Evaluation of GRACE derived groundwater storage changes in different agro-ecological zones of the Indus Basin

2021 ◽  
pp. 127369
Author(s):  
Fazlullah Akhtar ◽  
Rana Ali Nawaz ◽  
Mohsin Hafeez ◽  
Usman Khalid Awan ◽  
Christian Borgemeister ◽  
...  
2021 ◽  
Vol 13 (12) ◽  
pp. 6910
Author(s):  
Adil Dilawar ◽  
Baozhang Chen ◽  
Arfan Arshad ◽  
Lifeng Guo ◽  
Muhammad Irfan Ehsan ◽  
...  

Here, we provided a comprehensive analysis of long-term drought and climate extreme patterns in the agro ecological zones (AEZs) of Pakistan during 1980–2019. Drought trends were investigated using the standardized precipitation evapotranspiration index (SPEI) at various timescales (SPEI-1, SPEI-3, SPEI-6, and SPEI-12). The results showed that droughts (seasonal and annual) were more persistent and severe in the southern, southwestern, southeastern, and central parts of the region. Drought exacerbated with slopes of −0.02, −0.07, −0.08, −0.01, and −0.02 per year. Drought prevailed in all AEZs in the spring season. The majority of AEZs in Pakistan’s southern, middle, and southwestern regions had experienced substantial warming. The mean annual temperature minimum (Tmin) increased faster than the mean annual temperature maximum (Tmax) in all zones. Precipitation decreased in the southern, northern, central, and southwestern parts of the region. Principal component analysis (PCA) revealed a robust increase in temperature extremes with a variance of 76% and a decrease in precipitation extremes with a variance of 91% in the region. Temperature and precipitation extremes indices had a strong Pearson correlation with drought events. Higher temperatures resulted in extreme drought (dry conditions), while higher precipitation levels resulted in wetting conditions (no drought) in different AEZs. In most AEZs, drought occurrences were more responsive to precipitation. The current findings are helpful for climate mitigation strategies and specific zonal efforts are needed to alleviate the environmental and societal impacts of drought.


2021 ◽  
Vol 312 ◽  
pp. 107317
Author(s):  
Nirmalendu Basak ◽  
Biswapati Mandal ◽  
Ashim Datta ◽  
Manik Chandra Kundu ◽  
Arvind Kumar Rai ◽  
...  

2021 ◽  
Vol 3 (2) ◽  
pp. 383-393
Author(s):  
Patient Farsia Djidjonri ◽  
Nukenine Elias Nchiwan ◽  
Hartmut Koehler

The present study investigates the effect of intercropping (maize-cowpea, maize-okra, maize-okra-cowpea, okra-cowpea) compared to insecticide application on the level of infestation of insect pests and the final yield of maize, cowpea and okra. Field experiments were conducted during the 2016 and 2017 cropping seasons in the Guinean Savannah (Dang-Ngaoundere) and Sudano Sahelian (Gouna-Garoua) agro-ecological zones in Cameroon. Our experimental design was a split plot arrangement in a randomized complete block with four replications. The main factor was assigned to the use of insecticide (Cypermethrin) and sub plots were devoted for cropping systems. We compared the efficiency of intercropping to that of Cypermethrin application on the Yield of maize, cowpea and okra as influenced by insect pest damages. The comparison of monocropped sprayed by Cypermethrin to unsprayed showed that, in Dang, insect pests reduced maize yield by 37% and 24% in 2016 and 2017, respectively, whereas in Gouna, it was lower than 8% during the both years. Reduction in seed yield by insect pests on cowpea in Dang represented 47% and 50% in 2016 and 2017, respectively, whereas in Gouna, it was 55% and 63% in 2016 and 2017, respectively. For okra, insect pests reduced okra fruit yield by 25% and 44% in Dang and 23% and 28% in Gouna, respectively, in 2016 and 2017. Crop yield was lower in intercropping compared to monoculture due to competition of plants in association on different resources. Considering the total yields obtained from each intercropping, intercropping trials resulted generally in higher yields compared to mono-culture (LER > 1) in both sites and years but the respective yields were quite different. On the basis of the results obtained, we recommend maize-cowpea intercropping as a sustainable solution to reduce the infestation level of their pest insects.


2017 ◽  
Vol 33 (7) ◽  
pp. 713-722
Author(s):  
Hongyan Wang ◽  
Qiangzi Li ◽  
Xin Du ◽  
Longcai Zhao ◽  
Na Wang

2021 ◽  
Author(s):  
Yimer Mohammed ◽  
Kindie Tesfaye ◽  
Menfese Tadesse ◽  
Fantaw Yimer

Abstract Background: Climate change and variability has been significantly affecting the Ethiopian agricultural production and thereby smallholder farmers livelihoods. The level of vulnerability varied across agro-ecological zones (AEZs). Identification of difference in the level of vulnerability of a system is important in selecting appropriate and effective adaption options to climate change. Therefore, the aim of this study was to analyze the level of vulnerability of agricultural communities to climate change and variability at micro-scale level in five agro-ecological zones (AEZs) of south Wollo, north east highlands of Ethiopia. Data was collected from a representative of 502 sample households from five AEZs through multi stage random sampling methods. Focus group discussion and key informant interviews were also carried out to supplement and substantiate the quantitative data. The indicator based approach was used to empirically calculate vulnerability. Principal Component Analysis (PCA) was applied to give weight for indicators and generate index of vulnerability contributing factors. Results: The results showed that each of the vulnerability contributing factors (exposure, sensitivity and adaptive capacity) varied across the AEZs. M3, SM2 and SM3 are the most exposed AEZs but having a relatively better adaptive capacity whereas M1, M2 and M3 are the most sensitive AEZs with relatively low adaptive capacity to climate variability and change. Overall, SM2 is the most vulnerable AEZ which exhibited high sensitivity and low adaptive capacity followed by M1. Conclusions: The study explored sources and levels of vulnerability to each agro-ecology. Since the study is conducted at micro-scale level, it helps decision makers and development partners to have context-specific understanding of the impact of climate change and variability and design appropriate adaptation measures to address the specific situations.


2018 ◽  
Vol 66 (1) ◽  
pp. 526-536 ◽  
Author(s):  
Abdul Rehman ◽  
Franz J. Conraths ◽  
Carola Sauter‐Louis ◽  
Jürgen Krücken ◽  
Ard M. Nijhof

Nematology ◽  
2017 ◽  
Vol 19 (7) ◽  
pp. 751-787 ◽  
Author(s):  
Yao A. Kolombia ◽  
Gerrit Karssen ◽  
Nicole Viaene ◽  
P. Lava Kumar ◽  
Lisa Joos ◽  
...  

The yam nematode,Scutellonema bradys, is a major threat to yam (Dioscoreaspp.) production across yam-growing regions. In West Africa, this species cohabits with many morphologically similar congeners and, consequently, its accurate diagnosis is essential for control and for monitoring its movement. In the present study, 46Scutellonemapopulations collected from yam rhizosphere and yam tubers in different agro-ecological zones in Ghana and Nigeria were characterised by their morphological features and by sequencing of the D2-D3 region of the 28S rDNA gene and the mitochondrialCOIgenes. Molecular phylogeny, molecular species delimitation and morphology revealedS. bradys,S. cavenessi,S. clathricaudatumand three undescribed species from yam rhizosphere. OnlyS. bradyswas identified from yam tuber tissue, however. For barcoding and identifyingScutellonemaspp., the most suitable marker used was theCOIgene. Additionally, 99 newScutellonemasequences were generated using populations obtained also from banana, carrot, maize and tomato, including the first forS. paralabiatumandS. clathricaudatum, enabling the development of a dichotomous key for identification ofScutellonemaspp. The implications of these results are discussed.


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