随着气候变化的加剧,高温干旱事件频发,对植被健康生长造成了严重影响。针对相关性方法难以准确刻画复合干热胁迫下植被脆弱性的问题,利用1982—2015年去趋势和标准化的归一化植被指数(detrended and standardized normalized differenc...随着气候变化的加剧,高温干旱事件频发,对植被健康生长造成了严重影响。针对相关性方法难以准确刻画复合干热胁迫下植被脆弱性的问题,利用1982—2015年去趋势和标准化的归一化植被指数(detrended and standardized normalized difference vegetation index,SNDVI)、标准化降水蒸散发指数(standardized precipitation and evapotranspiration index,SPEI)和标准化气温指数(standardized temperature index,STI),构建基于Vine Copula的复合干热胁迫下植被脆弱性评估模型,量化黄土高原不同土地利用类型和气候区植被对高温干旱的响应关系。结果表明:1)黄土高原大部分区域SNDVI与SPEI呈正相关关系,与STI呈负相关关系,草地SNDVI与SPEI、STI的相关性最高,其次为耕地,林地最低;2)相对于单一干旱或高温事件,复合干热事件进一步加剧了植被脆弱性,复合干热胁迫下黄土高原6、7、8月植被损失概率分别为0.51、0.57和0.55,较高的区域集中在陕西北部、宁夏、甘肃东部和内蒙古等地区;3)黄土高原地区不同植被类型对复合干热的脆弱性各异,脆弱性从大到小依次为草地、耕地、灌木、林地。研究结果有助于深入了解植被对气候极端事件的响应,支持应对气候变化的陆地生态系统风险管理。展开更多
为明确我国高寒区积雪消融对春季农田土壤水分的作用,针对气象站点监测数据、遥感及陆面模式同化数据在时空分辨率方面存在的不足,以地处黑龙江省中部的呼兰河流域为例,利用SWAT(Soil and water assessment tool)模拟流域降雪、积雪、...为明确我国高寒区积雪消融对春季农田土壤水分的作用,针对气象站点监测数据、遥感及陆面模式同化数据在时空分辨率方面存在的不足,以地处黑龙江省中部的呼兰河流域为例,利用SWAT(Soil and water assessment tool)模拟流域降雪、积雪、融雪等过程,研究流域内降雪、积雪、融雪的时空变化特征及其对春季农田土壤水分的影响。结果表明:呼兰河流域的平均降雪量、最大日积雪量、融雪量空间分布呈现自西向东逐渐增加的相近特征;积雪量、降雪量、融雪量变化率的空间分布特征相近,这些变化率在流域内大部分区域呈现增长趋势;降雪量、积雪量、融雪量的年时间序列关系密切,与土壤水分的年际变化趋势相近,农田土壤水分的年际变化受降水量影响较大;上年11月至当年3月的各月积雪量、上年11月降雪量、当年4月融雪量与当年春季4、5月农田土壤水分含量的相关性较显著;融雪水在3月下旬至4月上旬补给土壤水分,能够促使农田土壤水分短期上升,积雪量决定了融雪水对农田土壤水分的补给作用;农田土壤水分在融雪前下降趋势平缓,但在融雪后急剧下降。展开更多
The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calcula...The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calculation of surface runoff was applied to results of the field survey, and components of monthly water budget were estimated. The unit area of 1 km2 was selected as the index area for the estimation. A component of habitant water consumption was added to the water budget to consider the contribution of human activity. Results indicated that the water storage was negative in May, June and July while the annual amount was approximately 0.0. Evaportanspiration attained maximum in August and its annual total accounted for 74.2% of annual precipitation. Results of this study are significant for the sustainable water conservation and utilization in the northern of Loess Plateau where annual water resources are relatively deficient.展开更多
文摘随着气候变化的加剧,高温干旱事件频发,对植被健康生长造成了严重影响。针对相关性方法难以准确刻画复合干热胁迫下植被脆弱性的问题,利用1982—2015年去趋势和标准化的归一化植被指数(detrended and standardized normalized difference vegetation index,SNDVI)、标准化降水蒸散发指数(standardized precipitation and evapotranspiration index,SPEI)和标准化气温指数(standardized temperature index,STI),构建基于Vine Copula的复合干热胁迫下植被脆弱性评估模型,量化黄土高原不同土地利用类型和气候区植被对高温干旱的响应关系。结果表明:1)黄土高原大部分区域SNDVI与SPEI呈正相关关系,与STI呈负相关关系,草地SNDVI与SPEI、STI的相关性最高,其次为耕地,林地最低;2)相对于单一干旱或高温事件,复合干热事件进一步加剧了植被脆弱性,复合干热胁迫下黄土高原6、7、8月植被损失概率分别为0.51、0.57和0.55,较高的区域集中在陕西北部、宁夏、甘肃东部和内蒙古等地区;3)黄土高原地区不同植被类型对复合干热的脆弱性各异,脆弱性从大到小依次为草地、耕地、灌木、林地。研究结果有助于深入了解植被对气候极端事件的响应,支持应对气候变化的陆地生态系统风险管理。
文摘为明确我国高寒区积雪消融对春季农田土壤水分的作用,针对气象站点监测数据、遥感及陆面模式同化数据在时空分辨率方面存在的不足,以地处黑龙江省中部的呼兰河流域为例,利用SWAT(Soil and water assessment tool)模拟流域降雪、积雪、融雪等过程,研究流域内降雪、积雪、融雪的时空变化特征及其对春季农田土壤水分的影响。结果表明:呼兰河流域的平均降雪量、最大日积雪量、融雪量空间分布呈现自西向东逐渐增加的相近特征;积雪量、降雪量、融雪量变化率的空间分布特征相近,这些变化率在流域内大部分区域呈现增长趋势;降雪量、积雪量、融雪量的年时间序列关系密切,与土壤水分的年际变化趋势相近,农田土壤水分的年际变化受降水量影响较大;上年11月至当年3月的各月积雪量、上年11月降雪量、当年4月融雪量与当年春季4、5月农田土壤水分含量的相关性较显著;融雪水在3月下旬至4月上旬补给土壤水分,能够促使农田土壤水分短期上升,积雪量决定了融雪水对农田土壤水分的补给作用;农田土壤水分在融雪前下降趋势平缓,但在融雪后急剧下降。
基金Supported by JSPS Core University Program, Japan CAS "Western Light" (2006YB04)
文摘The objective of this study was to analyze the water budget of a small basin in the northern of Loess Plateau. A small basin, Liudaogou in the northern Loess Plateau was chosen as the study area. The numerical calculation of surface runoff was applied to results of the field survey, and components of monthly water budget were estimated. The unit area of 1 km2 was selected as the index area for the estimation. A component of habitant water consumption was added to the water budget to consider the contribution of human activity. Results indicated that the water storage was negative in May, June and July while the annual amount was approximately 0.0. Evaportanspiration attained maximum in August and its annual total accounted for 74.2% of annual precipitation. Results of this study are significant for the sustainable water conservation and utilization in the northern of Loess Plateau where annual water resources are relatively deficient.
