当曲河流域牧区聚落演变及其资源环境效应

发布时间：2018-03-29 23:14

本文选题：当曲河流域　切入点：牧区聚落　出处：《中国地质大学(北京)》2017年硕士论文

【摘要】：青藏高原平均海拔高度在4000m以上,是世界上平均海拔最高的高原。鉴于牧区生态脆弱、城乡聚落分散、基础设施滞后、公共服务能力低等突出问题,国家启动了一系列区域发展与生态保护政策,如围栏禁牧、草原生态屏障建设与保护,尤其是游牧民定居工程的实施,从“逐水草而居”到“游牧定居”的转变,使牧民居住条件得到改善,公共设施得以完善,直接影响牧区聚落的空间格局和周边资源环境效应。本文基于2010年Google earth数据、2015年资源三号卫星高分辨率遥感影像,借助ENVI和ArcGIS,在村落-庭院尺度,刻画了西藏当雄县当曲河流域牧区聚落演变,分析了聚落演变的影响因子及影响机制,探讨了牧区聚落优化调控的路径和措施。同时运用降雨量、潜在蒸散发量、植物可利用含水量等数据,借助INVEST模型的水源供给模块评估了流域内的水源涵养功能,分析不同土地覆被和小流域范围的资源环境效应。研究发现:(1)2010-2015年当曲河流域聚落已经由传统的游牧迁徙演进到定居放牧阶段,聚落规模显著增大,分布海拔有所降低、选址改善,亚村落-庭院尺度的聚落斑块最近邻指数2010年、2015年分别为0.234和0.269,结合1990年的参考数据,流域内空间分布形态由随机型转变为集聚型,聚落分布呈现定居化、集中化趋势。(2)城镇化、定居化、产业化、生态化深刻影响着牧区聚落分布格局与发展演变。水源、草场、交通等是牧区聚落集聚的引力因子,高海拔、地质灾害、生态保护是牧区聚落集聚的斥力因子。当曲河流域牧区聚落主要分布在海拔4500m以下河谷阶地和山前冲积扇。分布在冷季牧场周边的聚落比重63.4%。离最近水域的距离在500m以下的聚落比重66.8%。离交通线路最邻近距离在400m以下的聚落比重73.6%。(3)由INVEST模型的产水量模块,得出当曲河流域水源涵养总量是3.2914×108m3,当曲河流域单位面积的水源供给量范围在50mm到333mm之间。单位面积的灌丛水源供给量为265.309mm,大于草地和湿地,说明其水源涵养功能要强于后者。当曲河流域每像素实际蒸散量集中在124mm到405mm之间,中部湿地实际蒸散量较其他区域高,实际蒸散量平均为383.597mm,流域内实际蒸散量平均值从大到小依次为:湿地、草地、水域、灌丛、未利用地、雪地、交通用地和居民地。
[Abstract]:The average altitude of the Qinghai-Tibet Plateau is over 4,000 m, which is the highest plateau in the world. In view of the ecological fragility of pastoral areas, the dispersion of urban and rural settlements, the lagging of infrastructure and the low capacity of public services, etc. The state has initiated a series of regional development and ecological protection policies, such as fencing and forbidding grazing, the construction and protection of grassland ecological barriers, especially the implementation of the nomadic settlement project, which has changed from "moving from water to grass" to "nomadic settlement." The living conditions of herdsmen are improved and the public facilities are improved, which directly affects the spatial pattern of pastoral settlements and the effects of surrounding resources and environment. Based on the Google earth data of 2010, the high resolution satellite remote sensing image of Resource-3 in 2015 is presented in this paper. With the help of ENVI and ArcGISs, on the village-courtyard scale, the settlement evolution of Dangqu River Basin in Dangxiong County, Tibet, is described, and the influencing factors and influencing mechanism of settlement evolution are analyzed. The paths and measures of optimal control of pastoral settlements were discussed, and the water conservation function in the watershed was evaluated by using the data of rainfall, potential evapotranspiration and available water content of plants, with the aid of the water supply module of INVEST model. The effects of different land cover and small watershed on resources and environment are analyzed. It is found that the settlement of the Quhe River basin has evolved from traditional nomadic migration to settled grazing from 2010 to 2015, and the scale of settlement has increased significantly, and the distribution of altitude has decreased. The nearest neighbor index of subvillage-courtyard scale settlements was 0.234 and 0.269 in 2010 and 2015, respectively. Combined with the reference data of 1990, the spatial distribution of the watershed changed from random type to agglomeration type, and the settlement distribution appeared to be settled. Centralization trend. 2) urbanization, settlement, industrialization and ecology have a profound impact on the distribution pattern and development of pastoral settlements. Water, pasture and traffic are gravitational factors, high altitude, geological disasters, etc. Ecological protection is the repulsive force factor of agglomeration in pastoral areas. When Quhe River Basin pastoral areas are mainly distributed in valley terraces and mountain front alluvial fans below 4500m above sea level, the proportion of settlements distributed around cold season pastures is 63.4. the distance from the nearest waters. The proportion of settlement below 500m is 66.8%. The proportion of settlement less than 400m from the nearest distance from the traffic line is 73.6. 3) from the water production module of the INVEST model. When the total amount of water conservation is 3.2914 脳 10 ~ 8m ~ 3 and the water supply range of unit area of qu River is between 50mm and 333mm, the water supply of shrub per unit area is 265.309 mm, which is larger than that of grassland and wetland. When the actual evapotranspiration per pixel of Quhe River basin is between 124mm and 405mm, the actual evapotranspiration of the central wetland is higher than that of other regions. The average actual evapotranspiration is 383.597 mm. The order of actual evapotranspiration in the watershed is wetland, grassland, water area, shrub, unused land, snow land, traffic land and inhabitant land.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P237;P208;C912.8

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