气候变化影响下青藏高原种植区的扩张：监测、模拟和适应对策研究

The Tibet Plateau is both a sensitive area and a promoter region of global change. Climate warming and humidity provides favorable conditions for agricultural development in the valley area of the Tibet Plateau, which has been seldomly studied.This study chooses the region of Brahamaputra River and its two tributaries in the Tibet and Huangshui River watershed as stduy area, investigates both the temporal and spatial variation of the staple crops and the change of multi-cropping index change in the study area during the past 15 years by high resolution remote sensing and the simualtion of DASST-AEZ model. Based on climate change tendency in the future, this study investigates both the distribution of the suitable cropping region and total production potential of the staple crops in 2030s, respectively. The adaptation strategies of famers and herdsmen is also investigatedand. we simulate the farmer's decision-making on grassland reclaim under the constraints of climate change, government subsidies and labor migration with a household model, in order to reveals the main influence factors. Based on a desertification risk evaluation, land reclamation scenarios and thematiic maps, we get the conflict areas and put forward the responding coordination measures. Based on the specific adaptation strategy of farmers and herdsmen, this project analyzes the conflict with the adaptation strategies of both state and local governments, and seeks the ways of coordination. The negative impacts and government planned strategies and the adaptive strategies of local people are evaluated and some appropriate measures for ecological protection are proposed.

青藏高原是全球变化的敏感区和启动区。气候暖湿化为青藏高原河谷农业的发展提供了有利条件。为了回答气候暖湿化背景下青藏高原的青稞安全和生态安全的问题，本研究选择一江两河流域和湟水谷地为研究区，基于高分辨率影像，提取2000年以来主要农作物种植区和复种指数的时空变化;通过DASST-AEZ模型模拟2000年以来主要农作物适宜区的时空变化和复种指数变化，并模拟预估2030s主要农作物适宜区域的分布和可能的新增耕地区域。在微观尺度，研究农牧民对气候变化的适应策略，并通过农户模型模拟气候变化、政府补贴、劳动力析出等因素如何影响农户垦殖土地和调整耕作制度，为政府决策提供依据。基于沙漠化风险评估，土地开垦情景和专项规划，发现冲突区域，提出规划管制措施。协调政府适应策略和农牧民自适应策略，提出生态保护措施。

在全球气候变化的影响下，青藏高原地区变暖趋势明显，改善了农业生产条件，提高了农作物种植上限，增加了适宜耕种的区域。为更好的利用气候变化的有利条件，以青藏高原典型农作物青稞为例，利用农业生态区域（Agro-Ecological Zone，AEZ）模型，对2000年后的青海省和西藏自治区青稞的适宜种植区域及气候生产潜力进行模拟和订正，得到气候变化背景下青海省和西藏自治区青稞潜在适宜种植区的分布图和气候生产潜力数据；对青海省和西藏自治区2000年、2018年的耕地进行遥感解译，提取2000年以来两省耕地变化情况。基于农户问卷数据，构建可持续生计分析框架，分析青藏高原区域农牧民的耕地开垦行为及其影响因素。结果表明：（1）2000年以来，青海省青稞潜在适宜种植面积达4418.95 km2，预计可新增青稞产量257.91万吨；西藏自治区青稞潜在适宜种植面积为1324.38 km2，预计可新增青稞产量106.53万吨，在气候变化背景下，青海省和西藏自治区新增青稞种植面积与产量潜力巨大。（2）2000-2018年，青海省耕地面积增加了280.44 km2，在潜在适宜种植区内开垦82.40 km2，；西藏自治区耕地面积增加了30.72 km2，在潜在适宜种植区内开垦2.92 km2，证实模拟结果真实可靠。（3）2018年之后，青海省有4336.55 km2的开垦潜力，预计可增长产量253.1万吨；西藏自治区有1321.46 km2的开垦潜力，预计可增长产量106.53万吨。（4）在当前气候变化背景下青藏高原地区已有部分农牧民开垦了新的耕地，证实了农牧民开垦是气候变化和人口压力共同作用的结果，还发现该地区农牧民非农收入与农牧民的开垦行为呈显著负相关关系。灌溉设施的缺乏是制约农牧民开垦的主要限制因素。（5）建议通过农田水利建设，提高耕地面积，增加粮食产量。