在气候变化与植被不断恢复影响下，中国北部半干旱流域的下垫面特征发生显著改变，水资源赋存受到剧烈影响，加剧了植被的动态变化，导致流域水资源与植被的稳态不断发生改变，流域水资源与植被能否可持续发展成为当前研究的重点和难点。生态水文恢复力通过描述流域受干扰后维持生态水文结构与功能稳定的能力，已成为定量揭示流域水资源与植被协同机制的重要方法。然而，已有的方法对刻画水资源稳态转化的流域水资源可持续供给能力的定量表达、反映植被稳态转化的植被生存能力的量化以及水资源与植被协同机制的揭示等方面存在一定不足之处。
针对上述不足，本研究以植被恢复的半干旱浑河流域为研究区，在系统分析近40 年来流域气象、水文及植被等要素变化特征的基础上，通过对流域水资源可持续供给能力和植被生存能力的定量表达，揭示了研究区水资源稳态和植被稳态的动态变化规律。在此基础上，将上述两种稳态变化特征系统地纳入生态水文恢复力量化研究中，构建了流域生态水文恢复力量化模型，据此揭示了研究区水资源与植被协同机制。取得的主要成果如下：
（1）通过数据收集与处理，系统分析了流域气象、水文及植被要素时空变化特征。结果表明，近40 年来流域气候呈气温显著升高，降水和潜在蒸散发缓慢增加的暖湿化特征，流域森林区水分约束作用比草地区小；在大规模植树造林影响下，流域植被土地在2000 年以后显著变绿，森林覆盖范围明显扩大；流域径流整体呈减小趋势，但自2000 年以来呈缓慢增大趋势，地表径流和土壤含水净增量的是决定流域水资源时空差异的主要组分，浅层地下水补给增长速率显著高于其它组分，但其含量远小于其它组分，这种差异与水资源组分对环境变化的适应性相关。
（2）在降水增加及林草覆盖变密影响下，流域水资源可持续供给能力自2000 年以来得到提升，但因缺乏对水资源供需匹配关系的全面考虑，大部分植被恢复区的植被可利用水资源匮乏程度加剧，导致流域水资源可持续供给能力从IV 类下降至III 类，水资源遭受干扰后从能迅速恢复稳态衰退至勉强恢复稳态。流域水资源组分对环境变化的适应度与流域水资源可持续供给能力的关联特征显示，地表径流和土壤含水净增量是影响流域植被可利用水资源时序趋势变化的关键组分。尽管植被可利用水资源在变化期（2000-2020 年）不断增大，比基准期（1982-1999 年）增长了9.33%，但其转化率仅提升了1.94%。地表径流、壤中流和土壤含水净增量以不同组合形式成为流域植被可利用水资源空间变化的主要组分，较丰富的植被可利用水资源自2000 年以来不断向草原变绿明显的清水河县西北地区扩张，其转化率高达79%以上，且稀少的植被可利用水资源在和林格尔县西部与东部以及右玉县东南地区大幅提升，土壤含水净增量是影响流域植被可利用水资源空间差异的主导因子。
（3）流域植被在变化期遭受气候干燥和水分亏缺压力分别以0.27/10a 和0.3/10a 的速率不断减小，植被生长功能退化得到改善，且流域森林恢复地区的植被水分亏缺压力随土壤蓄水能力的提升而不断减小。受降水增加和林草覆盖变密的影响，流域植被生存能力从II 类波动上升至IV 类，植被稳态遭受干扰后从无法恢复改善至能迅速恢复，流域东部森林密集地带的改善效果尤为突出。植被内部水分亏缺压力是影响流域植被稳态转化的主要干扰因素，自2000 年以来，影响流域东部及北部地区植被稳态转化的干扰因素从气候干燥转变为植被水分亏缺压力，且植被稳态恢复能力在林地扩张的东部地区随植被水分亏缺压力减小而不断增大。
（4）流域变化期的年均生态水文恢复力比基准期增长11.74%，但在生态水文抗干扰联合效应不断减小（减幅为10.71%）和人为干预提升效果不断下降（降幅为19.46%）影响下，流域生态水文恢复力在变化期从IV 类波动下降至III 类（降幅为24.26%），流域水资源和植被的稳态从能迅速协同恢复衰退至勉强恢复。尽管流域林草恢复明显地区的生态水文恢复力等级从基准期的I 类和II 类提升至变化期的III 类和IV 类，但绝大部分地区处于较低的III 类。草原恢复区的生态水文恢复力随生态水文抗干扰联合效应降低而不断减小，亟需加强草地生态环境的改善力度，森林恢复区的生态水文恢复力随生态水文抗干扰协同状态的改善（恶化）而增大（减小），且随人为干预提升效果的削弱而不断减小，亟需合理规划林地树木种植距离与结构。此外，根据流域生态水文恢复力的等级和变化趋势，明确了流域生态水文恢复力适应性管理类型的空间格局，因地制宜地提出了流域水资源和植被的稳态协同恢复能力的提升策略。
本论文以揭示半干旱流域水资源与植被协同机制为目标，在定量表达流域水资源可持续供给能力和植被生存能力基础上，明确流域水资源和植被的稳态变化规律，并将其系统地纳入流域生态水文恢复力量化模型构建中，进而实现对半干旱流域水资源与植被协同机制的定量揭示，为提升半干旱流域水资源和植被的稳态协同恢复能力提供科学依据与技术支撑。

Under the influence of climate change and continuous vegetation resilience, the characteristics of underlying surface in semi-arid basins in northern China changed significantly, and the occurrence of water resources has been greatly affected, which aggravates the dynamic changes of vegetation and leads to the continuous changes of water resources and vegetation in the basin. Whether the water resources and vegetation in the basin can be sustainable has become the focus and difficulty of current research. Ecohydrological resilience has become an important method to quantitatively reveal the synergistic mechanism of water resources and vegetation in watersheds by describing the ability of watersheds to maintain the stability of ecohydrological structure and function after disturbance. However, the existing methods have some deficiencies in the quantitative expression of the sustainable water supply capacity in the basin that characterizes
the steady-state transformation of water resources, the quantification of vegetation viability that reflects the steady-state transformation of vegetation, and the revelation of the synergy mechanism between water resources and vegetation.
In view of the above shortcomings, this study takes the semi-arid Hun river basin with vegetation restoration as the study area. Based on the systematic analysis of the variation of meteorological, hydrological and vegetation factors in the basin in the past 40 years, the dynamic evolution of water resources steady state and vegetation steady state in the study area was revealed by quantitative expression of sustainable water supply capacity and sustainable vegetation growth capacity in the basin. On this basis, two steady-state variation characteristics were systematically
incorporated into the study of ecohydrological resilience, and a watershed ecohydrological resilience quantitative model was constructed to reveal the co-evolution of water resources and
vegetation in the study area. The main achievements are as follows:
(1) Through data collection and processing, the temporal and spatial variation characteristics of meteorological, vegetation, hydrology and water resources in the basin were systematically
analyzed. The results showed that in the past 40 years, the climate of the basin was warm and humid with a significant increase in temperature, and a slow increase in precipitation and potential evapotranspiration. The water constraint effect in the forest area was smaller than that in the grass area. Under the influence of large-scale afforestation, the vegetation land in the basin became significantly green after 2000, and the forest coverage expanded significantly. The runoff of the whole basin showed a decreasing trend, but it has been increasing slowly since 2000. The surface runoff and net increment of soil water content were the main components that determines the spatial and temporal difference of water resources in the basin. The growth rate of shallow groundwater recharge was significantly higher than that of other components, but its content was much smaller than that of other components. This difference is related to the adaptability of water resources components to environmental changes.
(2) Under the influence of increased precipitation and dense forest and grass coverage, the sustainable water supply capacity in the basin improved since 2000. However, due to the lack of comprehensive consideration of the matching relationship between supply and demand of water
resources, the shortage of available water resources in most vegetation restoration areas has intensified, resulting in the sustainable water supply capacity in the basin decreasing from Class IV to Class III, and the interference of water resources from the rapid recovery of steady state to the reluctant recovery of steady state.The correlation between the fitness of water resources
components to environmental changes and the sustainable water supply capacity in the basin showed that surface runoff and net increment of soil water content were the key components affecting the temporal trend of vegetation available water resources in the basin. Although the vegetation available water resources increased during the changing period (2000-2020), which was 9.33 % higher than the baseline period (1982-1999), its conversion rate only increased by 1.94 %. Surface runoff, interflow and net increment of soil water content in different combinations became the main components of the spatial variation of vegetation available water resources in the basin. Since 2000, the more abundant vegetation available water resources have been expanding to the northwest of Qingshuihe County, where the grassland has become green obviously, and the conversion rate was as high as 79 %, and the scarce vegetation available water resources increased significantly in the west and east of Helingeer County and the southeast of Youyu County. The net increment of soil water content was the dominant factor affecting the spatial difference of vegetation available water resources in the basin.
(3) The vegetation in the watershed suffered from climate drying and water deficit pressure during the changing period decreased at a rate of 0.27/10a and 0.3/10a, respectively, which promoted the degradation of vegetation growth function, and the vegetation water deficit pressure in the forest restoration area of the basin decreased with the increase of soil water storage capacity. Affected by the increase of precipitation and the increase of forest and grass cover, the vegetation sustainable growth ability in the basin increased from class II to class IV, and the vegetation steady
state was improved from unable to recover to recover quickly after being disturbed, especially in the dense forest area in the eastern part of the basin. Vegetation water deficit pressure was the main
interference factor affecting the steady-state change of vegetation in the basin. Since 2000, the interference factors affecting the steady-state change of vegetation in the eastern and northern
regions of the basin changed from dry climate to vegetation water deficit pressure, and the steadystate recovery ability of vegetation in the eastern region of forest land expansion was increasing
with the decrease of vegetation water deficit pressure.
(4) The average annual ecohydrological resilience of the basin during the changing period increased by 11.74 % compared with the baseline period. However, under the influence of the continuous decrease of the combined effect of ecohydrological anti-interference (10.71 %) and the continuous decrease of the improvement effect of human intervention (19.46%), the
ecohydrological resilience of the basin decreased from Class IV fluctuation to Class III (24.26 %) during the change period, and the steady state of water resources and vegetation in the basin
recovered from rapid synergistic recovery to reluctant recovery. Although the level of ecohydrological resilience in the areas with obvious forest and grass restoration in the basin increased from class I and class II in the baseline period to class III and class IV in the changing period, most areas were in the lower class III. The ecohydrological resilience of the grassland restoration area decreased with the decrease of the combined effect of ecohydrological antiinterference, and it is urgent to strengthen the improvement of the grassland ecological environment. The ecohydrological resilience of the forest restoration area increased (decreased) with the improvement (deterioration) of the ecohydrological anti-interference synergy, and decreased with the weakening of the improvement effect of human intervention. It is urgent to rationally plan the planting distance and structure of forest trees. In addition, according to the grade and change trend of ecohydrological resilience in the basin, the spatial pattern of adaptive management types of ecohydrological resilience in the basin was clarified, and the strategy of improving the steady-state synergistic resilience of water resources and vegetation in the basin was proposed according to local conditions.
This paper aims to reveal the synergistic mechanism of water resources and vegetation in the semi-arid basin. Based on the quantitative expression of the sustainable water supply capacity and the sustainable vegetation growth capacity in the basin, the steady-state variation laws of water resources and vegetation in the basin were clarified, and it was systematically incorporated into
the construction of the quantitative model of watershed ecohydrological resilience, so as to quantitatively reveal the synergistic mechanism of water resources and vegetation in the semi-arid basin, and provide scientific basis and technical support for improving the steady-state synergistic recovery ability of water resources and vegetation in the semi-arid basin.