Water Conservation Function Research Articles

Response of Runoff-Sediment System to Vegetation Variation in the Yellow River Basin in the Last 20 Years

The Yellow River basin suffers from the most serious soil erosion of any area in the world. It is also a key area for soil–water conservation and ecological protection in China. It is important to determine the status of the ecological protection of the Yellow River basin in recent years. We examined the vegetation patterns and spatio-temporal changes in runoff sediment in the Yellow River basin in the last 20 years. The results can provide a sound basis for regional ecological management. Vegetation coverage in the Yellow River basin has increased in the last two decades. The natural runoff has more than doubled over this time and the runoff coefficient has increased by more than 30%. However, the growth in the measured runoff has significantly weakened owing to continually high water consumption. The sediment concentration from Toudaoguai to Tongguan has decreased by 74.11% and the sediment modulus has decreased by 34.75%. Ecological protection of the Yellow River has significantly improved the vegetation coverage since 2000. The functions of water and soil conservation have improved, but the latter function needs to be strengthened. In addition, measures for ecological protection are needed to strengthen the overall management of water resources.

Trade-off and synergistic relationship of land use function and zoning in coastal saline-alkali area: A case study of Huanghua, Hebei, China

Analyzing the multi-functional evolution of land use can help solve the confusion in the relationship between land use functions and unreasonable land use structure. From the perspective of ecological security, we integrated multi-source data on the basis of quantitative evaluation of various land use functions, and used the method of combining band set statistical model and bivariate local Moran's I to measure the dynamics of trade-off and synergy relationship between land use functions in Huanghua, Hebei from 2000 to 2018, and divided land use functional areas. The results showed that production function (PF) and life function (LF) showed the alternate evolution of the trade-off and synergy relationship, which mostly occured in the central urban areas such as the southern region. The PF and ecological function (EF) was mainly based on the synergistic relationship, which mostly occured in the traditional agricultural areas in the west region. The degree of synergy between LF and water conservation function (WCF) first increased and then decreased, with obvious regional differences in the degree of synergy. LF and soil health function (SHF)/ biological diversity function (BDF) was dominated by trade-off relationship, which mostly occured in western saline-alkali land and coastal areas. The performance of multiple EF was the mutual transformation of trade-offs and synergies. The land space of Huanghua could be divided into six types of areas, agricultural production area, urban development core area, urban and rural optimized development area, renovation and improvement area, nature reserve area, and ecological restoration area. There were differences in the dominant mode of land function and optimization strategies in each area. This research could provide scientific refe-rence for clarifying land function relationship and optimizing land spatial development pattern.

Evaluation of the Protection Effectiveness of Natural Protected Areas on the Qinghai-Tibet Plateau Based on Ecosystem Services.

Evaluating the protection effectiveness of natural protected areas is an important step in successful management. Adopting 330 natural protected areas on the Qinghai-Tibet Plateau as research subjects, the regional dominant ecosystem service function was selected, and various temporal and spatial analysis methods were employed to analyze the evolution characteristics and influencing factors of ecosystem service patterns from 2000 to 2020. Our results indicated that (1) the water conservation function stabilized after fluctuation and decline, the soil conservation function fluctuated upward, and the windbreak and sand fixation function exhibited an increase after a decreasing fluctuation. (2) The protection effectiveness of25 protected areas significantly improved, that of 151 protected areas improved, that of 84 protected areas stabilized, that of 56 protected areas worsened, and that of 14 protected areas significantly worsened. (3) The top three influencing factors in descending order were precipitation change > altitude > mining area density. (4) Remarkable protection results were achieved in national protected areas, established management institutions, earlier established areas (before 2000), and areas exhibiting alow built-up area density (<0.75%) and low mining density (<1%). Our study provides technical support for the construction and management of protected areas and improvement in ecosystem service functions on the Qinghai-Tibet Plateau.

The impact of multi-scenario land use change on the water conservation in central Yunnan urban agglomeration, China

As an important ecosystem service, water conservation is consistently disturbed and influenced by human activities. Land use change, as one of the main human influences, has extensive and far-reaching impacts on water conservation. Therefore, it is of great practical significance to accurately assess the impact of future land use changes on water conservation. Taking the central Yunnan urban agglomeration (CYUA) as an example, coupled with the PLUS-InVEST model, four scenarios of natural development (NDS), urban development (UDS), cropland protection (CPS) and ecological protection (EPS) were set to simulate the impact of land use change on water conservation under different planning scenarios in 2035, revealing the response mechanisms to land use change. The results showed that (1) under different planning scenarios, there were obvious differences in regional land use changes, and the expansion effect of construction land under the NDS, UDS, and CPS was significant, with increases of 27.54%, 27.95%, and 21.19%, respectively, compared with 2020. Under the EPS, the expansion rate of construction land was effectively controlled, and the growth rate was only 0.64%. (2) The EPS optimized the water conservation capacity of the CYUA, while the regional water conservation capacity showed a varying declining trend under the NDS, the CPS and the UDS. (3) The occupation of grassland by construction land and forestland was the main reason for the deterioration of the water conservation function of the urban agglomeration in central Yunnan. The results of this study can provide a reference for national land space planning, the efficient use of land resources and ecological environmental protection of the CYUA.

Evaluation of landscape ecological risk in key ecological functional zone of South–to–North Water Diversion Project, China

The key ecological functional zone plays a significant role in maintaining ecosystem security, water conservation function and environmental protection. However, owing to rapid industrialization and urbanization, some ecological functional zones have undergone great changes in land use, which has changed the landscape pattern characteristics and resulted in ecological risks, affecting the regional ecological environment and water security. In this study, the core water source area of the Middle Route of China’s South–to–North Water Diversion Project is selected as the case study. A regional landscape ecological risk index (ERI) was constructed to evaluate the landscape ecological risk driven by land use transformation. Moreover, the ERI's spatiotemporal characteristics were investigated using a combination of geographic information systems and geostatistical techniques, which reveal the dominant land use function types associated with ecological risks and their causes. We found that (1) there was not a notable shift in land use, and the level of ecological risk increased slightly from 2010 to 2015. The conversion of previously unproductive land into places for industrial production land and agricultural productive land played a significant role in this phenomenon. From 2015 to 2020, the Danjiangkou Reservoir officially started operation. Furthermore, the improvement of residents’ awareness of environmental protection and natural forest land significantly reduced the ecological risk. (2) The ecological risk has a strong positive autocorrelation, exhibiting a pattern of high in the east and center, low in the west and periphery. (3) An obvious corresponding relation exists between the impacts of topography, soil, and climate on patterns of land use and ecological risk. Additionally, the strict ecological protection policies implemented by the Chinese government have realized remarkable achievements in promoting the improvement of ecological risks. Our study can provide a decision–making basis for the local authorities to conduct ecological risk prevention activities and ensure the sustainable northward flow of clean water.

Spatial and Temporal Evolution and Driving Mechanisms of Water Conservation Amount of Major Ecosystems in Typical Watersheds in Subtropical China

The water conservation function of ecosystems is a research hot spot in the field of water resources, and it is also an important ecological service function of terrestrial ecosystems and a key point in eco-hydrology research. With the increasing frequency of human activities and climate change, how to reveal the response of ecosystem water conservation function to the changing environment is a scientific problem that needs to be urgently addressed in ecological hydrology research. To reveal the eco-hydrological processes under the changing environment, this study was based on the distributed hydrological model (SWAT) and used water conservation amount (WCA) as an indicator to assess the water conservation capacity of ecosystems. Scenario analysis and statistical analysis were also used to determine the spatial and temporal evolution of the WCAs of farmland, forest, and grassland ecosystems under a changing environment and to further investigate the influence mechanisms of land use change and climate change on the WCA. The findings show that (1) the climate conditions in the Hanjiang watershed have determined the distribution pattern of the ecosystem’s WCA. The spatial distribution patterns of the WCA of each ecosystem differed significantly between the dry season and the wet season. Under the combined influence of human activities and climate change, there was no significant change in the spatial distribution pattern of the WCA. (2) Climate change patterns, which were dominated by precipitation and influenced by evapotranspiration, determined the changes in the WCA of ecosystems. In addition, there were significant spatial differences in the response of the watershed WCA under changing environments in the dry season. Differences in land use type and local climate change were the main reasons for such differences. (3) There were differences in the WCA and the response to changing environments among ecosystems. Forest ecosystems had the highest WCA; grassland ecosystems were the most sensitive to land use change. This study can provide a theoretical basis for alleviating the increasingly serious water resource problems in the basin and ensuring water and ecological security in the basin.

气候变化驱动下黄土高原刺槐林气候适宜性和脆弱性

PDF HTML阅读 XML下载 导出引用 引用提醒 气候变化驱动下黄土高原刺槐林气候适宜性和脆弱性 DOI: 10.5846/stxb202003140544 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目(42141007, 41877539);中国气象科学研究院基本科研业务费专项(2020Z004) Climate suitability and vulnerability of Robinia pseudoacacia forest driven by climate change on the Loess Plateau Author: Affiliation: Fund Project: 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:刺槐是黄土高原乡土树种,具有优良的水土保持和固碳功能。黄土高原生态恢复实践中实施了大规模的植树造林,刺槐林面积占沟壑丘陵区人工植树造林面积90%以上。由于种植时没有考虑刺槐的气候适宜性,一些地区的刺槐林出现了退化现象。采用最大熵模型,在0.5km×0.5km空间精度上分别模拟了1961-1990、1966-1995、1971-2000、1976-2005、1981-2010,以及2100年(典型浓度路径RCP4.5和RCP8.5气候情景下)黄土高原刺槐的气候适宜性和敏感性。模拟结果显示:黄土高原刺槐分布及其动态变化主要受到最冷月温度、极端低温、降水量、年辐射量等气候因子影响,低温(最冷月温度、极端低温)是影响刺槐的最关键因子。黄土高原西北和北部广大地区,自然环境条件不适合刺槐林生长;黄土高原东南部(关中平原和山西南部)比较适合刺槐生长。相对1961-1990年,1961-2010年期间刺槐林适宜区分布格局基本没有改变,RCP4.5和RCP8.5气候情景下刺槐林适宜区分布格局也没有显著改变。图层叠加分析发现,刺槐的气候适宜度(即存在概率)发生了明显改变。黄土高原西部和北部属于不适宜刺槐生长的非敏感区,东部和东南部是适宜刺槐生长的区域,尤其是山西中南部和陕西关中平原对气候变化非常敏感,展示了刺槐气候脆弱性的一面。研究结果对植树造林,优化人工林空间分布格局,应对气候变化风险和维持黄土高原森林生态系统可持续健康发展具有重要参考价值。 Abstract:Robinia pseudoacacia is a native tree species on the Loess Plateau, which has excellent functions of soil and water conservation, and carbon sequestration. Large scale afforestation was carried out in the practice of ecological restoration in the Loess Plateau, and the area of Robinia pseudoacacia forest accounted for more than 90% of artificial afforestation in the gully and hilly areas. However, Robinia pseudoacacia forest degenerated in some areas because climate suitability of Robinia pseudoacacia was not considered during afforestation. In this study, MaxEnt (maximum entropy model) was used to simulate the climate suitability and sensitivity of Robinia pseudoacacia on the Loess Plateau in 1961-1990, 1966-1995, 1971-2000, 1976-2005, 1981-2010, and 2100 (under the climate scenarios of Representative concentration pathway RCP4.5 and RCP8.5, respectively) at the spatial resolution of 0.5 km × 0.5 km. The simulation results showed that the distribution and dynamic changes of Robinia pseudoacacia on the Loess Plateau were mainly affected by the coldest month temperature, extreme low temperature, annual precipitation, annual radiation and other climate factors. Low temperature (the coldest month temperature, extreme low temperature) was the most important factor affecting Robinia pseudoacacia. The natural environment was not suitable for Robinia pseudoacacia forest in the northwest and the north of the Loess Plateau, but it was suitable in the southeast (the Guanzhong Plain and the south of Shanxi Province) of the Loess Plateau. Compared with the period of 1961-1990, the geographical distribution pattern of Robinia pseudoacacia forest was basically unchanged during 1961-2010, and its geographical distribution pattern was not significantly changed under the climate scenarios of RCP4.5 and RCP8.5. Overlay analysis showed that climate suitability (namely exist probability) of Robinia pseudoacacia changed significantly. The regions in the west and north of the Loess Plateau were not suitable for Robinia pseudoacacia, where belonged to non-sensitive areas. The regions in the east and southeast were suitable for Robinia pseudoacacia, where was very sensitive to climate change, especially in the south central of Shanxi Province and the Guanzhong Plain in Shaanxi Province, showing significant climate vulnerability. This study has important reference value for choosing suitable area for afforestation, optimizing the spatial distribution of plantation, coping with climate change risk, maintaining the sustainable and healthy development of forest ecosystem on the Loess Plateau. 参考文献 相似文献 引证文献

Decadal Changes in Soil Water Storage Characteristics Linked to Forest Management in a Steep Watershed

Soil water storage properties, which are affected by land management practices, alter the water balance and flow regimes in watersheds; thus, it is highly plausible to clarify the influence of such management practices on the water storage condition by analyzing the long-term variations in discharge. In this study, the changes in soil water storage characteristics of the Ogouchi Dam watershed, which had undergone intensive forest management through the decades, were investigated using two approaches. Reported results from the rainfall–runoff correlation analysis show a gradual and steady increase in the soil water storage capacity at weaker continuous-rainfall events, i.e., uninterrupted wet days accumulating less than 70 mm. Meanwhile, the second approach utilizing the parameter calibration in the SWAT discharge model illustrated a constant trend in the runoff potential and the high possibility of a steady improvement in the soil available water capacity. Overall, the established decadal trends were able to prove the capability of sustainable forest management, i.e., thinning, regeneration cutting, multi-layer planting, deer-prevention fences, and earth-retaining fences (lined felled trees), in improving the water conservation function of the catchment.

Assessing the Water Conservation Function Based on the InVEST Model: Taking Poyang Lake Region as an Example

This paper analyzes the spatiotemporal patterns, water yield and water conservation function of different land use types in Poyang Lake Region, China, during 1990–2020 by using national land use, meteorological, soil, DEM data, etc., based on the InVEST model. The results showed that: (1) Cultivated land, forestland and water area were the main land use types in Poyang Lake Region during 1990–2020. Construction land and forestland were increasing, while grassland, unused land, cultivated land and water area were decreasing. (2) The increasing construction land was mainly derived from cultivated land. Mutual transfer existed between cultivated land and forestland, as well as between cultivated land and water area. (3) With a downward–upward–downward fluctuating trend, the average annual water yield of Poyang Lake Region was 16.17 × 109 m³, and the water conservation was 53.11 × 108 m³. The average water conservation capacity was 270.98 mm. The vegetation cover area with high water conservation value was mainly concentrated in the northwest of Jiujiang City and the northeast of Poyang County. (4) The average water conservation of different land use types during 1990–2020 was ranked as follows: water area &gt; cultivated land &gt; forestland &gt; construction land &gt; grassland &gt; unused land. The water conservation capacity was ranked as follows: water area &gt; grassland &gt; forestland &gt; cultivated land &gt; construction land &gt; unused land.

How Does the Water Conservation Function of Hulunbuir Forest–Steppe Ecotone Respond to Climate Change and Land Use Change?

The scarcity of water resources is becoming a global focus, and water conservation has become one of the most crucial service functions in the water security and sustainable development of ecosystems. Hulunbuir forest–steppe ecotone, as an important water conservation area in the northeastern provinces of China, plays an irreplaceable role in Northeastern China. However, the water yield and water conservation are rarely understood in the ecotone. In this study, the InVEST model was employed to analyze the spatiotemporal dynamics of water yield and water conservation from 2000 to 2020. Meanwhile, we explored the response of water conservation to climatic factors and human disturbance. The results demonstrated that water yield and water conservation presented a decreasing trend in the first decade and then increased. The land use transfer obvious from 2000 to 2010, and most vegetation types were converted into unused land. This transition intensified reduction of water conservation. The main factor affecting the water conservation was climate Precipitation had the greatest impact on water conservation. The findings of this study have great and important implications for regional sustainable water resource management and ecological protection policies and provide a convenient method for evaluating water conservation in other areas that are lacking climate, hydrology, and geological data.

Evaluation of soil and water conservation function in the Wugong mountain meadow based on the comprehensive index method

Wugong Mountain meadow landscape is well-known both at home and abroad because of its ornamental value. Our study aimed to comprehensively evaluate the function of soil and water conservation at different altitudes of Wugong Mountain meadow soil. The hydro-physical characteristics, including the soil bulk density, porosity, water content, water holding capacity, and permeability of meadow soil at 1600 m–1900 m altitudes, were analyzed. The results showed that the mountain meadow soil's hydro-physiological characteristics and water conservation function significantly differed with altitude. However, the trend of each index did not follow the same law with altitude change. There was a decrease in bulk density of the soil from 1700 m to 1900 m, but a significant increase in porosity and water-holding capacity. Despite the higher porosity and water holding capacity found at 1600 m than at 1700 m and 1800 m, a similar bulk density was found at 1600 m as 1700 m. In addition, the bulk density in the 0–20 cm layer was lower than that in the 20–40 cm layer, while the porosity and water-holding capacity were higher. A higher sequence of soil water conservation capacity was found in soil layers 0–20 cm depth at 1900, 1600, 1800, and 1700 m; in soil layers 20–40 cm depth, it was at 1900, 1800, 1700, and 1600 m. The study found that the sequence of the comprehensive performance of soil water conservation function was at 1900, 1600, 1800, and 1700 m altitudes in the Wugong mountain meadow area. Our comprehensive study of soil water conservation capacity provides a theoretical basis for the rational use of mountain meadow resources in subtropical regions.

Transcriptome and metabolome analyses of lignin biosynthesis mechanism of Platycladus orientalis.

Platycladus orientalis, as an important plant for ecological protection, is a pioneer tree species for afforestation in arid and barren mountainous areas. Lignin has the functions of water and soil conservation, strengthening plant mechanical strength and resisting adverse environmental effects and plays an important role in the ecological protection benefits of P. orientalis. In this study, annual dynamic observations of the lignin content in roots, stems and leaves of one-year-old seedlings of a P. orientalis half-sib family were carried out, and combined transcriptome and metabolome analyses were carried out during three key stages of P. orientalis stem development. The lignin contents in roots, stems and leaves of P. orientalis showed extremely significant spatiotemporal differences. In the stems, lignin was mainly distributed in the cell walls of the pith, xylem, phloem, pericyte, and epidermis, with differences in different periods. A total of 226 metabolites were detected in the stem of P. orientalis, which were divided into seven categories, including 10 synthetic precursor compounds containing lignin. Among them, the content of coniferyl alcohol was the highest, accounting for 12.27% of the total content, and caffeyl alcohol was the lowest, accounting for 7.05% only. By annotating the KEGG functions, a large number of differentially expressed genes and differential metabolites were obtained for the comparison combinations, and seven key enzymes and 24 related genes involved in the process of lignin synthesis in P. orientalis were selected. Based on the results of the metabolic mechanism of lignin in P. orientalis by biochemical, anatomical and molecular biological analyzes, the key regulatory pathways of lignin in P. orientalis were identified, which will be of great significance for regulating the lignin content of P. orientalis and improving the adaptability and resistance of this plant.

How to design an ecological restoration project in fragile inland basins: A case study in arid regions of China

Ecological protection is the basis for sustainable development of inland river basins in arid areas with fragile ecological environments. The aim of our study is to diagnose the ecological problems and build the ecological security pattern (ESP) of the Aksu River basin (ARB) in Xinjiang which is located in northwest of China. The spatial measurement of ecosystem service value (ESV) was employed to identified ecological problems. Using cold/hot spot detection analysis and the minimum cumulative resistance (MCR) model, the ESP at three security levels were constructed. The results showed that the ESV of ARB showed an upwards trend from 1990 to 2018, the function of water conservation, waste treatment and soil formation and retention grew fastest. The ESV of ARB in 2018 ranged from 5390 yuan/hm 2 to 131,080 yuan/hm 2 . The high-value areas were mainly located in the oasis and the northern mountainous, the low-value areas were widely distributed in desert. The ecological source areas of high, medium and low safety levels were 1806.30 km 2 , 3416.80 km 2 and 4804.32 km 2 , respectively. Three kinds of ecological protection engineering models were proposed for the four types of ecological protection zones based on the ecological problem identification in ARB. To provide a decision-making basis for ecological environmental management and regional sustainable development in the ARB, the optimization patterns of points (ecological protection projects), lines (ecological corridors) and polygons (ecological source areas) were constructed. The results of this study can also serve as a reference for ecological environmental protection in other arid inland river basins.

Spatiotemporal variations of water conservation function based on EOF analysis at multi time scales under different ecosystems of Heihe River Basin

Water conservation function is a critical terrestrial ecosystem service in providing water supply and achieving water security, which has raised concerns under the pressure of climate change. However, the knowledge of variance on multi-time scale, spatiotemporal dynamic, and ecosystem variance of water conservation is insufficient. In this paper, the annual, monthly, and daily scales of water conservation and the spatiotemporal pattern of monthly water conservation were estimated based on the SWAT model from 2010 to 2020 in the Heihe River Basin (HRB). Additionally, EOF (Empirical orthogonal function) analysis was conducted to decompose the time series of water conservation function distribution into temporal coefficients and spatial patterns. The HRB was categorized into six representative ecosystems with three slope grades to illustrate the variance of water conservation function. The annual water conservation depth (WC) slightly decreased (−10.36 mm/10a) from 2010 to 2020, the monthly WC was dominated by the effects of seasonal variation, and the daily WC was highly nonlinear. The high variability and importance region is mainly located in the upstream and the central area of midstream, which deserves more attention for ecological management and priority protection. Moreover, the forest ecosystem is of the highest resilience and great ecological significance, which increased risk of reduced water conservation under the lack of precipitation. Even in a forest-dominated basin, water conservation can be impacted by other ecosystems with the strong influence of human activities. Our results provide scientific evidence for the improvement of water conservation capacity and making the adapted land use policy in Yellow River basins.

Evaluation of Soil and Water Conservation Function in Dingxi City, Upper Yellow River Basin

Dingxi City is located in the upper reaches of the Yellow River Basin, at the intersection between the Loess Plateau and West Qinling Mountains. The water and soil conservation function of Dingxi City is very important and have become key constraining factors for economic and social development. Due to the fragmented terrain and landscape patches, high spatial accuracy in the assessment of water and soil conservation is required for proper management. In this study, we introduced an index system for the evaluation of soil and water conservation functions, including various influencing factors. The results showed that area percentages of the five levels (lower, low, medium, high, and higher) in soil conservation were 6.24, 6.25, 23.49, 30.95, and 33.07, respectively, and the areas with higher soil conservation were mainly concentrated in the hilly and gully areas of the Loess Plateau with low vegetation coverage. The percentages of water conservation in the five levels (lower, low, medium, high, and higher) were 40.49, 21.78, 16.66, 7.9, and 13.11, respectively, and the areas with higher water conservation were concentrated in Min County and Zhang County, with the most abundant precipitation and highest vegetation coverage. In addition, functional areas of soil and water conservation had obvious spatial heterogeneity. Among them, the proportion of high-grade functional areas for soil conservation decreased with an increase in precipitation, whereas a high proportion of high-grade functional areas for water conservation was concentrated in areas with precipitation of more than 600 mm. The conflict between agricultural production and ecological protection of soil and water conservation is prominent, and areas with serious conflict are concentrated in the central and northern areas of Dingxi City. Based on this, we suggest a spatial layout guidance for agricultural production and ecological protection, providing a scientific basis for decision-making that supports ecological protection and high-quality sustainable development in Dingxi City.

Impacts of Climate Change and Human Activities on Streamflow of Upper Yongding River Basin, North China

Streamflow in semiarid areas, especially in North China, was rapidly decreasing, which made it important to analyze the characteristics and influencing factors of streamflow. Using the hydro-meteorological data series of 1961–2017 in the upper Yongding River Basin (UYRB) (including the Yang River Basin (YRB) and Sanggan River Basin (SRB)), spatio-temporal variation characteristics of air temperature, precipitation, and potential evapotranspiration (E0) were analyzed. The results showed that precipitation has no significant trend; the temperature showed a significant increase of 0.1–0.5 °C per decade; E0 showed a significant decrease of approximately −2 mm/10yr (in 18 stations); the estimated rates of streamflow change were −7 and −8 mm/10yr for SRB and YRB. As for spatial distribution, the YRB presented a higher E0 value than the SRB; the mountain areas had more precipitation than the plain areas. The change points of streamflow occurred in 1982 and 2003. Both the Budyko and the DMC methods were used to evaluate the impacts of climate change and human activities on the mean annual streamflow. In variation stage I (1983~2003), impacts of human activities account for 90.6% and 62.7% of the mean annual streamflow changes in YRB and SRB, respectively. In variation stage II (2004~2017), the percentages were 99.5% and 93.5%, respectively. It is also noted that the first change point in streamflow was indeed at the beginning of China’s land reform, when the farmers could manage their reallocated lands and, therefore, there was an increase in agricultural water consumption. The second change point coincided with “Capital Water Resources Planning”, including water conservation projects and irrigation district construction programs. In general, human activities were mainly responsible for the significant decline in the annual streamflow of UYRB. This paper will provide valuable results for water resources planning and give guidance on the construction of water conservation function areas and ecological environment support areas in the capital.

Ecosystem Service Assessment and Sensitivity Analysis of a Typical Mine–Agriculture–Urban Compound Area in North Shanxi, China

The production–life–ecology balance in mine–agriculture–urban compound areas is receiving increasing attention in the context of urbanization and industrialization. This study aims to explore the coordinated development modes of ecosystem services and resident well-being in the Pingshuo open-pit mining area and the surrounding mine–agriculture–urban compound area in Pinglu District, Shuozhou City. Relevant models were used to evaluate the ecosystem service value of water and soil conservation, as well as ecological sensitivity. Additionally, using the hierarchical multiple regression method, we analyzed the responses of soil and water conservation services and ecological sensitivity to different land use patterns. The results showed the following. (1) The water conservation function (WCF) and soil conservation function (SCF) were greatly affected by land use and supplied mostly by the natural habitat, followed by the open-pit coal mining area. (2) Ecological sensitivity was greatly affected by land use patterns, with obvious differences in the same land use types in different spatial locations. (3) In order to enhance the WCF and SCF of the study area and reduce ecological sensitivity, the area and diversity of forest and grassland should be increased, and the area of open-pit mining, cultivated land, and urban land, as well as the land use compound degree, should be reasonably controlled. This study will help guide the regional land use layout and provide countermeasures and suggestions for the management of ecosystems in the mine–agriculture–urban compound area.

Ecological–Economic Assessment and Managerial Significance of Water Conservation in the Headwaters of the Yellow River

The water conservation function plays a vital role in the land–water cycle. As the “Chinese water tower”, the headwaters of the Yellow River are of great significance to the safety of the Yellow River basin and even the global ecosystem. Taking the grassland ecosystem in the Yellow River source area as the research object, the InVEST water yield model with modified parameters and the ecological value evaluation of the modified equivalent factor method were used to explore the simulated spatio-temporal changes and the value of grassland water conservation from 2001 to 2020. The results show that: (1) the average total amount of water conservation in the source area is 549 × 108 m3, which is 16% of the runoff in the Yellow River basin, with a growth rate of 7.5 mm/year 1 and a contribution rate of 30%; (2) the total ecological value of grassland water conservation in 2020 is USD 340.03 × 108. The proportion of improved grassland in ecological restoration and management is only 0.51%, while the proportion of original alpine meadow reaches 67% and its ecological function and value are irreplaceable; (3) based on the comprehensive indicators of water conservation capacity, value and importance, Qumalai, Chengduo and Maduo counties are ranked as priority areas for the ecological protection of water resources.

Spatiotemporal variations of water conservation and its influencing factors in ecological barrier region, Qinghai-Tibet Plateau

Study regionThe ecological barrier region is located in the northeastern of the Qinghai-Tibet Plateau, western China, serves as an important ecological security barrier and water conservation zone. Owing to its unique geographical location, this region has a sensitive and fragile ecosystem. Study focusThis study comprehensively quantified the water conservation volume, analyzed the spatiotemporal variations and its influencing factors, predicted the future changes of water conservation under different climate scenarios. New hydrological insights for the regionThe results showed that the average water conservation volume of the ecological barrier region was approximately 254 × 108 m3 from 1980 to 2019 with a increasing trend. The spatial distribution of water conservation showed a decreasing trend from southeast to northwest. There is a significant positive correlation between precipitation and water conservation (P < 0.01), the water conservation function in the area with elevation between 3 500–4 500 m and slope less than 10°is obviously stronger than other areas. From 2021–2100, the overall trend of water conservation in the study region is increasing, only part of the Yellow River source’s water conservation has a decreasing trend. This research provides scientific support for optimal allocation of water resources and sustainable development in alpine regions.

The Water Storage Function of Litters and Soil in Five Typical Plantations in the Northern and Southern Mountains of Lanzhou, Northwest China

Soil and water conservation is an important function of forest ecosystems; however, it remains unclear which forest type is best suited for water and soil conservation under the same site conditions. In order to clarify the soil and water conservation function of different plantations in the northern and southern mountains of Lanzhou city, we investigated several soil and water conservation function indicators (thickness and accumulation of litter, maximum water holding capacity and rate of litter, water holding capacity and water absorption rate of litter, soil infiltration rates, soil water content, soil bulk density, soil porosity, and soil water storage) of five plantation types (Platycladus orientalis plantations (Po), Robinia pseudoacacia plantations (Rp), Populus alba var. pyramidalis plantations (Pa), P. alba var. pyramidalis + R. pseudoacacia mixed plantations (Pa + Rp), and P. orientalis + R. pseudoacacia mixed plantations (Po + Rp)) and evaluated them using the gray correlation method. The results indicated the accumulation of litter varied from 13.50 to 47.01 t·hm−2 and increased in the order of Pa &lt; Rp &lt; Po &lt; Po + Rp &lt; Pa + Rp. The maximum water holding capacity of litter varied from 35.29 to 123.59 t·hm−2 and increased in the order of Pa &lt; Rp &lt; Po &lt; Po + Rp &lt; Pa + Rp. The soil physical properties (soil infiltration, porosity, and bulk density) of mixed plantations were better than those of pure plantations. The soil maximum water storage was significantly different among plantation types (p &lt; 0.05), with an average varying from 3930.87 to 4307.45 t·hm−2, and was greater in mixed plantations than in pure plantations. Gray correlation analysis revealed that mixed plantations had the best conservation function of the five plantation types, followed by broad-leaved plantations and coniferous plantations. This suggests that the planting of mixed plantations dominated by Pa + Rp is therefore recommended in the future construction of plantations in the northern and southern mountains of Lanzhou to realize sustainable forest development.