山区耕地细碎化对土地利用集约度影响——以贵州省亚鱼村为例   总被引：2，自引：0，他引：2  

葛玉娟  赵宇鸾  李秀彬 《地理科学进展》2020,39(7):1095-1105

为探索耕地细碎化与土地利用集约度之间的关系,论文以贵州省亚鱼村为例,利用无人机高分辨率影像和农户调查数据,在对比不同通勤距离情景耕地细碎化测度模型准确性的基础上,计算农户耕地细碎化指数,并定量分析不同农户耕地细碎化水平对土地利用集约度的影响。结果表明：对比分析6种通勤距离情景耕地细碎化测度结果,发现农户耕作地块到其宅基地的道路网络距离情景下测度耕地细碎化水平准确度更高;这一情景下亚鱼村平均农户耕地细碎化指数是187.98,该村农户耕作通勤时间成本高;随着农户耕地细碎化程度加剧,农业经营中劳动力投入、资本投入和作物产值呈不同程度的下降趋势,其中资本投入中,耕地细碎化对省工性投入的影响最为显著;山区农业人口乡城迁移背景下农村细碎的耕地资源促使农户加快退出农业生产,导致耕地低效利用,甚至撂荒。  相似文献   

农业生产转型类型诊断及其对乡村振兴的启示——以黄淮海地区为例     

戈大专  周礼  龙花楼  乔伟峰  李裕瑞 《地理科学进展》2019,38(9):1329-1339

城乡转型发展背景下,农业生产转型成为解析区域乡村人地关系演变的重要窗口。科学诊断中国传统农区农业生产转型的类型及其存在的核心问题,可为调控农业生产政策和完善乡村发展战略提供参考。论文以中国传统农区黄淮海地区为例,以农业生产转型的类型划分为突破口,系统诊断不同农业生产转型类型面临的困境及其破解方案。研究发现：“自上而下”和“自下而上”相结合的多尺度分析法是分析农业生产转型阶段差异的有效手段;空间弹性视角下,黄淮海地区农业生产转型类型可以划分为传统农耕型、现代市场型和城郊休闲型3类;传统农耕型地区耕地利用转型与农业劳动力转型的失调、缺乏核心产业支撑及实际城镇化率较低是限制乡村有序转型的关键问题;现代市场型地区不合理的土地利用状态和小农户的有效组织是当前亟需突破的难题;城郊休闲型地区完善农户的市场参与方式和降低资本风险是当前必须考虑的问题;针对各转型类型的差异化问题因地制宜科学施策,有利于推动乡村振兴战略的落实。  相似文献   

Environmental Perception,Sense of Place,and Residence Time in the Okavango Delta,Botswana     

Amelia C. Eisenhart  Kelley A. Crews Meyer  Brian King  Kenneth R. Young 《The Professional geographer》2019,71(1):109-122

Integral to the geographic discipline are cross-cultural analyses, many of which use languages outside of the researcher’s own. There are few analyses, however, that address issues of translation that are inherently geographic; namely, that language is understood as a manifestation of place and culture. This article argues that the results of environmental interviews must be interpreted through a lens that evaluates how the translation of a word, or even a concept, is understood differentially based on one’s sense of place. Interviews were conducted in three of the Etsha villages situated in the Okavango Delta, Botswana, comparing perceptions of changes in both the local area and the flooding regime. Findings show qualitatively and quantitatively how residents perceive environmental change in light of their residential histories and their production of place. These results highlight that environmental change in an area is perceived in the context of previous residences, including the length of time spent in residence and the environmental characterization of that place. The process of interviewing regarding such change, especially when translation is necessary, should therefore proceed by incorporating inquiries about previous residences and the environments of those areas to correctly contextualize environmental change in a particular area.  相似文献   

中国人口疏密区分界线的历史变迁及数学拟合与地理意义   总被引：3，自引：2，他引：1  

龚胜生  陈云 《地理学报》2019,74(10):2147-2162

采用历史时间断面方法和现代空间分析方法,对中国西汉、西晋、唐代、北宋、明代、清代、现代7个时间断面的人口分布进行分析。结果发现：① 中国人口疏密区的分界线就是中国农牧区的分界线,中国人口分布的大格局由中国农耕区和畜牧区的空间分异奠定,理论上中国人口疏密区分界线就是中国农牧交错带的拟合线。② 两千多年的历史证明,中国农牧交错带是一个弧状地带,不能用直线拟合,只能用弧线拟合;“沈天大弧线”（沈阳—天水—大理弧线）是该交错带的函数拟合线,“山兰防弧线”（山海关—兰州—防城港弧线）是该交错带的内缘拟合线,也是中原王朝衰弱时期的农牧分界线;“沈兰西弧线”（沈阳—兰州—西双版纳弧线）是该交错带的外缘拟合线,也是中原王朝强盛时期的农牧分界线;直线的“爱辉—腾冲线”理论上不能拟合弧状的中国农牧交错带,但因为它碰巧是中国农牧交错带的函数拟合线的切线,因而也能较好地刻画中国人口的宏观分异格局。③ 中国人口疏密区分界线有着丰富的地理学意义：一是分界线本身就是农牧业分界线;二是分界线与海岸线围成的区域是中国的“国家核心区”;三是分界线最大限度地刻画了中国东南和西北的自然地理和人文地理的分异。  相似文献   

Changing water regime and adaptation strategies in Upper Mustang Valley of Upper Kaligandaki Basin in Nepal     

Prem Sagar Chapagain  Jagat K. Bhusal 《寒旱区科学》2013,5(1):0133-0139

Recent climate change has brought changes to the water regime that has affected the traditional agro-pastoral production systems and livelihoods in the Upper Kaligandaki Basin of the Nepal Himalayas. Based on fieldwork and available meteorological and hydrological data, this paper examines the changing water regime and various adaptation strategies that local farmers have adopted in this cold arid region. Increasing temperature and decreasing rainfall and snowfall have resulted in a negative water balance. In this scenario, farmers have implemented six major adaptive strategies in the trans-Himalayan Upper Mustang Valley.  相似文献   

基于无人机可见光影像的紫菜养殖筏架信息提取方法及应用          下载免费PDF全文

许海蓬  高光军  杨晖  卢霞  孙玉曦  初佳兰 《应用海洋学学报》2024,43(1):075-083

海上紫菜养殖筏架分布无规律、大小不规则且数量较多,现场测量难度大、卫星影像空间分辨率低,不能精确测量出紫菜筏架面积。无人机机动性强、影像空间分辨率高,可在紫菜养殖调查中发挥重要作用。本研究以连云港海州湾紫菜养殖筏架为研究对象,开展可见光波段在养殖筏架与水体的光谱可区分度研究,基于6种植被指数,进行自动提取实验,以目视解译结果作为真值,进行精度分析,同时利用不同时相、不同区域的无人机可见光影像,开展方法的普适性研究。结果表明：绿色度坐标（green, G）和植被（vegetativen,VEG）指数方法在浅水区和深水区均表现较好,养殖筏架个数识别精度、面积识别精度均超过91.00%。基于此,利用上述两种方法,开展其他区域自动提取实验,养殖筏架个数识别精度、面积识别精度分别超过93.02%和89.37%。结果验证了无人机可见光影像可以实现紫菜养殖筏架的自动提取,精度基本满足紫菜养殖调查需求。  相似文献   

Impact of labor transfer on agricultural land use conversion at rural household level based on Logit model     

Taiyang Zhong  Xiuying Zhang  Xianjin Huang 《中国地理科学(英文版)》2008,18(4):300-307

Since land and labor force are primary resources to be used and controlled by rural households, the allocation of labor forces will influence land uses, and further lead to land use conversion. The present study used the Binary Logit model to investigate the influence of labor force transfer, characteristics of rural households, location, and land market on agricultural land use conversion at rural household level. This study was conducted based on 329 valid questionnaires, which were obtained in Changshu, Rudong, and Tongshan counties, respectively representing the southern, middle and northern areas of Jiangsu Province. The results showed that land market participation, location, zonal difference and labor transfer had strong influences on agricultural land use conversion. The participation of land market had a strong positive effect on land use conversion, especially for the farmland converted to the fishpond. The nearer to the county seat, the more conversion of land use occurred. Particularly, the labor force transfer caused by wage employment decreased this conversion probability, while the labor transfer caused by self-employment led to more conversion; and the increasing of income from labor transfer increased the conversion. Moreover, land use conversions demonstrated zonal difference, which were more in Rudong and Changshu counties than in Tongshan County, and the factors influencing this conversion were different in the three regions.  相似文献   

气候变化背景下江苏河蟹养殖高温热害风险评估          下载免费PDF全文

张旭晖  俞子闲  时冬头  任义方  王敦纠  吴洪颜 《气象科学》2021,41(5):696-702

利用江苏省及周边共85个气象站观测资料，筛选出夏季高温强度、持续时间、降水量和日照时数作为高温热害的关键气象因子，构建高温热害综合指数。在此基础上，利用高温热害发生频率和河蟹因灾死亡率加权建立风险评估模型，将河蟹高温热害风险划分为三个等级，结合地形和土壤的适宜性，最终得出江苏河蟹高温热害风险区划图。结果发现，河蟹高温热害的高风险区位于以高淳为中心的江苏西南部，沿淮和淮北东部沿海地区风险值最低，淮北西部—沿江东部的风险值介于二者之间。年代际高风险区面积有逐渐扩大趋势，1991年以来已外扩到沿江和苏南大部分地区，达到历史极值。河蟹高温热害风险增大，需加强防范。  相似文献