@inproceedings{fdi:010094507,
  title = {{A}gro-ecological impact assessment of irrigation canal rehabilitation scenarios under different hydrological conditions in the upper {M}ekong {D}elta, {C}ambodia [r{\'e}sum{\'e}]},
  author = {{O}rieschnig, {C}hristina and {B}elaud, {G}. and {V}enot, {J}ean-{P}hilippe and {M}assuel, {S}ylvain},
  editor = {},
  language = {{ENG}},
  abstract = {{T}he {C}ambodian part of the {M}ekong {D}elta, is characterized by specific irrigation infrastructures, namely {P}rek channels. {T}hese trapezoidal earthen channels traditionally connect the {M}ekong's mainstream to low-lying floodplains by breaching the elevated river banks. {T}hey act as vectors for both flooding and drainage during the annual {M}onsoon inundations. {F}urthermore, they fulfil a diverse set of ecosystem services for local communities, from providing dry season irrigation water to channelling nutrient-laden sediments to increase the fertility of agricultural plots. {G}iven the recent shifts in the hydrological regime of the {M}ekong {R}iver - mainly due to climate change, hydropower construction, and land use changes - the role of {P}reks  in the sustainable management of the  floodplain agroecosystems becomes a crucial issue. {F}or this reason, various initiatives by local stakeholders as well as national ministries and international development agencies have aimed to rehabilitate {P}rek channels in recent years and restore functionalities that have become impeded due to erosion and sediment clogging. {H}owever, there are different ways in which to rehabilitate {P}reks, and numerous potential project sites to choose from.  {T}he aim of this study is to build a method to assess the impact of different {P}rek rehabilitation scenarios on the local agroecosystem, under different hydrological framework conditions. {I}n order to do so, an eco-hydrological model has been constructed in {P}ython. {I}t depicts a case study area of 43 km², comprising 10 {P}reks, located approximately 70 km {S}outh of the {C}ambodian capital {P}hnom {P}enh. {T}he model is based on the results of remote sensing analyses combining {S}entinel-1 and -2 images to determine land use and land cover ({LULC}) evolution, as well as the spatial and temporal distribution of seasonal  inundations. {I}t also takes into account the results of field surveys and interviews with local stakeholders to make explicit the link between the hydrological processes catalysed by {P}reks and the ecosystem services from which local communities benefit, especially the provision of irrigation water during the dry season.  {S}ubsequently, this model was used to compare different rehabilitation scenarios - different canal excavation depths (called shallow and deep calibration), and the rehabilitation of different numbers of {P}reks in the case study area. {I}n addition, the simulations were carried out for three different hydrological scenarios, based on past observations - one in which the annual {M}onsoon flood peak is lower than average, one in which it corresponds to the long-term mean, and one in which it is higher than average. {T}his helps account for the likely long-term impact of delta- and basin-wide developments like {LULC} change, climate change, and hydropower construction, on local hydrological conditions such as the timing and duration of inundations. {I}nitial results indicate that {P}rek rehabilitation, especially using deep calibration, has a significant impact on agricultural production through irrigation water provision. {F}or instance, simulations show that, even in below-average hydrological years, blanket deep calibration of {P}reks in the study area could increase agricultural production by 33% in comparison to the reference year.},
  keywords = {{CAMBODGE} ; {MEKONG} {DELTA}},
  numero = {},
  pages = {{EGU}23--12853 [2 ]},
  booktitle = {},
  year = {2023},
  DOI = {10.5194/egusphere-egu23-12853},
  URL = {https://www.documentation.ird.fr/hor/fdi:010094507},
}