Farmers＇ vulnerability to flood risk： A case study in the Poyang Lake Region

This paper quantitatively explores farmers＇ vulnerability to flood in the Poyang Lake Region （PLR） with the supports of GIS spatial functions. The analysis consists of three major steps, which is based on the spatial unit of township. Firstly, the spatial extent and characteristics of flood risk areas were determined using a digital elevation model （DEM） derived from the 1：50,000 topographic map. Secondly, for each of the township, six indices indicating the economic activities of local farmers were calculated. These indices are： rural population proportion, cultivated land proportion, GDP per unit area, employment proportion of primary industry, net rural income per capita and agricultural income proportion. These six indices were then normalized and used for later vulnerability assessment. Thirdly, the normalized indices （as GIS data layers） were overlaid with the flood risk areas to produce the risk coefficient for each township and to calculate the overall vulnerability for each township. The analysis results show that in the PLR there are high flood risk areas where the farmers＇ livings are seriously influenced or threatened. About 55.56% of the total 180 townships in the flood risk areas have a high degree of flood vulnerability. The townships under flood risk are mainly distributed in the areas around the Poyang Lake and the areas along the ＂five rivers＂.

Research on the Variation of Population Distribution and Its Characteristics Based on Spatial Autocorrelation Method: A Case Study of Poyang Lake Region in Jiangxi Province

According to Statistical Yearbook of Jiangxi Province(2001～2006),We analyze the time-space variation of population distribution of Poyang Lake region from the two points of view.The former is quality of population,which involves culture structure,occupational structure,age structure and sex structure of population.The latter is quantity of population,which only involves the amount of population.Furthermore,we can reveal the internal relations and action mechanism of variation of population distribution by analyzing the regional economic development,population urbanization,land use and ecological landscape of Poyang Lake region.It is important to provide help for region planning,ecological landscape planning and environmental protection by correct understanding the man-land relationship of natural-human ecosystem in Poyang Lake region.

Changes in rice cropping systems in the Poyang Lake Region, China during 2004-2010

Rice cropping systems not only characterize comprehensive utilization intensity of agricultural resources but also serve as the basis to enhance the provision services of agro-ecosystems. Yet, it is always affected by external factors, like agricultural policies. Since 2004, seven consecutive No.1 Central Documents issued by the Central Government have focused on agricultural development in China. So far, few studies have investigated the effects of these policies on the rice cropping systems. In this study, based upon the long-term field survey information on paddy rice fields, we proposed a method to discriminate the rice cropping systems with Landsat data and quantified the spatial variations of rice cropping systems in the Poyang Lake Region （PLR）, China. The results revealed that： （1） from 2004 to 2010, the decrement of paddy rice field was 46.76 km2 due to the land use change. （2） The temporal dynamics of NDVI derived from Landsat historical images could well characterize the temporal development of paddy rice fields. NDVI curves of single cropping rice fields showed one peak, while NDVI curves of double cropping rice fields displayed two peaks annually. NDVI of fallow field fluctuated between 0.15 and 0.40. NDVI of the flooded field during the transplanting period was relatively low, about 0.20±0.05, while NDVI during the period of panicle initiation to heading reached the highest level （above 0.80）. Then, several temporal windows were determined based upon the NDVI variations of different rice cropping systems. （3） With the spatial pattern of paddy rice field and the NDVI threshold within optimum temporal windows, the spatial variation of rice cropping systems was very obvious, with an increased multiple cropping index of rice about 20.2% from 2004 to 2010. The result indicates that agricultural policies have greatly enhanced the food provision services in the PLR, China.

Study on Regionalization of High Efficiency Eco-agriculture in Eco-economic Zone of Poyang Lake

The high efficient eco-agricultural zone in Eco-economic Region of Poyang Lake was divided into three different areas. 12 indicators including per capita cultivated land,forest coverage,comprehensive utilization rate of straw,the ratio of the effective irrigation area to the arable land,amount of pesticide usage per unit area of arable land,the output value ratio of planting industry,the output value ratio of forestry and fruit industry,the output value ratio of stock farming,the output value ratio of fishery,the proportion of sown area of crop,proportion of sown area of oil plants and the proportion of sown area of vegetable were screened to construct the indicator system of regionalization of high efficient eco-agriculture. The average index values of the high efficient eco-agricultural regionalization of three regions were obtained,the development direction of the efficient eco-agriculture construction of three areas were analyzed according to the natural resources characteristics f eco-agricultural and requirements of high efficient eco-agricultural development of the regions.

A preliminary knowledge-driven prediction model of snail distribution in the Poyang Lake region

Present monitoring and prediction of schistosomiasis’s intermediate parasite, snail, are based on re-mote sensing image’s spectral signatures, and the calculation result is in fact an incom-plete-constraints solution. TM image of the Poyang Lake region on October 31, 2005 was combined with GIS thematic data (DEM, boundary of the Poyang Lake, vegetation, soil and land use) to make a prediction on snail spatial distribution in the region by remote sensing, geo-informatics and knowl-edge-driven modeling according to mechanism of snail occurrence. Result shows that with change of overall fuzzy membership of snail occurrence from high to low, snail occurrence of the snail samples of validation group goes up to 81% within 10% high fuzzy membership range, denoting high efficiency of the model in predicting snail occurrence.

鄱阳湖区洪灾风险与农户脆弱性分析

运用1:5万DEM地形数据对鄱阳湖区洪涝灾害风险区区域范围及空间分布进行了分析。在此基础上,以乡镇为基本研究单元,选取乡村人口比重、耕地面积比重为洪灾风险暴露分析指标,选取单位面积生产总值、农民人均纯收入、第一产业从业人员比重、农业收入占农村经济总收入比重等为农户洪灾应对能力分析指标,并引入了不同洪水水位特征值的影响系数,对鄱阳湖区农户洪灾脆弱性程度进行了定量研究。结果表明,鄱阳湖洪灾风险区面积广、影响深,农户对洪涝灾害总体上存在着较高的脆弱性;在所涉及的180个乡镇中,农户脆弱度高于平均值的有100个,占到乡镇数55.56%。脆弱度最高的乡镇主要集中在滨湖地带及五河干流沿岸地区,而脆弱度较低的乡镇则主要分布在湖区各县城关镇所在区域。

鄱阳湖区的土地利用结构定量分析

运用多种数学模型对鄱阳湖区11个县的土地利用的数量结构和空间格局进行了定量分析,研究表明鄱阳湖区各县的土地利用结构存在很大的差异,这些差异主要是与其所处的地理位置、地形地貌、经济水平等密切相关。

鄱阳湖区土地利用景观格局特征研究

在RS与G IS技术的支持下,该文对鄱阳湖区1990-2002年间的土地利用景观变化进行了分析。研究结果表明,1990-2002年鄱阳湖区面积变化的趋势是耕地减少、林地增加、草地减少、水体增加、居民点与工矿用地大幅度增加,未利用地维持不变。利用二级土地利用景观类型,对景观变化的原因进行了分析。利用多样性指数、优势度、分维数、破碎度等景观指数对鄱阳湖区土地利用景观格局特征的研究表明,1990-2002年鄱阳湖区土地利用景观格局总体变化趋势是多样性增加、优势度减少、分数维减少、破碎度增加。最后,该文利用典型相关分析法对鄱阳湖区景观格局变化的社会经济驱动力进行了定量分析,认为导致景观分维数、景观破碎度变化的主要驱动力是人口与国内生产总值,导致景观多样性和优势度变化的主要驱动力是境内公路里程与农村居民年均纯收入。

基于耕地质量评价的鄱阳湖区耕地整理规划

区域耕地质量评价是耕地整理的基础工作,为耕地整理专项规划、耕地整理项目设计提供了科学依据。从耕地整理的基本要求出发,选取耕地自然条件和耕地利用条件2个基本因素,土层厚度、土壤质地、土壤有机质、土壤侵蚀、地形坡度、排灌状况、田间道路状况、田块规整度等8个影响因子,建立耕地质量评价指标体系。采用多因素综合评判法将环鄱阳湖区12县(市)的耕地分成4个等级,分析其空间分异特征,并结合各区域耕地质量主要限制因子,提出可行性耕地整理措施,为区域耕地整理宏观控制提供了一种新思路。

鄱阳湖区生态环境自然脆弱性综合评价

针对江西省鄱阳湖区脆弱生态环境特征,从地质基础、地形地貌、土壤类型、气候条件、植被因素和水文状况等方面综合评价了鄱阳湖区自然脆弱性,各县自然脆弱度依次为南昌县<波阳县<德安县<永修县<新建县<星子县<余干县<九江县<湖口县<进贤县<都昌县。

鄱阳湖地区1985-2000年土地利用格局变化及其社会经济驱动力研究 Ⅰ·土地利用格局空间变化分析

利用鄱阳湖地区21个县市1985和2000年的两期土地利用类型图,借助景观格局指数、土地利用动态度和土地利用转移矩阵等分析该地区15年间土地利用空间格局的变化。结果表明,耕地、林地、草地、水域、建设用地和未利用地等6种土地利用类型在空间上的分布逐渐由分散变为聚集,主导地位的土地利用类型日益突出,并逐渐向规则、连片方向发展。转移矩阵和流向分析表明,耕地主要向建设用地转移,林地主要向草地和耕地转移,草地主要向林地转移,水域主要向草地转移,建设用地则没有向其他类型转移,未利用地则主要向水域转移。

鄱阳湖区土地利用变化的碳排放效应研究

土地利用是造成碳排放的重要原因。利用2000年、2005年和2010年的3期遥感影像,分析了2000—2010年鄱阳湖区土地利用变化特征,并运用碳排放估算模型,对鄱阳湖区不同土地利用方式的碳排放进行了计算和分析。结果表明:(1)2000—2010年鄱阳湖区碳排放量持续增加,从2000年的431.85×104t增加到2010年的1 194.37×104t,增加了1.77倍;(2)鄱阳湖区各县(市、区)的碳排放强度差异较明显;(3)调整土地利用方式、限制建设用地扩张、转变经济增长方式、优化能源结构是减少鄱阳湖区碳排放的主要措施。

鄱阳湖区水产养殖水体重金属污染研究

[目的]了解鄱阳湖区水产养殖水域受重金属污染情况及其潜在风险程度。[方法]在分析鄱阳湖区水产养殖水域污染现状的基础上,利用单项污染指数法和Hakanson生态风险指数法对鄱阳湖水产养殖水体和沉积物中的重金属污染进行综合评价分析。[结果]从采样点总污染的污染程度值来看,鄱阳湖区水产养殖的底泥污染属于低度污染;总的潜在风险RI分析表明,除蚌类部分区域外,鱼类和蟹类养殖水域的潜在生态风险指数均<150,说明该水域的底泥重金属污染潜在风险为低度生态风险;各污染物对该水域构成的生态风险影响程度排序为:Cu>Cd>Pb>Zn;不同类型水产养殖水域总的潜在风险程度排序为:蚌类>鱼类>蟹类。[结论]鄱阳湖区水产养殖水中重金属含量较低,污染等级属于安全级。

基于GIS技术的多目标土壤资源适宜性评价

土壤资源适宜性评价是进行土壤资源空间分析及优化配置的基础,为土壤资源的合理开发利用提供科学依据。该文以江西省鄱阳湖经济区土壤资源为研究对象,选取了7个参评因子,将GIS技术、统计模型和评价方法有机结合进行土壤资源的宜耕、宜园和宜林适宜性评价,评价结果表明:研究区生境条件整体较高,土壤资源适宜性较好;区域内宜耕土壤资源面积为19269.2km2,占总面积的48.5%;宜园土壤资源面积为4399.1km2,只占总面积的11.1%;宜林土壤资源面积为12579.1km2,占总面积的31.7%;三者的有机结合,克服了传统评价方法费时费力以及主观参与性强的不足,使评价结果更为客观合理,为土壤资源适宜性评价提供了一条新途径。

鄱阳湖区土地生态安全评价

在对鄱阳湖区土地生态安全特征研究的基础上,建立了土地生态安全评价模型。并对湖区11个县的土地生态安全进行评价,划定安全等级,分析了影响区域土地生态安全的主要胁迫因子,为该区土地生态安全建设提供借鉴和指导。

有机无机肥配施对潜育化水稻土的改良效应

为探索潜育化水稻土改良培肥措施,采用田间试验研究了工程排水条件下有机无机肥配施对潜育化低产水稻土的改良效应。结果显示：有机无机肥配施增加了早、晚稻的有效分蘖数。在早稻齐穗期,与CK和NPK处理相比,有机无机肥配施的叶绿素（SPAD值）均显著增加。有机无机肥配施显著增加了晚稻的产量,与NPK处理相比,产量增加了10.0%-23.7%;其中早稻配施紫云英、晚稻配施猪粪处理产量最高。在工程排水基础上,配施有机肥处理在早、晚稻收获时耕层土壤还原物质总量分别比单施化肥处理减少了15.0%-25.3%和32.5%-37.5%。这表明,在工程排水条件下,配施一定的有机肥可以明显提高潜育化稻田水稻产量,降低表层土壤还原物质总量,对改良潜育化水稻土有明显作用。

江西省鄱阳湖地区饮用水健康风险评价

按照美国环境保护局风险评价模型,对江西省鄱阳湖地区24个县市的饮用水中As、Cd、Hg、Pb、F、氨氮和酚进行了健康风险评价。研究结果表明,通过饮水途径所致健康风险中,As在彭泽县所引起的致癌风险最大（29.1×10^-6.a^-1）,Cd在鄱阳县的致癌风险最大（7.94×10-7.a^-1）,但均低于国际辐射防护委员会（ICRP）推荐的通过饮水途径最大可接受风险水平（5×10^-5.a^-1）;通过饮水途径引起的非致癌健康风险中,酚的风险最大,出现在鄱阳县（4.99×10^-9.a^-1）,远低于ICRP推荐的最大可接受风险水平。最后将致癌风险和非致癌风险相加得出鄱阳湖24个县市的整体健康风险,结果显示研究区的总风险水平介于10^-6-10^-11.a^-1,基本处于可接受的水平。高风险区主要为彭泽县、南昌市、南昌县、湖口县,这些地区的饮用水环境健康问题应引起更多的关注。

鄱阳湖区旅游资源空间整合研究

运用β指数、γ指数、通达度指数、平均路长等空间分析方法对鄱阳湖区域旅游资源的空间结构进行计算分析,探讨了该区旅游资源空间整合的策略,结论对提升该区旅游竞争力有一定意义.

控氮节磷施肥对鄱阳湖区水稻养分吸收及产量的影响

鄱阳湖区是江西主要的水稻产区,以双季稻为主。在双季稻单季高产推荐施肥水平(N∶P2O5∶K2O=180∶90∶150kg/hm2,100%化肥)基础上,进行了化肥减量后与猪粪配施、孕穗期增施氮钾肥、添加肥料增效剂等控氮节磷施肥对水稻养分吸收和产量影响的试验。结果表明,在养分等量条件下,80%化肥+猪粪处理较之100%化肥处理,早晚两季稻谷总量增加93kg/hm2、增长0.74%;化肥减量20%后,在穗期增施N、K养分,或添加肥料增效剂,早稻产量有所增加,晚稻有所减产,但全年稻谷产量基本持平。控氮节磷施肥均能明显提高水稻养分利用率。

鄱阳湖区湿地生态功能衰退分析及其恢复对策探讨

With the regional eco-environment deterioration,great attentions have been paid on wetland ecosystem in recent year;In this paper,the ecological characteristics and functions of wetland in Poyang lake were analyzed such as wetland quantity and quality,flood regulation,weather regulation,and biodiversity protection.According to wetland ecology problems,the countermeasures were put forward.