Ecohydrology & Hydrobiology最新文献

The investigation of the correlation between groundwater and surface water in terms of water origin and transformation is crucial for comprehending hydrological processes . Focuses on the Wulagai river and Xiliugou river basin located in East and West Inner Mongolia. It employs hydrochemical analysis and stable HO isotopes techniques to investigate the hydrochemical properties of the basin and quantitatively assess the interconversion between groundwater and surface water. The results suggest that the Xiliugou and Wulagai river basins were originally nourished by atmospheric precipitation, with lower δD and δ¹⁸O values in groundwater compared to surface water, attributed to factors such as evaporation, water vapor source, altitude, and latitude. The surface waters in the Xiliugou and Wulagai River exhibit dominance of Na•Ca-SO₄•HCO₃ and Ca•Na-HCO₃ types, respectively, while the groundwater is characterized by dominance of Na•Ca-HCO₃ and Ca•Mg-HCO₃ types, respectively. The water chemistry of surface water and groundwater in the two basins is influenced by water-rock interactions and processes of evaporation and concentration, primarily observed in the dissolution of carbonate rocks and evaporites. Hydrograph separation using End-Members Mixing Analysis (EMMA) revealed that during the growing season, groundwater in Xiliugou was primarily recharged by precipitation (76.87 %) and surface water (23.13 %), while in Wulagai, groundwater was mainly recharged by precipitation (65 %) and surface water (35 %). The presence of comparable hydrochemical constituents and shared regulatory mechanisms between groundwater and surface water within a given basin provides further evidence of a discernible hydraulic interconnection, primarily driven by the replenishment of groundwater through surface water recharge.

The quality of public health depends amongst others, access to safe water that would not cause waterborne diseases. In Botswana, water is obtained from various sources that include perennial rivers, lakes, seasonal water basins and underground aquifers, to sustain various ecosystems including human life. Therefore, assessing water for the presence of potential contaminants that include pathogenic microbes gives an understanding on the overall quality of water in the country. Here, we review studies that were conducted to determine the extent to which surface water is contaminated in Botswana. We discuss the nature and prevalence of different pathogenic microbes throughout the country, notably in the Thamalakane, Boro, Notwane and Okavango Rivers. It became apparent that microbial contaminants may display seasonal variability and reflect land use. We then discuss some of the available water treatment options and point out the relatively new technologies that can be developed further. This is to give a foundation for future research where innovation is required, such as in the development of portable homemade nanofiltration setups and next generation materials like graphene. The main aim of the review is to sensitise the readership, public and governmental bodies on the prevalence of contamination as well as plausible purification and disinfection means.

Acacia decurrens (AD) plantations are increasingly used as an agroforestry practice in the humid Ethiopian highlands, mainly for their economic and ecological benefits. However, their effects on runoff response and soil loss with their growth are poorly understood. The main objective of this study was to examine the responses of runoff and soil loss with AD plantation age in a highland agroecological setting of Ethiopia. A field experiment was conducted during the rainy season in 2019 and 2020 using bounded runoff plots (30 m long × 3 m wide) installed on control and AD plantations of 1 to 4 years. The result showed that soil chemical properties (TN, SOC, and av. P) were improved in AD plots compared to the control. Surface runoff loss increased with the age of the AD plantation. Seasonal runoff was significantly higher (P < 0.01) in year 3 (456 mm) and year 4 (539 mm) AD plots in 2019 and 2020, respectively. This was mainly on account of decreases in understory vegetation biomass and soil infiltration rate and an increase in soil bulk density with AD plantation age. But at all growth stages of AD plantations, sediment concentration and soil loss were significantly reduced compared to the control (P <0.01). Our results imply a need to use suitable soil and water conservation measures such as trenches combined with AD plantations to reduce surface runoff loss and related effects downstream. However, the effects of AD on soil water content need to be revealed by further research.

Urban ecohydrology research has assessed how several drivers interfere with the basin's response. These interactions can be utilized in urban basins to enhance flood risk management. This paper aims to show how socioeconomic narratives influence rainfall-runoff transformation under changing conditions. For this, the study used the Millennium Ecosystem Assessment (MA) scenarios to measure the influence of different storylines on the land cover and, consequently, the basin's response, measured as the Percentage of Peak Flow Variations (PPFV) of the starting scenario. MA scenarios consider postures reactive and proactive to solve problems and different levels of the protagonist of nature. We used 13 urban ecohydrological variables that are sensitive to the socioeconomic narrative and include the use of Nature-based Solutions (NbS). Then, we set up the qualitative scenarios to apply in two Brazilian urban basins (78.00 and 15.42 km²) to create quantitative scenarios. Finally, we used rainfall-monitored events in these basins and registered their responses as PPFV. The results indicated that socioeconomic narratives significantly impacted the urban basins. PPFV medians ranged, in the reactive scenarios, between 259 % and 70.5 %, and in the proactive scenario, between 54.5 % and -47.5 %. The scenario with NbS in their narrative shows significant decreases in the two basins. We concluded that socioeconomic narratives influence urban flood risk management. Societies with international cooperation focused on environmental solutions, such as using NbS, achieve better adaptation to challenging futures in the face of hydrological threats than reactive societies that do not prioritize the environment.

Drought is a normal disaster that profoundly impacts several factors, including the economy, agriculture, environment, and society. Using spectral indices from Landsat, the current research evaluated droughts' magnitude and frequency in the Diyala River Catchment, Iraq, during the growing season for 2013 through 2022. Fifteen mosaics were created over ten years using forty images in TM and ETM+ (167/36 and 168/37) that had been gathered from 2013 to 2022. The scenes are from two Landsat time series. The drought situation was assessed using the Normalized Difference Vegetation Index (NDVI), Vegetation Condition Index, and Normalized Difference Water Index. The research's findings revealed a rise in the DRC's occurrence and severity of drought over the past ten years, especially in 2000 and 2008. However, between 2021 and 2022, the total vegetation covered based on NDVI decreased by 20.67% and 36.33%, respectively. In 2021 and 2022, the vegetation cover significantly decreased (54.3% and 29.5%, respectively). Derbendekan and Hemrin lakes, conversely, experienced declines of 15.1%, 7.12%, 108.38%, and 143.33% in 2021 and 2022, respectively. Between 2013 and 2022, the DRC experienced an increase in drought, a decline in water body surface area, and a decrease in precipitation averages.

The effects of under-forest economic activities (UFE) on soil water repellency, soil hydraulic properties and preferential flow pathways of karst forest soils are not fully understood. To investigate these effects, the soil physical-chemical properties including soil penetration resistance, surface shear strength and soil water repellency, as well as saturated hydraulic conductivity (K_s) and soil water retention curves (SWRCs) at depths of 0–20, 20–40, and 40–60 cm were compared between undisturbed soils affected by human trampling on forest trails formed by UFE. Disk tension infiltrometers and dye tracing experiments were also conducted to quantify the effects of UFE on the field hydraulic properties and preferential flow pathways from the center of forest trails (CF), the edge of forest trails (EF), and undisturbed forestlands (FL). Our results showed that the forest trails formed by under-forest economic activities enhanced water repellency to various degrees. The K_s of CF (37.03 mm h⁻¹) was significantly lower than that of FL (115.29 mm h⁻¹). The SWRC slopes were steeper for the CF and the EF compared to the FL in the 0–20 cm, 20–40 cm and 40–60 cm intervals, and significant differences in van Genuchten model parameters (α, n, m, θ_r, and θ_s) in the 0–20 cm layer confirm that SWRCs were largely influenced by forest trail. In addition, the averaged preferential flow fraction (PF-fr) was significantly higher for CF and EF compared to FL, while the dye coverage (DC) and uniform infiltration depths (UniFr) were significantly lower. These results indicated that preferential flow is largely enhanced by the UFE. This study provides a field-based case study illustrating the negative effects of UFE on land development and degradation.

India's freshwater biological resources are threatened by multiple stressors and ongoing conservation efforts are insufficient to tackle these challenges. We therefore propose 14 recommendations to halt India's freshwater biodiversity loss. i) Set up a separate ministry on biodiversity to develop and monitor policies. ii) Collection of comprehensive ecological data and sharing with the global scientific community for better assessment. iii) Assessment of data reliability and relevance towards conservation and sustainable management. iv) Integrating terrestrial-freshwater ecosystem management to effectively conserve freshwater biota. v) Implementation of environmental flow regulations for maintaining hydrological connectivity. vi) Augmentation of Protected Areas to protect freshwater biota. vii) Implementation of regulatory frameworks for trade in exotic species to reduce invasiveness. viii) Avoiding fish seed ranching programs in rivers to evade contamination of natural stocks and disease outbreaks from aquaculture. ix) Increasing collaboration between neighboring states and countries on shared freshwater ecosystem for global and regional sustainability. x) Inclusion of compulsory curriculum on biodiversity at different educational stages for developing responsibility towards protecting biodiversity. xi) Building trust among all stakeholders for better management plans through their active participation. xii) Providing alternative livelihood options to improve the socio-economic status of local people to reduce their direct dependency on freshwater ecosystems. xiii) Promotion of citizen science approach on remuneration basis in conserving freshwater biodiversity. xiv) Enabling better use of digital technologies for freshwater biodiversity monitoring. Inclusion of these timely science-based and policy-backed aquatic ecosystems protection guidelines will therefore help to achieve freshwater biodiversity conservation goals successfully in India.