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Over time, river networks achieve a specific pattern as determined by the function of several factors such as climate, tectonic, geological structures, topography, lithology, and base-level fluctuations. The relative importance of mentioned factors on drainage systems was studied to determine the controlling factors of their heterogeneity across the tectono-stratigraphic zones of onshore Iranian Makran. We applied structural, geomorphological, and climate analysis. Results indicate that the dendritic patterns of N-S flowing rivers in the western part of Iranian Makran are mostly controlled by the Minab-Zendan Fault activity and distribution of olistostrome cover, whereas the dominant trellis patterns in the eastern part are controlled by the well-developed thrust fault-related fold systems. The channel steepness pattern demonstrates that the high values are mostly localized in the hanging wall of thrust and normal faults. Accordingly, the topographic profiles of the steep rivers show the old stages of incision in the Inner and Outer Makran. However, some rivers of the Coastal Makran are in the young stage of incision, where the normal faults are located and active. The sediment connectivity index shows that the Inner Makran has a high potential of sediment supplies, while the Outer Makran intra-mountain basins and the Coastal-plain are more prone to sediments accumulation. Our findings reveal that the river patterns and landscape evolution in the Inner and Outer Makran are controlled by thrust faults, olistostrome and related mini-basins, while rivers in the Coastal Makran are governed by activity of Pliocene–Pleistocene normal faults.

Background The distribution of the Chinese Glyptosternoid catfish is limited to the rivers of the Tibetan Plateau and peripheral regions, especially the drainage areas of southeastern Tibet. Therefore, Glyptosternoid fishes are ideal for reconstructing the geological history of the southeastern Tibet drainage patterns and mitochondrial genetic adaptions to high elevations. Results Our phylogenetic results support the monophyly of the Sisoridae and the Glyptosternoid fishes. The reconstructed ancestral geographical distribution suggests that the ancestral Glyptosternoids was widely distributed throughout the Brahmaputra drainage in the eastern Himalayas and Tibetan area during the Late Miocene (c. 5.5 Ma). We found that the Glyptosternoid fishes lineage had a higher ratio of nonsynonymous to synonymous substitutions than those found in non-Glyptosternoids. In addition, ω pss was estimated to be 10.73, which is significantly higher than 1 ( p -value 0.0002), in COX1, which indicates positive selection in the common ancestral branch of Glyptosternoid fishes in China. We also found other signatures of positive selection in the branch of specialized species. These results imply mitochondrial genetic adaptation to high elevations in the Glyptosternoids. Conclusions We reconstructed a possible scenario for the southeastern Tibetan drainage patterns based on the adaptive geographical distribution of the Chinese Glyptosternoids in this drainage. The Glyptosternoids may have experienced accelerated evolutionary rates in mitochondrial genes that were driven by positive selection to better adapt to the high-elevation environment of the Tibetan Plateau.

This geomorphological study discusses the characteristics of the watershed that compose the West Progo Dome, conducted using a field survey method, topographic map analysis, and remote sensing imagery. This is because the West Progo Dome is built by two different litology characteristics (volcanic and carbonate rocks) and different age. Analysis of watershed characteristics includes area, flow pattern, bifurcation ratio (R b ), and river density (D d ), accompanied by statistical analysis of the T 2 -Hotelling multivariate mean difference test. The results shows that the West Progo Dome has three large watersheds, namely the Bogowonto, Serang, and Progo watersheds, with an area of about 270.4, 110.9, and 140.3 km 2 , respectively. The drainage patterns in this area are dendritic, radial, sub-parallel, trellis, rectangular and angulate. R b of drainage in the study area varies from low to high, indicating the presence of tectonic influences. The R b value in System IIA is 2.0 - 5.8, and in System III is 1.290 - 6.630. The D d value on System IIA is 0.921-1.592 km/km 2 and on System III is 0.990-1.200 km/km 2 . This very rough D d also indicates the presence of tectonic influences. The average R b and D d values between System IIA and System III were not significantly different. It means that tectonics influences the watershed morphometry in the West Progo Dome and is still active until the Quaternary (neotectonic).

Morphometric analysis reveals the development of land surface processes and provides an insight into hydrologic behaviour of watershed. A morphometric analysis of landforms on basalt, granite gneiss and schist in north Karnataka was conducted with the objective of comparing various morphometric parameters among them. A sub-watershed each was selected to represent landform on basalt, granite gneiss and schist. The stream length was highest in sub-watershed on basalt and was least on schist with one on granite gneiss being intermediate. The stream number was highest in basalt and its values were similar in granite gneiss and schist. Total relief, relief ratio and ruggedness number were distinctly high in sub-watershed on schist compared to the other two. The low mean bifurcation ratios in all three sub-watersheds suggested stability of the landforms. Drainage density was relatively coarser in the sub-watershed on granite-gneiss compared to the other two. The drainage network was dendritic in the sub-watershed on basalt, sub-dendritic on granite gneiss and sub-trelis on schist. The drainage texture and texture ratio were slightly higher, overland flow values were lower in sub-watersheds on basalt and schist compared to that on granite-gneiss. All three sub-watersheds exhibited similar elongation ratio, form factor and circularity ratio.

Although irrigation systems largely sustain global agricultural production, their efficiency is often alarmingly low. While irrigation water (blue water) is critical for the water-saving irrigation of rice with a high water demand, the process and efficiency of irrigation water utilization need clarification. In this study, we examined the three commonly used irrigation and drainage patterns (frequent shallow irrigation (FSI), wet and shallow irrigation (WSI), and rain-catching and controlled irrigation (RCI)) in rice fields. We developed a tracking method for irrigation water flow decomposition, which includes irrigation water evapotranspiration (IET), irrigation water drainage (IDR), irrigation water leakage (IPC), and irrigation water field residual (IRE). Using this method, we established an irrigation water efficiency evaluation index system and a comprehensive evaluation method. Our tracking method is relevant to describing the irrigation water performance under varying irrigation and drainage patterns. The results revealed that the average irrigation water input for the three irrigation and drainage patterns between 2015 and 2018 was roughly 312.5 mm, wherein IET accounted for 148 mm. However, more than 50% of the irrigation water outflow, comprising IDR, IPC, and IRE, exceeded the total amount of irrigation water input. The mean values of the gross irrigation efficiency (GIE), net irrigation efficiency (NIE), and effective consumption ratio (ECR) for all treatments in the three-year period were 0.63, 0.47, and 0.75, respectively. Additionally, the irrigation water use efficiency was significantly higher in dry years compared to wet years. The fuzzy composite rating values of the three irrigation and drainage models from 2015 to 2018 were RCI, WSI, and FSI, in descending order, under varying precipitation conditions. The RCI patterns maintained a high composite rating value (greater than 3.0) under different precipitation conditions. Previous efficiency calculations disregarded the blue–green water migration process and did not differentiate the blue–green water flow direction in agricultural fields, creating significant biases in the outcomes. This study’s method offers a new approach to evaluate the use of blue water resources in farmland.

The collapse of dam structure leads to serious disasters for surrounding areas along the waterway. The objective of this research is to determine a new route for the waterway by using remote sensing techniques. Drainage patterns were determined from Digital Elevation Model (DEM) of Shuttle Topographic Radar Mission (STRM) by using the ARC-GIS software. The most appropriate route for the new valley is determined by using DEM and assisted by topographic maps of scale 1:500000 starting from Toshka lake until Qattara downrange and passing through the depressions of El Kharga oasis, El-Dakhla, El-Farafra and El-Baharia Oases. The route selection is matched with the expected new valley that proposed by Prof. Dr. Farouk El-Baz in his project ″ The Development Project / Corridor of Development Project [ 1 ].

River capture is of great significance to landform evolution and hominine migration. In the Qinling-Daba Mountains, there is a viewpoint that Jialing River captured Hanjiang River, but this is still controversial. In this paper, we discuss the drainage evolution processes in intermountain basins at the Qinling-Daba Mountains based on a combination of detrital zircon U-Pb geochronology and geomorphic indexes. We suggest that the Hanjiang River gradually captured the Jialing River from east to west, accompanied by the evolution of the ancient Yangtze River. In terms of geomorphic evidences, wide valleys did not match with discharge, and a series of wind gaps developed in the Shiquan-Ankang basin. In addition, the valley shapes and width-to-height ratios ( Vf ) indicate two possible rapid incisions. The hypsometric integrals ( HI ) reflect that the landform gradually changes from the old stage to the youth stage from west to east. The χ values show that the drainage divide is moving to the side of the Yuehe River, and the Yuehe River is gradually shrinking. According to the sedimentary records, the zircon U-Pb age distributions indicate the provenance change. The high-altitude terraces show three age peaks (200–250, 400–505, and 700–900 Ma), with the dominant Indosinian age peak (200–250 Ma), while the modern fluvial sediments only show a single peak of Jinning (700–900 Ma). These data show that there are two major river captures: (1) The ancient Hanjiang River cut through the regional compression ridge, and then captured the Hanzhong Basin river system (a part of the ancient Jialing river system) from east to west, and (2) The southern tributary captured the trunk with the uplift of the divide in the Shiquan-Ankang Basin, forming the modern drainage pattern in the upper Hanjiang River. The activities of the regional strike-slip fault, and the associated compression uplift played a key role in the river captures, the drainage evolution, and related landforms in the Shiquan-Ankang basin. In addition, it is shown that the evolution of the upper tributary basins lagged behind the response of the trunk channel to the tectonic activities and river captures. The interconnected wide valleys caused by river capture may have provided convenient geomorphological conditions for human migration into the Qinling-Daba Mountains along those river valleys.

Exhumation of the southern Tibetan plateau margin reflects interplay between surface and lithospheric dynamics within the Himalaya–Tibet orogen. We report thermochronometric data from a 1.2-km elevation transect within granitoids of the eastern Lhasa terrane, southern Tibet, which indicate rapid exhumation exceeding 1 km/Ma from 17–16 to 12–11 Ma followed by very slow exhumation to the present. We hypothesize that these changes in exhumation occurred in response to changes in the loci and rate of rock uplift and the resulting southward shift of the main topographic and drainage divides from within the Lhasa terrane to their current positions within the Himalaya. At ∼17 Ma, steep erosive drainage networks would have flowed across the Himalaya and greater amounts of moisture would have advected into the Lhasa terrane to drive large-scale erosional exhumation. As convergence thickened and widened the Himalaya, the orographic barrier to precipitation in southern Tibet terrane would have strengthened. Previously documented midcrustal duplexing around 10 Ma generated a zone of high rock uplift within the Himalaya. We use numerical simulations as a conceptual tool to highlight how a zone of high rock uplift could have defeated transverse drainage networks, resulting in substantial drainage reorganization. When combined with a strengthening orographic barrier to precipitation, this drainage reorganization would have driven the sharp reduction in exhumation rate we observe in southern Tibet.

Managing excess nutrients remains a major obstacle to improving ecosystem service benefits of urban waters. To inform more ecologically based landscape nutrient management, we compared watershed inputs, outputs, and retention for nitrogen (N) and phosphorus (P) in seven subwatersheds of the Mississippi River in St. Paul, Minnesota. Lawn fertilizer and pet waste dominated N and P inputs, respectively, underscoring the importance of household actions in influencing urban watershed nutrient budgets. Watersheds retained only 22% of net P inputs versus 80% of net N inputs (watershed area-weighted averages, where net inputs equal inputs minus biomass removal) despite relatively low P inputs. In contrast to many nonurban watersheds that exhibit high P retention, these urban watersheds have high street density that enhanced transport of P-rich materials from landscapes to stormwater. High P exports in storm drainage networks and yard waste resulted in net P losses in some watersheds. Comparisons of the N/P stoichiometry of net inputs versus storm drain exports implicated denitrification or leaching to groundwater as a likely fate for retained N. Thus, these urban watersheds exported high quantities of N and P, but via contrasting pathways: P was exported primarily via stormwater runoff, contributing to surface water degradation, whereas N losses additionally contribute to groundwater pollution. Consequently, N management and P management require different strategies, with N management focusing on reducing watershed inputs and P management also focusing on reducing P movement from vegetated landscapes to streets and storm drains.

The magnitude of stream and river carbon dioxide (CO₂) emission is affected by seasonal changes in watershed biogeochemistry and hydrology. Global estimates of this flux are, however, uncertain, relying on calculated values for CO₂ and lacking spatial accuracy or seasonal variations critical for understanding macroecosystem controls of the flux. Here, we compiled 5,910 direct measurements of fluvial CO₂ partial pressure and modeled them against watershed properties to resolve reach-scale monthly variations of the flux. The direct measurements were then combined with seasonally resolved gas transfer velocity and river surface area estimates from a recent global hydrography dataset to constrain the flux at the monthly scale. Globally, fluvial CO₂ emission varies between 112 and 209 Tg of carbon per month. The monthly flux varies much more in Arctic and northern temperate rivers than in tropical and southern temperate rivers (coefficient of variation: 46 to 95 vs. 6 to 12%). Annual fluvial CO₂ emission to terrestrial gross primary production (GPP) ratio is highly variable across regions, ranging from negligible (<0.2%) to 18%. Nonlinear regressions suggest a saturating increase in GPP and a nonsaturating, steeper increase in fluvial CO₂ emission with discharge across regions, which leads to higher percentages of GPP being shunted into rivers for evasion in wetter regions. This highlights the importance of hydrology, in particular water throughput, in routing terrestrial carbon to the atmosphere via the global drainage networks. Our results suggest the need to account for the differential hydrological responses of terrestrial–atmospheric vs. fluvial–atmospheric carbon exchanges in plumbing the terrestrial carbon budget.