Sökning: "arid zone"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden arid zone.

  1. 1. Unsaturated Solute Transport in a Semiarid Catchment - Nonlinear Analyses and Modelling

    Författare :Pernilla Öhrström; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; teknisk geografi; Hydrogeologi; teknisk geologi; unsaturated zone; Hydrogeology; geographical and geological engineering; solute transport; scaling; soils; semiarid regions; heterogeneity; preferential flow; fractals;

    Sammanfattning : Unsaturated solute transport is highly variable and therefore difficult to predict. In semi-arid areas, where water resources are limited, the presence of macropores is of great importance for crop production. The bromide ion (Br-) and dye tracers are useful for studies of water movement. LÄS MER

  3. 2. Evaluation of Modern Irrigation Techniques with Brackish Water

    Författare :Tarek Selim Aboulila; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Soil water; Soil Salinity; Drip irrigation; HYDRUS-2D 3D; El-Salam Canal; Egypt.;

    Sammanfattning : Modern irrigation techniques are becoming increasingly important in water-scarce countries especially in arid and semiarid regions. Higher crop production and better water use efficiency are usually achieved by drip irrigation as compared to other irrigation methods. LÄS MER

  4. 3. Urban Origins in Southern Sri Lanka

    Författare :Raj Somadeva; Paul Sinclair; Sunil Gupta; Uppsala universitet; []
    Nyckelord :HUMANIORA; HUMANITIES; Archaeology; Archaeology; Sri Lanka; Kirindi Oya; urbanism; ceramics; beads; historical archaeology; settlement archaeology; inscriptions; Land Unit classification; satellite image; Arkeologi; Archaeology subjects; Arkeologiämnen; arkeologi; Archaeology;

    Sammanfattning : This study focuses upon the development of urbanisation in southern Sri Lanka during the proto, early and late historical periods c. 900 BC onwards. The following research themes are addressed:(a). Why did the southern semi-arid zone become a focus of urbanism?(b). LÄS MER

  5. 4. Stem canker and dieback disease on Grevillea robusta Cunn ex R. Br : distribution, causes and implications systems in agroforestry systems in Kenya

    Författare :Jane Wangu Njuguna; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : A widespread stem canker and dieback disease threatened the cultivation of Grevillea robusta on farms in Kenya. Disease index increased from 18% in the humid zone to 67% in the semi-arid zones and strongly correlated with altitude and length of drought period in the zones. LÄS MER

  7. 5. On Sahelian-Sudan rainfall and its moisture sources

    Författare :Abubakr A. M. Salih; Qiong Zhang; Michael Tjernström; Alessandra Giannini; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Sudan; Sahel; rainfall; land use; deforestation; moisture sources; moisture transport; Lagrangian; moisture tagging; regional model; climate modeling; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

    Sammanfattning : The African Sahel is one of the most vulnerable regions to climate variability at different time scales. It is an arid to semi-arid region with limited water resources. The summer rainfall is one of these sources, but it exhibits pronounced interannual variability. This thesis presents several aspects of Sahelian Sudan rainfall. LÄS MER