Despite the Yangtze River Basin (YRB)’s abundant land and forestry resources, there is still a dearth of research on forecasting habitat quality changes resulting from various geographic and environmental factors that drive landscape transformations. Hence, this study concentrates on the YRB as the focal area, with the aim of utilizing the Patch Landscape Upscaling Simulation model (PLUS) and the habitat quality model to scrutinize the spatial distribution of landscape patterns and the evolution of HQ under four scenarios: the natural development scenario (NDS), farmland protection scenario (CPS), urban development scenario (UDS), and ecological protection scenario (EPS), spanning from the past to 2030. Our results show that (1) from 2000 to 2020, the construction land in the YRB expanded at a high dynamic rate of 47.86% per year, leading to a decrease of 32,776 km² in the cultivated land area; (2) the UDS had the most significant expansion of construction land, followed by the NDS, CPS, and EPS, which had higher proportions of ecologically used land such as forests and grasslands; (3) from 2000 to 2020, the HQ index ranged from 0.211 to 0.215 (low level), showing a slight upward trend, with the most drastic changes occurring in the low-level areas (−0.49%); (4) the EPS had the highest HQ (0.231), followed by the CPS (0.215), with the CPS increasing the HQ proportion of the lower-level areas by 2.64%; (5) and in addition to government policies, NDVI, DEM, GDP, and population were also significant factors affecting landscape pattern and changes in habitat quality.

Under the influence of climate alteration and human activities, the hydrological regime of rivers is changing dramatically, which has become a hot spot for water environment research. In this study, we quantitatively assessed the degree of hydrological variability of the Jialing River and the contribution of climate alteration and human activities to hydrological alterations using the ecohydrological indicator range of alteration (IHA-RVA) method and Budyko hypothesis formulations. The results showed that (1) The average annual runoff and the precipitation of Jialing River showed a decreasing trend, the potential evapotranspiration showed an increasing trend. (2) Compared with before the hydrological situation changed, the degree of alteration in the annual extreme streamflow is 31%, which is a low degree of alteration; the degree of alteration in monthly streamflow, annual extreme flow magnitude, extreme flow ephemeris, and streamflow alteration frequency are 51%, 43%, 54%, and 64% respectively, which are all moderate degrees of alteration; the overall hydrological alteration is 50%, which belongs to moderate alteration. (3) The contribution of precipitation, potential evapotranspiration, and human activities to the runoff alteration is 61%, − 16%, and 55%, respectively. This study provides corresponding references for ecological restoration and sustainable development of the Yangtze River Basin in China.

Changes in climate and the underlying surface are the main factors affecting runoff. Quantitative assessment of runoff characteristics, and determination of the climate and underlying surface contribution to changes in runoff are critical to water resources management and protection. Based on the runoff data from the Wulong Hydrological Station, combined with the Mann-Kendall test, Indicators of Hydrologic Alteration (IHA), Budyko hypothesis, and changes in climate and the underlying surface, this study comprehensively analyzed the runoff in the Wujiang River Basin (WRB). The results showed that: (1) The annual runoff of Wujiang River showed a downward trend, and an abrupt change occurred in 2005. (2) The overall hydrological change in WRB is 46%, reaching a moderate change. (3) The contribution rates of precipitation (P), potential evaporation (ET₀), and underlying surface to runoff changes are 61.5%, 11.4%, and 26.9%, respectively. (4) After 2005, the WRB has become more arid, human activities have become more active, vegetation coverage has increased, and the built-up land has increased significantly.

Construction of water conservancy projects has changed the hydrological situation of rivers and has an essential impact on river ecosystems. The influence modes of different factors on runoff alterations are discussed to improve the development and utilization of water resources and promote ecological benefits. The ecological hydrological indicator change range method (IHA–RVA) and the hydrological alteration degree method were integrated to evaluate the hydrological situation of the Min River in China. Based on six Budyko hypothesis formulas, the rates of contribution of climate change and human activities to runoff change are quantitatively analyzed. The results show that (1) the runoff of the Min River basin showed a significant decreasing trend from 1960 to 2019 and a sudden alteration around 1993; (2) the overall alteration in runoff conditions was 45% moderate and the overall alteration in precipitation was 37% moderate; (3) precipitation and potential evapotranspiration also showed a decreasing trend within the same period but the overall trend was not significant; (4) the contribution of climate variability to runoff alterations is 30.2% and the contribution of human activities to runoff alterations is 69.8%; human activities are the dominant factor affecting the alteration of the runoff situation in the Min River basin.

The flow regime is regarded as the key driver of the structure and function of riverine ecosystems. This study uses an ecologically meaningful indicator (range of variability approach method) to assess the dynamic runoff process in the middle and lower reaches of the Yangtze River, whose changes negatively affect the ecosystems in the study area. In addition, the study quantitatively analyzed the contribution rate of human activities and climate change to flow change. The effects of ecological index changes on four famous major carp species (FFMC) resources in the middle and lower reaches of the Yangtze River were studied. The results show that after the Three Gorges Dam (TGD) operation, the hydrological changes of Yichang Station, Hankou Station, and Datong Station were 65, 58, and 46%, respectively. The weight of the impact of human activities on runoff is smaller the farther away from the TGD. The impact weights of human activities at the three hydrological stations in the middle and lower reaches of the Yangtze River are 73.69, 67.98, and 56.84%, respectively. The operation of the Three Gorges Project caused changes in the hydrological regime of the Yangtze River, which adversely affected the structure and quantity of FFMC populations.

Ecological flow is a key element in maintaining the biodiversity of a basin's aquatic ecosystem. This study quantifies the degree of hydrological regime alteration in the Jialing River and the contributions of various driving factors using the indicators of hydrologic alteration and range of variability approach (IHA-RVA), the river impact method (RI), and the elasticity coefficient method based on long-term hydro-meteorological data. Cross-wavelet analysis is used to reveal the periodicity and coherence of runoff and driving factors. Additionally, the improved Q90 method presents a more effective annual ecological flow process. The results show that the overall hydrological regime in the Jialing River has undergone a moderate change, with RVA and RI values of 45.02% and 0.66. Human activities contribute 54.68% to the changes in streamflow. Streamflow has an extremely significant correlation with precipitation and aridity index (Φ). Approximately 85% of the wavelet cone of influence (COI) area, tested at a 95% confidence level, falls within the region. The study also found that the ecological flow obtained through the improved Q90 method is more conducive to the healthy development of the river ecosystem in the Jialing River. These findings can provide some assistance for aquatic ecosystem restoration in the Jialing River.