Monitoring and Modeling of Hydrological Processes in The Semiarid Region of Brazil: The Cariri Experimental Basins

2021 ◽  
Author(s):  
Vajapeyam S. Srinivasan ◽  
Hugo M. Alcântara ◽  
Carlos de O. Galvão ◽  
Ulisses A. Bezerra ◽  
John E. Brito Leite Cunha
Keyword(s):  
Hydrological Processes ◽  
Semiarid Region ◽  
Experimental Basins

scholarly journals MONITORING AND MODELING OF HYDROLOGICAL PROCESSES IN THE SEMIARID REGION OF BRAZIL: THE CARIRI EXPERIMENTAL BASINS

2020 ◽  
Author(s):  
Vajapeyam Srinivasan ◽  
Hugo Alc ntara ◽  
Carlos Galv o ◽  
Ulisses Bezerra ◽  
John Cunha
Keyword(s):  
Hydrological Processes ◽  
Semiarid Region ◽  
Experimental Basins

scholarly journals Hydrodynamics-driven uncertainty study in simulating terrestrial carbon cycle with a coupled water-carbon cycle model

2020 ◽  
Author(s):  
Guodong Sun ◽  
Mu Mu
Keyword(s):  
Carbon Cycle ◽  
Hydrological Cycle ◽  
Net Primary Production ◽  
Northern China ◽  
Hydrological Processes ◽  
Semiarid Region ◽  
Terrestrial Carbon ◽  
Dynamic Global Vegetation Model ◽  
Carbon Cycle Model ◽  
Terrestrial Carbon Cycle

Abstract In this study, an uncertainty degree of net primary production (NPP) simulation or prediction is estimated due to uncertainty of hydrodynamic processes. The Lund-Potsdam-Jena Wetland Hydrology and Methane Dynamic Global Vegetation Model (LPJ-WHyMe DGVM), which could describe the interaction between terrestrial carbon cycle and hydrological cycle, is applied to evaluate the above issue. Four regions with different climate backgrounds in China are chosen to explore different behaviors about the influence of the simulated NPP to hydrological physical processes on. It is found that the error of NPP modeling is 198.5 g C m− 2 yr− 1 (48.6%) in the arid and semiarid region of northern China due to the uncertainties in the hydrological processes, which is greater than those in other three regions. The errors of NPP modeling are 88.4 g C m− 2 yr− 1 (19.1%) in northeastern China, 117.0 g C m− 2 yr− 1 (21.1%) in southern China, and 64.4 g C m− 2 yr− 1 (13.2%) in the semi-humid region of northern China. Further numerical experiments reveal that the simulation ability of the NPP could be enhanced by reducing all hydrological parameter errors. Our results demonstrate the importance of hydrological processes to the simulation and prediction of the NPP.

Management of the Dutch Waddensea

1984 ◽  
Vol 16 (3-4) ◽  
pp. 485-495 ◽  
Author(s):  
D Vreugdenhil
Keyword(s):  
The Netherlands ◽  
Middle Ages ◽  
Human Activities ◽  
Nature Reserve ◽  
The Other ◽  
Hydrological Processes ◽  
Dutch Government ◽  
Shallow Sea ◽  
Management Objectives ◽  
Late Middle Ages

It was not until the late Middle Ages that the sea penetrated far into the interior of The Netherlands, thus flooding three quarters of a million hectares of land. Since then half a million hectares have been reclaimed from the sea. The Dutch Government chose to preserve the remaining quarter of a million hectares of shallow sea with mudflats of the Waddensea as a nature reserve. The management objectives are at one hand to preserve all characteristic habitats and species with a minimal interference by human activities in geomorphological and hydrological processes, and at the other hand to guarantee the safety against the sea of the inhabitants of the adjacent mainland and islands and to facilitate certain economic and recreational uses of the Waddensea without jeopardizing the natural qualities. These objectives are being elaborated in managementplans.

Insecticidal Active Rotenoids from Plant Parts and Callus Culture of Medicago sativa L. from a Semiarid Region of India (Rajasthan)

2020 ◽  
Vol 16 (6) ◽  
pp. 937-941
Author(s):  
Sharad Vats ◽  
Preeti Mehra
Keyword(s):  
Medicago Sativa ◽  
Callus Culture ◽  
Point Of View ◽  
Semiarid Region ◽  
Disease Vectors ◽  
Vector Borne Diseases ◽  
Plant Parts ◽  
Resistant Varieties ◽  
Medicago Sativa L

Background: Vector-borne diseases are quite prevalent globally and are one of the major causes of deaths due to infectious diseases. There is an availability of synthetic insecticides, however, their excessive and indiscriminate use have resulted in the emergence of resistant varieties of insects. Thus, a search for novel biopesticide has become inevitable. Methods: Rotenoids were isolated and identified from different parts of Medicago sativa L. This group of metabolites was also identified in the callus culture, and the rotenoid content was monitored during subculturing for a period of 10 months. Enhancement of the rotenoid content was evaluated by feeding precursors in a tissue culture medium. Results: Four rotenoids (elliptone, deguelin, rotenone and Dehydrorotenone) were identified, which were confirmed using spectral and chromatographic techniques. The maximum rotenoid content was found in the seeds (0.33±0.01%), followed by roots (0.31±0.01%) and minimum in the aerial parts (0.20±0.05%). A gradual decrease in the rotenoid content was observed with the ageing of subcultured tissue maintained for 10 months. The production of rotenoids was enhanced up to 2 folds in the callus culture using amino acids, Phenylalanine and Methionine as precursors as compared to the control. The LC50 value of the rotenoids was found to be 91 ppm and 162 ppm against disease vectors of malaria and Dracunculiasis, respectively. Conclusion: The study projects M. sativa as a novel source of biopesticide against the disease vectors of malaria and Dracunculiasis. The use of precursors to enhance the rotenoid content in vitro can be an effective venture from a commercial point of view.

scholarly journals Agroforestry Systems of the Tehuacán-Cuicatlán Valley: Land Use for Biocultural Diversity Conservation

Land ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 24
Author(s):  
Mariana Vallejo ◽  
M. Isabel Ramírez ◽  
Alejandro Reyes-González ◽  
Jairo López-Sánchez ◽  
Alejandro Casas
Keyword(s):  
Land Use ◽  
Agricultural Land ◽  
Agroforestry Systems ◽  
World Heritage Site ◽  
Biocultural Diversity ◽  
Semiarid Region ◽  
Agricultural Land Use ◽  
Visual Interpretation ◽  
Natural Ecosystems ◽  
Human Settlements

The Tehuacán-Cuicatlán Valley, Mexico, is the semiarid region with the richest biodiversity of North America and was recently recognized as a UNESCO's World Heritage site. Original agricultural practices remain to this day in agroforestry systems (AFS), which are expressions of high biocultural diversity. However, local people and researchers perceive a progressive decline both in natural ecosystems and AFS. To assess changes in location and extent of agricultural land use, we carried out a visual interpretation of very-high resolution imagery and field work, through which we identified AFS and conventional agricultural systems (CAS) from 1995 to 2003 and 2012. We analyzed five communities, representative of three main ecological and agricultural zones of the region. We assessed agricultural land use changes in relation to conspicuous landscape features (relief, rivers, roads, and human settlements). We found that natural ecosystems cover more than 85% of the territory in each community, and AFS represent 51% of all agricultural land. Establishment and permanence of agricultural lands were strongly influenced by gentle slopes and the existence of roads. Contrary to what we expected, we recorded agricultural areas being abandoned, thus favoring the regeneration of natural ecosystems, as well as a 9% increase of AFS over CAS. Agriculture is concentrated near human settlements. Most of the studied territories are meant to preserve natural ecosystems, and traditional AFS practices are being recovered for biocultural conservation.

Corrigendum to: Conservation agriculture effects on soil properties and crop productivity in a semiarid region of India

Soil Research ◽  
2019 ◽  
Vol 57 (2) ◽  
pp. 200 ◽  
Author(s):  
J. Somasundaram ◽  
M. Salikram ◽  
N. K. Sinha ◽  
M. Mohanty ◽  
R. S. Chaudhary ◽  
...  
Keyword(s):  
Soil Properties ◽  
Management Practices ◽  
Crop Yields ◽  
Cropping Systems ◽  
Soil Layer ◽  
Conservation Agriculture ◽  
Semiarid Region ◽  
Reduced Tillage ◽  
Organic C ◽  
Residue Retention

Conservation agriculture (CA) including reduced or no-tillage and crop residue retention, is known to be a self–sustainable system as well as an alternative to residue burning. The present study evaluated the effect of reduced tillage coupled with residue retention under different cropping systems on soil properties and crop yields in a Vertisol of a semiarid region of central India. Two tillage systems – conventional tillage (CT) with residue removed, and reduced tillage (RT) with residue retained – and six major cropping systems of this region were examined after 3 years of experimentation. Results demonstrated that soil moisture content, mean weight diameter, percent water stable aggregates (>0.25mm) for the 0–15cm soil layer were significantly (Pmoderately labile>less labile. At the 0–15cm depth, the contributions of moderately labile, less labile and non-labile C fractions to total organic C were 39.3%, 10.3% and 50.4% respectively in RT and corresponding values for CT were 38.9%, 11.7% and 49.4%. Significant differences in different C fractions were observed between RT and CT. Soil microbial biomass C concentration was significantly higher in RT than CT at 0–15cm depth. The maize–chickpea cropping system had significantly (P–1 followed by soybean+pigeon pea (2:1) intercropping (3.50 t ha–1) and soybean–wheat cropping systems (2.97 t ha–1). Thus, CA practices could be sustainable management practices for improving soil health and crop yields of rainfed Vertisols in these semiarid regions.

Paleoenvironmental analysis of wet meadow in the Deseado Massif: Implications for the Holocene occupation of Argentinian Patagonia

The Holocene ◽  
2021 ◽  
pp. 095968362110259
Author(s):  
Bruno Mosquera ◽  
María V Mancini
Keyword(s):  
Environmental Changes ◽  
Low Energy ◽  
Semiarid Region ◽  
Human Occupation ◽  
Wet Meadow ◽  
Radiocarbon Dates ◽  
Sedimentation Environment ◽  
Dry Conditions ◽  
Paleoenvironmental Analysis ◽  
Deseado Massif

Paleoenvironmental data from wet-meadow environments in the arid-semiarid region of Patagonia are still incipient and the paleoenvironmental records came from pollen sequences of caves and rockshelters. The main reasons to study wetland records are their undisturbed (by humans) sedimentologic continuity, in contrast to deposits in rock shelters and caves; and their regional presentation of environmental changes that can be compared to archeological data. The aim of this paper is to evaluate the past hydrological dynamic of a wet-meadow from Deseado Massif and its relationship with the human occupation. For this purpose, we present the results of the sediment and pollen analysis of Mallín La Primavera wet-meadow that provide a sequence starting in the mid-Holocene. The results indicate a lower water table in the mallín prior to 6900 cal yr BP. Sediment analysis indicates low energy sedimentation environment with flood events and very low energy streams. Human occupational data show chronological discontinuities in mid-Holocene in several regions of Patagonia and the southern cone. In the studied region, two chronological hiatuses (7828–6434 cal yr BP and 3005–2710 cal yr BP) where recognized that appear to correlate with shrub steppes, indicating dry conditions. These conditions may explain the lack of archeological radiocarbon dates in the area during this period. The integration of sediment and pollen results from the Deseado Massif indicates dry and windy conditions for the middle Holocene. The lack of archeological radiocarbon dates would have been influenced by the loss of moisture in water sources such as springs and their associated wet meadows ( mallines).

scholarly journals A STELLA-Based Model to Simultaneously Predict Hydrological Processes, N Uptake and Biomass Production in a Eucalyptus Plantation

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 515
Author(s):  
Ying Ouyang ◽  
Gary Feng ◽  
Heidi Renninger ◽  
Theodor D. Leininger ◽  
Prem Parajuli ◽  
...  
Keyword(s):  
Water Use ◽  
Biomass Production ◽  
Net Primary Production ◽  
N Uptake ◽  
Hydrological Processes ◽  
Modeling Tools ◽  
Eucalyptus Plantation ◽  
Simulation Scenario ◽  
Use Efficiency ◽  
N Use

Eucalyptus is one of the fastest growing hardwoods for bioenergy production. Currently, few modeling tools exist to simultaneously estimate soil hydrological processes, nitrogen (N) uptake, and biomass production in a eucalyptus plantation. In this study, a STELLA (Structural Thinking and Experiential Learning Laboratory with Animation)-based model was developed to meet this need. After the model calibration and validation, a simulation scenario was developed to assess eucalyptus (E. grandis × urophylla) annual net primary production (ANPP), woody biomass production (WBP), water use efficiency (WUE), and N use efficiency (NUE) for a simulation period of 20 years. Simulation results showed that a typical annual variation pattern was predicted for water use, N uptake, and ANPP, increasing from spring to fall and decreasing from fall to the following winter. Overall, the average NUE during the growth stage was 700 kg/kg. To produce 1000 kg eucalyptus biomass, it required 114.84 m3 of water and 0.92 kg of N. This study suggests that the STELLA-based model is a useful tool to estimate ANPP, WBP, WUE, and NUE in a eucalyptus plantation.

scholarly journals The Adjustment of China’s Grain Planting Structure Reduced the Consumption of Cropland and Water Resources

2021 ◽  
Vol 18 (14) ◽  
pp. 7352
Author(s):  
Yu Zhang ◽  
Jieyong Wang ◽  
Chun Dai
Keyword(s):  
Water Resources ◽  
Structural Adjustment ◽  
Land Reclamation ◽  
National Level ◽  
Cumulative Effect ◽  
Northern China ◽  
Semiarid Region ◽  
Market Demand ◽  
Continuous Growth ◽  
Northern Regions

Driven by technological progress and market demand, the optimization and adjustment of grain planting structure played an important role in increasing grain output. Due to the great difference between the yield per unit area of different types of food crops, the consumption of cropland and water resources has a significant change during the grain growth. From the perspective of structural adjustment, rather than the usual productive factor input, we analyze the process of adjustment for grain planting structure in China and its effect on the consumption of cropland and water resources by using the scenario comparative analysis method. The results show that: (1) From 2003 to 2019, China’s grain output has increased steadily and the planting structure has changed greatly. Rice was replaced by corn to become the grain crop with the maximum proportion of planting area since 2007. The increase of corn planting structure proportion is concentrated in the northern regions. (2) At the national level, according to the adjustment of grain planting structure, the saving of cropland and water resources consumption showed a “cumulative effect” as time went on. (3) The saving effects of structural adjustment in the northern regions on cropland and water resources consumption are better than that in the southern regions, such as Northeast China Plain, Northern arid and semiarid region and Loess Plateau. (4) In reality, although the adjustment of grain planting structure saved lots of cropland and water resources, the continuous growth of grain output has increased the pressure on the ecological environment in the northern regions according to theirs water limits. Therefore, it is necessary to continuously optimize the grain planting structure and restrict land reclamation in northern China. In addition, to ensure food security, it is feasible to encourage the southern regions with abundant water and heat resources to increase the grain planting area and meet its self-sufficiency in grain demand.

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