3.1 Overview

As mentioned in Chapter 1, someagro-climatic patterns emerge at the MRU level that are of global relevance. Inthis Chapter, observations are more refined and more specific for allcountries, and in particular for the 30 countries that make up the bulk of foodproduction and trade (especially exports). For those 30 countries, analysiswill also cover regional situations and agroecological zones. (A more detailedanalysis for China is provided separately in Chapter 4.)

As a result of global atmospheric dynamics,agroclimatic variables are usually correlated; for instance rainfall andtemperature may correlate as a result of normally abundant precipitation inequatorial areas. Other well-known examples include temperature and sunshine(positive correlation) as well rainfall and sunshine (negative correlation).Those “climatological patterns” are mostly zonal, but they are subjected tovariations according to the prevailing climate and season; the link betweentemperature and rainfall, for example, is much weaker in tropical areas than intemperate ones.[1]Despite these frequent correlations, however, it is much less common that departures from the reference value (inthis case the fifteen-year average used by CropWatch for RAIN, TEMP, andRADPAR) follow coherent patterns at the global scale. For the currentJuly-October 2016 reporting period, however, there is a very significantcorrelation between rainfall anomalies and RADPAR anomalies across the 439polygons that make up figuresXX1 (rainfall), XX2 (temperature), XX3 (PAR) as well as biomass (fig XX4).

The spatial departure patterns betweenrainfall and RADPAR are very visible (compare figures XX1 and XX3); in fact, thecoefficient of correlation reaches r= -0.33 for n=439.[2]The correlation is high (R=0.16) for rainfall anomalies below +40% (includingnegative ones) but levels off for higher departures (figure XX0). This mean that, particularlyfor rainfall deficit areas, the global patterns of anomalies roughly coincidefor rainfall and RADPAR.

Figure XX0. RADPAR anomaly vs rainfall anomaly

RADPAR anomaly vs rainfall anomalyis best modelled as piecewise linear regression with DOF=435 (number of pointsis 439 countries and sub-country units) with a breakpoint at a rainfall anomalyof +50% (r=0.44).

Areas with excess precipitation

Africa: Sahelian region

Abundant precipitation benefited the end ofthe cropping season in the semi-aridWest African Sahel, where Mauritania recorded in excess of 800 mm ofrainfall over the reporting period (and thus almost throughout the rainyseason), corresponding to 100% excess. Other countries with favorable rainfallinclude Niger (+39% of well-distributed precipitation), Mali, Burkina Faso, andSenegal, as well as the western Gulf of Guinea from Liberia to Guinea Bissau,which all experienced close to 20% positive rainfall departures. The regionexperienced radiation moderately below the reference values (RADPAR, -2%) andslight negative temperature departures (TEMP, -0.4°C). The expectedpotential biomass increase (BIOMSS) is nevertheless depressed by thetemperature and reaches +9%.

Asia: Arabian Peninsula

Chad, in the center of the Sahelian area(RAIN, +8%) provides the transition to North Sudan (RAIN, +28%) and the Arabian Peninsula where severalcountries also recorded unusually favorable rainfall: Jordan (+73%), SaudiArabia (+100%), and Qatar (+257%). The three countries normally record lowrainfall amounts (20 to 50 mm over the reporting period) but, consideringprevailing aridity conditions over the Middle-East, the amounts arenevertheless significant ecologically and agronomically, mostly so for Jordan.

Europe: easternEurope to western Russia

Several regions from western Russia to Northern-central Europe andGreece received precipitation amounts that are beneficial to the earlycrop stages of the beginning winter crop season in the area. Precipitation was28% above average with both relatively low sunshine and temperature (RADPAR,-5%; TEMP, -0.8°C). The resulting biomass production potential departure is 14%.

The region encompasses the areas betweenKarelya and the oblast of Pskov (RAIN, +32% to +48%) in the north, extendingsouth to the Belgorod oblast with excesses between 20% and 30% and west as faras Poland (+27%) and Slovakia (+13%) across Belarus (+23%) and Lithuania (+20).To the south of this area, after skipping Hungary (+4%), more significantpositive rainfall departures again occurred in Serbia (+11%), and especially inAlbania (+40%), Macedonia (+57%), and Greece (+77%). 

Europe to Asia:southern Russia to China

Not unlike the previous season, vastexpanses of land in and around central and southern Asia recordedabundant precipitation when expressed against the average of the recent fifteenyears (+67%). The area includes more than 30 countries and sub-national unitsillustrated in figure xxxx(rainfall by national and subnational boundaries). With very fewexceptions (Nagaland and Qinghai), temperature was systematically below average(-0.4°C) and so was radiation (-5%). The BIOMSS indicator increases by41%. Radiation was particularly low in the southern part of thenorthern-central Indian peninsula. Overall, this large area with abundantprecipitation is bounded by the following regions:

·        In the west: the southernRussian oblasts of Volgograd (+33% rainfall) and Saratov (+29%), as well as thewestern region in Kazakhstan (Zapadno-Kazakhstanskaya oblast; RAIN, +51%). Allexperienced a drop in RADPAR in the order of 5%. Temperatures were 0.5°C to1.0°C below average;

·        In the north: the Pavlodar regionof northeast Kazakhstan with +39% precipitation, about average RADPAR, andbelow average temperature (-0.8°C);

·        In the east: Mongolia and theChinese region of Inner Mongolia with +53% and +37% precipitation,respectively, and average TEMP and RADPAR;

·        In the southeast: the Chineseprovinces of Qinghai (+84%) and Xizang (+36%);

·        In the south: the Indian statesof Bihar (+38%), Madhya Pradesh (+62%), and Rajasthan (+79%). The drop insunshine was significant and reaches -10%, -11%, and -5%, respectively;

·        In the southwest: Uzbekistanwith +169% of precipitation but otherwise average conditions.

The large area also includes the followingadministrative units, which all experienced precipitation close to or in excessof +45%: Shanxi and Hebei provinces in China (+44% and +46%), Tajikistan andKyrgyzstan (+143% and +196%, with about normal TEMP and RADPAR), and severalregions in Kazakhstan. They include the Aktubinsk oblast (RAIN, +54%), theeastern region—Vostochno-kkazachstanskaya oblast—with +79% precipitation, theKyzylorda region at +129% precipitation, Yujno kazakhstanskaya oblast at +143%,and the Jambyl region with precipitation up 201% and a 1.2°C dropin temperature. The largest excess over average was recorded in the Xinjiang Uygur region of western Chinawith 410 mm of rain, corresponding to an increase of 224% over the average ofthe recent years. Sunshine (RADPAR) fell below average significantly or verysignificantly in southern Asia (Maharashtra and Chhattisgarh (-8%), UttarPradesh (-7%), Nepal and Bangladesh (-6%).

The contiguous regions of Jambyl insouthern-central Kazakhstan, Kyrgyzstan, and the Xinjiang Uygur autonomousregion of China are at the core of the high precipitation area. Kazakhstanincreased the cropped arable land fraction by a spectacular 23%, followed byUzbekistan with +20%.

Asia and Oceania: eastern Asia to central-easternAustralia

In this region, the excess precipitation isminor compared with the previous one, but nevertheless useful for the wintercrop areas in southeastern China, Southeast Asia, and the spring crops inOceania. The region approximately reaches from Jiangxu, Anhui, and Hubeiprovinces in China to all of maritime Southeast Asia and the eastern half ofAustralia except Victoria and Tasmania. The average precipitation excess in theregion is 36% with a correlated drop in RADPAR of -4% and close to averagetemperature. The largest precipitation increases over average occurs inIndonesia (+36%), Hunan, and Jiangxi provinces in China (+42 and +45%,respectively), the Northern Territory in Australia where 114 mm represents morethan a doubling of average rainfall amounts (+123%), and Timor Leste (+144%).

America: northernUnited States and Canada

A large contiguous area of above-averageprecipitation extends from British Columbia to Manitoba to Ohio to California,excluding Nevada. The average precipitation excess amounts to 67% with belowaverage sunshine (RADPAR, -4%) and a biomass production potential increase of42% above average. Rainfall was particularly abundant over Nebraska (+85%) andWisconsin (+90%), with other states even recording rainfall more than doublethe average, from 107% in Kansas to 150% in North Dakota, with valuesincreasing from Iowa (+109%) through Minnesota and South Dakota to Montana(+127%). The lowest precipitation excesses in Ohio (+11%), Michigan (+19%), andIndiana (+27%) were associated with the largest positive temperature anomalies(1.4°C, 1.5°C and 1.0°C, respectively). The largest RADPAR deficits occurred in Illinois(-7%), Washington State (-8%), British Colombia, and Manitoba (both provincesat -9%).

Deficit precipitation areas

Europe, theMediterranean and western Asia

The large rainfall deficit area (-34% onaverage) covers 30 countries from Sweden and Germany to Great Britain toMorocco, Iran and Afghanistan, and the Black Sea countries. Other variableswere average but the BIOMSS potential dropped 26% below average. The largestdeficits occur in the eastern Mediterranean (Lebanon -87%, Syria -65%, andTurkey -42%, where precipitation is normally low over the reporting period)while northern and north-western Europe is less affected. Nevertheless, bothFrance and Germany list a decrease in cropping intensity (-8% and -16%,respectively) that can be due to reduced rainfall. The same applies to Ukraine(cropping intensity down 18%) and Morocco, which suffered a bad drought in2014/15 and recorded 66 mm, a weak -16% departure from average. Winter cropshave now been planted in the region and prospects remain generally favorable.

Russia

The area under consideration includes theoblasts of Perm and Tomsk, the Komi-Permyak okrug andthe Krasnodar kray as the area with the largest precipitation deficit (RAIN,-34%, -31%, -31%, and -32%, respectively). It extends west to the NizhniNovgorod oblast and the Republic of Mordovia where the deficit decreases toabout 15%. The deficits need to be compared against actual values, which wereclose to 200 mm—sufficient for farm operations and early stages of wintercrops. The region had average temperature (+0.2°C), +3% RADPAR,and a BIOMSS expectation departure of -16%.

Eastern Asia

This particular rain deficit areaencompasses three Chinese provinces (Henan, Chongqing, and Shandong), Japan,the Republic of Korea, and the Democratic People’s Republic of Korea. Theaverage rainfall deficit is moderate (-19%) with a +3% increase in radiation(RADPAR). The area deserves mentioning because the most severe deficit occursin the Korean DPR with RAIN at -45%, a drop from 650 mm to 350 mm or about 3mm/day. This is very close to the evaporation values in the lowlands and thuspotentially the beginning of another drought year.

Southern India

The Indian states of Tamil Nadu, Kerala,and Karnataka, as well Sri Lanka suffered an average precipitation deficit of50% (-31% in Tamil Nadu to -62% in Kerala). It is likely that, due to high ETP values, therainfall deficit has created some stress for rainfed crops in the presence ofabove-average sunshine (+4%).

Southern Oceania and Western Australia

The average rainfall deficit was 50% onaverage in Tasmania (-69%), New-Zealand (-55%), and Western Australia (-52%)and Victoria (-24%). The region also had a marked reduction in RADPAR (-6%).

Eastern and Southern Africa

The area under consideration coversfourteen countries south of Ethiopia and Uganda, Zambia, and Namibia. Crops arecurrently growing at the higher elevations in eastern Africa while southernAfrica is just planting after a severe drought year that affected much of theregion. The average rainfall deficit reaches 33% with just above averagetemperature and RADPAR up 4% compared with average. The resulting biomass productionpotential is down 30%. The driest countries in relative terms include Somalia(-78%) and Kenya (-43%), while the situation is more favorable in Zambia (-15%)and South Africa (-12%). Theformer country reduces the cropped arable land fraction by 10% over the averageof the previous five years. It is worth mentioning that Tanzania, whichsuffered very little compared with the drought areas to its north and south in2015/16, is now recording a RAIN deficit of 31% with +4% RADPAR. Severalcountries in the region report large positive sunshine anomalies of 8% (Ugandaand Rwanda) and 11% (Burundi).

Southern United States

The area includes a group of states in thewest (Mississippi, Alabama, Tennessee, Georgia, Louisiana, and Arkansas), aswell as two isolated states: Nevada and New Mexico. The average precipitationdeficit reaches 24% with a slight positive temperature anomaly (TEMP, +0.5°C) butclose to average sunshine (-1%). The deficit is most severe in Mississippi(-41%) and Alabama (-36%), while it does not exceed 30% in the remainingstates. The largest sunshine anomalies occurred in Alabama (+5%) and Georgia(+8%).

South America: Southern cone

The drought (RAIN, -41%) in this regionaffected an area that includes Chile and Uruguay as well as nine provinces inArgentina, especially Chubut (-64%), Tucuman (-54%), and La Rioja (-48%). Bothtemperature and radiation were slightly below average.

Other areas of concern

Some small or isolated areas are listed inthis section, starting with part of the Brazilian Nordeste where Paraiba,Ceará, and Rio Grande do Norte all report a RAIN deficit between 70% and 75%.However, considering their very low average precipitation and the time of theyear, this is not concerning.

Figure XX2 shows that few areas with belowaverage TEMP experienced abnormally low temperatures (< 1.5°C).These include: 

·        An area between the Black andthe Caspian Sea: Armenia (-2.5°C), the Adyghe Autonomous Oblast (-1.8°C), Azerbaijan(-1.8°C), and the Kalmyk republic (-1.6°C).

·        Tunisia (-1.7°C)

·        The Karaganda region inKazakhstan (-1.5°C)

·        Sikkim (-1.5°C)

[1]. This was discussed in some detail in a recent CropWatchpublication: https://link.springer.com/article/10.1007%2Fs00484-016-1199-7.

[2]. The same patterns are also veryvisible for rainfall and BIOMSS, but this is a direct consequence of themethodology used to derive BIOMSS from rainfall and temperature (BIOMSS anomaly % Vs. rain anomaly %: r=0.91;BIOMSS anomaly % Vs. rain anomaly %: r=-0.08).

Table 3.1 CropWatch agroclimatic and agronomic indicators for July-October  2016, departure 15YA and 5YA