Mapping environmental and climate variations by GMT: A case of Zambia, Central Africa

Ekosistem Zambije doživljava pretnju usled nastalih klimatskih promena, poput suša, porasta temperature i povremenih poplava, a koje utiču na održivost poljoprivrede i dobrobit populacije svojim delovanjem na biljku i uzgoj useva. Cilj ovog rada je prikazati varijacije u nekoliko klimatskih i ekoloških parametara u Zambiji, prikazujući prostornu varijabilnost i trendove u različitim regijama ključnih za ekosistem: reka Zambezi sa pritokama, Livingstone (u blizini vodopada Victoria) i središnjeg regiona Muchinga planina. Kreirano je 10 karata korištenjem informacija iz TerraClimate skupa podataka: padavine, vlaga zemljišta, Palmerov indeks suše (Palmer Drought Severity Index - PDSI), kratkotalasno zračenje, deficit i anomalije pritiska pare, potencijalna i stvarna evapotranspiracija i brzina vetra u odnosu na nadmorsku visinu (korišćenjem GEBCO/SRTM podataka). Raspon PDSI vrednosti se kreće od -5.7 do 16.6, sa srednjom vrednošću 7.169 i standardnom devijacijom 4.278. PDSI je efikasan u kvantifikovanju suše u dugoročnom periodu. Budući da PDSI indeks primenjuje podatke o temperaturi i model vodnog bilansa, on ukazuje na uticaj povećanje temperature na sušu korelacijom s potencijalnom evapotranspiracijom. Vrednosti vlage u zemljištu Zambije se kreću u rasponu od 1 mm/m do 413 mm/m, dok je srednja vrednost 173 mm/m. Primenjena metodologija se tehnički temelje na korištenju Generic Mapping Tools (GMT) softvera, koji predstavlja skup GIS alata baziranim na korišćenju programerskih skripti. Rad doprinosi monitoringu ekosistema Zambije predstavljanjem niza klimatskih i ekoloških karata koje su korisne za poljoprivrednu proizvodnju.

Zambia recently experienced several environmental threats from climate change such as droughts, temperature rise and occasional flooding and they all affect agricultural sustainability and people wellbeing through negative effects on plants and growing crops. This paper is aimed at showing variations in several climate and environmental parameters in Zambia showing spatial variability and trends in different regions of Zambia's key environmental areas (Zambezi River and tributaries), Livingstone near the Victoria Falls and central region with Muchinga Mountains. A series of 10 maps was plotted using data from TerraClimate dataset: precipitation, soil moisture, Palmer Drought Severity Index (PDSI), downward surface shortwave radiation, vapor pressure deficit and anomalies, potential and actual evapotranspiration and wind speed with relation to the topographic distribution of elevations in Zambia plotted using GEBCO/SRTM data. The data range of the PDSI according to the index values ranged from minimum at -5.7 to the maximum at 16.6 and mean at 7.169, with standard deviation at 4.278. The PDSI is effective in quantifying drought in long-term period. Because PDSI index applies temperature data and water balance model, it indicates the effect of climate warming on drought by correlation with potential evapotranspiration. The maximum values for soil moisture of Zambia show minimum at 1 mm/m, maximum at 413 mm/m, mean at 173 mm/m. This study is technically based on using the Generic Mapping Tools (GMT) as cartographic scripting toolset. The paper contributes to the environmental monitoring of Zambia by presenting a series of climate and environmental maps that are beneficial for agricultural mapping of Zambia.