1. SITE DESCRIPTIONThe Cathedral Peak research catchments, which form part of a strategic water source area for South Africa, consist of ten (named I – X) well defined hydrological catchments, ranging in altitude from 1 820 m.a.s.l to 2 463 m.a.s.l (Figure 1). The catchments fall within the summer rainfall region of South Africa, experiencing wet, humid summers and cold, dry winters (Everson et al ., 1998). The mean annual precipitation (MAP) for the area is approximately 1 400 mm (Bosch, 1979), with 84 % of this rainfall occurring between the months of October and March (Schulze, 1976). Half of the rainfall events in the catchments are thunderstorms (Schulze, 1976). Approximately 49 % of the rainfall is converted to streamflow, with two thirds of the streamflow yield occurring during the four months from January to April (Bosch, 1979). The natural vegetation of the catchments is fire-adapted montane grassland, dominated by the grass (Themeda triandra) . Woody communities dominated by Leucosidea sericea and Buddleia salvifolia occur in narrow, fire-protected zones along the streams in some catchments (Bosch, 1979).

The waters mize the flow conditions in the spawning grounds by controlling the opening mode of the Gezhouba Dam generator units, a mathematical model of the three-dimensional hydrodynamics of the Chinese sturgeon spawning grounds was established in FLOW-3D. The model was verified with velocity measurements, and the results were in good agreement. Additionally, the model was used to invert the flow field of monitoring results from 2016-2019, and it was concluded that the preferred velocity range for the Chinese sturgeon was 0.6-1.5 m/s. The flow fields of different opening modes of the generator units were simulated with the same flow rate, and the results showed that the suitable velocity area was the largest when all units of the Dajiang Plant of the Gezhouba Dam were open and that conditions were especially favourable on the left side. Comparison of the suitable velocity area with different flow rates showed that when the flow rate was less than 12000 m3/s, more than 90% of the area was suitable and that when the flow rate was greater than 12000 m3/s, the suitable area decreased rapidly with increasing flow rate. Moreover, the suitable areas under different opening modes under high-flow conditions were compared, and the results showed that at flow rates of 12000 ~ 15000 m3/s, opening 11~13 units on the left side was best. When the flow rate reached 15000 m3/s, it was best to open all of the units. In this paper, the optimal opening scheme at different flow rates was analysed, and the results provide new ideas for Chinese sturgeon protection and ecosystem protection.

Since the Eastern Route of the South-to-North Water Diversion Project (SNWD-ERP) officially began operation, it was found that the concentrations of sulfate rapidly increased after water transfer from Jiangsu Province to Shandong Province, especially in Nansi Lake (NSL). The direct and original sources of sulfate in NSL and its surrounding inflowing rivers were investigated by analyzing the hydrochemical properties of the water bodies and sulfur and oxygen isotope compositions of dissolved sulfate during nondiversion and diversion water periods. During the diversion water period, the largest direct source of high SO42- concentrations in NSL was evaporite dissolution, accounting for 52.18% of the total contribution. In contrast, during the nondiversion water period, the maximum contribution of SO42- came from inflowing river inputs. To ensure the safety of the water supply of the SNWD-ERP, some measures must be taken to decrease the sulfate inputs from inflowing rivers, such as formulating strict discharge standards to reduce the direct discharge of sewage into the inflowing rivers around NSL.

Hydrological series frequency analysis is a fundamental task for water resources management and water conservancy project design. Given the deficiencies of higher distribution for the upper tail section of hydrological frequency curve and safer designing result of water conservancy project utilizing empirical frequency formula and Pearson-III type function based curve fitting method, the normal cloud transform algorithm based approach for hydrological series frequency analysis was proposed through estimating sample empirical frequency by normal cloud transform algorithm, and determining the cumulative probability distribution curve by overlapping calculation of multiple cloud distribution patterns. It can be revealed from its application result in norther Anhui province, China that, the varying trend of cumulative probability distribution curve of annual precipitation derived from the cloud transform algorithm based method was basically consistent with the result obtained through traditional empirical frequency formula. Meanwhile, the upper tail section of annual precipitation frequency curve derived from cloud transform algorithm was distributing below the calculation result utilizing traditional empirical frequency formula, which indicated that the annual precipitation frequency calculation result utilizing cloud transform algorithm was more optimal than the corresponding result obtained by traditional empirical frequency formula. Therefore, the proposed cloud transform algorithm based approach was reliable and effective for hydrological series frequency analysis, which can be further applied in the related research field of hydrological process analysis.

In this study, we unveiled the lumped effects at the reach spatial scale over three decades in one of the braided rivers in the Qinghai-Tibet Plateau of China, the Upper Lancang River (ULR). Using Landsat images obtained in 13 years between 1989 and 2018, we extracted flowing and non-flowing channels, active channel widths (unvegetated bars and flowing channels), and calculated lateral shifting rates of the main channel for the 13 periods. We also developed an empirical equation between vegetation area (Av) calculated from the high-resolution ortho-photo derived from an Unmanned Aerial Vehicle survey and Normalized Difference Vegetation Index for pixels of the Landsat image obtained at the same time. This relationship allowed us to estimate Av for other 12 selected years. We found that (1) braiding intensity increases with low discharges, indicating that the ULR is a very well-connected braided system with groundwater providing a large set of aquatic habitats, (2) this braided system is very well-supplied and actively shifting in relation to peak flow and flood duration, and (3) The ULR supports a progressive vegetation encroachment, which seems to be linked to temperature rising. Our study showed several similar morphological patterns to those in other braided rivers, such as the ones observed in the European Alps but much more active, well-supplied and highly connected. These similarities suggest that similar morphodynamic processes might take effect in the braided rivers with very high elevations and potentially high spots of biodiversity, indicating the ULR may be a reference for this region similarly to the Tagliamento in the Alps, but it seems that this system can be very sensitive to global change due to vegetation encroachment following temperature rising and decreases of low flows.

Due to the Doppler effect in waves, one can't efficiently transmit signals underwater. This paper takes you to novel approaches that utilize sonar conversion techniques as well as different UART communication methods and software defined networking mechanisms, in order to build underwater wireless networks. The case for UWNs being utilized for oceanic colonization is also presented, as well as how this applies to the creation of "Aquatic IOT type technologies" and new forms of telemetry. Presented in this paper are concepts that were deployed by the Stark Drones Corporation in competing for various challenges such as "The Internet of H2O Challenge" and GigabitDCx. Also presented, is a proposal to apply these technologies for monitoring lake contamination and various forms of e-coli buildup as well as phosphorus run-ons. These networks allow for a cleaner, more sustainable and observable ocean. 

Although large-scale implementation of SWC measures has been used to reduce soil loss and sedimentation in Ethiopian highlands, no method exists to evaluate how implementation of such measures affect erosion and sedimentary processes. In this study we measured and simulated the impacts of various SWC measures on soil loss and sediment yield using spatially distributed WATEM/SEDEM model calibrated at three sub-watersheds. The methods used comprised of field sampling and monitoring to characterize erosion and sediment yields and GIS analysis to calculate various model input parameters. The measurement and model simulation result showed all SWC scenarios reduced soil erosion and sediment yield and bund structures have reduced erosion by more than 57 to 65%. The integrated use of bund structures, contour cultivation, strip cropping and grass strips (scenario IV), sediment yield was reduced from 44.5 to 8.6 t ha-1 y-1, 30.7 to 5.3 t ha-1 y-1 and 36.6 to 6.3 t ha-1 y-1 in the upper, middle and lower part of Koga catchment respectively. Bund structures and grass strips had the highest specific contribution in controlling soil erosion and sediment yield in both study sub-watersheds. The measured and simulated erosion and sediment yield values were relatively lower at the middle of Koga for scenario I (present-day situation). This might be due to the lower transport capacity and lower sediment connectivity as a result of larger coverage of bunds and subordinate conservation measures such as: traditional diches and diversion channels in Debreyakob. This emphasises the importance of integrated use of conservation strategy to reduce soil erosion and sediment delivery. The calibration of WATEM/SEDEM at sub-watershed level has provided good model performance for measured and simulated erosion and sediment yields. Therefore, WATEM/SEDEM representing the underlying erosion and sedimentary processes can further be used to evaluate the impacts of land use and existing or new SWC scenarios.

Human pressure on the water resources provided by natural wetlands has intensified in Brazil due to an increase in agricultural land equipped with irrigation. However, the amount of water stored in these areas, and its contribution to aquifer recharge is unknown. The objectives of this study were to determine the amount of water that can be retained in a natural wetland surrounded by farmland and to propose a model of groundwater recharge. We used remote sensing techniques involving Unmanned Aerial Vehicle (UAV) to map the area and highlight the wetland internal morphology, using RGB orthomosaic and its respective digital surface model. According to the topography of the study area three compartments were defined. Compartment 1, corresponding to the external border of the wetland, can store 313,121.00 m³ of water; compartment 2 and 3 can store 85,923.20 m³ and 17,952.10 m³, respectively. The 2D inversion and a pseudo-3D model produced from Electrical Resistivity Tomography (ETR) data were used to visualize the subsurface geologic structure and hydrologic flow paths. Our results showed the direct interactions between groundwater (GW) and surface water (SW) in the center of the wetland (compartment 3), which constitutes the aquifer recharge zone with vertical infiltration. As the depth increases, infiltration and water flow deviate laterally in the southwest and northeast direction. The wetland is characterized as an unconfined aquifer that plays an important role in the hydrogeological dynamics of the catchment. Remotely sensed images allied with geophysical techniques allow complete surface and subsurface imaging and offers visual tools that contribute to understanding the hydrodynamic of an area.