for statistical analyses. Six linear regression models are estimated using SAS; in effect, two models for each elevation range representing the 1975–1990 and 1990–2000 periods of change to identify SDF influences on deforestation. These regression analyses reveal that deforestation in the CDR is related to multiple factors, such as farming population, genders of various ages, migration, elevation, road, distance from road to forest, meandering and erosion of river, and most importantly the conversion of forestland into farmland.     

民族地区优势产业振兴路径的三重维度——以广西百色芒果产业为例

民族地区受自然条件、市场和资金等因素影响,产业发展缓慢。从“深度”、“广度”和“融合度”三重维度出发,提升产业层次、培育品牌产业、延伸产业链、挖掘产业附加值、对接生态保护,实现乡村振兴,构建民族地区产业新模式。以百色芒果产业为例,从三重维度出发创新优势产业,总结实践贡献和理论成果,发挥其在西南少数民族地区的示范引领作用,为实现民族地区巩固脱贫攻坚效果和乡村振兴有机衔接做出积极贡献。     

Assessing Ecological Integrity of Ozark Rivers to Determine Suitability for Protective Status

Preservation of extraordinary natural resources, protection of water quality, and restoration of impaired waters require a strategy to identify and protect least-disturbed streams and rivers. We applied two objective, quantitative methods to determine stream ecological integrity of headwater reaches of 10 Ozark rivers, 5 with Wild and Scenic River federal protective status. Thirty-four variables representing macroinvertebrate and fish assemblage characteristics, in-stream habitat, riparian vegetation, water quality, and watershed attributes were quantified for each river and analyzed using two multivariate approaches. The first approach, cluster and discriminant analyses, identified two groups of river with only one variable (% forested watershed) reliably distinguishing groups. Our second approach employed ordinal scaling to compare variables for each river to conceptually ideal conditions that were developed as a composite of optimal attributes among the 10 rivers. The composite distance of each river from ideal was then calculated using a unidimensional ranking technique. Two rivers without Wild and Scenic River designation ranked highest relative to ideal (highest ecological integrity), and two others, also without designation, ranked most distant from ideal (lowest ecological integrity). Fish density, number of intolerant fish species, and invertebrate density were influential biotic variables for scaling. Contributing physical variables included riparian forest cover, water nitrate concentration, water turbidity, percentage of forested watershed, percentage of private land ownership, and road density. These methods provide a framework for refinement and application in other regions to facilitate the process of establishing least-disturbed reference conditions and identifying rivers for protection and restoration.     

Georelational Analysis of Soil Type, Soil Salt Content, Landform, and Land Use in the Yellow River Delta, China

The Yellow River Delta, one of China’s three major river deltas, is becoming a major region for the development of agriculture and fisheries. Protecting the delicate ecology of newly formed aquatic systems as well as the evolution of soils, natural vegetation, and fauna on older upland environments in the delta is a priority in planning for the wise use of the delta’s resources for future agricultural development. In this article, we use a Geographic Information System (GIS) to analyze relationships between land-use/land-cover characteristics in the Dongying municipality, one of the most intensely developed areas of the delta, and spatial variations in soil salinity and landforms. This analysis reveals that soil salt content decreases from regionally high values in isolated depressions to relatively moderate values in embanked former back swamps, with the lowest values occurring in abandoned river courses. Comparing the present land use on this soil salinity–landform pattern shows that it is basically at odds with general concepts of land suitability for agricultural utilization of saline soils. Crop-based agriculture in the region is probably overdeveloped, whereas more appropriate agricultural development, like cattle and forest production, is underrepresented. Future development should focus on converting farmland in embanked former back swamps and abandoned river courses into grasslands and forests. Crop-based agriculture (up to 151,000 ha) could be planned at the low-salinity terrace uplands and flood plains. The article provides guidelines for decision-makers regarding agricultural land use and wetland protection in the Yellow River Delta.     

Improving public information about large hydroelectric dams: Case studies in France and West Africa

It is becoming more common for public authorities in charge of dam construction and management to inform the population living in the area soon to be submerged by a proposed dam. However, populations living further downstream along a river to be dammed, have often been left to find out by chance, despite the fact that the changes to the river flow regime will have an important impact on their lives, sometimes serious negative impacts. This article makes a comparison between two dams, one at Bort-les-Orgues across the upper Dordogne River in southern France, the other the Bagré Dam over the Nakambé (or White Volta) River in south-eastern Burkina Faso. The article discusses dam construction and operation from the point of view of the concerned populations living in the reservoir and downstream areas.
In 2000, a study was carried out in the Dordogne Valley to ascertain downstream impacts of dam operations and information needs of the population. Suggestions from local river users related mostly to improving public information about predicted and actual flow rates and actual flow in real time along the 300 km course of the Dordogne between the dams and the estuary. Such information should be disseminated as widely as possible through available media, including the Internet, and also displayed visibly in key locations along the length of the river.