Modeling the long-term natural regeneration potential of woodlands in semi-arid regions to guide restoration efforts

2014 ◽  
Author(s):  
Adriana Príncipe ◽  
Alice Nunes ◽  
Pedro Pinho ◽  
Lúcio do Rosário ◽  
Otília Correia ◽  
...  
Keyword(s):  
Natural Regeneration ◽  
Arid Regions ◽  
Regeneration Potential ◽  
Semi Arid

scholarly journals Extreme rainfall deficits were not the cause of recurring colonial era famines of southern Indian semi-arid regions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ranjini Ray ◽  
Atreyee Bhattacharya ◽  
Gaurav Arora ◽  
Kushank Bajaj ◽  
Keyle Horton ◽  
...  
Keyword(s):  
Arid Regions ◽  
Human Impacts ◽  
Rainfall Variability ◽  
Extreme Rainfall ◽  
Southern India ◽  
Colonial Era ◽  
Regional Rainfall ◽  
Semi Arid ◽  
Rainfall Deficits

AbstractUsing information contained in the eighteenth to twentieth century British administrative documents, preserved in the National Archives of India (NAI), we present a 218-year (1729–1947 AD) record of socioeconomic disruptions and human impacts (famines) associated with ‘rain failures’ that affected the semi-arid regions (SARs) of southern India. By mapping the southern Indian famine record onto long-term spatiotemporal measures of regional rainfall variability, we demonstrate that the SARs of southern India repeatedly experienced famines when annual rainfall reduced by ~ one standard deviation (1 SD), or more, from long-term averages. In other words, ‘rain failures’ listed in the colonial documents as causes of extreme socioeconomic disruptions, food shortages and human distress (famines) in the southern Indian SARs were fluctuations in precipitation well within the normal range of regional rainfall variability and not extreme rainfall deficits (≥ 3 SD). Our study demonstrates that extreme climate events were not necessary conditions for extreme socioeconomic disruptions and human impacts rendered by the colonial era famines in peninsular India. Based on our findings, we suggest that climate change risk assessement should consider the potential impacts of more frequent low-level anomalies (e.g. 1 SD) in drought prone semi-arid regions.

scholarly journals Simulation of water and salts dynamics in Bouhajla (Central Tunisia): exceptional rainfall effect

2012 ◽  
Vol 7 (No. 1) ◽  
pp. 36-44 ◽  
Author(s):  
S. Kanzari ◽  
M. Hachicha ◽  
R. Bouhlila ◽  
J. Battle-Sales
Keyword(s):  
Model Calibration ◽  
Arid Regions ◽  
Flood Irrigation ◽  
Central Tunisia ◽  
Term Evolution ◽  
1D Model ◽  
Semi Arid Region ◽  
Semi Arid ◽  
Hydrus 1D

Arid and semi-arid regions face the risk of soils and aquifers salinization. Rainy events are rare which is characteristic of these regions. They play a significant role in the leaching of salts from topsoil to deeper layers, which increases the risk of aquifers salinization. For this reason, a plot was selected in the semi-arid region of Bou Hajla (Central Tunisia). The simulation of water and salts dynamics was carried out by Hydrus-1D. Model calibration was realised on a flood irrigation experiment during 10 days and in a depth of 4 m. The hydrodynamic parameters were determined by inverse modelling. Model validation was performed successfully during 577 days. The simulation of water and salts dynamics has allowed the analysis of two scenarios: (i) the effect of a very rainy event (> 50mm/day) on the dynamics of salts. This type of event allows leaching of the accumulated salts in the topsoil which promotes their burial in the depth; (ii) the long-term evolution of the saline profile in 20 years showed the cyclical nature of salts leaching in the topsoil, the permanent accumulation of salts in the depth of around 2 m, and a continuous leaching in the deeper layers (around 4 m), which may increase groundwater contamination risk.

scholarly journals QANATS AS AN ENDANGERED TRADITIONAL HYDRAULIC HERITAGE. AN INTEGRATED METHODOLOGY FOR DOCUMENTING, RESTORING AND REUSING AN ANCIENT IRANIAN

2021 ◽  
Author(s):  
Paola Nella Branduini ◽  
Federico Zaina ◽  
Fereshteh Zavvari ◽  
Yasaman Nabati Mazloumi
Keyword(s):  
Water Supply ◽  
Arid Regions ◽  
Structural Features ◽  
Structural Instability ◽  
Economic Benefits ◽  
Northern Iran ◽  
Regional Conflicts ◽  
Sustainable Water Supply ◽  
Semi Arid

Qanats represented a major technological solution for water supply in arid and semi-arid regions for millennia. Thanks to their multiple social and economic benefits, qanat-like systems spread from Iran through the Middle East in most of the arid and semi-arid regions of the world. In recent years, this valuable traditional hydraulic technology has been neglected in preservation and reuse due to the lack of management as well as the lack of legal support. This precious heritage and sustainable water supply system according to their sustainable structural features has been replaced by modern water collection and management systems such as dams and other hydroelectric infrastructures along with new pumping technologies. However, there is a growing consensus on the number of short, medium and long-term issues emerging from these systems including pollution and other environmental damages, regional conflicts, political pressures as well as their limited lifetime and structural instability. The purpose of this paper is to show qanats as an example of endangered heritage which could also represent a sustainable and clean technology. To do so, we apply a multi-disciplinary perspective integrating archaeological, architectural, sociological and conservation methodologies on a specific case study from the Tabriz region in Northern Iran: the “No-Ras” qanat.

scholarly journals Global-scale modeling of groundwater recharge

2008 ◽  
Vol 12 (3) ◽  
pp. 863-885 ◽  
Author(s):  
P. Döll ◽  
K. Fiedler
Keyword(s):  
Water Resources ◽  
Groundwater Recharge ◽  
Arid Regions ◽  
Groundwater Resources ◽  
Global Scale ◽  
Unbiased Estimation ◽  
Data Sets ◽  
Total Runoff ◽  
Semi Arid

Abstract. Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the-art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961–1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3/(capita yr) for the Falkland Islands, the global average in the year 2000 being 2091 m3/(capita yr). Regarding the uncertainty of estimated groundwater resources due to the two precipitation data sets, deviation from the mean is 1.1% for the global value, and less than 1% for 50 out of the 165 countries considered, between 1 and 5% for 62, between 5 and 20% for 43 and between 20 and 80% for 10 countries. Deviations at the grid scale can be much larger, ranging between 0 and 186 mm/yr.

scholarly journals Finding Optimal Nutrients With Farming Techniques to influence Maize Productivity, and Mitigate Global Warming Potential Under Water-saving Agriculture in Semi-arid Regions

2021 ◽  
Author(s):  
Tiejun Zhang ◽  
yueling xi ◽  
Xiengchang Ma
Keyword(s):  
Arid Regions ◽  
Ghg Emissions ◽  
Biomass Productivity ◽  
Water Saving ◽  
Soil Water Storage ◽  
Maize Production ◽  
Maize Productivity ◽  
Greenhouse Gas Intensity ◽  
Semi Arid

Abstract Background and aims: Effective nutrients management under various farming techniques is critical for improving maize productivity and ensuring the long-term protection of water-saving agriculture under semi-arid regions. However, the impacts have not been well documented in determining the features of soil greenhouse gas intensity (GHGI) emissions and the driving factors of nutrients fertilization is important for optimizing crop-land nutrients management under various farming techniques.Methods: The nutrients with farming techniques strategies were investigated under water-saving agriculture of maize during 2019-20 years, using the following nine treatments: BF: ridges covered with biodegradable film; CF: soil crust ridges; TF: conventional flat planting; 0: N:P at 0:0 kg ha-1, 1: N:P at 120:60 kg ha-1, 2: N:P at 280:140 kg ha-1. Results: Our results showed that the nutrients fertilization with various cultivation strategies had a significant influence on the GHG emissions. The BF2 treatment considerably increase soil water storage, soil respiration rate as a result of decreased ET rate and GHG emissions compared with the other treatments. The BF1 treatment significantly mitigated GWP, CH4, N2O, and CO2 emissions, changes in CH4, N2O, and CO2 cumulative emissions. The GHGI differently responded to nutrients with farming techniques strategies. Under the BF2 improved (25.0%) the average net GWP than that of TF2, but reduced GHGI, due to improved (18.5%) biomass productivity. The BF2 and BF1 farming methods results in greater N2O, CO2 emissions, GWP, and changes in cumulative CH4, N2O, and CO2 emissions, as a result, have an adverse effect on the soil than that of CF and TF treatments. Conclusions: However, obtained the higher area-scaled GWP (42.1%), WUEg (96.7%), WUEb (65.4%), and (41.1%) grain yield under the BF2 which may offset the negative environmental effects linked with climate change. Thus, it is recommended to use the BF2 treatment in water-saving agriculture under semi-arid regions for cleaner and more efficient maize production.

scholarly journals Global-scale modeling of groundwater recharge

2007 ◽  
Vol 4 (6) ◽  
pp. 4069-4124 ◽  
Author(s):  
P. Döll ◽  
K. Fiedler
Keyword(s):  
Water Resources ◽  
Groundwater Recharge ◽  
Arid Regions ◽  
Groundwater Resources ◽  
Global Scale ◽  
Unbiased Estimation ◽  
Data Sets ◽  
Total Runoff ◽  
Semi Arid

Abstract. Long-term average groundwater recharge, which is equivalent to renewable groundwater resources, is the major limiting factor for the sustainable use of groundwater. Compared to surface water resources, groundwater resources are more protected from pollution, and their use is less restricted by seasonal and inter-annual flow variations. To support water management in a globalized world, it is necessary to estimate groundwater recharge at the global scale. Here, we present a best estimate of global-scale long-term average diffuse groundwater recharge (i.e. renewable groundwater resources) that has been calculated by the most recent version of the WaterGAP Global Hydrology Model WGHM (spatial resolution of 0.5° by 0.5°, daily time steps). The estimate was obtained using two state-of-the art global data sets of gridded observed precipitation that we corrected for measurement errors, which also allowed to quantify the uncertainty due to these equally uncertain data sets. The standard WGHM groundwater recharge algorithm was modified for semi-arid and arid regions, based on independent estimates of diffuse groundwater recharge, which lead to an unbiased estimation of groundwater recharge in these regions. WGHM was tuned against observed long-term average river discharge at 1235 gauging stations by adjusting, individually for each basin, the partitioning of precipitation into evapotranspiration and total runoff. We estimate that global groundwater recharge was 12 666 km3/yr for the climate normal 1961–1990, i.e. 32% of total renewable water resources. In semi-arid and arid regions, mountainous regions, permafrost regions and in the Asian Monsoon region, groundwater recharge accounts for a lower fraction of total runoff, which makes these regions particularly vulnerable to seasonal and inter-annual precipitation variability and water pollution. Average per-capita renewable groundwater resources of countries vary between 8 m3/(capita yr) for Egypt to more than 1 million m3/(capita yr) for the Falkland Islands, the global average in the year 2000 being 2091 m3/(capita yr). Regarding the uncertainty of estimated groundwater resources due to the two precipitation data sets, deviation from the mean is less than 1% for 50 out of the 165 countries considered, between 1 and 5% for 62, between 5 and 20% for 43 and between 20 and 80% for 10 countries. Deviations at the grid scale can be much larger, ranging between 0 and 186 mm/yr.

scholarly journals Economic Policy and Desertification in Arid and Semi-arid Developing Countries

1997 ◽  
Vol 36 (2) ◽  
pp. 191-201
Author(s):  
Mark Speece
Keyword(s):  
Arid Regions ◽  
Economic Benefits ◽  
Resource Utilisation ◽  
Economic Policies ◽  
Daily Lives ◽  
Trade Offs ◽  
Sustainable Resource Use ◽  
Semi Arid ◽  
Local Farmers

Environmental degradation in arid and semi-arid regions often results from trade-offs between immediate and long-term needs. Ecological (and ultimately economic) benefits of restrained, sustainable resource use are well-understood by scientists, and are usually apparent to local farmers and herders as well. However, immediate economic needs often conflict, and excessive exploitation of resources may be necessary to subsistence producers’ survival. Such issues are illustrated in a variety of settings. Solutions to problems containing important economic components require appropriate economic policies, as well as technical action. Long-term sustainable resource utilisation rather than short-term exploitation must be made more attractive to local producers in their daily lives.

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